Accuracy with a 300 Blackout when suppressed

[Hoss]

Shooting my 16" 300 Blackout suppressed, cannot hit a 11x18 target at 50 yards. Take the suppressor off and it shoots 1.5" group. Any suggestions, It is a banish 30 suppressor. Thanks, Hoss.

 

[inkd]

Direct thread or a QD mount? Not that at 50yds it should make a huge difference.

Have you checked alignment of the suppressor? Any evidence of baffle strikes?

Are you hitting the target at all? If so, is there any evidence of tumbling?

 

[holesonpaper]

Wow... If that's the case, that seems.. significant. I shoot a 10.5" 300 blackout with SilencerCo suppressor, and at 100 yards - I see about a 1.5" POI shift (low/right) with 110gr and a tad more with 220gr.

From a 1.5" group to off the paper at 50... Ouch.

 

[smokey]

It should improve accuracy if anything, although it might shift POI. Did you check alignment of the can before shooting? I'd think that big of a difference would be caused by baffle or endcap strikes.

 

[outrider58]

Barrel, barrel concentricity, suppressor, suppressor QD mounts, all play a part on accuracy.

If you're only seeing 1.5" groups at 50 yds(?), I'd start with barrel and barrel concentricity. Has the barrel and suppressor been checked for that?

Here is what is attainable when everything is in harmony. 10.5" SBR, suppressed and unsurpressed @100 yards.

 

[Coehorn]

"You won't be able to shoot as straight with that thing on".

 

[Hoss]

Direct thread or a QD mount? Not that at 50yds it should make a huge difference.

Have you checked alignment of the suppressor? Any evidence of baffle strikes?

Are you hitting the target at all? If so, is there any evidence of tumbling?

Direct thread, no evidence of baffle strikes.

 

[Hoss]

Barrel, barrel concentricity, suppressor, suppressor QD mounts, all play a part on accuracy.

If you're only seeing 1.5" groups at 50 yds(?), I'd start with barrel and barrel concentricity. Has the barrel and suppressor been checked for that?

Here is what is attainable when everything is in harmony. 10.5" SBR, suppressed and unsurpressed @100 yards.

View attachment 476037
View attachment 476038

Kinda new to this, How would I Check concentricity. I did bore sight the upper after about five shots, and then removed the suppresser after that didn't seem to help.

 

[alucard0822]

Yea, something is really wrong, unless it is simple like going from supers to subs, it should be close, and a similar group size. Usually need a suppressor rod, or a drill rod to check it for concentricity. Doesn't take much for a strike to throw the bullet way off target. Some combos of barrel/bullet/suppressor can under-stabilize or yaw the bullet a little, even if the bore is perfectly concentric. Doesn't take much of a yaw being subs might have a nearly 2" long bullet with a bore that might only have .025" or so clearance between the bullet and baffles.

 

[outrider58]

Kinda new to this, How would I Check concentricity. I did bore sight the upper after about five shots, and then removed the suppresser after that didn't seem to help.

You need a bore rod to make sure your suppressor is straight with the bore of the barrel. That's where you need to start, once you have your rifle zeroed. You need to zero the gun without the suppressor so as to realize what accuracy you can expect with the can on your gun. You can expect a point of impact shift with and without the can, but ideally, it shouldn't be a night and day difference.

You can spend $80+ on a bore concentricity rod or go to McMaster-Carr (like in this Youtube) buy the proper drill rods for a good bit less for the calibers you'll be using.

 

[inkd]

Direct thread, no evidence of baffle strikes.

Okay. Other than ammo selection, I can't think of anything off the top of my head that would cause that type of a change in accuracy at 50yds just by removing a suppressor.

What twist rate of barrel and what weight bullet? Were the rounds impacting the target at all? If so, were they elongated holes like they were tumbling?

 

[Melnic]

My 300BLK with 10.5" barrel (SBR) will do about 2-3MOA @ 100 yards suppressed and unsuppressed from the bench with powder coated cast reloads. I have a threaded mount and a Form 1 suppressor.
I wonder if the barrel is flexing more w/ the suppressor?
Full floating barrel or is there a FSB and forward grip is connected from Upper to FSB?

 

[accokeek]

You need a bore rod to make sure your suppressor is straight with the bore of the barrel. That's where you need to start, once you have your rifle zeroed. You need to zero the gun without the suppressor so as to realize what accuracy you can expect with the can on your gun. You can expect a point of impact shift with and without the can, but ideally, it shouldn't be a night and day difference.

You can spend $80+ on a bore concentricity rod or go to McMaster-Carr (like in this Youtube) buy the proper drill rods for a good bit less for the calibers you'll be using.

Many thanks for both the insight/idea and the video. Have alreadyh ordered 3 and will probably order more nice addtion to the "tool box"

 

[outrider58]

Many thanks for both the insight/idea and the video. Have alreadyh ordered 3 and will probably order more nice addtion to the "tool box"

Glad to help.

 

[atblis]

Carefully inspect those drill rods when you get them. They’re often very not straight even though they’re supposed to be.

Depending on caliber, carbon arrow shafts work well.

 

[outrider58]

Carefully inspect those drill rods when you get them. They’re often very not straight even though they’re supposed to be.

Depending on caliber, carbon arrow shafts work well.

Yes. When using drill rods, it's always best to rotate the rod every 90 degrees to get a consensus.

 

[atblis]

I meant more that you should return them and get new ones as I suspect they get bent at the McMaster warehouse or in shipping.

 

[outrider58]

I meant more that you should return them and get new ones as I suspect they get bent at the McMaster warehouse or in shipping.

Anything's possible, I guess. I have four from them and they've been fine for this purpose. They can be easily checked and even straightened by rolling them across a stone countertop.

 

[John from MD]

Anything's possible, I guess. I have four from them and they've been fine for this purpose. They can be easily checked and even straightened by rolling them across a stone countertop.

True dat.