Thursday, August 12, 2021

It took a Texan to state the obvious

The year was 2011 and I was standing in front of an interested crowd giving a power point presentation in a Country Club just outside of San Antonio Texas. I was doing my best to visually show those assembled the steps required to modify, blue print the receiver, then fit and chamber a barrel. The next images showed me modifying the underside of a current production Model 70 receiver to except one of my floor-plate, bow and magazine assemblies. Then I did my best to described the art of surface grinding the receiver to install a set of my scope mounts. Fitting the stock came next and then going over the final finish work to turn the project into a finished Legend rifle. 

When the presentation drew to a close I asked if there were any questions from the audience. A gentleman in what looked to be his early seventies rose to his feet and asked me the following “ Son, if it takes that much work to make a Model 70 into what a Model 70 should be, why in the hell don’t you build your own action ? ” 

I can't remember what response I gave, I’m sure it was vague at best. He was polite sat back down and listen to me field other questions for another 45 minutes. As everyone stood up to go he walked up to me and said “Young fella you ought to think about what I said” he then shook my hand, winked, bid me safe travels home and walked off. You gotta love Texas. 

To this day I do remember I didn't sleep much that night nor was I smugly content on the flight home. The gentleman did have a point. 

Through a series of similar events I was eventually recruited to design a receiver for the CorBon Bullet Company. The CAD design and manufacturing of this receiver was done by Central Valley Machine. I flew in Steve Wickert who's background is pretty deep in this area for some consulting advice to round out the brain pool. While most of my "blue prints" both mental and physical were drawn on napkins the CVM team looked at the process as standard machine work and not as a black art. 

Soon we had a handful of prototype receivers and waited for approval of the overall design. Then the anticipated go-ahead to start the 1st run of production. One receiver went to the Shot Show early that year and another one of these receivers was auctioned off at the 2012 SCI Convention in Las Vegas. During that convention a the steady stream of interested parties came by my booth to ask me about the CorBon Model-1 receiver. My impression was the bullet company was sitting on a winner. 

Sadly some ideas never make it off the cutting room floor or the launch pad. Over the next two and half years I received a lot of phone calls from those interested in purchasing this receiver and I dutifully referred them to the Bullet Company as directed. Production never began. 

Sadly the Model-1 stuttered, stalled and eventually died a quiet death. No one ever heard the tree fall.

Remember that one receiver that was auctioned at the 2012 SCI Convention ? It was purchased by one of my clients that was then sold to another one of my clients. The new owner wanted a 375 H&H and below is how it all turned out. This first attempted at a receiver for both myself and Central Valley Machine laid too rest the the reservations any of us had. The barreled action fed like a shark from the 1st dummy rounds that entered the magazine and all the combined metal work operated as designed. The accuracy with this Model-1 was simply outstanding. You could load a tuna can over a case filled with charcoal briquettes and  it would shoot at the 1/2"or under mark, this barrel will literally shoot anything. I give Kudos to both Krieger and William Hambly Clark Jr as this was the first barrel I ever fit using his # 4 technique as described in his book Centerfire Rifle Accuracy. 

Despite the untimely death of the project it was evident what we had was a solid platform to begin with, All the ducks were lined up at CVM, but still, I held the reins tight.

One thing was sure the fire had been lit, all thanks to a Texan that had a lot more common sense than I did.  Make an action indeed, the nerve of that guy.

Sunday, June 6, 2021

Converting a Pre-64 30-06 to 300 H&H Part 3

OK now lets tie all this together. The first thing to do is file the different flat widths we've cut into that wasp waist shape between each feed rail. Had we been using a CNC we could have programed this step hit the RUN button and watched these mirrored contours take shape. 

Instead we must make the modification blend by hand. This is best done with 6" to 8" medium cut mill files followed up with a # 4 cut file blending our stepped cuts together in an uninterrupted transition from front to rear. Since we made these mill cuts into the rails with use of the digital readout, both the depth and length these two apposing sides should blend out in almost a mirror image. The upper and lower edge of each rail must also be filed with a slight corner breaking radius. The transition along both rails should feel smooth and interrupted. The plan is to just blend these milled flats not hog out more rail width than is necessary.

