In Your Opinion, How Many Rounds Is An M&P15 Sport II Good For?

Status
Not open for further replies.

Scrod314

Member
Joined
Aug 10, 2020
Messages
376
Hello... I hope this isn't a really stupid question, but I was shooting over the weekend and some guy at the range commented on my M&P15 Sport II that it is only good for 15,000 rounds before it will lose accuracy and start "key-holing". I'm not worried about it at all, but I tried to look up some information about it and couldn't find anything to support this claim. I don't think I'll be spending $6000-$9000 on ammo for it in my lifetime, so, like I said, I'm not worried. Just curious. If it matters, I take really good care of all my firearms and at this point, only put 100 rounds through per range trip. I'm not rapid firing or dumping magazines. Thanks for any thoughts. Oh, the guy was also telling me I need to spend $2000-$3000 on an AR if I want a good one.
 
At 15K I wouldn't be surprised if you might need a new barrel to maintain accuracy, and Id slap a new bolt in at that point too- broken lugs can be a thing eventually- but if properly lubed (and cleaned once in a blue moon), the rest of the gun will likely be doing just fine.
Ignore the "know-it-all-range-guru," the M&P is a perfectly good AR with factory support and will probably outlast you unless you shoot it daily and have super deep pockets for ammo......
 
The $2000-3000 AR’s he was trying to sell you would keyhole just as soon as your S&W M&P Sport II.

Dude’s a dummy.

Equally, wearing out a barrel isn’t the end of an AR’s life. We don’t buy new cars every time we need new tires or an oil change.
 
Just about ANY AR will start having accuracy issues at that kind of round count.

Considering a new barrel and bolt is about $160+ for "plinking grade" to about $300 for a "Duty grade" combo, versus the MULTIPLE THOUSANDS of dollars spent on that 15k rounds of ammo... I wouldn't worry about it too much.

That guy is 10 pounds of something stuffed in a 5 pound bag.
 
I've had my M&P 15 for 9 years, still shoots the same was as if it were new. Maybe I just plain suck at shooting. Regardless I bought this AR strictly for home defense in case of a home invasion. I am not to worried about key holing because from room to room distances I don't even have to figure trajectory.;)
 
When you get 14,999 rounds let us know.:)

Reminds me of Desert Eagle barrels...

1. They're rarely shot by their original owners
2. They almost never really wear out due to the type of rifling they use
3. Unless the gas port is plugged, they last forever
3. They're rarely shot by their original owners
4. They're rarely shot by their original owners

:rofl:
 
commented on my M&P15 Sport II. . .
LOL. It's good for, very approximately:
- 500 rounds between adding oil
- 5000 rounds before you want to look closely at locking lugs, and have a spare bolt
- 10,000 rounds to the faintest hint of loss of accuracy
- 50,000 rounds to noticeable loss of accuracy
-100,000 rounds to loss of combat accuracy. At this point the rifling will be firelapped smooth half way down the barrel.

If you had the finest National Match target barrel, you might be able to appreciate a loss in accuracy at 5,000 rounds. You don't: you won't.

And when you do, buy a barrel.
 
Hello... I hope this isn't a really stupid question, but I was shooting over the weekend and some guy at the range commented on my M&P15 Sport II that it is only good for 15,000 rounds before it will lose accuracy and start "key-holing". I'm not worried about it at all, but I tried to look up some information about it and couldn't find anything to support this claim. I don't think I'll be spending $6000-$9000 on ammo for it in my lifetime, so, like I said, I'm not worried. Just curious. If it matters, I take really good care of all my firearms and at this point, only put 100 rounds through per range trip. I'm not rapid firing or dumping magazines. Thanks for any thoughts. Oh, the guy was also telling me I need to spend $2000-$3000 on an AR if I want a good one.

