GunnerHAF Posted August 13, 2006 Report Share Posted August 13, 2006 I built me a tatical rig in 308 out of a K98 action I had. I got one little problem, on my 20MOA base I ran out of down travel on my scope. The rifle will shoot about 2 1/2" high at 100 yards. Anybody have an idea on what size shim I should use to get the elevation back in check. Link to comment Share on other sites More sharing options...
tinkerfive Posted August 14, 2006 Report Share Posted August 14, 2006 Dang! That should work out to about a 300 yard zero. Leave it right there if it's not doing funny things to the optics with the adj at the limits. I alway set my scopes high at 100 yards. I prefer to drop my point of aim at close yardage rather than raise my point of aim at a distance. Link to comment Share on other sites More sharing options...
J Bird Posted August 14, 2006 Report Share Posted August 14, 2006 It is not good to shim very much on bases, stresses your scope tube. The most I will add is one thickness of a beer can which is about .004". You really only need to lower impact about 1" to give you about 1 1/2" high at 100 yds. I try to ajust to use the center of the scope if I can or close to it. The best glass is in the center of the scope lens. If you want it on center of the bulls eye at 100 would be best to use Burris Signature rings with offset inserts. No stress on tube. They are $25.90 (matte) from www.midsouthshooters.com need a $40.00 order. Probably need something else also, cleaning supplies etc. nice folks. Link to comment Share on other sites More sharing options...
donmarkey Posted August 14, 2006 Report Share Posted August 14, 2006 If you shim make sure you lap the rings, unless it's a 1 pc mount then don't worry. I lap all mine anyway. There's probaby a formula, but I don't know of one. I've just trial and errored it with a boresighter. -Don Link to comment Share on other sites More sharing options...
z1r Posted August 14, 2006 Report Share Posted August 14, 2006 Why would you put a 20 MOA base on and expect to zero at 100? Link to comment Share on other sites More sharing options...
fmsniper Posted August 14, 2006 Report Share Posted August 14, 2006 Why would you put a 20 MOA base on and expect to zero at 100? like Zr1 said 10 MOA base should have been enough (if your scope needed the extra MOA at all) I normally do not use MOA bases with a 308, since 1000 yards is about max performance for that round and honestly 800 is optimal, get a good scope with enought MOA ....... Link to comment Share on other sites More sharing options...
GunnerHAF Posted August 15, 2006 Author Report Share Posted August 15, 2006 My scope is a IOR 2.5-10 X 42 with the MP-8 reticule on a 20 MOA Farrell 1 piece base in TPS low rings. And rings were lightly lapped in. Every thing when torqued looked good. I was just trying to get the most travel in elevation out of the scope as I could. The zero is not bad I just have to hold on the first top mil mark to zero at 100 yards. And yes it is close to zero at 300 on the center dot. I was just trying to make things easy with a 100 yard zero and keep things simple. Even with this hold over she still shoots sweet. Thanks for the help. Link to comment Share on other sites More sharing options...
fmsniper Posted August 15, 2006 Report Share Posted August 15, 2006 I also have IOR and they have enogh travel for 1K, with out the MOA rail, but I would suggest getting a 10 MOA or standard, sell the 20 MOA, I only use 20 MOA on my 50 BMG and 338 Lapua for shootng past 1500 meters Link to comment Share on other sites More sharing options...
Recommended Posts