Then starting with 180 grit W&D paper both rails should be polished top and bottom, front to rear. This sand paper work should be continued up through 320 grit. Keep the radius theme on both sides of the rails

Next you need to file an angular ejection bevel on the underside right leading edge of the rear bridge as we have left a very sharp corner that will catch on every cases being ejected. In addition any sharp corners generated by and end mill need to be chamfered with a file and then paper. 

You need to address the side walls and radius of the feed well. This operation is best done with mold making stones and stoning fluid. These rapid break-down stones will take on the contoured surface you're working with and starting with approximately 180 grit and progressing up to a 300 then a 400 grit stone the sides of the feed well should soon shine like a new dime. 

You must remove the sharp corner at the rear of the feed well wall that we've generated by widening the feed well. 1st with a pillar file, then a stone and finally with paper we need to turn that sharp corner into parabola shape. Failure to do so will cause the belts on the case to hang up on that sharp corner. 

Next we begin blending the 90 degree shelf above the leading edge of the magazine box ID we have established by cutting the feed well forward with the existing angle of the 30/06 bullet ramp. Some would suggest making this new angle straight from the top of the mag box to the rear edge of the flat behind the lower recoil lug seat, you could. However if you blend the standing material into the established bullet ramp angle with again a parabola shape you will in fact be leaving much more steel in the ramp area than Winchester ever left behind on factory 300 H&H receiver. This leaves the lower lug area with significantly more material and removes the knife edge effect at the top of the bullet ramp found all too often on a factory 300 or 375 H&H receiver. Another advantage of this extended parabola shaped ramp also puts the bullet nose in contact with the ramp sooner allowing the bullet nose to begin its rise towards the chamber as well as rolling the base of the case into the bolt face and under the extractor sooner. Remember the beaten to death term "controlled round feed" in my experience the sooner this control starts as the bolt is pushed forward the better the entire concept design becomes.

When converting any Standard action to a Magnum you need to make up a complement of dummy rounds to cycle through the receiver to fine tune the effort. I choose to use round nose bullets on this project as if you can get these to feed perfectly every other semi or Spitzer bullets will feed but not necessarily vice versa.

At this stage I choose whatever brass is available or the brass the client wants to use to properly fit the extractor hook to the those cases. 
       Say what ?????????

As an example the extractor groove diameter on a cross section of six different manufactured 300 Winchester cases I measure a while ago showed a + and - .020 variation in the six brands of brass. 

Without plowing up too much old ground I have mentioned this in other post in the past. The fit of the claw extractor is critical to actually give you controlled round feed. Go back and re-read that last sentence. Now read it again. 

A milling machine vise and a simple indicator is the best fixture to use for determining the proper extractor tension 

Depending on the extractor, zero, some or a lot of material will need to be removed from the extractor for this operation. Starting with a Standard bolt face extractor will take more time to fit than an extractor already converted for a a magnum bolt face. But starting with a standard allows more control over the final results. The actual shape of the finished extractor hook depends largely on the gunsmith and the number of these he has taken the time to actually look at the contours and geometry of one that really works well verses a dud. 

The fit of the extractor hook to the chosen manufacture case should allow the extractor spring away from the bolt body .004 to .006 when the case is rolled and centered into the bolt face in the chambered position in my opinion. 

                       Note: This is a pic of a Left Hand G series bolt and a properly fitted extractor 

In short if the extractor is too tight it will inhibit and retard the process as the case tries to roll into bolt face coming out of the magazine box. To loose a fit and the case will not be captured and controlled by the extractor hook and fall away from the bolt face if the bolts forward or rearward movement is stopped for any manner. This loose round or spent case will drop into the open gap between the rails. Can you say "Jam" "I knew you could boys and girls" 

A finished right hand extractor, filed, polished, blued and installed. Note the shape

So with the now extractor fit we need to alter the length of the Bolt Stop. The amount to remove will vary. I like to have the leading edge of the extractor hook buried just behind the back end of the magazine box opening. I alter the bolt stops length with a carbide cutter in the mill making sure the face of the shortened stop is perpendicular to centerline of the action, this part was designed to fit flush or evenly on the back of the left recoil lug when the two surfaces come in contact. 

The ejector blade is done in a similar manner BUT the angle of the ejector sticking out of the fully retracted bolt face needs to be considered. I want a minimum .110 of ejector blade sticking out of the bolt face with the blade parallel to the bolt face when fully when retracted. That's why we alter the Bolt Stop 1st. 

