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Posted: 11/14/2008 5:08:48 PM EDT
I would like to know how ammunition other than combloc 7N6 is working out in the S&W MP15R.

Specifically I would like to know how the following work out of your rifle/upper:

Barnaul 55gr JSP
Barnaul 59gr FMJ
Wolf 60gr JHP

Link Posted: 11/15/2008 1:44:30 PM EDT
Since no one feels the need to reply, I'll answer myself.

Barnaul 55gr JSP - accuracy OK
Barnaul 59gr FMJ - keyholes
Wolf 60gr JHP - keyholes

Surplus 7N6 shoots good
Link Posted: 11/15/2008 1:52:56 PM EDT
Sorry, the only thing I've shot in mine is the surplus stuff.  You're right, it sure does shoot good.

As long as I can get the surplus cheaper than the other stuff you listed I won't be ordering any of the higher dollar ammo.  That's why I bought it - to shoot cheap ammo.
Link Posted: 11/16/2008 6:52:21 AM EDT
Originally Posted By miltonshooter:
Since no one feels the need to reply, I'll answer myself.

Barnaul 55gr JSP - accuracy OK
Barnaul 59gr FMJ - keyholes
Wolf 60gr JHP - keyholes

Surplus 7N6 shoots good


Why does the Wolf 60gr keyhole? That is disturbing. I just ordered 1000 rds of it.

I thought it was the Hot Shot stuff that had the warning about keyholing? I'll be highly pissed if this is the case. I have NO intention of shooting corrosive shit through the gun. The AR is probably the worst platform you could think of for corrosive ammo.

Damn!

Link Posted: 11/16/2008 3:50:12 PM EDT
After pulling some bullets and shooting a lot of ammo over the chronograph I think I know what is going on.  The commercial rounds that keyhole are using the same long bullet profile as the 7N6 round, but they are moving about 200fps slower at the muzzle.  I think the Russians used a 1:8 twist because it was the slowest that would stabilize the 7N6 round (barely stabilized=tumbles on contact), and the slower commercial rounds are right at the stability limit in hot weather.  This would explain why I did not have any full profile keyholes when I first sighted in the upper with commercial ammo (Sept in FL is still nasty hot), but had a few oblong holes on target.  I then shot nothing but surplus 7N6 until this weekend and the cooler weather (50-70 degrees F) slowed the commercial ammo down a bit thus making the oblong holes full on profile holes.  As most owners will only shoot the cheap surplus I don't think they will have a problem, but if I had stocked up on the Hotshot 68gr ammo I would be sweating.  YMMV
Link Posted: 11/16/2008 4:32:43 PM EDT
Originally Posted By miltonshooter:
After pulling some bullets and shooting a lot of ammo over the chronograph I think I know what is going on.  The commercial rounds that keyhole are using the same long bullet profile as the 7N6 round, but they are moving about 200fps slower at the muzzle.  I think the Russians used a 1:8 twist because it was the slowest that would stabilize the 7N6 round (barely stabilized=tumbles on contact), and the slower commercial rounds are right at the stability limit in hot weather.  This would explain why I did not have any full profile keyholes when I first sighted in the upper with commercial ammo (Sept in FL is still nasty hot), but had a few oblong holes on target.  I then shot nothing but surplus 7N6 until this weekend and the cooler weather (50-70 degrees F) slowed the commercial ammo down a bit thus making the oblong holes full on profile holes.  As most owners will only shoot the cheap surplus I don't think they will have a problem, but if I had stocked up on the Hotshot 68gr ammo I would be sweating.  YMMV


Not having shot any over the chrono (or ANY yet for that matter) I have read where the Wolf 60gr is supposed to do about 2900fps out of a 16" barrel––-which is what the round is designed for. Also, S&W twist rate is supposed to be 1:8.

Here are my "improvements":
-Getting the bolt carrier group hard chromed by Metaloy Industries.
-Installing an MGI adjustable gas tube
-Magpul MOE stock and grip
-Whole rifle Duracoated externally.

Once these changes are done I will actually shoot the damn thing and see if I have any keyholing with the 1,000rds of Wolf 60gr I have coming. (potential for )

Link Posted: 11/16/2008 5:17:06 PM EDT
Wolf 60gr JHP averaged 2780fps out of my upper

Barnaul 59gr FMJ averaged 2783fps

The three lots of combloc surplus I chronographed averaged 2911-2965fps

These rounds were fired in low 50 degree F weather

Link Posted: 11/16/2008 6:16:22 PM EDT
Don't forget also, the combloc surplus has an enclosed air pocket in the nose setting the weight back in the long bullet. I bet the commercial market stuff, (barnaul, wolf, hot shot) are a solid lead fmj with different balance characteristic than the mil-surp stuff.

