DPMS upper for precison

[rundownfid]

I have a DPMS upper that I would like to make over into a long range capable rifle. As I have access to a 1,000 yd range that seems the logical goal distance. My thinking is to barrel the rifle with a .260, 6.5 Creedmore, or perhaps a .243? As I already have the upper and bolt I really think a barrel, forearm and gas tube-block is what I need. In an Ar 15 this would be no problem.

However, it seems the DPMS LR is not nearly as rich an environment, choice wise.

I am not a terribly dedicated Long range shooter, but would like a good gas gun capable of first round hits inside the 1,000 envelope, given my doing my part of course.

What are your thoughts on my best bet to put this upper together?

[Graham Smith]

For long range, you have to spend more to get a gas gun that's going to be as precise as a bolt gun. So before you start sinking a lot of money into this, it would be a good thing to define your objectives.

I can hit a target at 1000yd with a .223 if the target is big enough and the wind is calm and I haven't had too much coffee. But if I want to go for a 1 MOA target, I'm going to go with something much better suited to the task.

So, what kind of precision are you looking for?

Edited February 24, 2015 by Graham Smith

[blairmckenzie1]

Build a 6.5 grendel or 6mmAr and shoot 1000yards for maybe half the price on an AR15 platform.

[Bill Schwab]

I'm in the process of rebuilding an LR-243 upper, and also building a Mega Maten 260.

For the DPMS LR-243 the original barrel was VERY accurate (but a slow twist so not ideal for 1,000 yards). I am keeping the barrel and swapped out handguard, BCG, and gas block, waiting on handgaurd right now (should be here tomorrow), and bolt. My point being that you may want to shoot some groups and see if your original barrel is worth keeping. DPMS barrels surprise you sometimes. Also, I was very surprised to see my old DPMS parts (which I considered substandard, particularly the handguard and gas block) sell on eBay for far more than I anticipated.

For the Maten I planned on a 6.5 caliber. 6.5 Creedmoor is probably the better choice, but I went with 260 because I already had dies and brass. Lilja is taking preorders right now for 6.5 Creed barrels.

[lee blackman]

Personally, I'd go 260rem with a 20 or 22" barrel. But thats me. Push 140gr Berger Hybrids with IMR 8208 powder. I wouldn't bother with the 6.5 creedmore in a semi-auto, just me, I like the shoulder on the 260rem for feeding versus the benefit of the creedmore case not having to trim as much.

The 243win and 6mm creedmores are pretty sweet when you have enough barrel to push a 105gr fast and with the proper powder combination, they shoot like a laser. I don't know if you can tune a gas gun to run 4350 powder with a 27" barrel though? I haven't seen it done. I think you'd loose any advantage you would have had before trying to confine one to an AR-10 platform.

The 308 has been doing it for years. Just not as flat or fast as the 260. I've been running 175 and 178gr BTHP's with IMR4064, and finally changing over to Berger 155's and 185's using Varget and 8208. I recommend a 22 or 24" barrel if you go that route.

The 6.5grendel which blairmk mentioned is a great little cartridge, but it won't push as far or fast as a 260rem. You can build one pretty cheap, just get a barrel and a 7.62x39 AR bolt, a 6.5 magazine and your in the game. The downside is your pushing a 123gr Amax under 2600fps and it takes 24" barrel to even get that, where you can push the same bullet from a 260rem from a 22" barrel almost 3000fps. That 20 or so grains of extra case capacity in the 260rem makes a considerable difference.

[38superman]

Based on your original question, you already have a DPMS LR which I believe is 308.

That should be capable of 1000yd shooting.

It won't be as flat as a 260 or 6.5 CM but if you know your trajectory, you can get your hits.

If you feel you must change caliber, Remington markets a .243 that I think is made by DPMS.

I would try to get my hands on one of those.

Should be a simple barrel swap and nothing more.

Tls

[ShooterSteve]

I have a DPMS in 6.5 CM. It feeds just fine NO worries there, but the accuracy was so inconsistent that I scrapped the project and built a bolt gun to replace it. I still kept the upper, and will probably rebuild it one day with JP parts. If you run a gas gun, many people will advise you to go with 123s, as they load to mag length, without too much of the bullet back in the case, taking up valuable room for the powder. I think which ever bullet shoots best would be the one to go with. If I was going to build a small ar right now, it would probably be a

6ar or a fat rat. Good options there. If you want to see what a Grendel will do at 1k, check out the Facebook page for scotg13, and look at the targets. Pretty impressive. Doesn't hurt that it was shot by a former scout sniper.

