One rifle, two scopes?

MPFD

MPFD

Well-known member
I have two different good quality scopes in two different "good" quality mounts. Neither are quick detach mounts. One is a Burris PEPR and the other is a RRA cantilever. I wanna get your opinions on how well swapping scopes on the one rifle will work out for me. Are the tolerances of these mounts good enough that I would be able to swap from one to the other on my AR, with out "needing" to re-zero? I know they won't probably be perfect but 1"+/- change in POI would be acceptable, I guess. Has anyone else done this? What do you think? Are the tolerances of fitment between mount and rail precise enough?
 
I tried this with two good scopes on my AR. I had a Burris Signature 6x-24x-44mm in some crappy weaver rings and a Nikon Buckmasters 4x-12x-50mm in a set of Warne Tacticals. I was able to swap them back and forth multiple times at the range without having more than about 1/2" at 100yds shift. I wanted to take a calling scope and varminting scope to NM to hunt with Tony Tebbe. It turned out that I was too paranoid to remove the calling scope once out there and just ran it for prairie dogs and coyotes since we were back and forth between the two. I recommend when mounting them up that you push the slop out of your mounts by moving the mounts as far forward as possible against your picatinny rail before locking them down. It should work like a recoil lug on a bolt gun with any slop to the rear and tight to the front. You might also want to make note of which slots you use for each mount incase they are different. You don't want to accidentally change your eye relief.
 
Thank you very much sir! The RRA mount has a protruding notch machined in it that is the exact width of the slots in the rail. I believe the Burris does also. I agree with you on marking the slots. I was thinking about using some paint pins to make a small dot in slot that each mount goes in. So you have done it with rings and had very little POI change, huh? I could easily live with a half inch on my 1-3x. I'm pretty confident that it will work, I was just wanting to see if anyone else does it.

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You can see the "notch" or locating pin in this picture circled in red. This in not the cantilever, but the original has it also.
 
You shouldn't have much change if any. I of course range tested the theory back and forth a bunch of times as I recommend you do. The lug under yours should fit tighter than my rings, but will likely still have at the minimum a slip fit tolerance. I would still push forward on the mount when securing it. When I did my rings I did the same thing when securing the individual ring bottoms to the upper. After mounting the scope in them they stay just like a 1 piece mount. Matching colored dots to the appropriate mount is the way to go. It would be a quick no brainer. Something like red dot on one mount and upper rail, white dot on other and rail. Match the dots.
 
Thanks what I'm thinking. Probably use some of the wife's finger nail polish on the bottom side where no one can see it.
 
Got a decent torque wrench? Wheeler's Fat Wrench would fit the ticket. Torque it the same each time and do some tests at the range to make sure your theory works. I see no reason why it wouldn't be possible. Plus it's justification to buy a nice tool.
 
Well see. I got the other scope all set up and then put my low power back on. I'm gonna shot it and see how close it is.
 

I do it all the time. Why buy a scope for every rifle you own.

You can only shoot one rifle at a time. It lets me buy better scopes.

I use a Laserlyte boresite and then few rounds down range, go hunting.

I keep a notebook on what I am doing. The notebook saves time.

I know everyone likes LaRue but I use A.R.M.S. "Swan" #63 & #19, I think LaRue is over priced.

It works for me and keeps cost down.
 
your thinking the reverse, but that's cool. I wanna be able to have both a 3-9 and a 1-3 in mounts sighted in and ready to be clamped on and hunt with out having to do much if any re-sighting.
 
I have found that i can swap from say my sa savage bases to my other sa savage bases and be on within 1" at 100yds and then fine tune it from there, the same for my ar's.
 
I should probably be even closer since I'm not gonna change rings or mounts. I'm gonna try my theory this weekend and I will let you know how it worked out at the range next week.
 
I went thru this myself. I wanted to be able to pull the scope off on my 5.56 and use irons or my eotech when I'm at the range "playing" around, but still be able to return to zero when I returned the scope. I also wanted to swap between my Leupy 1.5-5 and my Bushnell Elite 4200 2.5-10x50 or iron sights on my AP4 .308 depending on the terrain I'm hunting (drives, stand hunting, weather).

I started out with the the regular PEPR. Then I purchased a couple of QD PERPS. I had so-so results. I heard everyone stating how they had 1/2" or less shift at 100 yards. That was not the case for me. I tested it multiple times with shifts ranging from dead on to a couple of inches. For a varmint rig, this was not acceptable.

I eventually bit the bullet and purchased a LaRue and a Bobro. After using and testing these, I will never go back. I don't think I've had a shift of more than 1/4" using either mount on either my 5.56 or my .308. I may try an ADM next time as these are about $40 cheaper than the other two and are suppose to be right up there with the other two.

I could never really get myself to drop the coin on these super expensive mounts (super expensive in my opinion). However, after making the jump, I truly feel you get what you pay for. Buy once, cry once, you will be further ahead.
 
Originally Posted By: jasonprox700Buy once, cry once, you will be further ahead.

I did just this on an SD 6.5 AR. I used the SWFA one piece quick detach mount with some forward allowance (like the LaRue 104) and have one mount on each scope. Once I had both scopes ( #1 a 3 x 9 SWFA super sniper and #2 a 6 x 24 Sightron SIII) sighted in it and zeroed it has been NO PROBLEM swapping them. Just mount to the correct rail position notch on your AR. I have less than 1/4 MOA change in impact. So slight that it is usually me or the ammo or the wind and not the scope.

Both of my scopes happen to track superbly so once I range verified them on the same ammo at 100 yards and also at 200 yards, my elevation changes are simply recorded in my notebook for that scope and rifle. So I can set for a 100 yard zero or for a 200 yard zero with very high confidence. I keep my logbook updated with the scope adjustments for my favored 6.5 ammo loads (123 grain Hornady AMAX or 95 Grain Hornady VMax.) So not only can I swap optics I can set my zero pretty quickly for terrain.

It is not the cheapest way to go, but it is virtually foolproof on an AR platform. I can lend out a scope to a buddy with a flat top AR and we just keep track of any adjustments that he makes in zeroing on his rifle. Remount on mine and reset the windage and elevation and I am right back on again. Very impressed with the repeatability-- just write it down in your notebook/logbook.

I demonstrated it to a buddy by shooting the 6.5 with the Sightron and then pulling it off and popping the SWFA on top and then shooting it--- absolutely spot on at 100 yards-- and then remounting the Sightron and doing the same thing. The repeateability and sturdiness of mount is just as simple as it gets if you know or mark which rail slot to put it in.

Oh and make yourself ballistic field cards for your 100 and your 200 yard zero on your favorite loads and you are really good to go. Then all the misses are due to the trigger puller, not the set up!
 
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