The mil-surp is a 53 grain bullet, but again, very long. Length is supposed to have more to do with twist than weight.

A little of the topic, I bought 10 of the 1080 tins of corrosive mil-surp ammo just for training and plinking with this rifle. I also got the product call Ballistol for neutralizing and cleaning up after shooting corrosive ammo. AND, I purchased a 5.56 barrel and bolt and put it away for the future, when the 5.45 barrel has eaten all 10 cases of ammo, I figure it will be "shot out" and I'll installed the 5.56 barrel.

Don't be afraid of the corrosive ammo; enjoy it because it's cheap and ave a good time shooting!

Link Posted: 11/17/2008 4:07:08 AM EDT
Originally Posted By miltonshooter:
...but if I had stocked up on the Hotshot 68gr ammo I would be sweating.


What about if you had stocked up on 60gr Wolf?

Link Posted: 11/17/2008 4:47:27 AM EDT
I shot just over 100 rounds through mine (surplus Russion?? from Aim Surplus) 2 ro 3 weeks ago.  I sat down, tore it down and scrubbed it with a tooth brush and some cleaner called Black Magic (a black powder solvent) I got from WalMart.  I cleaned the bolt, carrier, barrel/chamber, and scrubbed out the upper, lower and mag well.  Then wiped it down with a few patches and sprayed Rem-Oil on it.  Opened it up three days later and didn't see any rust/corrosion.

I'm wondering if the Russian surplus is corrosive.
Link Posted: 11/17/2008 1:19:12 PM EDT
really, corrosive ammo in a AR is not as bad as you think, just scrub down a little with hot water, or similer water based cleaner, wipe things out and hose down with some WD-40 to displace any water, lube and there you go.  Corrosive salts not too bad on a AR, as most of it is either stainless, or anodized alum. and those are pretty resistant to corrosion,(notice I said resistant not proof!!)

Feel free to disagree, that's what I do, and everything is just fine!
Link Posted: 11/17/2008 3:33:56 PM EDT
Originally Posted By ABNAK:
Originally Posted By miltonshooter:
...but if I had stocked up on the Hotshot 68gr ammo I would be sweating.


What about if you had stocked up on 60gr Wolf?



I did stock up on 60gr Wolf JHP and 59gr Barnaul, however this was a few years ago and was for my SAR-2.  I still have about 2500 rnds of the two combined and will use them for the originally intended use.  I will stick some back for next summer to see if they still keyhole in the AR upper when it is hot outside.

Now if I can find a few boxes of Hotshot 68gr to try.
Link Posted: 11/17/2008 4:45:53 PM EDT
So, if they DO keyhole, how bad is accuracy affected? I know it's FAR from optimal, but I wonder how it does at 100-200yds.
Link Posted: 11/17/2008 5:16:09 PM EDT
Originally Posted By ABNAK:
So, if they DO keyhole, how bad is accuracy affected? I know it's FAR from optimal, but I wonder how it does at 100-200yds.


Keep in mind that just because my rifle does not like them does not mean that your rifle will not.  Having said that I am getting patterns of several feet at 100 yrds.
Link Posted: 11/18/2008 5:29:42 AM EDT
Originally Posted By miltonshooter:
Originally Posted By ABNAK:
So, if they DO keyhole, how bad is accuracy affected? I know it's FAR from optimal, but I wonder how it does at 100-200yds.


Keep in mind that just because my rifle does not like them does not mean that your rifle will not.  Having said that I am getting patterns of several feet at 100 yrds.



Ouch!

Having heard about the keyholing issues not affecting everybody, even with the same ammo, I wonder if it's differences between lots of ammo or rifles? If it's the rifles that are the problem then I wonder what could be done to fix it? Or even more basic: what IS the problem if it is the rifles and not the ammo?

Link Posted: 11/18/2008 5:05:17 PM EDT
I only shoot the Wolf 60gr black box ammo through mine and get excellent results with it at 50 yards.  At what distance are you shooting and getting keyholes using this ammo?
Link Posted: 11/19/2008 2:22:46 PM EDT
Today I shot 90 rounds of the Wolf 60gr JHP through my SAR-2 (AK type rifle) and had zero keyholing rounds.  The ammo chronographed @ 2848fps, so it is faster out of this rifle than the S&W.  I also believe the AK has a slightly faster twist (1:7.65").  I don't know if this helps anyone, but it is food for thought.
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