Elongated holes at close range. Why???

Steve Janes said:
Hate to revive an old thread like this, but while on an Advanced Carbine Course from Phase Line Green Tactical this past weekend, at least one other shooter experienced elongated holes while shooting the Norinco Yellow Box, he was shooting an AR but I don' know what twist it was, the target had at least 5 out of 20 that were entering the paper completely sideways, I wish I had taken a picture but several others were there and witnessed it as well.

I actually had some more elongated holes myself, and when I switched to American Eagle they stopped right away.

As suspected, this confirms 100% for me that it was completely an ammo related issue.

There were also a couple guys who had just a couple light primer strikes on the Norc ammo, but this was not persistent like the elongated holes were, the QC on the ammo just sux, undersized projectiles every 10-15 rounds or more in some cases.
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It was weird to actually see this happen. I believe the other rifle that experienced it was a Stag AR. I shot a couple hundred rounds of the norc ammo through my rifle the weekend before and had no issues. I also inspected the OP's FH and couldn't find any evidence of impact on it. That course was shot all at under 25m.
 
I agree with jethunter. Its a nothing more than the round is being forced out of the barrel and it hasnt the range to stabalize yet at 5 to 50 meters. Its spinning as it leaves the barrel, yet it's in a wobble state till the spin can straighten out the round, (like a top spun on a table), this takes distance and time. Which it seems to be doing as you say, once it gets down range. The round "quiets" down and spins as it should. Nothing to worry about. The crown, as someone mentioned, will not affect this wobble that you seem to notice, I heard of the same thing on bench guns.
my .02 cents worth....
Steve B
 
tritium said:
In both cases, the extreme yaw occurred with Norc 55 grain yellow box ammo. Given that and that two separate carbines had similar issues then it would most likely be under-sized bullets that caused the issue.
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PLEASE EVERYONE LISTEN TO EARL

Steve B - no. What you are discussing is the minor destabilization that can occur, this is a factor of barrel length, projectile velocity, and powder burn rates. Unburnt, or still burning gasses that start to pass the projectile and cause sonic waves that will temporarily destabilize projectiles till their rotational forces can correct.
IT IS MINOR -- its observable in high speed video, and its not going to make a round go sideways.

What is most likely is as stated above - ammo issue -- either undersized (effectively bouncing in rifling and deforming in bore) or offcenter weight which will cause deformation and other issues (likely odd flight paths, and bullet jacket separation mid-flight))
 
KevinB said:
PLEASE EVERYONE LISTEN TO EARL

Steve B - no. What you are discussing is the minor destabilization that can occur, this is a factor of barrel length, projectile velocity, and powder burn rates. Unburnt, or still burning gasses that start to pass the projectile and cause sonic waves that will temporarily destabilize projectiles till their rotational forces can correct.
IT IS MINOR -- its observable in high speed video, and its not going to make a round go sideways.

What is most likely is as stated above - ammo issue -- either undersized (effectively bouncing in rifling and deforming in bore) or offcenter weight which will cause deformation and other issues (likely odd flight paths, and bullet jacket separation mid-flight))
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tritium said:
In both cases, the extreme yaw occurred with Norc 55 grain yellow box ammo. Given that and that two separate carbines had similar issues then it would most likely be under-sized bullets that caused the issue.
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Thanks Earl

And Kevin B

While this is what I thought the whole time, it feels great to hear it from guys like you.

It was also a huge relief to see it occur with a different rifle.

Andrew, do you know the twist rate on the Stag that we saw key holing with?
 
Yup my rifle. 14.5 stag. 1/7... I was using the yhm 5c2 fh. No debris. First time using norc yellow box. Normally its wolf or mfs or north american stuff...

Inwas shooting from a knocked down position with my back on the ground unsupported.

Note that the week prior i was using wolf mfs and fed in both guns and was taping up perfect circles. The keyholing was certainly a suprise.
 
nza said:
Yup my rifle. 14.5 stag. 1/7... I was using the yhm 5c2 fh. No debris. First time using norc yellow box. Normally its wolf or mfs or north american stuff...

Inwas shooting from a knocked down position with my back on the ground unsupported.
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Being on your back shouldn't make a difference.

It's gotta have something to do with the 1in7" twist, and the undersized projectiles. All the other barrels with different twist rates seem to shoot it fine.

Interesting that it's only the 1in7's that are doing it.
 
The ballistic instability of the round attempting stabilization is not enough to cause a 90 degree yaw in any bullet at close range regardless of twist rate. In my former employment, we examined yaw and penetration in various mediums at various distances with various twist rates and not once did we see rounds striking surfaces at 90 degrees. Yaw only occurred AFTER the bullet passed through a medium that altered velocity which would also alter trajectory.

Kevin is much more an expert than I am due to his industry experience and prior service. however, we are both shooters, professionals, researchers and know our guns.

Steve's gun was a full size Classic Green with a 1 in 9 twist rate (Steve: a you sure you have a 1:7 twist?). NZA's was 14.5 with a 1 in 7. The 90 edge yaw occurred before striking the paper.

It was the ammo! Not the guns, not the thick air, not a random fly in the air, not space aliens, not illegal aliens.... Well maybe illegal aliens. If you followed the logic of some of the folks who have posted on this thread then rather than knowing height over-bore or the effects of wind at distance, you'd have to know yaw rates based on distance to target and shooting position. As Kevin stated, the ballistic instability isn't heavily exaggerated when viewed in high speed and is also not predictable.

