[TinStar]

I hope someone can help me. I'm interested in knowing if my rifle is capable of shooting out to 1K. I have a 24in 308 bolt action, LR/M1 3.5x10x40 scope, and a 20 min. rail. I've learned from this forum that I,ll need to shoot 175's to be successful (sonic). I guess it all comes down to this....do I have enough elevation available to get there with this setup?

Thanks, Phil

 

[mele]

Its going to be close. It really depends on how many MOA you burn up with the zero.

the 3.5-10x40mm LR/M1 has 65 MOA of adjustment. Taking half of that gives you 32.5. Now, you have a 20 MOA rail which moves the zero down 20 MOA, giving you 52.5 MOA of UP. Now, take into account any adjustments required to zero the scope at 100. Usually +/- 5 or so MOA. If it stayes within that 5 MOA or perhaps requires "down" adjustments to zero, you will be fine. You have 52.5 on tap and need about 45 to be safe at 1000 yards (more if shooting 1000 meters).

Summary: You should be fine, but depends on how the 100y zero goes and you won't know for sure until you head to the 1000y line.

MEL

 

[Crazdgunman]

'Star, I have the same scope on a flat base and I can reach 900 yards.

Whether or not you can reach 1K with your 20 MOA base depends on the random chance of barrel/action alignment and, as Mel said, how many clicks you have left after you zero.

Your odds of making 1K with a 20 MOA base and a Loopy M1/LR are pretty high.

 

[spade]

You know what ive heard that makes sense in theory? If you shim the base of the barrel a bit, raising it up and effectively free floating it, youll gain 2-3 MOA of adjustment. I cant say whether this is true or not, but thought id throw it out there.

 

[Jeffvn]

Spade is correct, you can shim teh base to get a few MOA. I did so on my Patriot, and the effect was about 4 MOA. The potential for disaster is pretty high, as the torque effects of tightening the rings down on the scope with it shimmed can permanetly damage the scope. If you do it, understand that it can wreck the scope. My trick was to tighten the rings a little at a time until they were snug then tighen the front fomr than the back. I had to continuously check the rings screws for the two or three weeks I had the shim in there, but it worked and I didn't hurt the scope or the rings (Of course the rings and scoep were US Optics and basically bullet proof.)

JeffVN

 

[Crazdgunman]

Indeed, you can shim the scope base and get some more elevation. Shims made for this are available through Sinclair and others.

As Jeff noted, however, they misalign the scope rings to greater degrees as thicker shims are used. They are meant to be used with special ring inserts commonly used in benchrest shooting (another sport of mine) to relieve this misalignment. Using shims with standard solid tactical rings would put stress on the scopes body and action to varying degrees dependant on the thickness of the shim, of course.

A much better solution is to contact tactical base makers and have a base with greater taper custom made for you.

(I'll bet this whole line of thought is a moot point though, considering the vast majority of .308's will make 1K with a generously-elevating tactical type scope and 20 MOA base. Like I said, I have the same scope on a FLAT base and I'm only three MOA short of 1K.)