Rifle Scopes Weaver rings on Picatinny rail

[dinkydonuts]

I'm currently using Warne Maxima rings to mount a SWFA SS 10x on a LaRue Tactical 20MOA Base.

The rings are really nice, not surprising for Warne, but the recoil crossbar is not the full width of the Picatinny slot, so there is some back-and-forth play before you lock down the rings. The instructions for the rings say to push the rings as forward as possible in the cross-slot before securing them down.

So far, this has been an OK setup. One time I made the mistake of locking the rings down at the back of the slot and the recoil of the rifle knocked them forward, which was only noticed when the zero changed.

Are others living with this problem? I'm thinking of seeing if I can exchange the Warne rings for a brand that uses a picatinny-spec recoil bar, but I have no idea which brands are guaranteed to follow this spec.

Any advice?

 

[NoExpert]

Re: Weaver rings on Picatinny rail

Good luck, the specs allow variance so there's no guarantee of a snug fit. I push my rings towards each other to secure them front/back. No issues that I've seen. On a bolt gun it's not much of an issue, but on a semi-auto the forward recoil can cause problems.

 

[dinkydonuts]

Re: Weaver rings on Picatinny rail

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: NoExpert</div><div class="ubbcode-body">Good luck, the specs allow variance so there's no guarantee of a snug fit. I push my rings towards each other to secure them front/back. No issues that I've seen. On a bolt gun it's not much of an issue, but on a semi-auto the forward recoil can cause problems. </div></div>

I was under the assumption that the Picatinny specification means the recoil crossbar needs to be wide enough to fit in the cross-slot without allowing movement. I read that the Weaver spec works simply because it is smaller in dimension than Picatinny. On the other hand, you wouldn't be able to use a Picatinny mount with a cross-bar in a Weaver rail because it is too wide.

I looked through the various rings available on MidwayUSA and was surprised that some rings specified for Picatinny are still using Weaver sized crossbars.

This is my first foray into bolt-action rifles. Before this I was in the AR world where it's nothing but mil-spec rails on everything. I seem to recall that many of those products and add-ons didn't exhibit back and forth play when mounted to a rail.

Surely it can't be that hard to follow the spec on a set of scope rings?

 

[NoExpert]

Re: Weaver rings on Picatinny rail

A lot of times it's about the market, making a part to fit a wider market means more money with less effort.

Picatinny specifications allow slight variance, here it is:

Not much, but it's there and ring manufactures have to account for that.

All the rails I've had have fallen within the specs. However rings are a whole other story... so far the best fitting have been my current ARC M3 rings, almost no front/back movement. All the others, including Badger Ordnance, have had some front/back play.

When you start looking for picatinny specific rings the cost typically jumps up. TPS, Seekins, Badger Ordnance, ARC and several others make picatinny spec rings (there are more differences besides the recoil lugs/rail slots). The recoil lugs will fit the rail slots better, but no guarantee they'll be a snug fit.

Measure your rail slots and see if you can get measurements from a few manufacturers, then go with who gets you closest to a "perfect" fit.

 

[m1match]

Re: Weaver rings on Picatinny rail

I have Steyr Scout rifle that is supposed to have rail slots that meet 1913 Picatinny spec but guess what?, they don't and I had to use TPS TSW rings to mount my scope on this rifle. They work fine and I push the ring all the way forward before torquing it down so that recoil won't drive the rings forward.

 

[dinkydonuts]

Re: Weaver rings on Picatinny rail

Great information. I appreciate it.

So then it seems that many manufacturers are actually making "picatinny-compatible" rather than true MIL-STD 1913.

Considering the weaver rings were around $70, brands that would use a true width crossbar aren't too far away. I had originally ordered seekins rings but they were out of stock, and it looks like there is a shortage on the tps 30mm low rings at the internet retailers I use.

I guess ill stick with the warnes. I'm thinking of getting some delrin blanks and creating small shims that fill the width of the slot to prevent movement. Can't be too hard and is easier and cheaper than buying new rings when the warnes are great otherwise.

 

[Jon A]

Re: Weaver rings on Picatinny rail

The spec was never intended to remove all front to rear play. Making .206" wide lugs on rings/mounts is a great way to ensure 1/2 of the rings/mounts aren't going to fit 1/2 of the rifles.

That's the exact opposite of the spec's purpose.

Push the rings forward on the rail until the lugs make contact and tighten. Whether that's .01" or .001" matters not. The scope tries to slide forward under recoil, that's where you need the support.

The reverse motion (due to brake or action slamming back, etc) is usually much smaller and the clamping force of the ring to the rail is sufficient to keep the scope held forward. In some extreme cases, such as lightweight hunting rifles built on .408-case based wildcats, etc, this reverse acceleration can be great enough to cause problems. That's why you sometimes see such rifles with four rings in use--two pushed forward and two pushed rearward (or in the case of my rings one pushed forward and one rearward). But those are pretty rare cases, this is typically not even needed on a 50 Cal.

 

[callen3615]

Re: Weaver rings on Picatinny rail

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: NoExpert</div><div class="ubbcode-body">A lot of times it's about the market, making a part to fit a wider market means more money with less effort.

Picatinny specifications allow slight variance, here it is:

All the others, including Badger Ordnance, have had some front/back play.

</div></div>

Im not sure if Im reading this right or not but it looks like the groove is .206+.008 but it also has a MMC modifier that adds another .006. So is that a 14 thou tolerance? That seems more than a "slight variance". Then again GD&T always blew my mind so Im probably wrong.