Now we address the follower, the 30-06 follower is not going to work as it's now to narrow to use in the 300/375 magazine box. A Pre-64 300/375 H&H OEM follower might work but much of this depends on the shape and width of the parabola you cut into your rails or if you chickened out and elected to leave the rails straight per the factory Winchester theme. Likely the OEM 300/375 follower is going to slip up through the new rail contour with the wasp waist and not hold the last round in the magazine under the rail properly. So what follower do we use ? That is a damn good question. 

NECG offers a 98 375 H&H length and width follower, Swift/Blackburn sometimes has them in stock, if Jim Wisner has any on hand I'd recommend his hands down. A 375 G Series Model 70 follower might work but frankly I've never tried one. 

No luck finding one ? If you've gotten this far then making a follower shouldn't be beyond your capabilities and given the choice I'd make it with similar geometry to a Mauser 98 follower instead of the Pre-64 Winchester follower. Having made more than my share of these over the years just plan on most of a day making and polishing the follower from a block of steel. When I've read online that someone felt scalped by paying more than $50 for a follower I know this cry baby has never had to make one.

Note: The follower on the left and is chrome-moly 300/375 Echols Classic/Legend follower. The center follower again made in this shop is for a 300/375 magazine and the material is 7075 Aluminum that will be hard anodized when completed. The other follower on the right is a steel 300/375 follower made by Winchester. 

7075 Aluminum what the f_____?

The original 300/375 OEM Winchester magazine box is very thin and subject to a lot of abuse resulting in major dents appearing in the both the front and rear walls of the magazine box in recoil if the rifle is fired a lot. The owner of this rifle shoots quite a bit so the 7075 was chosen as the follower material. It will also have a 3/16" Delrin bumper placed in the leading and rear edge surface of the follower to further negate any mag box deformation caused in recoil. Slight modifications can be made to the follower if necessary to tweak the functional movement of last round coming out of the magazine. Holding the last round under the feed rail and then releasing the last round in the magazine is one of two functions of the follower, so you better get it right. You will need to have the fixtures or a means to hold the follower to make as well as tweak one, kind of chicken before the egg situation. 

With the barrel installed we now begin checking the progress of what we've done by cycling one, then two, then three and then all four of the dummy rounds through the receiver.  What we're doing now is likely removing steel from the area in the newly established bullet ramp to allow the rounds to slide easily up the bullet ramp. I want to monitor the contact point on the bullet ramp with Red or Black Sharpie and remove with a Crossing or Pippin file the required amount to do so. Great" you say "How much is required ?". The simple answer is, you file and blend the outer edges of the bullet ramp until the bullets contact the ramp on either side of the ramp when driven forward with the bolt. Each side of the ramp should require the same amount material removed when the final shape is established. 

The larger the bullet diameter or the further away the bullet nose is from the centerline of the action the more material will need to be removed. This can take 5 minutes to a number of hours depending on the case and cartridge design. When you feel you have the best shape working for you then you can use a Foredom hand tool with the proper sized cartridge rolls and or the rapid break down stones to go over and remove the file marks and then I paper polish entire bullet ramp. You want that bullet ramp smooth as a Beagle's ear. 

You need to also make sure that the rear of the receiver above the magazine box has a smooth transition above the box opening with no, zero, nada lip over hanging the box for the case rim to catch on. These two surfaces should be flush. The rear of the feed rails should also have a radius that is filed and then polished so as you load the magazine the cartridge rims won't catch on a sharp corner anywhere at the rear of the mag box and receiver. We good ?

Strip all the parts and clean all bits of steel and polishing grit out of the receiver, ejector and stop bolt area with a good solvent and compressed air. Wipe it all dry but do not oil it.

Now is the time to cycle the bolt at normal speed and then very aggressively with a dummy round in the chamber and a full magazine to look for any problems. There will be a few and most will stem from sharp edged corners you neglected. Now lightly oil the rails, bolt body, raceway, etc and try it again. 

When this conversion is 100% complete you will have a Pre-64 300 H&H that Winchester would have been proud of and possibly would have done if given a little more slack in their leash. 

