Bullet weight in DPMS LR-308?

[Token]

Is there a recommended bullet weight to use in the LR-308?  Generally I use 147-150gr. ball ammo, but I have some old 180gr soft points to use up, and it got me wondering...

 

I know it's generally the rule to use something approximating military ball in M1A platform rifles to avoid bending the op rod and etc. but how about AR-style 308s?

[Zebra644]

Depends on your barrel length and twist rate

[Token]

16"; 1 in 10 twist.  I was wondering more about the safety for the gun...not the actual performance of the round.

[98Z5V]

Alot of commercial 180 loads are too long to fit in a magazine.  If they fit in the mag, then they won't be in the lands when you chamber them, and you can shoot them fine through a 1:10' twist barrel.  They'll probably shoot pretty well, accuracy-wise.

[Dane Armory]

I think the answer he wants to hear is .... 168gr BTHP .

The 180 gr soft points run like $h!T through my 308s !

The 150gr FMJ w/CANN work great as a plinker round.

[survivalshop]

  You can use the full spectrum of data in the reloading manuals for the 308AR rifles. No need to worry about bending anything like in the M1 series of rifles.

  As long as you use proper safe loading procedures . Some of the larger weight bullets don't work too well in the rifle if wanting to load them for feeding from the magazine .

[Token]

Gentlemen: Thank you.  I was more concerned with possible damage to the rifle internals than performance [maybe I was unclear in my original Q].

 

While scouring around for some brass-cased .308 [i have a ton of Norinco steel case] I found some S&W headstamped 180gr hunting ammo that must be 35 years old. I figured I'd shoot it up and recycle the brass, but I got wondering...

Edited April 4, 2015 by Token

[survivalshop]

 Should not be a problem if the ammo chambers. If it loads in the mag ok , it will chamber & shoot .

 

Some will ask if you have a 308 or a 7.62x51 chamber , but all newer barrels should handle the slightly higher pressure 308, if barrel stamped 7.62x51 .

 

   Shoot old ammo at your own risk . You can always pull the bullets & reload with know good components , if you really want to be safe .

Edited April 5, 2015 by survivalshop

[Lazerus2000]

My three Remington R25 rifles shot EVERYTHING I tried.

Factory ammo only,

ancient history/decades old 110 gr varmint loads,

125 gr TAP,

Federal Blue Box 150 gr SP hunting ammo,

three brands of 168 Gr HPBT MATCH,

Various 7.62 NATO ( including Chinese brass cased Ball),

ancient history/ decades old 200 gr Winchester Silvertip

All of my R25s Fed and functioned with them all, and most of this ammo shot MOA or better.

In my new LR308B, which has an 18" barrel and a short gas tube, there is definitely an issue with NOSLER 168 HPBT MATCH, which is loaded HOT ...100 FPS MORE than FED GMM. The Nosler brass showed signs of pressure ... flattened primers and distinct bolt face imprints. No signs of pressure with the Nosler ammo shot in a bolt rifle, so I am assuming the powder used is too slow with too much residual port pressure for the shorter gas tube. Other AR 10 rifles with longer gas tubes may be just fine, or look into an adjustable gas plug.

With .308 Win commercial ammo can vary tremendously in bullet weights and powder speeds. Generally, while CHAMBER PRESSURE stays below SAMMI specs, residual port pressure may vary considerably. With some factory .308 Win loads, and some slower powders, the residual gas pressure at the port may be way too high. This is especially true for AR10 rifles with the shorter gas tubes.

In general, I consider powder speed and pressure at the port much more critical than bullet weight.

YPMMV

LAZ 1

Edited April 19, 2015 by Lazerus2000

[Token]

In general, I consider powder speed and pressure at the port much more critical than bullet weight.

 

 

Hey Laz...thanks for the info.  Another question:  Will the Norinco steel cased/copper washed 7.61x51 be okay in the DPMS rifles?  The DPMS manual says to stay away from lacquered ammo, but is the Norc stuff lacquered?  I have a 1/2 case of PPU on order and I'll reserve it for the LR308 if that seems advisable [already put about 80 rounds downrange],   I can shoot the Norc stuff through my M305s

[Lazerus2000]

I have shot lots of the Norinco brass cased ammo in my M14 / M305 type rifles. It is reliable and fairly accurate in the M305 types. I have no personal experience with steel cased 7.62 X 51 ammo so I have no credible opinion about this.

I would go with what DPMS says.

The Norinco M305 M14 clones, while usually marked as .308 Win on their receivers, are notorious for having excessive headspace ( 7.62 NATO PLUS ) right out of the box on many of their new rifles. Using any ammo that actually meets 7.62 NATO mil spec standards ( marked with cross in a circle as part of the headstamp), with the thicker / tougher brass, is advised for the Norincos. However, just because the ammo box is marked 7.62x51 does not mean true mil spec.