[rundownfid]

Some very good suggestions. I may not have made it clear that I already have 2 DPMS uppers, both in .308, one is 18" and very accurate, but a bit short for long range work, will probably keep this upper together and use it on the lower I use for the longer barreled .243 or 6.6. I have a very accurate .223, and yes on a windless day with enough elevation I suspect I could hit a large target at 1000 with it, occasionally. However, I will probably try some long range matches and although it is rare in the East this might go even a bit beyond 1,000, so I think I want a real long range ready rifle. Good Ballistic Coefficient (lets say over .500) and as close to 3,000 fps as I can muster. So in a .308 sized mag that sounds like .260, 6.5 Creedmore or .243. I had thought of the 6 Fat Rat, and Keystone right here in Pa has a couple of long range loads in .223 and 6MM based on 6.8 brass. Thanks for the tip on Lilja, they make 20 and 24" barrels in .260 that are reasonable at $505, and that does look good.

Bill, I totally agree with " DPMS barrels surprise you sometimes." I have a 20" in 223 that is very good .5-.75 MOA with a number of loads. However, the 18" barrel on one .308 upper is sub 1-MOA, but just barely. Unfortunately, the other barrel just won't shoot better than 2.5 " so it will get sold.

By the way, something I forgot, one of the uppers has a high picatinny and the other the low, are there any advantages, on a precision rifle, one way or the other?

[mic2377]

I would switch to a high quality barrel in either 260 Rem or 6.5 Creedmoor. You could get a Lilja, Criterion, or custom of your choice. I have had great luck with Criterion's, and they are available from Fulton Armory for a good price with no wait. I personally bought a custom 24" 6.5 Creedmoor barrel from McGowen, but I have yet to shoot it. The price was reasonable but the wait was ~6 mon. Another option would be a custom in 6XC or 243 Win, but I think the extra barrel life of a 6.5 would push me away from a 6 mm.

The AR-15 based 6 mm calibers are limited in potential, and have a tough time running with something like a 123 Scenar @2950-3000 fps.

There is no difference in uppers besides just needing a different rail to match the upper height.

[rundownfid]

A little update, but I have not made final decisions. What I am looking at now: a Fulton Armory 6.5 Creedmore 24" barrel, AP Custom Carbon Fiber Forearm, Vortex Viper 6-24 Scope. Comments?

[TonytheTiger]

Great scope, get the EBR2C reticle if you like shooting in the wind.

[michael1778]

A little update, but I have not made final decisions. What I am looking at now: a Fulton Armory 6.5 Creedmore 24" barrel, AP Custom Carbon Fiber Forearm, Vortex Viper 6-24 Scope. Comments?

All three components sound solid to me.

I own a different Criterion barrel (.223 18" hybrid profile), have owned the early Carbon Arms hand guard in .223 size, and I have two Vortex scopes (1-4x Viper capped and 2.5-10x PST). I think highly of all of them.

What are you thinking about for an upper receiver? I'm gathering from other threads that the barrel-to-upper fit can be critical for accuracy.

I don't have any recommendations, unfortunately. But, the 6.5 Creedmoor should rock nicely.

Edited March 3, 2015 by michael1778

[rundownfid]

I bit the bullet and bought the pieces yesterday. I have two DPMS uppers, one high Pi and one low. I have ordered a Fulton Armory 24" 6.5 Creedmore barrel. AP Custom 15" forearm (Carbon fiber), and a bunch of the stuff one never thinks of until it is time to reload a new cartridge. I'll try to post some pictures once I get the gun together and can shoot some targets. The weather report for next week is finally above freezing os I should be able to get to the range?

[mic2377]

I am very excited to see how it turns out. I imagine it will be a nice shooter, Criterions are very good barrels for the $$$. Are you planning on handloading for it? I am planning to focus my load development on 120-123 gr bullets and H4350, although I have some 140 gr bullets as well. Fortunately the factory Hornady ammo is very good and even comes with the load recipe on the side of the box!

The are differing opinions regarding upper/barrel fit - I personally believe a properly torqued barrel nut and good quality handguard are more important.

[rundownfid]

I will probably try a variety of bullets from 120 up, and it appears that H4350 is indeed the go to powder. I' be getting to my local shop to buy powder, as my supply is mainly oriented towards .223, 30-06, 30-30 etc, all using a medium burn and I'll need a bit slower for best results. Barrel is scheduled to arrive today, but no word on the forearm. I have 3 orders in and can't build until all 3 have arrived.

