Preferred scope mounting "system" for a hunting rifle (without BUIS)?

[Art Eatman]

1858, my "keeper" hunting rifles generally shoot five-shot groups inside one MOA. Some, half-MOA. I'm dubious that any sure-enough stiffening would make any worthwhile difference.

With a one-piece base, any stiffening depends on the shear strength of the mounting screws, seems to me. Compare their shear strength with the mass of the receiver itself, and, I guess, consider any "give" in the steel of the receiver; not much, but some. I dunno. I never was really worth a hoot on structural analysis. Find a good bridge design engineer. And a bunch of strain gages, testing "with" and "without".

 

[Maverick223]

Art as an [non-bridge] Engineer myself I agree with your assessment. The screws are the weak point of the typical base (fastened to the receiver with screws). The best base for minimal movement is the one machined into the receiver of a rifle with a large moment of inertia to reduce the bending stresses that can change POA. The best rings are milled from one piece of stock (two attached rings) to give more vertical stability. Keep in mind that none of the above "ideals" are necessary or even wanted (due to weight) on the average hunting rifle.

 

[Ed Ames]

I would expect the 1-piece mount to add rigidity to the scope. Two-piece mounts allow the rings to move more independently so any bend/twist in the receiver will be resisted by the scope tube. That may actually add rigidity too but is more likely to damage the scope. With a 1-piece you have two structures (the receiver and the base/rings/scope system) held in contact by the screws, which will probably have enough elasticity to allow the two to work independently if they need to.

I suppose a decent test would be to remove a well-installed 1-piece that has been installed awhile and look for wear polishing between the receiver and base.

My guess would be "not an issue".

And I like the 1-piece mounts w/ integral rings....

 

[Maverick223]

That may actually add rigidity too but is more likely to damage the scope.

I don't think that would be an issue because the screws are far weaker than any decent scope. They would shear off completely before a scope is likely to sustain damage, but this is only conjecture, as I have never tried it.

 

[Ed Ames]

I'm thinking more about fatigue from flexing. That can eventually lead to cracking at any stress risers, as well as plastic deformation of the aluminum if it is too soft. Think small cracks and small internal parts shifting or loosening.

This is an extreme example, but look at this video and consider how it would've been worse if the one piece scope mount assembly wasn't actually making the scope more rigid.

http://www.youtube.com/watch?v=s5pVya7eask

Now, a typical hunting rifle won't be that extreme but there will be similar flexing. Everything should be designed to handle it, but a one-piece scope mount will make the scope more rigid, and that probably helps.

 

[Uncle Mike]

23lb. bench gun, aluminum receiver, 30"X1.375" straight tapper barrel that is free floated and these guys use 2pc. scope mounts.

And a... they are makin' really small groups way far away! lol

Go figure.

Also, tings havta wiggle and move around lest they break.
You couldn't stop the deformation of the receiver to any noticable degree short of welding a rather large lug across the top of it. Screws just can't accomplish this..... on and on.... sorry!

 

[Maverick223]

I'm thinking more about fatigue from flexing. That can eventually lead to cracking at any stress risers, as well as plastic deformation of the aluminum if it is too soft. Think small cracks and small internal parts shifting or loosening.

True over time it will fatigue, especially if it has an aluminum tube, steel tends to strain harden and last much longer, but I doubt (but don't actually have any proof to back up my claim) that it would take a long time for this to occur. Also your link didn't work, but I am sure that it is a 50BMG with high speed cameras to show the flexure. In that case a machined receiver and one-pc. machined steel ring is the only way to go. That is a great deal of force that must be tamed. Ed you don't really think a 1pc. is better for hunting do you (Considering the additional weight, and marginal cartridge when compared to 50BMG)?

 

[Ed Ames]

Ed you don't really think a 1pc. is better for hunting do you (Considering the additional weight...

IIRC they are about 4oz. (I'm not going to take them off a rifle and re-weigh them but it's in that range) for everything you need to attach the scope. Not a huge deal. I have a set of Warne rings (take-offs, now replaced by the one-piece) that weigh 2.5oz each before you get to the base.

Seems a good tradeoff to me. It won't make the receiver more rigid but it might help the scope, it's light, and IIRC I paid about $45 for the whole get-up. It is ugly.

 

[Maverick223]

Fair enough, I agree looks aren't the best, but use what you like (just like a rifle you won't be satisfied with what you don't like).

 

[Dr.Rob]

1 piece base and permanent rings, all steel and loctite. Aluminum rings are junk (IMHO) and don't belong on a centerfire rifle.

Think my rings and bases on my Savage 116 are Burris. Once that's on there, it's not supposed to move.

