20 WOA Upper not shooting consistently...

[DMack]

I have a sort of technical question here... let me see if I can phrase this correctly.

I have a 20" varmint upper that I got from White Oak Armament. It is a 1 in 7 twist... and I have it on a lower that I usually mount my 18" White Oak SPR upper.

The lower is complete with a Geissele SD-E trigger, and has a Magpul ACS stock, with an H1 buffer.

I shot my 20" today, for the first time. The glass on it, is a Bushnell Elite 6500 2.5-16 with MIL DOT reticle and Tactical (3200 type) turrets.

My question is this:

WOA says on their website, that their barrels are good to go out of the box. No break in required. However, running some rounds through it today... I could not for the life of me get any groups worth writing about. I was shooting at 100 yards, off of a Caldwell style bag rest.

I was using 69 grain Federal Tactical Rifle Urban (TRU) which is the Sierra MatchKing BTHP.

This upper comes with a "headspaced" bolt carrier group, and functioned flawlessly.

I am building a dedicated lower for this upper, with the Geissele SD-E trigger and rifle length buffer tube / buffer... with the MAGPUL PRS stock.

Does this barrel need to be conditioned? I have put exactly 50 rounds through it so far. All have been the 69 grain Federal TRU. Could the rifle length gas tube in conjunction with the carbine buffer tube / buffer be jacking with the lock up time on the bolt? The rifle cycles fine, no FTF / FTE at all. I just can't get the thing to group the way it should.

I have the Bushnell mounted in a Burris P.E.P.R. mount. All bolts are torqued correctly, and the optic is square.

For the life of me, I could not get the rifle to repeat any decent groups at all. The rate of twist in this barrel is the same as in my 18 inch... so it should be fine with the ammo I am feeding it.

I'm gonna shoot it again tomorrow, to see if it gets any better.

I'm scratching my head on this one. Any thoughts? Advice? Much appreciated...

 

[Oodin]

Re: 20 WOA Upper not shooting consistently...

Maybe your rifle doesn't like Fed TRU ammo. What exactly are groups not worth writing about? How well do you usually do with your SPR upper?

 

[DMack]

Re: 20 WOA Upper not shooting consistently...

Sorry about that Brother... I meant to include that in my text. I was shooting at three inch Shoot N C targets on solid white backer, at 100 yards. I was lying prone on my shooting mat, with the rifle in my black bag rest.

I was shooting five shot groups, getting the Bushnell zeroed at 100 yards. Once I got the rounds impacting where they needed to be, the best I was able to do is put four in the three inch Shoot-N-C target.

On occasion, I was able to stack rounds on top of each other, but never consistently.

My 18 inch WOA upper, has 1 in 7 twist, and I'm able to keep the rifle within a half inch at 100 yards with this same ammo. I have not chronographed the TRU stuff yet through the 20 inch.

Needless to say, I was very frustrated.

I'm doing a long term test for the Primary Weapons System MK114 piston gun... it has a 14.5 inch barrel. I ran some M855 through it today, with an ACOG, and it shot tighter than this 20" upper did. The PWS gun has over 5500 rounds through it, and I shot with a dirty barrel today.

Things that make you go hmmmmm...

 

[tullius]

Re: 20 WOA Upper not shooting consistently...

Try Hornady 75gr BTHP Match. Different barrel may like different ammo. Check everything over. Crown ok?

 

[DMack]

Re: 20 WOA Upper not shooting consistently...

Yes Sir... the crown is very nice. I'm guessing it's the ammo. I have some Black Hills 77 grain that I will try in it. The only thing is... I have about 3k rounds of this TRU. I'd be a shame if I could not get it to shoot the way I know this rifle is capable of shooting with it.

I was initially worried about shooting the rifle length gas tube with a carbine buffer... but, it cycles flawlessly. So, that can't be effecting it. I had all the parallax dialed out... and the Glass ran the box drill very well. So, it's not the glass...

I'm not the best shot on the planet, but I shoot very consistently. So, unless I was just completely out of my mind today, it HAS to be the ammo.

Sorry to ramble, things are just not computing in my old brain housing group...

 

[Strangedays]

Re: 20 WOA Upper not shooting consistently...

The barrel and upper might not be torqed together right. I would try some other ammo and work back from there. Also it never hurts to let someone else shoot the gun just to see what they do with it. Another thing is are you letting the barrel cool between shots? I have a 16" Recon Barrel that shoots half MOA and WOA build some nice barrels.

 

[kgreylgrey]

Re: 20 WOA Upper not shooting consistently...

Is the scope new or has it been mounted on your 18" that shoots so well? If new, you might want to put it and the mount on your 18" and see if it will still shoot 1/2 inch groups. At least that would confirm or rule out the scope/mount as the problem. With 3+ inch groups, I'm not sure what a box drill would or would not prove.