Consistent Tension

Older guns need a proper review and strip down before use

It seems the more things I buy/own, the more time I spend maintaining them, or at least troubleshooting issues. I pulled my late father’s Parker Hale out of the safe in what I thought would be a quick once over and cleaning in order to get it ready for the upcoming hunting season for my son to use. It took but a few seconds to see a glaring issue right off of the bat. The rear scope ring appears to have slid forward off of its base. Did this happen under recoil or was it mounted this way intentionally? I didn’t know, but I figured it was a good opportunity to show my son how to properly mount the scope. I had intended to upgrade the old aluminum mounts and rings with modern steel ones, but after stripping the old equipment off of the action, it was soon apparent that this wasn’t going to be as simple as we had thought.

Illustration by Mike Del Rizzo.
Illustration by Mike Del Rizzo.

When the rifle was produced, Parker Hale used proprietary bases with their own hole spacing. No modern mounts matched up with the tapped holes, this was further complicated with the holes on the rear action bridge not lining up with the front holes or anything else. This was not some special way of mounting, it was simply poor craftsmanship and quality control. Unfortunately, I still encounter this on occasion with modern-built firearms as well. It can be fixed by having the holes welded and re-drilled and tapped, but that wasn’t in the cards at this point. With the original equipment still being functional, I cleaned up the mounting equipment, action and re-assembled it.

I torqued the bases down to consistent, equal torque values and re-installed the rings on the bases. Using proper tools and torquing the screws is an important part of getting the most out of your firearms and optics. Torquing is more than just tightening the screws. It puts the correct amount of tension on the assembled pieces, it allows stretching and compression (microscopically) for proper operation. I still hear many debates over the use of a thread locker, if it is required or not. I have used thread lockers in the past, now I tend to use a very small amount of a light oil on the screws and torque to the recommended specifications. I have never had any mounts shake loose after being correctly installed with not using a locker. These specs do/may change from application to application, so check with the manufacturer of your equipment.

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I was concerned that with the rear base being slightly off centre, it may not allow the scope to fit in the rings, which may cause added stress to the tube when the rings were installed. Abnormal stresses inflicted on the main tube of the scope can lead to poor accuracy from the optic due to inconsistent stresses and vibration inflicted on the scope during the firing/recoil process. Improperly aligned rings are seldom blamed or even diagnosed for the cause of the poor accuracy; most of the time, the shooter will erroneously blame the scope, rifle, ammunition or even their own ability, while all the time the issue lies elsewhere. Misaligned rings and bases often are symptoms of the machining on the action of the firearm itself. Even the correct torquing can’t correct that.

That being said, we got the rifle back together with the use of alignment bars to check the rings/bases and bore sighted. Using a boresighter that has been proven to be close on prior occasion is a great asset. If you can’t get the scope zeroed on the boresighter, it very likely won’t work at the range either. An afternoon at the range and the rifle was sighted in with the ammunition we are planning to use and it’s technically ready to go for many seasons to come.

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If you have acquired an older rifle, as we had here, it might be a good thing to strip it right down to its major components and re-assemble it. This allows you to know that everything has been done correctly and there shouldn’t be any unexpected equipment failures in the field. I also recommend doing this well in advance of any planned trips, just in case issues are uncovered that may require some time to correct. With that being said, after our hunting season is over, this rifle will head to gunsmith to have the action holes welded up and re-drilled and tapped correctly.