This is not the time to call your favorite smith and ask for the exact same conversion without being willing to go the distance to pay for the effort. The smith will have the better part of two solid days in this endeavor and we haven't even re-addressed the one original scope base hole in the rear bridge being removed. That's for another Blog post I'm afraid. 

The 1st of these conversions will seem a bit daunting, after the 3rd you'll be wondering why you hadn't done this long ago.

Wednesday, August 26, 2020

Converting a Pre-64 30-06 to 300 H&H Part 2

A majority of machine work has now been completed to the magazine cavity and feed well but the rail width modification is still required.  The OD of the belted case as well as the shoulder OD is larger than the 270/30-06 class of cases so additional room through the rails must be made to accommodate for these larger case diameters. 

It is the height of the case that protrudes above the rails and allows the lower edge of the bolt face to engage the protruding case and then allow the bolt to shove it towards the chamber. The case must stick up through the rails ENOUGH as its pushed forward or the bolt face will override the case head and cause a jam. Most 270/30-06 Model actions are approximately .545 to .550 in width from one feed lip or rail to the other side at the very rear of the feed well opening directly above the magazine box and then widens to .600 to .610 directly above the bottom of the bullet ramp. This geometry has work since the 1st Pre-64 stepped off the bus so it's hard to argue that it isn't adequate, is it prefect? well...............

All the next cuts will be made from the center-line of the receiver so you must establish the best means to do so. Again the fixture I use allows me to do this very easily. Finding the center-line I start off and finish using only a 3/32" carbide end mill. I widen the existing width at the rear of the rail from the original .545  to .610. Taking a photo of this operation is difficult at best due to the close proximity of the mills spindle being so close underside of the action. 

With the help of the DRO I will now cut stepped flats into the rails in incremental lengths from the rear forward and later on file and blend these transitions. If you had a CNC you could write a program to do this parabola shape, push start and step back. 

You can just make out the stepped width progressional flats cut into the rails 

Cutting the width and or SHAPE of the rails becomes a matter of interpretation and just how anal retentive you choose to be and still live with yourself. I would say that every Pre-64 70 I have ever worked on left the factory with the rails being straight in nature and wider across the front of the rails above the feed ramp. What I prefer to do today is the widen the rails in the partial parabolic fashion. Tom Burgess referred to this as a candle flame shape. Wider in the mid section of the rails than in the front and in the rear sections, How much you say ? at the widest point .620 to.625 seems to work out pretty well for me for the 300 H&H. When the parabola cuts are blended you also need to file or stone a radial profile to the top and bottom side of each rail. Failure to so will cause the brass to hang up as each case if rising out of the feed well and mag box. Time spent polishing the blended rails will pay off 

The ejection port is next and again carbide is your only reasonable option. I make a pass or two usually removing .006 to .010 of steel to clean up the leading edge of the ejection port and back of the front ring. I then begin opening up the ejection port to the rear. 

The number 3 scope base screw hole will always be cut away in this operation so you'd better have plans for repositioning that screw hole and what rear scope base you will ultimately use after this conversion.

How far you go to the rear is up for considerable debate and much of the next series of cuts will depend on your extractors length. The Standard OEM Pre-64 extractor is approximately 4.420 in over length. Some gun smith's will insist that the tail end of the extractor MUST be tucked under the right side of the rear bridge with the bolt turned down into full battery so the extractor's tail has no possible way of becoming jammed in ejection port. If you follow this as a rule then you can really only open up the ejection port to approx. 3.400. 

So if this is a concern you can modify the rear bridge as shown below, similar to the original factory receivers leaving a standing wall and blending an angular cut from the 3.600 opening you've established from the center line of the action out to the edge of the standing wall. 

This Pre-64 30-06 length action below has been chambered and set up for a 7mm Mashburn with an extended throat and uses up most the 3.600 real-estate in over all loaded length. To keep the 4.420 OEM extractor tail under the rear bridge I needed leave some standing wall as shown at the arrow. The OAL of the new opening is 3.600 but the port length is still 3.400. This still requires snaking the rounds in though the ejection port and under the scope mounts. While this takes some finesse and practice for rapid loading the extractor stays contained 100% of the in time in or out of battery. I've done many conversions in this manner especially when chambered for heavy calibers and are iron sight dedicated rifles. 

