223 ar wont shoot

[Cemetery21]

Properly sized bullets should not keyhole in a 7 twist barrel.
The only time I had 224 bullets keyhole was in a new 700 varmint many years ago. I cleaned the new barrel as normal, started break in and got keyholes. Got ready to send it back and thought I would try a tighter brush. Maybe used a 24 cal brush (back before I had access to a borescope). Scrubbed it good. It then shot excellent and was my primary PD gun for several years. I guess there was some gunk in the grooves and it wasn't spinning the bullets enough to stabilize.

 

[thatguyshm]

that's bout how mine shoots the upper group..I'm happy it will get the job done

The other thing for sure is getting used to the ergonomics of an AR rifle vs a standard stocked rifle. I actually sold an MDT chassis because I just couldn't get comfortable behind it. Not one bad thing to say about them, just not for me.

 

[JAlfred]

Try

I have a Armalite ar 15 a-2 nm went out to try loads yesterday looks like a shotgun I tried 7 different powders there 55 gr. btsp bullets had 5 that key-holed at 100 yds. loads are all from 3080 fps to 3300 fps bbl is one in seven twist I think I got some bad bullets going to try some different bullets when the weather get better the bore looks great cleaned up with no fouling and the crown is good the scope is good yes a bad scope wont make bullets key-hole

Try 52 gr smks, if those won't shoot there may be a problem

 

[Nick Caprinolo]

That barrel is way too slow for those light bullets. I have a 1/8 that loves 80 gr Bergers over 21.8 grs of Varget.

 

[Ron IA]

the bullets are not coming apart they are unstable this gun shoots fine with factory 55gr fmj ball amo running at 3210 fps mv my best guess is the bullets are 2nds and don't have a properly seated lead core I will try a few more things including my other ar that shot 40gr. bullets fine in it's 1and 8 twist bbl

 

[Ggmac]

I have a Armalite ar 15 a-2 nm went out to try loads yesterday looks like a shotgun I tried 7 different powders there 55 gr. btsp bullets had 5 that key-holed at 100 yds. loads are all from 3080 fps to 3300 fps bbl is one in seven twist I think I got some bad bullets going to try some different bullets when the weather get better the bore looks great cleaned up with no fouling and the crown is good the scope is good yes a bad scope wont make bullets key-hole

Any chance they are hitting the muzzle brake ?

 

[Ron IA]

no muzzle break and the crown looks great

 

[Oso]

the bullets are not coming apart they are unstable this gun shoots fine with factory 55gr fmj ball amo running at 3210 fps mv my best guess is the bullets are 2nds and don't have a properly seated lead core I will try a few more things including my other ar that shot 40gr. bullets fine in it's 1and 8 twist bbl

Ron,

The soft points have tendency for the tip to smear as it gets stripped off the magazine and slammed into feed ramp. It i common enough to find unfired rounds with the lead tips blunted, pushed off center, or even angular flst spots... all of which would result in a shotgun pattern or if bad enough potential to key hole. You can test for this by taking a shot and then manually extracting the next loaded round in the chamber to see if the lead tip has been damaged. Repeat the process a couple of times. As you mentioned it could also be faulty manufactured bullets.

 

[Ron IA]

Ron,

The soft points have tendency for the tip to smear as it gets stripped off the magazine and slammed into feed ramp. It i common enough to find unfired rounds with the lead tips blunted, pushed off center, or even angular flst spots... all of which would result in a shotgun pattern or if bad enough potential to key hole. You can test for this by taking a shot and then manually extracting the next loaded round in the chamber to see if the lead tip has been damaged. Repeat the process a couple of times. As you mentioned it could also be faulty manufactured bullets.

I will give that a try

 

[jelenko]

Not sure that damaged tips could produce keyholing. With the amount of spin from a good barrel, it's got to be tough to get the bullet sideways, regardless of the condition of the tip. Shotgun pattern, yes; keyhole, doesn't seem right.

