When a good scope is going south

Recently we received 3 Legends to clean up and prepare for resale. All three rifles had been used on numerous Safaris as well a hunts in the western US. While used, non of the rifles showed any abuse. One of these Legends, a 7-mm Remington Magnum, did need to have the original scope removed and returned to the manufacture not to many years ago as the reticle had snapped at the duplex intersection. In due course the scope was returned from the repair department, re-mounted, re-zeroed and returned to the client.

As we now had a potential buyer for this particular rifle I had Matt completely dis-assembled and clean this 7-mm and per protocol he went to the range to zero the rifle before shipment to the prospective buyer. When he returned I was less than impressed with the size of the 3 shot groups he had just shot. I say this because I had done all the original shooting and load development for this rifle and had used this very rifle in Tanzania very effectively on wide variety of plains game. The ammunition Matt used was the same that had always been shot in this rifle. As we had all the construction and load data on file a quick look at the many targets from the past confirmed my suspicions that something was indeed amiss. This rifle with a select load and 175gr Partitions had historically turned out group after group in the .500 range with boring regularity. Having gone down this road more times than I care to remember I had Matt remove the clients scope and install our Leupold Mk-4 16X test scope on the rifle and head back to the range with the same loads.

It seemed we had a minor mechanical "issue" going on and I suspected the clients scope was the culprit. The results from this second trip to the range is shown in the enclosed pic.

Not being an optical engineer I can only speculate as to the cause. One could say that the 10X magnification limited Matt in precise bullet placement as compared to the 16X test scope. Maybe, But I do not think the extra 6X can equate to such a dramatic percentage in accuracy enhancement at 100 yards. Parallax? All the previous .500 groups were shot by myself with the very same 10X scope prior to the client receiving the rifle originally. If we didn't have a known history with this rifle we might except the groups shot with the original scope as typical for this rifle or that particular load. In reality 1.5"  three shot groups would be more than adequate for any hunting rifle. However since we knew the rifles background It was obvious there was now a weak link somewhere in the chain.

The modern hunting scope has advanced so much in the last 20 years that even Darwin would be impressed by the rate of evolutionary growth. What with click up turrets, range finding reticles, internal range finding lasers and illumination it's a wonder how optical companies can manage to cram all that stuff in that tube. We the consumer have demanded these innovations and the optic companies have given us what they think we need. It's a wonder how we ever managed to kill anything  in the past with those "obsolete" fixed powers.

What I have learned over the years is not all scopes are created equal even when assembled in the same plant. It matters little as to the manufacture or the retail cost. I am painfully aware that when a rifles typical accuracy mysteriously takes a dump the problem is more than likely due to a cave in the optical department and not the rifles construction or ammunition. It is cross we all have to bare and having a pre-zeroed spare scope in you're hunting kit is a really smart move. It can be a trip saver.

Having a test scope is always a good thing to have at your disposal, but finding a good one is sometimes a roll of the dice.