Then along came the Willams Firearms Company and their version of a M-70 retro fit extractors. The beauty of this Williams extractor is some of these were machined with an extra .130 in extractor length. I can't remember what date these came to my attention but I've used a dozen or so of these and still have a few squirreled away. This now gives us another option if you have one of these longer Williams units. To my knowledge Willams has ceased production and these are no longer available. 

Jim Wisner from time to time will make a run of an even longer extractor 4.900 as seen below for both right and left handed current production model 70 actions and these are also of excellent quality.

Williams Long Extractor 

Wisner Long Magnum M-70 

Provided you have on hand 0ne of the Williams longer than normal Extractors you can now open the ejection port to 3.600 completely. "But," you say "the tail will not be buried under the rear bridge !!!! " Well Yes and No as you lift the bolt out of the battery position and the bolt body rotates up the extraction cam the rearward movement in rotation places the LONGER Williams extractor tail under the rear bridge well before the bolt has completed its rotation.

To confuse the issue even more below is a standard Pre-64 action and OEM follower that is chambered for 280 Remington that has the ejection port opened up the 3.416. Note the tail of the extractor showing with the bolt in full closed battery and then the tail tucked under the rear bridge as the bolt is opened. The result is a longer loading port and a captured extractor tail. 

The wonder of it all !

A lot depends in any conversion or modification on the the materials at ones disposal. You will see similar adaptations of this on many of the Magnum length actions chambered for long cartridges. Note the visible exposed tail on this extractor fit to this H&W magnum 98 action, lift the bolt and the tail end slips under the rear bridge before the bolt rotates completely up the extraction cam, no fuss-no muss.

Time for lunch 

Sunday, August 9, 2020

Converting a Pre- 64 Mod-70 action from 30-06 to 300 H&H Part 1

In the late eighties as I began to set up or build more 375 H&H's for hunters and finding suitable actions/rifles to do so could be a challenge. By this time I had used quite a few original Pre-64 Model 70's that had left the factory as 300 H&H and 375 H&H rifles and while they all mechanically worked except-ably there were a few things that seemed to crop up over and over again with these factory long-magnum receivers that could use some attention to detail and revision.

I began to consider using the standard 270/30-06 receivers as they came from the factory and modifying them to remove the factory idiosyncrasies that I felt I could correct. Do they need correcting ? Yes, No, Maybe, so let's see.

The one area of contention is usually the 300/375 magazine cavity that holds the magazine box in place just under the feed well is usually cut with a gross amount of clearance. In short most mag boxes rattle in place. Not always a great feature to have a full magazine migrating in recoil as it will begin to distort the mag box over time and use. Then there's the amount of material removed from the lower recoil lug seat as the actions underside is by design opened up forward to allow the 3.600 length cartridges to be used. Yet another major issue is the way the factory then changed the bullet ramp angle and usually left a razor sharp edge at the top edge of the bullet ramp. There had to be a better way.

A radial notch was then cut into the rear edge of the front ring and another large radial cut was added to the front of the rear bridge to allow loading the rifle quickly from the top side of the action with these longer rounds. All was great when those rifles were fit with the Lyman or Redfield receiver sights or even kitted out with the shallow V's found on many older Model 70's. You had an opening in the top of the receiver you could fill the magazine as you back peddled away from danger.

Scope use changed this paradigm radically. Once the 1 piece scope mount became vogue you then had to really practice to load that rifle quickly. A fault ???? not in the original design idea but the system still worked day in and day out. Especially by those that had to make a living with these Model 70's.

Thousands of standard length 98 actions have been altered too except the 300/375 H&H and those suffered the same fate. It works, no doubt about it and still does.

Where was I ? 

So in an effort to make a "better" mouse trap can we use a a Standard Model 70 chambered for a 270 Win or 30-06 ? You bet.

I going to assume you have already opened up the .473 bolt face to .538 or what ever you deem the right Magnum bolt face size and fit and chambered the 300 H&H barrel. At the same time you've also modified your standard extractor hook to a magnum hook. As you're going to need that H&H chamber to use for feeding trials sooner than you think. 

