Range Report LR-308 Ammo question

[Strangedays]

I took my rifle out shooting today and tried some 7.62 ammo by American Tactical which is made in turkey.The rifle is a DPMS LR-308 The problem was it would not have enough pressure to operate the bolt so the rounds I had to rack back every shot. Anyone had this problem? I have shot Nato through my gun before with no problems but was wondering if anyone had some tips. Thanks ahead of time! Besides the problem the ammo was sub moa accurate.

 

[1SMALLJOHNSON]

Re: LR-308 Ammo question

Port pressure is directly tied to charge weight. Pull a round and see if you've got right about 42 grains or more powder. If lighter, and if velocity is down below spec, there's your answer.

 

[okiefired]

Re: LR-308 Ammo question

Did you fire any other ammo after you fired the AT from Turkey? If you did, did it cycle properly? Just making sure the rifle didn't develop a problem recently.

okie

 

[Strangedays]

Re: LR-308 Ammo question

I fired some .308 match ammo and it works fine as did the FMJ magtech. I think I am going to pull a round and see what the powder measures in at. Like I said the stuff shoots great it just won't cycle the bolt. I was wondering if I put an adjustable gas tube in if I could get this stuff to work? Anyone have any luck with those? Thanks again,

 

[okiefired]

Re: LR-308 Ammo question

strange, if your rifle came with a non adj. gas block then I believe that should mean it is cycling "wide open". In other words, its cycling as hard as it can concidering gas port size in barrel and ammo used. An adj. gas block should only serve to "lesson" cycling preasure or rate, so not sure it would help at all. AR guru's may correct me on this. Opening up the barrel port may help but I dont know if I would recommend this because of the risk of opening it up too much and causing reliability problems. Guess you could use that adj. block then. So, I'm sure I didn't help you out at all but maybee one of the great smiths that are on this forum will chime in now and help. Good luck.

okie

 

[DustyJacket]

Re: LR-308 Ammo question

"usually" when they install an adjustable gas block they open the part a bit........


strangedays - was that ammo particularly dirty when fired?
It it true 7.62 NATO?

 

[Strangedays]

Re: LR-308 Ammo question

The label shows 7.62 NATO. I pulled a round and found it only has 41GR of powder charge. The powder is in a circular shape.
Most of my other NATO stuff comes in at 41-43GR depending on the manafacturer but still works so maybe this powder is just bad in this stuff and not igniting right? Thanks for all the help,

Jed

 

[okiefired]

Re: LR-308 Ammo question

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: DustyJacket</div><div class="ubbcode-body">"usually" when they install an adjustable gas block they open the part a bit........
</div></div>

Never heard that, learn something new everyday. Thanks.

okie

 

[Strangedays]

Re: LR-308 Ammo question

You know whats interesting about the ammo is the bullet has a black tar looking stuff where it meets the case. I will not be shooting this stuff anymore.

 

[okiefired]

Re: LR-308 Ammo question

Ya, I've seen military ammo with that kind of sealer before, not sure what it is exactly. Dont know that it caused any problems or not though.

okie

 

[ricka0]

Re: LR-308 Ammo question

I don't want to hijack this thread, but since it's on the DPMS LR-308 I thought I'd ask.
My LR-308 loves 155gr Scenars with 50 gr of 4350 - the same load I use in my Rem 700. (Actually, I just used my bolt gun ammo and was surprised how well it worked.) I've been told I should be using the small base die, but my regular full length dies works fine, it cycles with no problem. Is there any reason to go to small base die?

I read last month in a reloading magazine that autos should use the fast burning H4895 to prevent the gas mechanism from fouling up. My 1977 Speer reloading manual recommends trying to match factory ammo. I guess I'll try 4064 and perhaps H4895, but I've got good results with the 200 rounds of 50 gr/4350/155gr Scenar I've fired.

 

[Strangedays]

Re: LR-308 Ammo question

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ricka</div><div class="ubbcode-body">I don't want to hijack this thread, but since it's on the DPMS LR-308 I thought I'd ask.
My LR-308 loves 155gr Scenars with 50 gr of 4350 - the same load I use in my Rem 700. (Actually, I just used my bolt gun ammo and was surprised how well it worked.) I've been told I should be using the small base die, but my regular full length dies works fine, it cycles with no problem. Is there any reason to go to small base die?

