Tumbling Projectiles from MP-15?

[tg1stlavmt]

I have been trying to get a solid zero out of my MP-15. The zero seems to change every outing. I've gone through a red dot, and 4 scopes. I seem to get dialed in at 50' or 25 yds and then at 100 yds I can't hit a 24" X 40" target. I took it to the 50' range and dialed it in today. But the holes in the target were not round. They looked like the round hit sideways.Any thoughts? For the record I have an MP15/22 and an AR chambered in 9mm. I also shot expert back when at Pendleton and 29 Palms with an M16-A2.

 

[TX-Dennis]

I'd call S&W. They will email you a shipping label to return it for service at no cost to you.

Something is definitely amiss. I would hesitate to guess at what it is, though.

 

[cyphertext]

Agree with TX-Dennis. Chances are it is going to be something that you can't fix yourself, outside of swapping a barrel.

 

[MichiganScott]

Are you shooting 55gr or 62gr bullets or some of the heavy for caliber (75gr on up) loads? The heavy ones probably won't stabilize in a M&P15. Are they gun show reloads?Try a different brand before contacting the mother ship. The projectiles could be undersized as has been reported on this forum a couple of times.

Is the rifle new or did you purchase it used? There have been a couple of postings on this sub-forum from shooters that have worn out their barrels in as few as 2k rounds.

Lastly, if new did you examine the barrel and crown? It wouldn't be the first barrel that was defective from Smith.

 

[vonn]

Let us know how you resolve this.

 

[Arik]

Are you shooting 55gr or 62gr bullets or some of the heavy for caliber (75gr on up) loads? The heavy ones probably won't stabilize in a M&P15. Are they gun show reloads?Try a different brand before contacting the mother ship. The projectiles could be undersized as has been reported on this forum a couple of times.

Is the rifle new or did you purchase it used? There have been a couple of postings on this sub-forum from shooters that have worn out their barrels in as few as 2k rounds.

Lastly, if new did you examine the barrel and crown? It wouldn't be the first barrel that was defective from Smith.

Bullet weight shouldn't matter. Depending on the twist rate some bullets will stabilize better but the only difference down rang should be more or less accuracy depending on the bullet weight. If rounds are key holing (hitting sideways) there's something wrong with the barrel. Either the lands/groves were cut wrong, or the barrel wasn't finished or it's the wrong diameter. Could be really bad crown.

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[hdwhit]

tg1stlavmt wrote:
For the record I have an MP15/22 and an AR chambered in 9mm. I also shot expert back when at Pendleton and 29 Palms with an M16-A2.

Which of these two guns is your post concerning; the MP-15/22 or the AR whose maker is not specified?

Before anyone offers advice on fixing your problem, I think we need to know which gun it is that is causing the problem.

Also, you say you have gone through a red dot and four (4) scopes, but you didn't mention whether you have iron sights on the rifle that has the problem and whether you can establish a consistent zero with them.

 

[ChattanoogaPhil]

Are you shooting 55gr or 62gr bullets or some of the heavy for caliber (75gr on up) loads? The heavy ones probably won't stabilize in a M&P15.

AmmoLand did a test of just that-- 80gr bullets in a 1/9 twist barrel. Every shot was a sideways bullet strike at 25yds with a group of 10 inches.

 

[Arik]

AmmoLand did a test of just that-- 80gr bullets in a 1/9 twist barrel. Every shot was a sideways bullet strike at 25yds with a group of 10 inches.

When talking about 556/223 I never consider anything less than 55 or greater than 77.

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[S&WIowegan]

Is it possible your barrel is heavily fouled? The situation you're describing...accurate up close but way off at 100 yds. just might be severe fouling that has never been completely removed. Not to upset you but many of us never get our rifle barrels totally clean.

Good Luck.

 

[patrickd]

The answer is to build your own AR and then you'll know what went into it. I built mine on our dining room table in a couple of hours from scratch. It runs flawlessly. Lastly, any AR out there these days should stabilize anything 62 gr and under as it is hard to find one with anything slower than a 1/9 twist rate. If you're running something north of 69 gr you'll be wanting a barrel with a 1/7 twist.

 

[lrrifleman]

In the original post, it sounds like the problem is with an M&P 15-22. Have you tried different brands of 22s? Have you inspected the bore to see if the lands and grooves are distinct? It is possible that the bullets in your 22s are undersized, and it is possible that the problem lies with the barrel! It is possible that the barrel is severely fouled, or that the rifling is not fully cut. It is also possible that a 0.224 centerfire barrel was mistakenly in with rimfire barrels. If the bore is clear of lead fouling, let the job fall in S&W's hands under warranty!

 

[Steve912]

Bullet weight shouldn't matter.

No..

Depending on the twist rate some bullets will stabilize better but the only difference down rang should be more or less accuracy depending on the bullet weight.

No..

If rounds are key holing (hitting sideways) there's something wrong with the barrel.

Not necessarily.

Either the lands/groves were cut wrong, or the barrel wasn't finished or it's the wrong diameter.

Not necessarily.

Could be really bad crown.

NO...lol

Ouch!!!!!!!!!!

 

[Arik]

Bullet weight doesn't matter (unless you're picking some hard to find obscure weight). Nothing will tumble using a 1/9 twist with weight ranging from 55-77gr. Nothing tumbles using the same weight in 1/7 twist. Groups may open up or shrink but not key hole. Any off the rack AR will shoot 55-77gr just fine. Unless you have some unusual combo of twist and ammo.

Only time I've seen key holing was with poor barrels. And bad crowns do cause key holing. To both of those.....go buy some Century Arms made barrels. Look em up. Years and years worth of key holing problems due to oversized barrels and bad crowns


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[tg1stlavmt]

The problem is with my mp15. My other ar's are fine. This final test was with Winchester granules recommended for this twist rate. I'll call s&w and see about sending out in. It's a safe queen so its absence is not upsetting.

When I I know more I'll pass it on.

Thanx

 

[tg1stlavmt]

Not granules. Frangibles.

 

[tg1stlavmt]

As many recommended I contacted S&W. They did not seem overly surprised and sent me a mailing label. I m quite pleased with this as I was wondering why this particular rifle was defeating me.Thanks for the help and I'll let you know how it works out.

Thanks again!!

Tim

 

[tg1stlavmt]

I got the rifle back in about 1 month, with the 2 week downtime. I think that they put a new complete upper on the rifle. At the 100 yd line, once I got a zero, I was able to put ten rounds in a 2" box regularly. Now to get back in practice with a rifle at 100yds.

 

[MichiganScott]

Sounds like bad barrels happen.

 

[Disabled1]

I got the rifle back in about 1 month, with the 2 week downtime. I think that they put a new complete upper on the rifle. At the 100 yd line, once I got a zero, I was able to put ten rounds in a 2" box regularly. Now to get back in practice with a rifle at 100yds.

This is the outcome I like to read about. You own a firearm that has a lifetime warranty, why not use it? Why keep throwing money and/or guessing at it with this or that when S&W will fix it, FREE!
SMH!