100 rounds per range trip, 150 range trips, 1 per month... so in 12 1/2 years, you'll let us know?
 
some guy at the range commented on my M&P15 Sport II that it is only good for 15,000 rounds before it will lose accuracy
Wonder if he "outed" himself, and meant to say 1500 rounds.
Which is a "mere" thirty (30) boxes at 50 rounds each.
And absurd.
But, there are plenty out there who have read that nnn rounds will "degrade accuracy" and not ready any further to see that the "degradation" is 1/16 or 1/8 MOA, within, say, the width of a bullet hole in a paper target. Such things matter in F-Class. Not a lot of ARs in F-class shooting.

Now, I'm wondering which side of 15,000 rounds I have in shooting all ARs over my life. I probably scared 15K rounds at Crane, but no where near all of that was in ARs.
 
Scrod314: Some of this info might be applicable.

You're probably already familiar.

Brass vs. Steel Cased Ammo - An Epic Torture Test (luckygunner.com)

:cool:The main point is that they have some interesting info on bore wear with Brass-cased ammo in their tested AR-15s, in case that is all that You use.

Near the very bottom is a small chart with colored graphs, which included when barrels were replaced.

I'm not suggesting that any of this is absolutely scientific, but I've never seen any Other test which has even a small fraction of the types of measurements taken.

Avoiding overheating barrels certainly extends the useful life.
This factor seems easy to understand- but I heard really young guys at our private club who might Not be aware…dozens upon dozens of rds. In 2-3 minutes.
 
Last edited:
Check out School of the American Rifle. They did an examination of a 10.5” barrel with 900 magazines through it on full auto. It had finally started to loose enough accuracy to be a concern. Most or all of that was with a suppressor. The throat was worn but not shot out. Back pressure from the suppressor appeared to wear the muzzle end to the point bullets did not contact the rifling evenly before leaving the barrel. It was a Roscoe barrel, nitrided I believe but maybe chrome lined.
 
15k rounds is a pretty decent number to go by for when you need to replace a barrel. Might last longer and you can easily burn one out sooner if you abuse the barrel. But for regular shooting, 15k is probably a decent estimate. My friend Will was around 18k+ rounds through his BCM before he unfortunately passed away. He said it was getting time to replace it but that it was still "accurate enough" for the shooting he did.
 
How long a barrel lasts depends on the cartridge. Generally speaking, rounds that burn more powder through a smaller bore will wear out faster than the same amount of powder through a larger bore. Or less powder through the same diameter bore.

Rounds like 25-06, 243, 264WM and such burn up barrels much faster than 30-06, 308 or larger bore magnums. Some can become inaccurate in fewer than 2000 rounds. Others can go well over 10,000 rounds.

223 isn't known for wearing out barrels particularly fast. Yes, the bore is small, but so is the powder charge. I've seen tests going over 20,000 rounds of 223 with no measurable loss of accuracy.

Some barrels are chrome lined, some are not. A chrome lined barrel should last longer, but may not be as accurate. A chrome lined barrel will increase costs some. You can spend $3K on an AR if you want, but for 90% of us there are lots of $700 AR's that will do everything we need to do.
 
How long a barrel lasts depends on the cartridge. Generally speaking, rounds that burn more powder through a smaller bore will wear out faster than the same amount of powder through a larger bore. Or less powder through the same diameter bore.

Rounds like 25-06, 243, 264WM and such burn up barrels much faster than 30-06, 308 or larger bore magnums. Some can become inaccurate in fewer than 2000 rounds. Others can go well over 10,000 rounds.

223 isn't known for wearing out barrels particularly fast. Yes, the bore is small, but so is the powder charge. I've seen tests going over 20,000 rounds of 223 with no measurable loss of accuracy.

Some barrels are chrome lined, some are not. A chrome lined barrel should last longer, but may not be as accurate. A chrome lined barrel will increase costs some. You can spend $3K on an AR if you want, but for 90% of us there are lots of $700 AR's that will do everything we need to do.
Agree, AR's do not shoot barrel burning bullets.
 
Status
Not open for further replies.
Back
Top