Long, short actions?

[plumeja]

I just starting to read about 20 moa scope mount bars. I have a 308 browning x-bolt and can't find out what at length I have. Are these bars neede or a bad idea if you're shooting from 200 yards and up. I'll be shooting even at 100yrds sometimes when I can't get to a long range. Any views on this. Thanks guys an gals

 

[ShtrRdy]

Well, the 20 moa, or more, scope base is nice if you're shooting long distance. By using one it allows you to use more of the range of reticle movement in the scope. Be aware that the scope needs to have enough elevation adjustment to compensate for the 20 moa base. What scope do you plan on using?

 

[plumeja]

I have on order a vortex pst viper 6-24x50. Just waiting for Amazon to mail it out still. I'm shooting a x-bolt eclipse target. Don't know if I was that clear on my first post. I have read about scopes needing so many moa on elevation of the reticle and this scope meets that number that I read.

 

[B-P-UU]

The X-bolts actually have 3 action lengths: X-short (for .223), Short and Long. You have a Short action. Murphy Precision probably makes the nicest Picatinny rails for the X-bolts. Give him a call and he'll set you up; really nice guy.
I think i went with a 15 MOA rail on mine, but they have a 20 or he'll do custom cants as well. With a .308 and PST, i think i would go 20 MOA.

 

[FEENIX]

I have on order a vortex pst viper 6-24x50. Just waiting for Amazon to mail it out still. I'm shooting a x-bolt eclipse target. Don't know if I was that clear on my first post. I have read about scopes needing so many moa on elevation of the reticle and this scope meets that number that I read.

Below is probably one of the best advice you'll get from an optics SME ...

Originally Posted by bruce_ventura
Even though the scope adjustment range may be large enough to get to 1,000 yds, you should use a 20 moa base. That's because off-axis optical aberrations that degrade resolution increase with incidence angle. You should set up your rifle so that the incidence angle is minimized for long distance shots (where resolution matters most).

Assume the base is within +/-10 moa of alignment with the rifle bore. Let's also assume your bullet drops no more than 30 moa at 1,000 yds, and you like to zero your rifle at 100 yds. With a standard base, you would need up to -40 moa of adjustment to get to 1,000 yds. That means you need a total 80 moa of adjustment.

With a 20 moa base you would need up to -20 moa to get to 1,000 yds, but up to 26 moa to get to a 100 yd zero (worse case boresight alignment in each case). That means you need a total 52 moa of adjustment. With a 20 moa base, however, the incidence angle at 1,000 yds is 20 moa less, so the image will have less blur.

Good luck and happy safe hunting/shooting.

Ed

 

[BergerBoy]

MY PST has 65 MOA elevation although I think they advertise 60.
A 20 MOA base worked fine on mine, if that was your question.

 

[plumeja]

Thanks guys you all helped. I am looking at the 20 moa at a short action. I bought the book the ultimate sniper so that will help a ton too. Can't wait to get everything mounted