You also need to understand that this is not a one hour conversion, requires a milling machine, carbide tooling and a very secure way of holding the receiver while it is being modified. The barrel should be removed and in this case the rifle receiver was also going to be fit with my scope mounts. So the 1st course of action for me was to true up the underside of the receiver as my fixtures for fitting a set of my mounts are made to work with the underside of the action being machined flat, so we're now killing two birds with one sledge. With the underside of the action leveled off the feed rails I then make a number of passes along the bottom of the receiver with usually with a 4 Flute 1/2" carbide end mill until the bottom side of the feed well and trigger area and tang are of the same level. Then I insert a 1/2" end mill into the collet that has a .030 corner ground onto the end mill. I then cut the recoil flat pocket behind the recoil lug so it is also flat. At the same time the recoil flat pocket is being cut the back face on the contact surface of the recoil lug is also being machined 90 degrees to the the recoil flat. The pic below illustrates why this alone should be done.

While not the same Pre-64 we're going to open up the photo below display's a very common occurrence with all Model 70's and that is the recoil Lug being originally machined into a wedge shape unfortunately being wider or thicker depending on your perspective at the BOTTOM of the lug. All with complements from New Haven.

Below .006 has already been removed from the back of this G -series recoil lug face and were still not cleaned up or perpendicular. Tightly Glass Bed such an action with this integral wedge into a stock and you risk breaking the stock before you get the barreled action back out of your bedding job. This issue is more common than you think with the Model 70 having machined a couple hundred of them I can guarantee this anomaly. 

Since we're converting a 270 action to 300 H&H the next step is to carefully begin to open up the feed well originally set up for the 3.400 width and length magazine box. Now we're making room for the longer and more tapered 3.630 length 300/375 OEM mag box.

Since the client supplied and original 300/375 magazine we begin fitting the new box into the feed well cavity. We measure the thickness of the back wall of the magazine and note its .030 thick. The box will rest on the lip at the rear of the mag well. Usually this lip is recessed approx. 200 deep into the feed well just ahead of the middle guard screw. The 270/30-06 magazine box back wall is approx. .050 thick and the 300/375 box is .030 in wall thickness. So we can move the back wall of the feed well even further to the rear by another .015 to .025 usually. 

The lip that the rear of the box sits on is machined to the same thickness as the back of the 300/375 mag box. There must be a seamless transition for the base of the belted mag cases to slide up the magazine and into the feed well. As the 300/375 magazine is wider at the back of the feed well the width on our 270 action must also be modified to reflect this new width. Measure the width at rear of the 300/375 box and cut away for the center-line of the action accordingly on either side at the rear.

Note the 2 red arrows as they show other areas I will need to machine to allow for the proper width in the feed well with the new 300/375 magnum box.

But first the forward end of the receiver must be cut away to the overall extend length of the longer mag box. The cavity being cut will also serve as a Depth Stop for the forward end of the mag box like the shelf in the rear of the feed well. So it will also be cut to the same depth as the rear shelf at .200.

This OP is best done with a 1/2" end mill to match the radius on the front of the 300/375 magazine box. Cutting away from either side of the actions centerline establishes the front cavity shape. Again care must be taken to the cut this overall length to the numbers, now is not the time to be sloppy

The area inked in red will also have to go but not just yet.

If I have done my math correctly the new 300/375 length box should now PRESS into place. I have controlled the amount of steel removed to a minimum to try and arrest box migration in recoil.

Sweet!!!!!! you say, but the job is far from over. Now we have to remove steel from the feed well that is currently still set up to facilitate the 270/30-06 box geometry and over hanging the the newly installed longer box. To do this OP we need to be able to rotate the action as well as off set the taper to make these cuts. As the fixture I use will allow me to pivot the action this it's not at all difficult. The taper is generated by running an indicator done the inside wall of the feed well with pivoted offset until it reeds as close to as you can get  to ZERO front to back. Being gang milled in the factory nothing on a 70 is every super  precise from one action to the next, frankly they didn't need to be. 

So the action is rotated on its axis and then locked down with which ever side of the action you chose to start on at an 8 degree angle. It is best not to guess. 

Then the new magazine box is place back into the feed well and you need to determine of much additional  steel to remove that is overhanging the new magazine box. This transition BEHIND the feed rib needs to be flush with the top or opening of the new box. This is done one side at a time and in this case with a 1/4" ball nose carbide cutter to match the original radius as cut into the action at the factory. The steel was removed .005 at a time until the top of the box and feed well blended seamlessly up to the rib in the box. DO NOT remove any material above the rib or there will be hell to pay.