To test, you could single load the rounds and get them far enough in the chamber so the bolt closing doesn't run them up the feed ramps.

If some are still keyholing, I think it's almost for sure it's the barrel.

 

[Lone Hunter]

Try some different Bullets. Those bullets are for blasting tin cans and that's about it. I can shoot 52 gr Speer HP's and Nosler 50 gr BT out of a 1/7 with great accuracy. The Hornady bulk 55 gr's I had I found out real quick that they just wouldn't shoot good period. To me your not saving any money by buying cheap bullets and wasting powder. When I shoot I want to hit it and when they act like yours are doing it's very frustrating . Good Luck

 

[searcher]

That barrel is way too slow for those light bullets

I think you meant to say the barrel is too fast. The lower the number - the faster the twist. Anyway - a 1-7" is not too fast for light bullets. A too-fast barrel can make bullets come apart if driven too fast - otherwise they just slow the bullets down some as opposed to a slower barrel.

 

[skeeljc]

The 1 in 7 twist AR is for a SBR with a barrel length of 8" to 10". A 16" AR barrel should be 1 in 8 or 1 in 9. Try some Hornady 75 gr. HP BT match bullets. They are available in bulk from Midway at a moderate price. My AR-15 with a White Oak 18" 1 in 8 will keep the Hornady 75 gr HPBT sub MOA all day long.

 

[thatguyshm]

Interesting article on bullet tip deformation.

https://www.handloadermagazine.com/does-it-matter

 

[jelenko]

If I read it right, there's not much effect on accuracy from deforming the tips. There is a big impact if the bases are deformed.

 

[Walt Krafft]

7" twist is the standard NATO twist for 20" barrels. That is not the problem. Check your gas tube to carrier key alignment. Remove the bolt, turn the upper up side down and slide the bolt carrier forward. The gas tube should enter the key with no movement. Load 24.3grns Varget with a 69 Matchking. AR's are difficult to shoot as benchrest guns. If that does not shoot it is time to put a good barrel on it.

 

[thatguyshm]

If I read it right, there's not much effect on accuracy from deforming the tips. There is a big impact if the bases are deformed.

That was my understanding as well. BC will be effected but it will still be accurate. The 45 degree cut was what really shocked me.

 

[Bocephus]

I have a Armalite ar 15 a-2 nm went out to try loads yesterday looks like a shotgun I tried 7 different powders there 55 gr. btsp bullets had 5 that key-holed at 100 yds. loads are all from 3080 fps to 3300 fps bbl is one in seven twist I think I got some bad bullets going to try some different bullets when the weather get better the bore looks great cleaned up with no fouling and the crown is good the scope is good yes a bad scope wont make bullets key-hole

Had some Hornady 55gr btsp that would shoot 2 of 5 shots in about 0.3", but trying to figure where the other three would go was about as easy as guessing winning lottery numbers.
I thought it might be the soft tips but tried the old 50gr Sierra Blitz over CFE-223, and low 'n behold, things just tightened right up.
Almost positive the 1st shot was a "Cold Hillbilly."

 

[msinc]

…….. the bore looks great cleaned up with no fouling and the crown is good...….

If I may ask....what kind of borescope did you use to determine this????
How much slop between the upper and lower receivers??? What do you have for a trigger???
Just because it's an AR does not automatically exempt it from still needing a good trigger. Factory or "issue" triggers are right up there with a Savage or an X-mark Pro. None promote accuracy.
If the upper and lower have movement in relation to each other that needs to be addressed. There needs to be none. How accurate would a bolt gun shoot of the action and barrel slid back and forth in the stock??? Same problem, movement where you don't want it.
No, a borescope wont make it shoot and I see folks that don't have one constantly posting that they should all be thrown away, but way too many bores are dismissed as being "clean", "good" or "okay" without seriously having a real look at them.
Not saying you wont eventually stumble upon the magic bullets that will fix it, as suggested so many times in this thread. But you should at least consider the above before you go all out on the ammo related quest. Best of luck sir!!!