Can you guys school me on the ar-10?

[Evoken]

Afternoon folks,
I have been contemplating getting a 308 platform semi rifle an stumbled on one at a small lgs. The m14 and m1a prices are ridiculous right now, like everything else of course. At any rate, I picked this up for a reasonable, in today's standards, price.

It is a DPMS Lr308, slick side upper, carbine length 16" barrel, and has a carbine buffer system. From looking at pictures and reading I believe it is a gen 1. It has a commercial buffer tube.

Any info on this platform would be helpful, I am familiar with the ar15 platform but this is new to me. Can I change the commercial tube to milspec? I believe I can, and only wish to due so because the stock has a hard plastic butt and I have a nice magpul that would work for it.
Any concern on reloading for it? I've been reading that 7.62x51 is lower pressure than 308, but being marked caliber .308 that should not make a difference?? Any concern using 7.62 brass,I have collected quite a bit of it and would rather use it in this than beat up my good hunting brass.

I look forward to shooting it and may have a chance to tomorrow if the sun shines for me.


Thank you in advance,
Ken

[Winger Ed.]

Any concern on reloading for it? I've been reading that 7.62x51 is lower pressure than 308,

7.62NATO from other countries seems to be loaded a bit down from USGI which is reputed to be hotter than .308.
I had a quantity of German military surplus 7.62 that hit a few inches lower at 100 yards than factory .308.
Both had 150-165 grain bullets.

I'd reload for yours at the best accuracy which should come up around 85-90% of max. loads with 150-ish bullets,
or 170-ish with cast. I've done that for my M1A. It works well, and keeps a lot of 'stress & strain' off of it.
For shooting at paper--
heck, I'd down load to where I could see a boolit in flight if it would let me shoot one hole groups.

As far as it being some what reduced for a hunting load- If you're not at extreme ranges,
good accuracy and proper shot placement will make up for giving up a little bit of velocity.
Or, gas a few on up and save them just for hunting.

[Evoken]

Thanks for the quick response sir. It sounded strange to me that 7.62 was downloaded, as we know 5.56 is hotter. Seems like the brass is thicker, so I'm sure case capacity is less.

The barrel is a 1-10" so it should stabilize most anything from 150-180. For my bolt guns I mostly run 165-180 and am not running fire snorters. I have a few boxes of I think pmc or ppu el-cheapo fmj 147gr that I will run through it and see how she does. I will also try a few of my hunting rounds, just to see how they act. Out of 3 bolt guns, my 180 load is the load for them would be nice if it runs well in this thing also.

[Moleman-]

You can swap out the buffer tube to the skinnier mil-spec type to use your mil-spec magpul stock. The castle nut is most likely loctited and will need heated up with a heat gun. The buffers and springs are different between 308 and 223 platforms and also different between fixed and collapsible stocks on both. The DPMS lr308 likely has the most aftermarket support for it but there are others that not all parts will interchange as there is no "standard" like with an ar15. Make sure whatever parts you get for it are compatable with a LR308. I have 3 LR308 style guns, but only 1 is a DPMS.

[DougGuy]

This has nothing to do with the AR10 platform, but you mentioned a 1:10 twist rate. My experience has been that my Ruger M77 has 1:10 twist and it don't want NO part of boattails. Throws them all over the place. 180gr plain base will go 3 into a guitar pick @ 200yds if I do my part.

[Winger Ed.]

Thanks for the quick response sir. It sounded strange to me that 7.62 was downloaded, as we know 5.56 is hotter. Seems like the brass is thicker, so I'm sure case capacity is less.

.

There's ways around the case capacity issue.

Somebody told me once they'd talked to a trooper from a allied nation and he said USGI 7.62 was harder
on their weapons and sort of wore them out faster.

Allied countries don't always have the big budgets our military does, and are more inclined to take better care of their stuff.
For us, if we have a problem with a rifle-- ya just hand it back to the armory and they hand you a new one
from a basically unlimited supply. European militaries may not get that same deal.

[Evoken]

This has nothing to do with the AR10 platform, but you mentioned a 1:10 twist rate. My experience has been that my Ruger M77 has 1:10 twist and it don't want NO part of boattails. Throws them all over the place. 180gr plain base will go 3 into a guitar pick @ 200yds if I do my part.

My 7mm-08 is like that, phenomenal with 139 plain base hates the boat tails.

[Evoken]

You can swap out the buffer tube to the skinnier mil-spec type to use your mil-spec magpul stock. The castle nut is most likely loctited and will need heated up with a heat gun. The buffers and springs are different between 308 and 223 platforms and also different between fixed and collapsible stocks on both. The DPMS lr308 likely has the most aftermarket support for it but there are others that not all parts will interchange as there is no "standard" like with an ar15. Make sure whatever parts you get for it are compatable with a LR308. I have 3 LR308 style guns, but only 1 is a DPMS.