Any rifle, especially a semi auto rifle, is only as reliable as the ammo you feed it.

That beinng said, I just bought 125 rds of Norinco ball (on sale at my LGS). I have shot thus ammo out of my LR308, and it goes bang nicely, but in my rifle only gives 3 MOA. It usually does a bit better in the M3O5s.

[98Z5V]

Hey Lazerus, better watch it with the steel-cased and that box-stock DPMS rifle.

 

I've already seen your statements about experience, all over the place, but you may not be aware of the notoriously-tight DPMS chambers, from the factory.  Wouldn't take very much to stick a steel case in your new chamber.  You'll have one hell of a time getting that thing out.

 

These new rifle configurations are not the Original Armalite AR10s.

[Lazerus2000]

Thanks for the heads up on the tight DPMS chambers.

I said I had zero experience shooting steel cased 7.62x51 ammo and I have no intention of starting now with my new DPMS. In a few of my M305 rifles, I shot up a case of CHINESE made 7.62 BALL machine gun ammo that was still linked in five round chains. It worked well in the M305s, but varied up to .010" in OAL, so unless you sorted by length, accuracy was erratic.

As for my experience with the modern AR15/AR10 hybrids, to date I have owned (4) of the DPMS built rifles. All were very accurate with a wide range of ammo. I had one R25 that shot five out of eight factory loads MOA or better ... but the three that didn't shoot great were all around 150 gr. This surprised me.

None of my R25 rifles had too tight chambers, and exhibited no overpressure or overgassing symptoms with any ammo I tried. But these had the rifle length gas tubes.

Judging from my fired brass, my new LR308B has a larger chamber than my RUGER American bolt rifle. I have not measured it yet, but it is obvious to the eye that the brass from the Ruger shows zero pressure symptoms, while the brass from the DPMS shows bolt face marks on the headstamp and cratered primers ( but not flattened). I suspect the shorter carbine length gas system is passing too much gas ... but long headspace or oversized firing pin hole might also be an issue. I will check head space length with gages and we will know for sure.

Thanks again for the heads up

LAZ 1

Edited April 20, 2015 by Lazerus2000

[98Z5V]

Loquacious.

[Lazerus2000]

OOPS!!!

All this talk of steel cased 7.62 ammo got me thinking.I just checked my unopened package of ammo with a magnet and the magnet does stick. Looks like I just bought some steel cased ammo.

My last case of CHINESE 7.62 BALL was definitely brass cased, boxer primed ...supposedly for a Hong Kong police contract and I assumed these were the same.

As penance for making a bad assumption, I will try a few rounds in my DPMS .and report back.

That way we will.have first hand information on using steel cases in a DPMS rather than theories.

HOWEVER,

as pointed out, chamber dimensions can vary.

Just because it works in my rifle doesn't mean it will work in yours. So unless you can afford to take the risk, and possibly void your warranty, stick with what DPMS tells you.

PS: The DPMS website mentions problems with laquer coated cases and uncoated steel cases.

The ammo I just bought is COPPER washed. A range test tomorrow is on my agenda.

Edited April 20, 2015 by Lazerus2000

[survivalshop]

Loquacious.

<thumbsup>

[Malig8r]

Laz,

I may be reading your post wrong but I am hearing two possible misnomers. You said that DPMS states to stay away from steel cased ammo but then say your ammo is copper washed.

The copper washing is in reference to the bullets themselves (projectiles) not the cases. The steel cases whether they be lacquer coated, zinc coated, pick your coating, will not obturate (seal the chamber) as well as brass cases will. This may lead to premature throat erosion.

Some argue that by the time you shoot enough ammo to erode the throat of the barrel you will have saved enough on ammo to replace the barrel a couple times over.

Just wanted to clear things up a bit so that we are all on the same page when giving or receiving information to assist in this discussion.

[Lazerus2000]

NOTE: I AM IN CANADA, and we have access to lots of Chinese gun stuff thst cant get into the US.

These NORINCO 7.62 X51 rounds are definitely copper washed on both the steel cases and the steel core bullets. A magnet sticks to both the cases and the bullets. And the copper coating is glaringly obvious on both.

AND

both the DPMS website and 98Z5V are right to warn against using the NORINCO COPPER WASHED ammo in the LR308 rifles.

I grabbed 20 rds of this stuff off of a buddy who has thousands of rounds. He shoots it in one of the Chinese M14 rifles I built for him. In his M14, it has been very reliable and shoots into about 2MOA. BUT, Another guy I talked to at the range today swore that this ammo was horrible in his Chinese M14, with very poor accuracy, and some split case necks.