With a smooth transition at the junction of the mag box and the feed well to the rear of feed rib we can now work on area ahead of the mag box rib. This feed well width in this area should allow clearance for just the loaded necks of the 300 H&H rounds and no more. Again a 1/4" ball end mill ties the 8 degree side wall cuts into the 1/2" ball mill cuts I will now make to finish up at the front end of the feed well. Confused yet ??? 

Remember the front of the 300/375 mag box has a 1/4" radius and feed well must reflect the same radius at the not only the front of the magazine on the level but also on the 8 degree taper in the feed well itself. Here a picture is worth a 1000 words. Now that we have one side done we rotated the action and re-adjust taper to cut the opposite side of the feed well. If you've gotten this far, take break for lunch you've earned it.

So far so good

Wednesday, July 15, 2020

Hmmm ?

Recently I was asked to machine and partially replicate a Holland & Holland 98 Mauser stock. When the rifle was in my hands there were two things that really stuck out that I have yet to encounter in the past.

Chambered for 458 Winchester the H&H scope mounts had been installed with their own answer to heavy scopes moving under recoil. You simply drill through the ring bands and install set screws that bite into the scope tube.

I'm not sure if the Zeiss warranty covers this type of upgrade ? It would have been interesting and easier to have actually left the appropriate .030 gap between the upper and lower ring halves to see if that might have solved any recoil movement issue with proper ring tension. Clearly no attempt was made in this regard. Rifle making at its best.

Then we have the TWIN safety arrangement. Since I do not know how the rifle originally left the factory the following is purely a guess on my part.

Clearly the rifle began life set up for iron sight use as the butt stocks drop and cast off is perfect for acquiring those sights, you throw it up and you're looking straight down the line of sight. All the parts carry the original Mauser Serial number stamps. The Mauser Wing/Flag safety would have been a perfectly serviceable set up in tandem with its original 98 trigger. You can see they engraved the SAFE into the wing.

Then at some point the rifle re-entered the factory with the idea of adding the scope. Here's where things get a bit interesting.

Clearly with the scope in place this original wing safety is not going to be our best choice. It's either On or Off SAFE. Not really convenient in a tight spot. I suppose you could slip a round into the chamber and lower the firing pin carefully onto the primer as some do I'm told and then when required to shoot you'd lift the bolt to cock the rifle and you're into game, so to speak.

I would imagine your professional hunter would require physical therapy by the end of your hunt by spinning his head around trying to monitor where that muzzle was pointing every minute in the field.

I THINK ????? the barreled action was then fit with a very nicely inletted secondary Sako style 98 Trigger with a recessed pocket for the safety button to nestle into. The inletted mortise for the Sako style trigger and the an original 98 trigger require a very similar inlet footprint so we have to assume the Sako unit was the 2nd trigger unit fit into this stock. 

Now For some reason that is not at all clear the Sako trigger assembly was then modified in such a way to keep the safety in the FIRE position permanently, So the rearward, falling sear block would not rotate into the SAFE position on this trigger unit. I could not move it at all, it has been completely deactivated.

A lot of keen effort has been expelled to properly install this Sako trigger unit such as to machine and then hand file a slot through the tang to allow the bolt lock feature to operate as designed. Which then begs the question if you de-activate the SAFE position mechanically and freeze the mechanisms rearward movement so it can't move reward.

 What was the goal ? 

It would have been nice to install and original looking Oberndorf style bolt knob but with the proper geometry to clear the scopes ocular bell as seen so often since the early seventies.

Another question is instead of removing the original wing safety altogether and perhaps plugging the cavity at the rear of the original shroud/sleeve they choose to leave the safety wing in place. If this rifle is carried in the field with the scope in place it's again either on SAFE or FIRE until you remove the scope and rotate the original wing into the desired position then replace the scope. 

Did someone really signed off on this ?

As a new stock is being made to replace the original the Stock Maker requested I sort out the safety-trigger issue as we're starting with a clean slate. The rifle will now a a conventional 2 position wing safety to clear the scopes Ocular bell and a 3rd trigger installed which is a Swift Blackburn trigger unit. 

Now if we could just get someone like Steve Heilmann to replace the forged bolt handle with a proper looking conversion for scope we'd be in tall cotton. These are just one guys thoughts. 

Its a grand old rifle and needs to go into the field again.