I read last month in a reloading magazine that autos should use the fast burning H4895 to prevent the gas mechanism from fouling up. My 1977 Speer reloading manual recommends trying to match factory ammo. I guess I'll try 4064 and perhaps H4895, but I've got good results with the 200 rounds of 50 gr/4350/155gr Scenar I've fired. </div></div>
Ricka you are shooting 50grains? I always use the FL die and I always use H4895 but I only shoot with 43 grains on 150 grain FMJ and not more than 44 on 168 HPBT.

 

[ricka0]

Re: LR-308 Ammo question

Yes, 50gr of IMR 4350 and 155gr Scenars. They were loaded for my 308 bolt - tried them when I got my LR-308 (it has a trigger job, muzzle break). I was surprised they all worked.

No pressure signs. Because the standard FL dies work fine, I'll stick with them. I've read for auto's you usually need a small base die.

 

[1SMALLJOHNSON]

Re: LR-308 Ammo question

41 grains of powder, I assume a 147 gr slug and "Black Lucas" on the mouth. That's a tar based mouth water proofing, commonly referred to as above. It's standard issue. No big deal. It should burn off in the firing cycle, and leave little/nothing behind.

Question: Is the bullet a 147 grainer? If yes, they're using too little powder to get good port pressures. Plain and simple. Likely, they had a fast powder, used it, but stayed within pressure specs and not NATO velocity specs. Long story short, it ain't your gun if the bullet is a 147 to 155 grainer.

 

[Strangedays]

Re: LR-308 Ammo question

1SMALLJOHNSON the bullet is 150gr FMJ and yes it must be the black lucas stuff on the mouth. The package states it all NATO specs. All my other ammo works so I am sure now there is nothing wrong with the gun. I guess I will pull the bullets and redo the powder charge on the ones I have left. Thanks to everyone who has jumped on this subject!

 

[Grump]

Re: LR-308 Ammo question

Get an M1A. Using WW748 and 147-gr bullets, they will still cycle with velocities below 2000 fps.

White gas system, no adjustments needed. Not as finicky as an AR-type gas system.

 

[Strangedays]

Re: LR-308 Ammo question

If you could get your M1A to shoot as nice as my LR-308 I would like to see it, but thats the problem with M1As they don't shoot as well at longer distance so I think I will keep the gun just shoot better ammo!

 

[Lt. Arclight]

Re: LR-308 Ammo question

42 gr of RL15 in Lapua brass Fed GMM 210 primer and 175 SMK shoots 1/2 moa in my DPMS. (24"1x10 twist).YMMV.

 

[Strangedays]

Re: LR-308 Ammo question

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lt. Arclight</div><div class="ubbcode-body">42 gr of RL15 in Lapua brass Fed GMM 210 primer and 175 SMK shoots 1/2 moa in my DPMS. (24"1x10 twist).YMMV. </div></div>

I get a little under 1/2 MOA through my DPMS LR-308 with a 18 Fluted Bull Barrel, Cryo'd.

 

[Grump]

Re: LR-308 Ammo question

Strangedays:
The relative ease that those LR-308s shoot closer to 0.5 MOA compared to the M1A standard of 1 MOA, or less if you're lucky, makes me want to try one.

Having been cheated out of at least $64,000.00 gross on one deal, and at least $25,833 on another, back in Feb-April of this year, I just don't have that amount of play money around right now.

 

[Strangedays]

Re: LR-308 Ammo question

Hey Grump, Sorry to hear about the losses. I hope that things look up for you! My brother has a M1A and it shoots great and I gave him the ammo and yes it worked with his so some things are better for the M1A and some are better for the LR-308. I wish I had the cash for both but like you have to cut things where I can. Have a great night!

 

[Pat M]

Re: LR-308 Ammo question

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lt. Arclight</div><div class="ubbcode-body">42 gr of RL15 in Lapua brass Fed GMM 210 primer and 175 SMK shoots 1/2 moa in my DPMS. (24"1x10 twist).YMMV. </div></div>

Same for mine, cept 41.5gr RL15 (got a 5rd 1" group at 290yds)