[rundownfid]

Damn. no forearm. After receiving the barrel and doing some preliminary fitting I called the supplier of the AP Custom ferearm and they don't have it, although that isn't what the web site had said. So I have been searching for another carbon fiber forearm, so far to no avail. Any suggestion on a good substitute. I don't want a lot of rails, I think it needs to be at least 15" and 17' would probably be better (24" barrel). At this point I will consider aluminium, it looks like the rifle is going to be over 10lbs, so a few extra ounces isn't a deal breaker.

mic2377; thanks for the tip on the Fulton Armory barrel, it is a beauty, now if I get the forearm I could even shoot it.

[mic2377]

I personally like the Midwest Industries Gen 2 SS - you can get them in a 15" length, and high or low profile to match the rail of the upper. It comes with a single upper rail, and 3 separate lengths of rail as well. It is slim, very light, and comes with a steel barrel nut and wrench. It is not even than expensive. I already have several of them and they have proven to be durable and easy to service.

[michael1778]

Damn. no forearm. After receiving the barrel and doing some preliminary fitting I called the supplier of the AP Custom ferearm and they don't have it, although that isn't what the web site had said. So I have been searching for another carbon fiber forearm, so far to no avail. Any suggestion on a good substitute. I don't want a lot of rails, I think it needs to be at least 15" and 17' would probably be better (24" barrel). At this point I will consider aluminium, it looks like the rifle is going to be over 10lbs, so a few extra ounces isn't a deal breaker.

mic2377; thanks for the tip on the Fulton Armory barrel, it is a beauty, now if I get the forearm I could even shoot it.

Might find a long 308 hand guard from SLR Rifleworks.

CarbonArms.us is possibly an even better option.

And I'd look over at JP or Lancer.

Edited March 7, 2015 by michael1778

[striped1]

Damn. no forearm. After receiving the barrel and doing some preliminary fitting I called the supplier of the AP Custom ferearm and they don't have it, although that isn't what the web site had said. So I have been searching for another carbon fiber forearm, so far to no avail. Any suggestion on a good substitute. I don't want a lot of rails, I think it needs to be at least 15" and 17' would probably be better (24" barrel). At this point I will consider aluminium, it looks like the rifle is going to be over 10lbs, so a few extra ounces isn't a deal breaker.

mic2377; thanks for the tip on the Fulton Armory barrel, it is a beauty, now if I get the forearm I could even shoot it.

Might find a long 308 hand guard from SLR Rifleworks.

CarbonArms.us is possibly an even better option.

And I'd look over at JP or Lancer.

This. Give them a call. He will make a key mod with no upper rail for you for no extra charge and it will be lighter than carbon fiber. Great guy and company to work with. He might even be able to do a one-off longer version too.

[dauntedfuture]

If you want a serious LR gun then get a bolt gun. No one serious shoots a semi auto in any of the big "tactical" LR shoots and you will not find a gas gun on the line at Camp Perry unless its a service rifle for LR. There are many drawbacks to a gas gun notably that you cant push the cartridge in a gas gun as hard as in a bolt gun. A semi auto gun vs bolt will perform almost the same at 600 yds and in.

A bullet from a .243 or 6.5 Creedmoor etc make it to the target at a supersonic velocity at 1000 yds from a 22-24" barrel. Pushing a .308 of .223 to remain supersonic at 1000 yds is tough business. Is can be done in a 20" but it is hard to do and even then its marginal at best. Consider that a winning score at Perry for a service rifle at 1000 is normally in the low 190s and the real LR guns are shooting 200's with a high X count, they are not in the same class.

If you are satisfied with .260, 6.5 or .243 performance out of a gas gun then go for it, you are still much better off then you will be with a .308. All three of those cartridges will still work well out of a gas gun at 1K but understand that you will be giving something up to the same ctg. in a bolt gun with a longer barrel. Also consider that DPMS uses relatively inexpensive barrels and they are just not going to perform like a high end barrel.

A 6.5 creedmore barrel is going to last longer then a .260 or a .243. You need to see what twist rates the barrels are rated for; ideally you would shoot 115g Tubb 6mm bullets or 142g SMK or Bergers in a similar weight class. A 107g 6mm SMK would be the minimum you should consider for the .243 for 1000 yds.

Also, don't forget to crono your ammo. You need 40 FPS or less ES at a minimum for a ctg pushing at 3K fps for 1000 yds.