I did enough research to know I wanted the Dpms platform based on what was available for them. It interests me that it is not standardized like the 15's are. I may eventually get a rifle length buffer set up for it, but figured i already had the carbine spring and buffer so a short tube is my cheapest route.

I want to make sure i like it before i tear into it too much.... but I typically just can't leave well enough alone.

[GONRA]

GONRA wouldn't be surprised it countries using RETARDED BLOWBACK 7.62x51mm NATO caliber
German H&K or Spanish CETME rifles shoot 'em with slightly downloaded ammo.....

[Evoken]

Another thing that came to mind is it should be able to run cast fairly easily with the carbine gas system. I find the 15's are usually over gassed with hotter milspec speed loads in a carbine system.

[M-Tecs]

As others have stated the AR10 platform is not standardized. The AR10's came onto the civilian scene during the Assault Weapons ban. Lots of manufactures did various proprietary version to get around mag issues and the AWB. Same for other parts since there was no standard to be copied like the AR15/M16 platform. Standardization was getting somewhat better since the adoption of the M110 but then the manufactures started the different Generation games so parts interchangeability still requires research to ensure you get the correct parts unless it's trigger group stuff since those are AR15 parts.

7.62 x 51mm verse 308 pressures are not any simpler. Different pressure measuring methods and locations of the testing points doesn't help and creates a great deal of confusion and misinformation. Here are some actual test results doing an apples-to-apples comparison that addresses some of the misinformation/myths that is commonly spread on this issue.

https://castboolits.gunloads.com/showthread.php?113528-308-Win-Vs-7-62-X-51-NATO

As to the boat tail is that is an individual firearm/load issue. The 1:10 twist has a mainstay of NRA Highpower Services, Match and Long-Range rifles. The Palma shooters like 1:12 or 1:13 for the 155's. The joke was the 1:11 twist was for people that could not decide between the 1:10 or the 1:12. The point being they all shoot boattails very well. To be competitive ten shoot groups of 1/2 MOA required in the single shot or bolt guns. The M1a's/M-14's 3/4 to 7/8" MOA was more realistic.

Most of the 308 match/Service rifles that I have built have been in 1:10 unless they were straight Palma rife built specifically for the 155's. The 1:10 normally would be shot with 155, 168, 175, 178, 185 and 188 grain boattails and they all performed very well.

[Moleman-]

Use a full size 3 pin castle nut wrench on it and heat the castle nut up to release the loctite and you should have no issues.

For hunting, I've taken quite a few deer in MO and WI with the Hornady 150gr SP # 3031 or the 165gr SP # 3040. Couldn't really tell a difference between them. In MI I hunt a straight walled zone but have used one of my LR308 pattern guns in 44x1.8"

[Evoken]

Use a full size 3 pin castle nut wrench on it and heat the castle nut up to release the loctite and you should have no issues.

For hunting, I've taken quite a few deer in MO and WI with the Hornady 150gr SP # 3031 or the 165gr SP # 3040. Couldn't really tell a difference between them. In MI I hunt a straight walled zone but have used one of my LR308 pattern guns in 44x1.8"

Nice firearm! One of these days I will take the plunge and pay the man for the privilege of being allowed to own a can.

[charlie b]

This has nothing to do with the AR10 platform, but you mentioned a 1:10 twist rate. My experience has been that my Ruger M77 has 1:10 twist and it don't want NO part of boattails. Throws them all over the place. 180gr plain base will go 3 into a guitar pick @ 200yds if I do my part.

My Savage .308 with 1:10 loves boat tails. 155 Berger, 155 and 175 Hornady ELD-M, 168 AMax, 168 and 175 SMK's. It also likes 165 and 210gn cast (flat base) but only out to 500yd.

PS the SMK's would be my pick in an AR10 since they tolerate a lot of jump to the lands. The Bergers I load seated to touch the lands and they won't fit in a magazine.

[country gent]

The most popular load for 308 across the coarse high power matches was around 41.5 grns IMR 4895 LC match case and 168 sierra match king this shot very well and was very close to lc m852 match ammo. Rwist rates were from 1-10 -1-12 both 4 groove and 6 groove both were a good argument starer when brought up.

[M-Tecs]

Rwist rates were from 1-10 -1-12 both 4 groove and 6 groove both were a good argument starer when brought up.

