Viper PST 6-24x50 for 1000yd shooting

sprink · Apr 1, 2014

I'm new to rifles and scopes but have recently decided to try some long range shooting. I've decided on either the sps tactical in .308 or the model 10fcp also in .308. My question is is there enough elevation adjustment in the PST to get a .308 out to 1000 yards if I used a 20 MOA base? I don't plan on shooting 1000 yards from the start but want something I can grow into as my abilities improve. Any help would be great, thanks.

the4thshake · Apr 1, 2014

There should be enough. You can get a few more mils of holdover by using the reticle if necessary. It should take you somewhere in the neighborhood of 10 mils of holdover to reach 1k from a hundred yard zero.

Gun Mechanic · Apr 1, 2014

To me, this is where the fun begins. To do the math you need to know the trajectory of a typical 308 bullet capable of a 1,000 shot. Let's take the Federal Gold Metal Match Sierra Match King (SMK) 175 grain hollow point boat trail (HPBT) which should drop about 377.5" at 1,000 yards, if you zero your rifle at 100 yards. This means you need roughly 37.75 MOA or 10 mrad of vertical adjustment. The Viper PST 6-24x50 has 19 mrad of elevation adjustment. So in theory, no, you do not need the 20 MOA base. My friend shoots a 1,000 yards with his 308 which has a PST 4-16 and he has a zero MOA base and does just fine.

I'm no expert but if I got all my numbers right and my math is good you shouldn't "need" a 20 MOA base. Will it hurt? probably not. If you ever switch scopes with one without all the elevation adjustment, you might need to buy a new base to comp for it. I got a 20 MOA base on my rifle and couldn't be happier.

Anyone with more experience want to chime in?

sprink · Apr 1, 2014

Gun Mechanic said:
To me, this is where the fun begins. To do the math you need to know the trajectory of a typical 308 bullet capable of a 1,000 shot. Let's take the Federal Gold Metal Match Sierra Match King (SMK) 175 grain hollow point boat trail (HPBT) which should drop about 377.5" at 1,000 yards, if you zero your rifle at 100 yards. This means you need roughly 37.75 MOA or 10 mrad of vertical adjustment. The Viper PST 6-24x50 has 19 mrad of elevation adjustment. So in theory, no, you do not need the 20 MOA base. My friend shoots a 1,000 yards with his 308 which has a PST 4-16 and he has a zero MOA base and does just fine.

I'm no expert but if I got all my numbers right and my math is good you shouldn't "need" a 20 MOA base. Will it hurt? probably not. If you ever switch scopes with one without all the elevation adjustment, you might need to buy a new base to comp for it. I got a 20 MOA base on my rifle and couldn't be happier.

Anyone with more experience want to chime in?

Thanks for the insight. This is all new to me and kinda makes my head spin.

stmcelroy · Apr 3, 2014

A 20moa base will not hurt anything and it will for sure allow you to shoot to 1,000 yards and beyond.

erslll · Apr 6, 2014

Gun Mechanic said:
This means you need roughly 37.75 MOA or 10 mrad of vertical adjustment. The Viper PST 6-24x50 has 19 mrad of elevation adjustment. So in theory, no, you do not need the 20 MOA base. My friend shoots a 1,000 yards with his 308 which has a PST 4-16 and he has a zero MOA base and does just fine.

Without a 20 MOA base, you would probably have to hold over a little in this scenario. Yes, you have 19 MRAD of adjustment but that is from top to bottom. With a 0 MOA base, your zero will be some where in the middle of that 19 MRAD so you might have 10 MRAD left to adjust up or you might have 9 or who knows for sure how much you will have until you try it. As has been said in this thread a few times already, a 20 MOA base will not hurt anything. Another thing to consider is that you might not have much windage travel available if you are at the extreme top of your adjustment range.

SquidHC · May 10, 2014

For what it is worth I have the scope you mentioned, and had a 20 moa base, and could not get a zero at 100 yards. The scope simply bottomed out, which meant that I could not adjust the windage or make the elevation any lower. Now, you don't have to have your zero on your crosshairs, but for me I preferred it.

sprink · May 10, 2014

SquidHC said:
For what it is worth I have the scope you mentioned, and had a 20 moa base, and could not get a zero at 100 yards. The scope simply bottomed out, which meant that I could not adjust the windage or make the elevation any lower. Now, you don't have to have your zero on your crosshairs, but for me I preferred it.

That's good to know. Would it adjust low enough for a 200yd zero? I'm curious if a 10 moa base would work. I'd rather hold over at 1000yds than hold under at 100yds since I plan to hunt with it.

SquidHC · May 10, 2014

Yes, a 200 yard zero wasn't an issue. I prefer 200 for hunting also, since my impact is 0.6 mils high at 100 and 0.7 mils low at 300. It's super easy to just remember and not have to dial your dope, and frankly if you put it on your cross hairs at either of those ranges, you should still hit your target.

the4thshake · May 10, 2014

I have the scope with a 20 moa base as well. It zeroed at 100 yards no problem. I run out of travel on the dial around 1200 yards and have to start using lower hash marks on the reticle.