My pre-ban AR15 (Oly Arms)has begun to experience tumbling bullets. I've owned the rifle for two years. The barrel, when bought, had less than 200 rounds through it (not chromed lined) and I've put @ 2K through it. I use Wolf 55 and 62 grain and until two weeks ago, I could group under an inch at 100 yds. with either. Now most of the 55 grain and some of the 62 grain tumble.The barrel is regularly cleaned with Hoppes and industrial strength ammonia mix. A local gunsmith said I had a "flat spot" on the muzzle crown, but I don't know if that's the issue. I'm thinking of having it re-crowned just to eliminate that possibility. What'dya think?

I think I'd just get a new barrel, and save the cost of the re-crown.  WITH chrome lining this time.

And I wouldn't use anything other than Hoppe's #9 and CLP on my bore, regularly.  Maybe the ammonia copper remove every 1000 rounds or so.  I think you can do more damage over/miss cleaning than without cleaning at all.

Barrels on rifles are like tires on a car.
They both wear out if you use them enough.
You probably could get a new barrel and never have to look back. A damaged crown, unless it is really damaged badly won't tumble bullets.
I'd opt for the new tube...

KyARGuy

binazone, just replace the barrel.  As for going chrome or not, the choice is yours.

As for the muzzle being flat, it sounds like you have cleaned the rifle way too much, and have cleaned it by the muzzle and not the breech.

Remember, when you clean the barrel, always drive the rod from the chamber.  This will prevent the muzzle from being worn out well before the barrel.

Falarak,
Thanks very much for the reply. I agree a new barrel is the way to go.

binazone

Dano,

I've only just started using the ammonia solution and except for a few times, the barrel gets cleaned from the chamber end, but your points are well taken. Thanks for your reply.

binazone

Kyarguy,

The consensus is new barrel and that's where I'm going. Thanks.

binazone

Kyarguy,

The consensus is new barrel and that's where I'm going. Thanks.

binazone

Kyarguy,

The consensus is new barrel and that's where I'm going. Thanks.

binazone

Whoa! Before new barrel/recrowning, try it with a different ammo brand.  Wolf is notoriously inconsistent to the point of infamy.  Run Winchester Government white box or american eagle or if you can afford it Sierra Match King or Hornday TAP to test it out.

How do you know the bullets are tumbling?
Is the rifle printing keyhole on the target?
Just wondering.

No barrel is going to wear out in 2k. Geez, I've put that through in a day. Check and see if your flashhider is loose.

Loose flash hider?  I dont think so.  Even if it was barely threaded on, it wont make the bullets tumble.

The only thing that I know that could make them tumble is not enought twist.  However, he is using 55gr bullets and still getting this result.

I dont care if it IS Wolf.  As poor quality components as they may be, they aint gonna tumble unless something else is WRONG.

Add to that, he stated this is a new issue, it did not do this before.  He would know if he made an ammo change at the same time.

Therefore, the barrel is most likely suspect.  Should it wear out in 2k rounds.  Nope.  But who knows how/what it has been through?  It is a preban.... that means it was made before 1994.  He has only had it for two years.

Who knows what has happened in the meantime.  

Get a new barrel and dont look back.

Ditto, kind of buying a car that the salesman told you was only driven to church on the week ends by a little old lady.

Chances are since the muzzle is worn out, it was cleaned by the first owner/s by jamming a rod down the muzzle.  The fact that it lasted him a few thousand round before the barrel finally gave up the ghost is just luck of the draw.

P.S. Most barrels are worn out, not by shooting, but by over cleaning/bad cleaning habbits.  

sar3K,

I was going to do the new barrel thing, but not wanting to leave any stone unturned, I went to a friend's range today and tried several different types of .223. I should mention that the barrel in question has had a Smith Enterprise Sommers compensator on it for almost a year and a half and it has worked very well.

The first five rounds was some Venezuelan .223 (55gr) with the comp on - all tumbled.

The next was Winchester 55 gr. without the comp - five rounds - none tumbled.
The next was 55 gr. ballistic tip - five rounds - no comp, none tumbled.
Next was five rounds of Remington 62 gr - n comp, none tumbled.
Next was my Wolf 62 grain -  shot ten - no comp, none tumbled.

All the testing was done at 60 yards.

I'm going to test further with a different comp and the original flash hider and see what happens, but it's lookin' like the comp is somehow to blame. Weird, eh?

Any thoughts on that?

Thanks,

Binazone

The bullets are striking the comp on the way out.

Somehow when you re/installed the comp, you twisted something and caused the comp to be out of alignment with the bore, or the flat spot is causing the bullets leave the bore off bore line. Look for signs of brass streaks on the inside of the comp.

If the comp is new, then maybe it was threaded canted.  If you have problems with the stock FS as well, then the threads may have been canted/bent, and the barrel will need to be cut and re-threaded.

Last time I checked with Kurt, he quoted me a price of $35 to cut and re-thread. It's been a while, so his price may be a little more, but much cheaper than a new barrel.

Hope this helps.

Yeah, forgetting to mention the COMP would throw off the diagnosis.
Glad to hear your barrel is not shot!