ar -15 tumbling help!!!!!!

[budlight2256]

I recently put together my AR-15 . It has a DPMS lower matched with RRA upper 16" car style. The gun feeds and fires fine. The problem I think I might have is tumbling. I first shot at 100 yrd, walked up and checked the target and didn't see no definite holes, just what looked to be slashes. Same at 50 yards. I was shooting Winchester 55 gr 5.56 (white box) old ammo from I don't know when. Any ideas? Thanks for your help.




1:9 twist sorry for not posting! and it is Winchester ammo

 

[Nhsport]

Start with some brand name known quality ammo . XM193 if you can find it.fed American Eagle,rem umc, Privi . Winchester is generally ok but it sounds like you aren't sure what your ammo is. Could it be handloads that somebody cobbeled together?
Did you buy or build your upper? what barrel twist?

 

[Heavy Metal Hero]

But tumbling makes it so much deadlier.

 

[HorseSoldier]

My initial thought was to wonder what twist your barrel is, but if you were shooting 55 grain that should not be an issue (and it's probably 1:9 anyway) -- it definitely sounds like the keyholing you'd see with a 1:12 shooting M855. I'd second the recommendation to try some premium ammo through it and see if that corrects it.

 

[Bartholomew Roberts]

What twist is the barrel of the rifle? It should be marked on the barrel somewhere. Are you sure as to the type of ammo?

 

[Siderite]

Are you shooting paper targets without some sort of hard backing (plywood, cardboard)? I've found that hanging paper rips in unpredictable ways for anything other than .22LR and some hollowpoints.

 

[Gator]

Excellent home defense combo there!

 

[GigaBuist]

Everythin above, and:

If you started out at 100 yards how do you know you're even on the paper? Your rounds might be impacting in front of the target and skipping into it, or just tossing debris at it.

 

[the naked prophet]

If you started out at 100 yards how do you know you're even on the paper? Your rounds might be impacting in front of the target and skipping into it, or just tossing debris at it.

^
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My bet. I've done that with my AK at 250 yards. There were no normal bullet holes, but lots of keyholes and dirt spray.

 

[Harley Quinn]

I'd get a nice target that has good backing and set it up at 25 yds and sight it in at 2 " high and then move it back to 50 yds and shoot at it keeping the same hold. (I use the 6 oclock with open sights). Follow that up and then shoot at 100 yds

 

[Onmilo]

As stated, a 1 in 9 twist and 55 grain bullets shouldn't cause tumbling.

If you have a flash suppressor installed check to see if the F.S. bore is properly aligned with the barrel bore.
If you have a plain muzzle check to see if there is a nick or burr in the crown.

Heck the flash suppressor may be OK and there is still a nick or burr in the barrel crown underneath.

Try another brand of 55 grain ammo too.
Even US ammunition makers let out lots of marginal product once in a while.

 

[SoCalShooter]

Well the 55gr rounds are meant to tumble that is how they do damage.

But you should be getting nice holes. I use a DPMS DCM upper with 1:8 twist and I get nice groups and nice holes. 20" barrel.

Try moving up to heavier loads. They usually do not tumble as much. But with a 16" barrel and 55grain loads I expect the tumbling. But honestly I am not absolutly sure.

Also take it to a gunsmith and make sure you it together properly.

 

[Gator]

But they are only supposed to tumble after they hit the target.

 

[earplug]

Respectfully, SoCal shoooter is dead wrong. Tumbling of the bullet should happen only after impact with A flesh like target.
For some reason your rifle is not able to stabalise your fired bullet.
To slow or A bad barrel.

 

[geekWithA.45]

Start out @ 25 meters to make sure you're on paper. If you dig around, there's directions on how to setup your battle sight at that range.