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-   -   Mounting problem - Rem 700 (http://www.firearmstalk.com/forums/f65/mounting-problem-rem-700-a-73886/)

Khromo 10-07-2012 04:35 PM

Mounting problem - Rem 700
 
I recently received a left-handed Remington Model 700 SPS Varmint in .308. I mounted a Brownell's steel Picatinny base, Brownell's Picatinny rings, and a Nikon Monarch 6-24x50 scope. I tried to rough in the zero using a Sitelite 100, and found the scope was looking at a point way above and to the left of the bore line.

The knobs maxxed out long before I had any sort of a zero. I had decided to follow the shoot one/clean process for the first five rounds, and couldn't get a round on the large target at 100 yards.

I took the scope and rings off, and completely loosened the two rear base screws. With the two front base screws torqued down, I can slide a .020" feeler gauge between the rear of the base and the top of the receiver easily.

I am thinking I need to cut a piece of shim stock to fill this space, or use bedding compound to build up the rear of the receiver, but this is uncharted territory for me so I would sure appreciate any guidance! I am obviously not a smith, but I am pretty handy in my reasonably well equipped garage!

Thanks in advance for any help or condolences!

Khromo 10-07-2012 06:30 PM

Looking over the Brownell's site, it seems I can purchase a couple of shims with the correct hole spacing that will fill the 0.021-0.022" gap.

Is there any great advantage to using bedding compound to fill this gap? Do the shims need to be loc-tited or otherwise bonded in place, or can they be stacked in place and torqued down?

hiwall 10-08-2012 02:44 AM

I would use shims before I ever used bedding compound. no glue or loctite needed on the shims. you can use any metal for shims.

ryguy00 10-08-2012 03:28 AM

Pop cans work great for shims. Just cut small pieces and test it out. If it looks terrible, dont worry. After testing and deciding what you need to make it work, then you can make it all look pretty.

Khromo 10-08-2012 12:38 PM

Thanks for the advice, guys. I will shim that gap. Looking at where it is aligned now, I think that will solve my problem.

Stay safe!

Khromo 10-25-2012 08:50 PM

All right, here is an update.

I got some shims from Brownell's. I stacked two 0.008 shims and one 0.006 shim under the rear of the Brownell Picatinny base, and torqued it down. I put some Leupold Mark 4 rings on and gave them a little lapping. I installed my new Nikon Monarch 6-24x44 scope.

I lit up a laser bore sighter, and everything looked reasonably well aligned, so I went to the range.

A few inches of adjustment, and this rifle was throwing Sierra 168 grain MatchKings straight. I fired four groups at one hundred yards. The first one measured 0.60", then things settled down and it coughed up groups of 0.40", 0.40", and 0.30". This indicated to me that I was having a lucky day, because that wasn't skill, so I went to the local Stop'N'Rob and bought a few lottery tickets.

There is a good sized gap under the base, so I think I will pack some black grease in there to keep the moisture out. The problem would appear to be fixed, though. I'll keep my fingers crossed, and I will keep loading those MatchKings over 41.5 grains of Reloder 15. Whew.

gunnut07 10-26-2012 05:44 PM

HUM you shouldn't have to shim the scope mount. Sounds to me like the mount was bad or your rifle is not right.

jpattersonnh 10-26-2012 08:35 PM

My thought was left hand rifle, w/ a standard 1 piece mount for a right hand. Mount is backwards.

TCH2FLY 10-26-2012 10:45 PM

Quote:

Originally Posted by gunnut07 (Post 990710)
HUM you shouldn't have to shim the scope mount. Sounds to me like the mount was bad or your rifle is not right.

x2

Quote:

Originally Posted by jpattersonnh (Post 990900)
My thought was left hand rifle, w/ a standard 1 piece mount for a right hand. Mount is backwards.

Brownell's bases are cut to work with right or left actions ... perhaps a 20moa base on backwards :eek: :confused:

Khromo 10-27-2012 12:59 PM

Thanks a lot for the suggestions! I need all the help I can get.

I don't think the base could be on backwards, as the front and rear mounting surfaces have different radii (Sp.?), with the front being much more round. The screw spacing is different as well.

My memory tells me I ordered a 0 MOA model, but my memory is even worse than my personal hygeine, so I will check up on that to be sure.

I recently read on this board or possibly another that this problem is not rare, and it stems from Remington's manufacturing practices. Some guy, who may or may not know what he was talking about, said something to the effect that the round, forward part of the receiver is mostly finished or dimensioned on a lathe, but the flatter mounting surface at the rear of the receiver gets more hand finishing. He said this sometimes results in uneven mounting surfaces, and helps to support the shim market!

It looks like Brownell's sells a few of those little guys, with correct screw spacings for the front or rear of the mount.

While I was wandering aimlessly around the garage this morning I stumbled across an EGW base that will fit that rifle. After the initial lust for the new rifle wears off, I may install that base and see if the fit is any better, to see if the base is indeed at fault.

On the other hand, if this thing continues to print under 0.5 MOA, I may just learn to love it as it is, like a homely woman who can curl my toenails, or an obnoxious neighbor who knows how to fix cars and solve plumbing emergencies. After all, I have a few minor, very very very small, very minor faults myself. Hard as that may be to believe. :eek: :):):)


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