 

[Art Eatman]

Ed, I doubt that "flexing" is a problem. I put a Leupold on my '06 in 1973-ish, and used it some 3,500 to 4,000 rounds' worth until 1997. It's now on my 77 Mk II in .223, and has worked on a fair number of prairie dogs. So, 36 years and several thousand rounds of flexing.

I don't see why the material of a scope mounting system is a problem. The aluminum is allegedly aircraft-grade, which undergoes far more stress and flex in an airplane than on a rifle.

 

[ECVMatt]

I have two ways I normally go

First for my heavy varmint rifles I usually go with Leupold QR bases and PQR rings. This is a very solid set up and works well.

For my lighter hunting rifles, I use the Talleys. They are great and look like they are part of the rifle.

I had bad luck with the Dead Nutz. They are just too big and look like I am using two doughnuts to attach the scope to the rifle.

Good luck with your survey.

Matt

 

[Ed Ames]

I too doubt flexing is a problem. I was mostly addressing the idea that any of these mounts would make the receiver more rigid in any significant way. IMO they will not. They may make the scope more rigid...which is probably harmless if not beneficial.

What some will do (and others won't) is act as a suspension for the scope.

Any of these mounting systems will create at least four stress risers in the scope tube (the corners where the tube enters or leaves the rings). Stress risers are where fatigue sets in. The use of a very rigid steel scope mount actually makes those stress risers worse. If you have an aluminum tubed scope, using an aluminum one-piece mount should reduce the impact of the stress risers (the mount can yield somewhat) and additionally the mount structure should make the scope more rigid (may or may not be a good thing). That aluminum system will float above the steel receiver, linked by the screws.

Re: aircraft grade... there are a LOT of aircraft grades. They could mean 1100 which is basically pure aluminum and quite soft, or 3003 (aluminum manganese alloy), 6061 (general purpose heat treatable), or 7075 (one of the highest strength aluminum alloys around). Without knowing WHAT aircraft grade they mean, there is no telling what the fatigue resistance is. Aircraft designers are very aware of fatigue and choose their alloys part by part. A typical light aircraft wing may be made of 3 or more grades of aluminum, with each serving a different roll and chosen to balance strength, fatigue resistance, and other qualities.

Will fatigue matter in a hunting gun? No, very few hunting guns see even 5,000 rounds in their lifetime and they are usually carried in padded cases that will damp vibration during transport.

 

[Art Eatman]

"...they are usually carried in padded cases that will damp vibration during transport."

Well, yeah, okay, except for those of us who road hunt around the ranch in a 4WD pickemup on jeep trails.

A good test of the system is when the rifle bounces between the floor and the roof and doesn't lose zero.

The first time I ever took Darling Bride the 20 miles back to hunt camp, her comment afterwards was that she'd lost all desire to try to ride a mechanical bull. Further, a sports bra would have been a Good Thing.

 

[Dr.Rob]

OK it's completely subjective but the bases that came with my 116 just looked like junk. Given what I'd spent on the rifle, the bases and rings were a let down. Lightweight, easier to chip bend and break than steel (or strip of you're over zealous tightening) so I ditched them in favor of a one piece stainless base where you twist lock the front ring in place.

I used Weaver 2 piece mounts for years but I have also shot one loose over time on a 30-06. (Boy did that cause some head scratching at the range.) Be liberal on your use of loc-tite and check them periodically and you won't likely have an issue.

I have never purchased a QD or knock off mount for a bolt action rifle.

 

[Uncle Mike]

Re: aircraft grade... there are a LOT of aircraft grades. They could mean 1100 which is basically pure aluminum and quite soft, or 3003 (aluminum manganese alloy), 6061 (general purpose heat treatable), or 7075 (one of the highest strength aluminum alloys around). Without knowing WHAT aircraft grade they mean, there is no telling what the fatigue resistance is. Aircraft designers are very aware of fatigue and choose their alloys part by part. A typical light aircraft wing may be made of 3 or more grades of aluminum, with each serving a different roll and chosen to balance strength, fatigue resistance, and other qualities.

Many thanks for clearing that up! After working in the aerospace community for years it is a chuckle to hear some of the advertisements used by manufactuers as to the quality and or grade of their aluminum products.

 

[MCMXI]

In the firearms industry, aircraft grade usually means one of two things ... 6061-T6 or 7075-T6 ... not that complicated really. No one is going to use 2024-T3 or 1060 or some other exotic metals/alloys. Most AR receivers are made from 7075-T6 and then Type III hard coat anodized. 7075-T6 is mechanically superior to 6061-T6 but offers less corrosion resistance. I would bet the farm that most, if not all, scope rings and bases advertised as aircraft grade aluminum are in fact 6061-T6.

I had bad luck with the Dead Nutz. They are just too big and look like I am using two doughnuts to attach the scope to the rifle.