Obviously, wth this ammo,

YPMMV.

I tried some of the copper washed NORC ammo in my NEW LR308B. I have only 5 shot mags, and the first five rounds went off nicely, shooting into about 3 " . Cleaned the chamber and bore. Shot another five rds. Same. Cleaned the bore and chamber, shot only three more rds, with the 4th rd being a failure to fully chamber. Bolt was about half inch back on live rd. Had to POGO the butt stock to get the live rd out. Put that FTF off to the side. Cleaned chamber and bore again, loaded another rd, went bang, but another failure to chamber fully.

GAVE UP ON FURTHER TESTING WITH THIS AMMO.

Cleaned the chamber and bore, shot five rds of 168 gr NOSLER HPBT MATCH. 1.2" group with three in same hole, and with the first and last rds into a different hole at different POI.

CURSED THE STUPID CANADIAN LEGAL 5 RD MAGS. I knew that the first and last rds in an M14 magazine can often shoot to a different POI than the rest of the mag, but was surprised to find that the LR308 seems to do this too.

On a slightly different note, first time at the range I shot five into .82", using a PMAG. This time I only managed 1.2" using the DPMS metal mag.

Will test further with different mags and shooting all five from middle of mag.

PPS: I agree that in my personal LR308B, metal cased ammo is not a viable choice.

Lesson learned from first hand experience.

Edited April 21, 2015 by Lazerus2000

[98Z5V]

Oh, Sweet Jesus, you have to be kidding me.  I don't think I've EVER seen someone as wordy as you.

 

Cleaned the chamber and bore, shot five rds of 168 gr NOSLER HPBT MATCH. 1.2" group with three in same hole, and with the first and last rds into a different hole at different POI.

 

Pics.  Or it didn't happen.

[Lazerus2000]

Dont we get paid by the word??

If my posts annoy you so much, why not just put me on your ignore list?

PS: here is a link to a very comprehensive steel VS brass ammo comparison. It is for AR15s, and for .223, but some interpretations can be made for the .308 ammo.

WARNING: LOTS OF WORDS IN THIS ARTICLE.

Lots of pics and graphs too. If details annoy you, just go for a sandwich instead.

LAZ 1

Edited April 21, 2015 by Lazerus2000

[98Z5V]

Dont we get paid by the word??

If my posts annoy you so much, why not just put me on your ignore list?

 

No reason to put you on an ignore list - it's just the same junk everytime...   <lmao>

 

Steel vs. Brass article - that might be "new news" to you.  Enjoy your read.  <thumbsup>

[Token]

Lazerus - I for one appreciate your long and thorough posts....

 

What your experience says to me is that I should reserve my brass-cased ammo for the LR-308 [i just picked up my 500 rounds of PPU yesterday] and shoot the steel-case stuff in my M305s.  I guess I shouldn't be surprised that the DPMS rifles have tight chambers...this goes hand-in-hand with good accuracy, right?  [For the record, all three of my Norc M305s have relatively generous headspace, although they all are within NATO spec].

 

The brass rounds cost twice what the Norc steel does...maybe this will impel me to get set up for reloading again. I don't generally shoot more than 60 rounds or so at a time [often fewer than that], so reloading isn't that much of a task.

[Lazerus2000]

Token,

with the M305 M14 type rifles, YPMMV when it comes to ammunition.  this is true of all fire arms, but especially true with the 14s.  I have a buddy who bought three cases of the NORC copper washed ammo, back when it was cheap.  He has shot off the first case,  loves this stuff in his two M14s, He gets about 2" - 3" in his 14s.  I borrowed some of this ammo for my personal tests in the LR308B,  I wanted to check for myself to confirm what was posted on the internet and oon the DPMS site. In my case, with my particular LR308B, this was was a disaster, with failures to chamber on rounds 13 and 15.

 

But the day was not a total loss.  The guy at the bench shooting next to me had a new to him factory shorty M305, with no flash hider. The muzzle blast was EXTREME.  I asked him how he liked it so far, and he loved it. We discussed his experience with shooting the NORC BALL in his 305, and for him it was AWFUL.  5 -6" groups and he had split three case necks.  Good to get another hands on opinion, but obviously, again, YPMMV.

 

And before we left, I had emptied out his wallet, and he had a brand new compensator and a bunch of other M14 junk i just happened to have in my tool box.  A great day for both of us and we both left with smiles on our faces.

 

And after he handled  my LR308, he knew what his next rifle was going to be.

 

Good luck with finding the perfect factory ammo for your rifle.

 

I just picked up a few different boxes of  factory .308, including some 168 Gr AMAX  Hornady. I only have 60 rds through my new LR308B so still have much experiemntation to do.

 

Next range session I will post my results ... if I am still here.

(;{)