In the late 80's early 90's the popular belief at was the M72 & M118 special ball 173's performed best in the 4 groove barrels and the 168's Match Kings excelled in the 6 grooves. I never found that to be the case. The M852 or 168 shot well in 4,5 and 6 groove. The 173 never shot that great in anything I tried with 1 MOA to 1 1/4 MOA being normal.

I never detected an accuracy differences but the common wisdom was the 4 & 5 groove gave longer accuracy life. I would tend to agree with that but I did see some exceptions to that. One of the team members had a 6 groove M-14 that had over 7K on it and he was still posting HM scores at 600 when he retired and turned the rifle in. That was about double of normal.

[country gent]

I had 1 Obermeyer barrel with the 5r 1-10 twist in SS That went a lot longer than I normally got also.

[M-Tecs]

I had 1 Obermeyer barrel with the 5r 1-10 twist in SS That went a lot longer than I normally got also.

Both John Kreiger and Boots Obermeyer were shooting the WI matches when I first started. I had dinner with both a couple of times. John stopped when the bussiness really took off. Boots and Eric continued on shooting the WI matches and I made a point to go out to dinner with him whenever possible. When I would call to order barrels it was always 45 minutes to an hour and a half. I don't believe I never received a barrel I ordered but I would ask him what he had that he could ship that day and total I received 30 to 35 barrels. One day 3 showed up out of the blue. My name was on the invoice so I sent him the money. I do know they did not match anything I ever ordered. Boots would send the invoice with the order and I would send the money when the barrels were received. Boots made great barrels but dealing with paperwork not so much.

[Evoken]

Got to shoot it today. 10 rounds of the PMC 147g fmj to check function and zero, did alright after an adjustment. 6 rounds 180g rem core lokt, because that is what was in the box. 5 touching and one flier that I knew I flung when I pulled the trigger. This is at 100yd. So it seems to definitely be a capable rifle.

Very hard on brass. The scope will need swapped out. It has a millet 1-4 30mm tube, would be great for a 22 but even at 100yd not real clear.

[Moleman-]

By hard on brass, do you mean lots of scratches and brass glitter? If so, a goodly portion of it is coming from the ejector pin and the two inside corners of the barrel extension on either side of the extractor slot. Dents and flat casemouths aren't anything to worry about. Some barrel extensions are much worse about it than others, but most will leave a set of dings or gouges in the neck and shoulder area. You can dull the sharp corner and it will just about stop along with polishing the ejector. The cases in the pic were only getting gouged by one lug, but it was cutting off a noticable patch. If it's bad enough you can get neck splits that start where the gouge is. Middle pic the two lugs on either side of the arrow have been dulled, it doesn't take much and can be done with a cratex bit.

[Evoken]

Typical dents and scratches from a semi gun. But also circular dents and gouges on the head stamps, from the extractor and bolt face.

[upnorthwis]

15 years ago or so I bought a DPMS LR308 for shooting 3-Gun. Couldn't get thru a stage without it jamming. Found out that they had a bad batch of magazines. Called them up and they sent me two new ones, no charge.

[Evoken]

Can anyone tell me what barrel wrench I need to get the delta ring nut off? The only ones I am finding for the lr308 say they are for a free float system or for that proprietary handguard. I would like to put a low profile gas block and free float guard on to lighten the front end up a bit.

Any recommendations on a gas block would be appreciated as well.

Thanks,
Ken

[popper]

DPMS Lr308 Like mine that does MOA (3 shot) @ 200 with cast at 2400 fps. Yes, good enough.
Standard 3 pin wrench but the (round) fore end is glued to the nut. Use the carbine buffer, spring and tube. Adj gas block helps. Break the edges of the extension lugs.
Actually mine is a rifle buffer setup as I bought it with the rifle barrel. Put a carbine upper on it as the rifle is to heavy for me.

[Moleman-]

If it has a delta ring, then a standard ar15 wrench should take it off. This is one of those times where the USGI tool or it's copy is not the best choice. Just get a cheap cast wrench that has more than 3 points of contact, most will grab about 2/3 of the teeth on the nut V/S 3 for the USGI version. I'd look for one that has the 3pt castle buffer tube castle nut wrench at the opposite end of the delta nut wrench.

[Evoken]

If it has a delta ring, then a standard ar15 wrench should take it off. This is one of those times where the USGI tool or it's copy is not the best choice. Just get a cheap cast wrench that has more than 3 points of contact, most will grab about 2/3 of the teeth on the nut V/S 3 for the USGI version. I'd look for one that has the 3pt castle buffer tube castle nut wrench at the opposite end of the delta nut wrench.

