1:9 Twist barrel keyholing.

A replacement barrel is pretty cheap for an AR that's for sure. Maybe a major scrubbing inside the barrel along with some copper remover might do it justice? Soak it on and off with bore fame for a a day or two and see what comes out. Could be shot out and your rifling is poor or what's left of it. BCA has barrels for a hair over a $100. They are cheap but shoot way under sub moa for me.
 
Last edited:
And make sure your pushing/pulling the rod A: with a mark on it to accurately note turns per inch (tape measure handy), and B: that you are not unthreading the jag in the push/pull (been there, done that -- one pc rod with a bearing under the handle so it spins freely rules here - multi pc rod has multiple sets of threads to unthread as the jag twists.). Took me a couple tries to get it right the first time. Let us know what you find out.
 
Dultimatpredator said:
A replacement barrel is pretty cheap for an AR that's for sure. Maybe a major scrubbing inside the barrel along with some copper remover might do it justice? Soak it on and off with bore fame for a a day or two and see what comes out. Could be somebody really put it to the Kohl's and shot it out in your rifling is poor or what's left of it. BCA has barrels for a hair over a $100. They are cheap but shoot way under sub moa for me.
Click to expand...
Yes I’ve have several BCA barrels, great shooters.
 
When it is all said and done ....... My curiosity would make me come to a definite conclusion as to WHY that barrel refuses to shoot properly.
 
That's really strange. I'd have to know they why's also. I'm thinking back and I don't remember dpms making a slow twist barrel but maybe they did. Rock River had a 12 twist as a choice iirc.
 
Yeah, it’s kind of weird. I’m guessing that maybe it was either machine improperly inside with a rough cutter. Or it could be shot out or a big but is somewhere hiding inside of it. I wonder if where the gas tube hole is drilled out could have a burr hanging from it? Either that or it’s just massively copper folded? I know we all went over this, but it still keeps running circles in my mind thinking about it.
 
DP, he said he bought it new and it has very few rounds through it. I'd still like to hear a definite number on the twist rate. I know I haven't seen them all, but I've never seen nor heard of a Sportical barrel that wasn't 1:9 twist.
 
I'm on my way to check twist rate right now. My grandpa knows how to do it. My Uncle said we ought to run lapped bullets through it and see what it'll do for it. I don't have a clue.
 
I've lapped one barrel, also a dpms but on one of my 30 RAR uppers. Only because it had some pretty rough rifling, it shot well as is, but fouled bad. The Tubbs final finish kit polished it up pretty well. I'm not going to say it looks like a custom barrel, in fact it might be the worst looking dpms barrel I've scoped. BUT, I just happened to be shooting it today, and it shot a four shot group with factory ammo at 200 yds you could cover with a quarter, maybe a nickel idk. Pretty small group though. My other 30 RAR upper, and most all dpms barrels I've looked through looked great for the money and I've had more than a couple fantastic shooters. I have seen a couple, both were 260's, where the chamber was reamed off center or crooked as the rifling was not concentric at the chamber. I wish I would have bought a couple of their 204 barrels when they were available for $200 back in the day.

I'll be curious to see what you guys find out. It would be helpful if you had access to a bore scope.
 
Hidalgo said:
When it is all said and done ....... My curiosity would make me come to a definite conclusion as to WHY that barrel refuses to shoot properly.
Click to expand...
I'm with the Hman on this one! Now I wanna know why this thing wont shoot for you with a bit heavier bullets??!! Maybe just try a couple more 55+ grain loads to be sure. Check for a burr at the muzzle? Dunno what else to say.....
 
The muzzle looks okay. Had my grandpa take a look and he said it looks fine to him. He just said all he knows to do is shoot those 40 grain bullets this weekend and see what the groups look like. He don't know why it is doing what it's doing either. He said he thinks if the barrel is messed up it'll shoot those 40 grain bullets all over the place and possibly keyhole some. He didn't know what to tell me other than shoot it some more.

He thinks it'd be interesting to see what it'd do with some of those 36 grain Barnes Varmint Grenades. It may shoot them good. As weird as it's acting I wouldn't be surprised I guess. I don't know what the heck I'm gonna shoot with light bullets if that's all it's gonna group well. Badgers and raccoons I guess.
 
Last edited:
OKRattler said:
The muzzle looks okay. Had my grandpa take a look and he said it looks fine to him. He just said all he knows to do is shoot those 40 grain bullets this weekend and see what the groups look like. He don't know why it is doing what it's doing either. He said he thinks if the barrel is messed up it'll shoot those 40 grain bullets all over the place and possibly keyhole some. He didn't know what to tell me other than shoot it some more.

He thinks it'd be interesting to see what it'd do with some of those 36 grain Barnes Varmint Grenades. It may shoot them good. As weird as it's acting I wouldn't be surprised I guess. I don't know what the heck I'm gonna shoot with light bullets if that's all it's gonna group well. Badgers and raccoons I guess.
Click to expand...
36-40gr will work just fine for coyotes, fox and cat.

I actually just loaded some 40gr last night for my 223 Ackley. They work just fine, fairly easy on fur too.
 
Update on the AR 1:9 twist barrel. Shot it today, grouped 40 grain Nosler Ballistic Tips at a little less than 1". But now I'm having a different issue. 3 spent casings ejected but didn't pick up the next round. Threw the brass about 2 foot away directly to the right of the gun. Almost straight across. One stove piped in the gun and I had one that I had to pull back the charging handle to eject. I'm guessing it's either a buffer spring issue or a gas issue. But I don't know that for sure either. Just my best guess.

Didn't have any keyhole with the lighter bullets. But it's sort of a single shot AR using the lighter ones. No bueno.
 
Back
Top