Ballistic issue/question with 300Blk SBR - need advice!

[Sendit6.5]

I have a 10.5” SBR in 300Blk that I set up for coyote hunting and my son and I were sighting it in today. It shoots pretty well with some 110g V-max Hornady Black; but what threw me was the results from some Beck Subsonics with the Lehigh 190gr pills. I expected the considerable drop in POI (from the zero with supers) even at just 50yd. What I did NOT expect is that it groups well but about 4” right of POA at that 50yd range? WTH? Of course I know that every load shoots differently but I’ve never had any rifle that had such a drastic windage shift from one load to another - not without some other major factor like removing or adding a suppressor or a brake. I’m going to get a different sub load but I was really hoping to use these Lehigh bullets on some closeup coyotes! I can handle holding over when I want to use subs (when I know that shots won’t exceed about 60-70yds) but if I have to also hold windage at close range, that’s a no-go for me. It’s just TOO much to have to consider on a small moving target when you only have a couple seconds to see it, get on the rifle, find the animal, track it AND shoot it!

I’m a very experienced hunter and shooter with more than 40 years of experience but I’ve never seen a rifle be this far off in regards to windage from one load to another. On the other hand, I have almost NO experience with subs. Is this fairly common with subs or 300Blk? Anyone else have this happen or, better yet, find a solution to a conundrum like this?

FWIW - I am shooting this rifle suppressed -Omega .30. However, we never touched/removed the suppressor today. Hard to see where it could be the culprit.

 

[cmoore806]

and you're certain you aren't yanking the trigger or inducing any movement yourself? shooting from bench? also what optic are you using? could there be a problem with the optic?

 

[Skeptic1]

Those Lehigh bullets have that funky cross sectional nose don't they. I wonder if with a right hand twist if they are clawing themselves to the right like a paddle in the wind? Just a thought......

 

[Gatorshark]

I'd try different subs first. Albeit they shot to the right of POA, how tight did they group? Or were they all over the place?

If POI was tight, that's the twist and the boolits.

 

[Sendit6.5]

Thanks for the replies!!

and you're certain you aren't yanking the trigger or inducing any movement yourself? shooting from bench? also what optic are you using? could there be a problem with the optic?

Anything is POSSIBLE but it’s unlikely it’s a trigger issue. I’m a good shooter and this is a unique experience. Shooting from a great tripod and ball head with a hog saddle. I shoot animals for work with it (and a bolt rifle) out past 500 regularly. So, it’s unlikely. Could be the optic - it’s the only cheap one I own - but since it shoots good groups and the issue is only the shift between ammo types. So, an optic issue is unlikely. These are the obvious questions to ask but I already asked them myself. I really don’t think it’s the problem. Gun did the exams to same thing for my son

Those Lehigh bullets have that funky cross sectional nose don't they. I wonder if with a right hand twist if they are clawing themselves to the right like a paddle in the wind? Just a thought......

Possible. Maybe I’ll call Lehigh and ask them if they’ve had an issue like this before.

I'd try different subs first. Albeit they shot to the right of POA, how tight did they group? Or were they all over the place?

If POI was tight, that's the twist and the boolits.

They grouped pretty well. Real nicely with the supers. I was pleasantly surprised with them, actually. The subs weren’t as good but actually better than I expected from something moving that slow out of a super short barrel. I’m going to try to make the drive to the nearest town with a gun shop and see if they have some other ammo. We shot all the supers i

 

[loveha]

I wish I still had my 50yd targets for the Underwood loaded Lehigh ME ammo out of my Proof barrel. They are unstable, and shot about 4-6 MOA. Hornady Sub-X out of the same barrel was about 1 MOA.

 

[Docsherm]

I have a 10.5” SBR in 300Blk that I set up for coyote hunting and my son and I were sighting it in today. It shoots pretty well with some 110g V-max Hornady Black; but what threw me was the results from some Beck Subsonics with the Lehigh 190gr pills. I expected the considerable drop in POI (from the zero with supers) even at just 50yd. What I did NOT expect is that it groups well but about 4” right of POA at that 50yd range? WTH? Of course I know that every load shoots differently but I’ve never had any rifle that had such a drastic windage shift from one load to another - not without some other major factor like removing or adding a suppressor or a brake. I’m going to get a different sub load but I was really hoping to use these Lehigh bullets on some closeup coyotes! I can handle holding over when I want to use subs (when I know that shots won’t exceed about 60-70yds) but if I have to also hold windage at close range, that’s a no-go for me. It’s just TOO much to have to consider on a small moving target when you only have a couple seconds to see it, get on the rifle, find the animal, track it AND shoot it!

I’m a very experienced hunter and shooter with more than 40 years of experience but I’ve never seen a rifle be this far off in regards to windage from one load to another. On the other hand, I have almost NO experience with subs. Is this fairly common with subs or 300Blk? Anyone else have this happen or, better yet, find a solution to a conundrum like this?

FWIW - I am shooting this rifle suppressed -Omega .30. However, we never touched/removed the suppressor today. Hard to see where it could be the culprit.

I would try different ammo.

If it is not that then the only other thing could be the FH mount. Try taking it off and remounting it.

 

[hlee]

Not subs v supers, not Lehigh, and not 300 blackout. However, my 308 Winchester Barnes tsx bullet handloads shoot 3" right of my amax handloads. I just record it and roll wit it. Then again, I check zero before a hunt and don't mix ammo...

 

[Hayden#69]

Another fan of the Hornady SubX. I got a 16" V7 barrel that loves them. PSA Pistol loves em as well.

Hayden.

 

[Glassaholic]

A 4" shift at 50 yards shouldn't happen with anything, that is not normal. I shoot all kinds of loads with my 300BLK SBR and have never experienced such drastic shift with anything??? Even shooting suppressed to unsuppressed doesn't offset POI that much, this is one for Sherlock

 

[loveha]

When are we, late 00's with that broomstick handle? Haven't used, let alone seen one in use in over a decade lol.

Nice rifle, tan furniture looks out of place though.

 

[Glassaholic]

When are we, late 00's with that broomstick handle? Haven't used, let alone seen one in use in over a decade lol.

Nice rifle, tan furniture looks out of place though.

Hey now, I'm an old guy I assume by broomstick handle you mean my bipod grip? I think it was called the grip-pod or something like that. And since I shoot 99% subsonic loads from it, it has worked quite effectively when I need something a little more steady.

 

[cmoore806]

if different ammo does not fix it then my bet is its an optic or optic mount problem.