Quality Of Smith & Wesson MP15 Barrel

[irocracer89]

What is the quality of S&W MP15 Barrel, machine work, and finishing. My problem is my MP15 does not group at 100y is about 4inch.Here is whats done.

1)Changed stock to fixed A2
2) Changed trigger to Geissele SSA
3) Have used 55g PMC
4) Have used 55g Lake City 5.56
5) Have used 62g Lake City 5.56
6) Have used 75g Hornady Match .223

Hornady did produce the closest group, nothing that would zero on the weapon. In a DPMS 20" bull barrel the Hornady ammo I can put muti rounds through each other.

[Joeywhat]

Shooting off a bench? Is the barrel resting on something?

[Pumpkinheaver]

75gr bullets might be too much bullet depending on your bbl twist. The other ammo listed is not known for stellar accuracy. Try a lighter bullet match load and see what happens.

[500grains]

I got excellent accuracy from a S&W with the VTAC setup. Every once in a while a barrel maker turns out a dud, which could be what happened to you.

[bkb0000]

4 MOA would be lame, and outside the general acceptable accuracy standard of no worse than 3 MOA, but some chromoly barrels just shoot that way. luck of the draw, as always, with non-precision guns.

check the crown for problemos.. burrs, gouges, etc. a damaged crown can greatly effect accuracy. i've even seen a couple barrels that somehow left the manufacturer uncrowned, over the years- very rare, but still happens. then i'd check the barrel nut for tightness, and double check your optic's mount. what optic are you using?

[VirginiaTactical]

Here is the test data on my M&P VTAC that I purchased October of 2008. I made a small gunbook for it to log in all my rounds and conduct preventive maintenance.

The test procedures: All moa tests where done at the US Marine Precision Weapons Section Test Shed. The gun was bolted into the machine, and the machine fired a 5 round group at 300 yards. The group size was measured from the outside of the rounds, and not the center like most companies / organizations do. Three seperate groups were taken. The numbers were then added and divided by three to achieve the best MOA test attainable. This MOA test is the same MOA test all M40A5s, DMRs, EMR, and M16A2 Match go through in the Marine Corps.

Results:

test 1: 3.25x2 inches at 300 yards
test 2: 2.5x6.5 inches at 300 yards
test 3: 5.5x4.25 in at 300 yards

MOA Average: 1.25x1.44 MOA
Ammo used: 77gr Moly Coat Special Match 5.56

In my opinion this is a pretty damn good barrel for a stock S&W. I know the VTAC is a little nicer, but this gun shot really well. The gun is a nail driver for sure.

I know this gun isnt as nice as my LaRue Stealth, but once again its plenty good.

It is actually my wife's gun, ... and she likes the 1 points better than 2. She is left handed!

https://www.m4carbine.net/attachment.php?attachmentid=5486&stc=1&d=1278631676

[irocracer89]

Thanks for replys...More info 16" barrel with 1:9 twist with Burris one piece mount..I have a Caldwell led sled, sand bags, bench, and even prone. I have been trying to get a consistent three round group, in order to zero. Standard Army m16 zeroing, even have the 25m zero for the buis.

[Pumpkinheaver]

Your 1-9 twist might not like those 75gr bullets. I have seen some shoot well some horriable.

[irocracer89]

Thanks. I will probably just try some different ammo and see what happens..

[irocracer89]

One more dumb question, Explain why a 20 inch barrel will be more accurate then the 16 inch carbine barrel..Thanks

[nickdrak]

what optic are you using?

are you using the same optic on both rifles that you are comparing?

[nickdrak]

One more dumb question, Explain why a 20 inch barrel will be more accurate then the 16 inch carbine barrel..Thanks

The added 4" of barrel will give you better velocity, but not necessarily better accuracy. The design & materials of the barrel is what will likely most effect the overall accuracy. A standard chrome lined Milspec grade 16" barrel shouldn't do much better than an inch @ 100yds. Some manufacturers can produce some amazing chrome lined barrels, but a match grade stainless steel barrel will always have an edge in accuracy.

Fyi: if you are using an Army 25m target to get on paper, you will not be point of aim/point of impact @ 100yds if that is what you are trying to achieve.

[bkb0000]

true dis. length does not for accuracy make. leade and crown have much more to do with accuracy, followed by barrel shape, steel type, rifling, bore shape, etc.

[irocracer89]

Optics are Leupold Mark AR Scope on the DPMS, I have a Leupold scope and an Ecotech that I would like to start using. The S&W will not produce a good group, so the Ecotech is still in the box. Would the slight variation between the 5.56 NATO chamber, effect accuracy when using the .223 round?

Thanks

[nickdrak]

Optics are Leupold Mark AR Scope on the DPMS, I have a Leupold scope and an Ecotech that I would like to start using. The S&W will not produce a good group, so the Ecotech is still in the box.

¿QUE? What scope are you using on the S&W?

[irocracer89]

Leupold 3x9, but have an Ecotech when i get shooting correct..

[B.K.]

.....

[perna]

No sale, sorry...This not my first trigger work only my first aftermarket unit. So I feel confident it is installed correctly.. I took it out to the range recently and must say it is worth the investment, started grouping right out.. It still fires like a single stage, there is no noticeable second stage.. But for the improvement it grouping it's a keeper..

Same rifle?