I've been taught and taught on tons of courses and not once have I seen an lecture on yaw rates from some very checked out people.

The commonality in this equation was ammunition.

I meant to obtain empty boxes from both of you to determine if there is a lot number that is common to both.

It's Norc ammo! It is far from match grade, your guns are fine.:ninja:
 
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tritium said:
The ballistic instability of the round attempting stabilization is not enough to cause a 90 degree yaw in any bullet at close range regardless of twist rate. In my former employment, we examined yaw and penetration in various mediums at various distances with various twist rates and not once did we see rounds striking surfaces at 90 degrees. Yaw only occurred AFTER the bullet passed through a medium that altered velocity which would also alter trajectory.

Kevin is much more an expert than I am due to his industry experience and prior service. however, we are both shooters, professionals, researchers and know our guns.

Steve's gun was a full size Classic Green with a 1 in 9 twist rate (Steve: a you sure you have a 1:7 twist?). NZA's was 14.5 with a 1 in 7. The 90 edge yaw occurred before striking the paper.

It was the ammo! Not the guns, not the thick air, not a random fly in the air, not space aliens, not illegal aliens.... Well maybe illegal aliens. If you followed the logic of some of the folks who have posted on this thread then rather than knowing height over-bore or the effects of wind at distance, you'd have to know yaw rates based on distance to target and shooting position. As Kevin stated, the ballistic instability isn't heavily exaggerated when viewed in high speed and is also not predictable.

I've been taught and taught on tons of courses and not once have I seen an lecture on yaw rates from some very checked out people.

The commonality in this equation was ammunition.

I meant to obtain empty boxes from both of you to determine if there is a lot number that is common to both.

It's Norc ammo! It is far from match grade, your guns are fine.:ninja:
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I was pretty sure my rifle was a 1in7" twist. Swiss barrels only come in 1in7 and 1in10 to my knowledge.

I went and measured it just in case, and it's definitely a 1in7" Twist, I measured it several times to be sure.

Earl, being that there are now two distinct commonalities, do you still think the twist had nothing to do with it? I thought maybe the Norinco coupled and the 1in7 was a bad mix, but I am only pondering what my limited experience allows, and by no means was I ever sure of anything other than Norinco being crap ammo, and likely the root cause.
 
I've seen 55 grain bullets run out of all of the available variety of twist rates and barrel lengths and have only seen this happen on this course with Norc ammo. While it was not consistent to each round fired, it's the only ammo that I've seen do this.

The commonality in this case is most likely bad ammunition. If you and nza could grab the lot numbers off of the boxes, it might be telling.
 
tritium said:
I've seen 55 grain bullets run out of all of the available variety of twist rates and barrel lengths and have only seen this happen on this course with Norc ammo. While it was not consistent to each round fired, it's the only ammo that I've seen do this.

The commonality in this case is most likely bad ammunition. If you and nza could grab the lot numbers off of the boxes, it might be telling.
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No distinctive marking on the yellow boxes at all.

I can take pictures if you'd like but the only markings I see are C J 93 as the head stamp, besides that every yellow box is the same. There is a bit of chinese that I can't read. I think maybe the lot number was on a little piece of paper that came loose in the big wooden crate the ammo came in. Unfortunately I think that went out in the garbage long ago.
 
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yup, same headstamp. Mine was in loose boxes as I'm too poor for crates.
no markings on ammo. I can't remember if it was from Henry at BGS or canAm.
Since I still have this ammo, I'm just going to keep shooting it.
 
Lol, I was just thinking, my wife actually warned me about buying made in china when she saw me breaking down those yellow boxes. Damnit she's right again.
 
Stumbled upon this pic from the course today. Not my target, but when I was shooting Norc mine looked similar, I switched to AE and extreme yaw stopped. Just another real life example of how bad this Norinco ammo can get boys and girls. The stuff is dirt cheap for a reason.

559746_428000550622375_363865774_n_zps2609d855.jpg
 
Steve Janes said:
Stumbled upon this pic from the course today. Not my target, but when I was shooting Norc mine looked similar, I switched to AE and extreme yaw stopped. Just another real life example of how bad this Norinco ammo can get boys and girls. The stuff is dirt cheap for a reason.

559746_428000550622375_363865774_n_zps2609d855.jpg
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Didn't you learn your lesson with your last crate well before you bought another at Rustwoods? :p
 
loki_81 said:
Didn't you learn your lesson with your last crate well before you bought another at Rustwoods? :p
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should have learned his lesson when he threw his rails out of spec using very poor quality ammo. some folks insist on learning the hard way.
 
dizzy said:
should have learned his lesson when he threw his rails out of spec using very poor quality ammo. some folks insist on learning the hard way.
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As stated in my last post guys, I shot mostly AE on the course and did not experience the extreme yaw while doing so. This target was shot by someone else shooting Norinco, I thought maybe some guys who were on the course that day would like to see it.

I still have most of the case I bought from rusty wood, and at the price it was selling, I don't regret getting more. Just know what your getting.
 
You should check each bullet with a caliper, and load the undersized ones in your mags strategically.

See if you could shoot a cool smiley face or spell your name or something.
 
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