Thanks for the info. I don't have any delta ring uppers, all my 5.56 have floaters. I'm sure I can find a cheapo wrench. I've already got a 3 point castle nut wrench, so one without will out be a deal breaker.

[barkerwc4362]

Some variants of the DPMS LR-308 use the standard AR-15 barrel wrench, but when I put mine together I had to use a barrel wrench that was specifically labeled as being for the LR-308. So, you need to see what size of barrel nut you have.
Bill

[M-Tecs]

Some useful compatibility charts here:

https://www.wingtactical.com/blog/what-parts-are-interchangeable-between-ar15-ar10/#:~:text=Handguards%20and%20rail%20systems%3A%20Be cause%20of%20the%20barrel,AR-15%20will%20normally%20not%20work%20with%20an%20AR-10.

https://www.americanfirearms.org/ar-10-vs-ar-15-a-comparison/

[Evoken]

All good info gents. I bought a cheapo armorers wrench so hopefully it will work, the consensus is it will. I don't want to tear into it until I have all the parts laid out.

I am waiting on a response from aero to see if the barrel nut they sell will work with their atlas hand guards. I have an extra one that I replaced with a longer version for one of my 15's. I cannot see a difference in the guards other than the nut itself.

As to the gas block, I think I will order the superlative arms bleed off block. I believe too much gas is why some of my brass is getting beat. The pmc ammo was kinda weak and the brass looks fine, the remington core lokt got hammered. So it would be nice to adjust on the fly if need be.

[Moleman-]

The freefloat barrel nut is different than the delta barrel nut as others pointed out. I just made a 5-pin wrench for the DPMS free float barrel nut. The original DPMS quad rail on mine was over twice the weight of the one that I replaced it with. It's like they were trying to make the gun heavy.

[Evoken]

The freefloat barrel nut is different than the delta barrel nut as others pointed out. I just made a 5-pin wrench for the DPMS free float barrel nut. The original DPMS quad rail on mine was over twice the weight of the one that I replaced it with. It's like they were trying to make the gun heavy.

The weight is part of why I want to change a few things. Between the big clunky gas block with the rail and the plastic guard with the metal shields in it the rifle is very nose heavy.

I get that the platform itself is heavier due to larger parts, but I think I can certainly trim some fat off it.

[popper]

superlative arms bleed off block its a good one but get the right size - depends on barrel IIRC mine is 1". I also changed to the clamp-on vs the grub screw. Tried to get one off and lead had it 'soldered' on - not coming off (dremel did the trick). The clamp type lets you get a wedge on it to break any bonding. Use a shorter guard though as ID of the guard might interfere with the block. Gen I hand guard (round one) might be glued, my carbine was but rifle isn't and it tends to unscrew. They aren't that much weight but the nut is a chunk. Changing the barrel nut to one that uses a 'normal' wrench but watch out. I got a light weight one for my BO, had no real retention system, just some locking screws that applied tension. Hand guard kept coming off! It needs a positive lock system. Real bummer when you are shooting and the guard comes off. If you can swing it, remove the flash hide (you have to anyway) and put a LINEAR comp on it. Or just a thread protector. I put the L.C. on my BO pistol and it is great. Does add back some weight.

[Evoken]

superlative arms bleed off block its a good one but get the right size - depends on barrel IIRC mine is 1". I also changed to the clamp-on vs the grub screw. Tried to get one off and lead had it 'soldered' on - not coming off (dremel did the trick). The clamp type lets you get a wedge on it to break any bonding. Use a shorter guard though as ID of the guard might interfere with the block. Gen I hand guard (round one) might be glued, my carbine was but rifle isn't and it tends to unscrew. They aren't that much weight but the nut is a chunk. Changing the barrel nut to one that uses a 'normal' wrench but watch out. I got a light weight one for my BO, had no real retention system, just some locking screws that applied tension. Hand guard kept coming off! It needs a positive lock system. Real bummer when you are shooting and the guard comes off. If you can swing it, remove the flash hide (you have to anyway) and put a LINEAR comp on it. Or just a thread protector. I put the L.C. on my BO pistol and it is great. Does add back some weight.

Good advise on the pinch block vs. set screw, I never would have though of that.

The other reason I would like to change the hand guard is I want the ability to put a sight up front as I may run irons on the short barrel set up. Counterintuitive since the gas block already has a rail, I know, but i would like an adjustable setup. I would like to be able to crank it up for light loads and cast and turn it down for my hotter hunting loads.

I have given a small amount of thought to the muzzle device, but not much. No real worries about side noise or concussion blast as I shoot at my range. If you don't like it leave, haha. Although I have been considering taking the plunge and getting a can. Darn are they pricey though, plus the man gets his cut of course.