[irocracer89]

Perna.. Yes same gun.. The day after I got the trigger inI did get a three round group maybe 2 or 3 inches at 100y. Sorry I did take anything to measure. switched lower to DPMS with a fixed adjustable stock, still all around the bulls eye at 100y, I am starting to think it may be me. I saw one review from Gandar Mountain, it was 10 round group at 75y within 4". So is this good for a carbine?? I may be compairing the military standard M16/A2 to my carbine,this what was trained on. And if memory serves me right was an excellent shooting gun, and maybe thinking the carbine will shoot the same...

[RPD03]

We've had similiar problems with a couple of our dept MP-15's, they just didn't like anything heavier than 69gr. The 75-77gr stuff was 4+ inches at 100 but they all dropped to @ 2.5 inches with the 69gr loads.

[bkb0000]

We've had similiar problems with a couple of our dept MP-15's, they just didn't like anything heavier than 69gr. The 75-77gr stuff was 4+ inches at 100 but they all dropped to @ 2.5 inches with the 69gr loads.

hmm.. maybe it's time to check rifling... make sure they didn't slip a 1/9 in on you.

[irocracer89]

Thanks, I was looking up some different ammo options. Both in 223 and 5.56 and go from there....I have used 1500 rounds of 55g PMC. I guess its going to be like my Savage 10FP-LE1 it likes the expensive stuff. Tried Honady 168g .308 match grade, will never shot any thing else in it..

[irocracer89]

Correct me I am wrong! I take a standard Ar-15 carbine with 16" barrel, and retractable stock, primary design was for CQB. Where primary target range is 0 to 200 yards or so. And design to make a quick shot on a human sized target. But not designed to make precision shot to reduce a target. So if ammo change can get my shot group down to 1" to 1.5 inch at a 100y, it would considered accurate for a carbine..

Thanks

[Jungo2]

hmm.. maybe it's time to check rifling... make sure they didn't slip a 1/9 in on you.

Please correct me if I'm wrong, but I believe that standard M&P 15 barrels are 1/9 twist.

[irocracer89]

Yes 1:9, Rounds out around 2000, so I don't think the barrel is shot out yet. But anything is possible..

[bkb0000]

Ah.. well that would explain that, then.

[irocracer89]

Explain what??

[bkb0000]

Explain what??

why the individual i was replying to has difficulty with heavier grain ammunition.

[Pumpkinheaver]

He stated it was 1-9 in his second or third post.

[irocracer89]

That why I started the post, to ask why. From what I have read the 1-9 twist should theoretically stabilize between 45g to 75g...I have used 55g, 62g and 75g, and it does not seem to be accurate. Have 45g Remington and 50g Remington ordered when they arrive I will go again. I have also read that a carbine is not known for the best accuracy. To me if it groups 1 to 1.5 inches at 100y, that's no accurate. Yes you can reduce a human size target at 100y, but if you want to blast Alvin at 75y you may be 1 to 1.5 inches over...All this you would think I never had seen an M16/Ar15 in my life..

Also picked up some Federal 55g .223 tonight, try another manufacture this time also..

Thanks

[bkb0000]

We've had similiar problems with a couple of our dept MP-15's, they just didn't like anything heavier than 69gr. The 75-77gr stuff was 4+ inches at 100 but they all dropped to @ 2.5 inches with the 69gr loads.


hmm.. maybe it's time to check rifling... make sure they didn't slip a 1/9 in on you.

c'mon, people.. connect the ****in dots here.

[irocracer89]

I guess Hank wants to be an ass..One in every crowd.

[uwe1]

According to the abundance of information on this site, 1:9 barrels may not reliably stabilize anything above 69 grain projectiles. I haven't shot my M&P15 for groups yet so I can't comment on mine. Yours may or may not.

Also read one of the "stickies" and I believe it addresses what kind of accuracy to expect out of your fighting gun. If I remember correctly, most ARs will deliver between 1-4 MOA performance. Guns might also be finicky with the ammo they shoot small groups with. My 1:7 twist DDM4 will shoot 1.25-1.5" groups with LE 75 grain TAP OTMs (this is stock, non match trigger on a Grippod, with a 4-10x Bushnell 3200 on 10x). It only gets 2-3" groups with 69 grain Prvi Match OTMs and 3-4" groups with 55 grain PMC Bronze. Both of the latter ammo types are far cheaper and lower in quality than the LEO TAP.

You can get better accuracy (sub-MOA) from match grade or higher quality barrels, or you can buy better ammo and find out what your gun likes the best.

Keep in mind, the highest quality ammo you listed as using, the Hornady, is possibly not suitable for your rifle due to the twist rate. As others have said, the other bullet types you listed are not known for their stellar accuracy. You might want to try to get some Black Hills 69 grain SMKs or Hornady TAP in the 60-ish grain projectiles. Your current testing is not playing to the strengths of your rifle.

[perna]

Or you could just call S&W.

[irocracer89]

Good luck today...I decided to try some from a different manufacture today. Went with Federal 55g .223 FMJ BP223BL, set target at 50y to check my group. First three rounds was low, but all three rounds touched each other. After adjustments was able to hit the x more than in the past. I think my try of Federal has won them another customer. After looking back my 10FP-LE it was a nice shooter but when I switched it to Hornady 168 match round, it really worked then..Thanks for all the post and help!! Maybe tommorow I will get my trigger taken care of, it should be a sweat shooting gun...