rstimpfling Posted February 13, 2011 Share Posted February 13, 2011 I have a stock DPMS 308 upper with a chrome plated bolt. I am going to add a side mounted (right side as I am left handed) charging handle. I was wondering what other modifications to the upper could or need to be made to accurize it? Since I will be getting machine work done on it I might as well get it all done at once. What about the BCG? In adding the addition reciprocating mass of the charging handle I intend to have the BCG lightened at least the same amount. Should I have it lightened more? The stock barrel I plan to shoot until I wear it out then replace with a better one. I will be having the barrel threaded and a sure fire compensator mounted. I am toying with the idea of fluting the barrel. For weight reduction and cooling efficiency. I have heard pros and cons of fluting. Any opinions? The last thing is a +20 to +30 scope riser as I plan to shoot this out to 1000 Yards (more often around 800 - 850). Thoughts? Robert Link to comment Share on other sites More sharing options...
Kevin J Posted February 17, 2011 Share Posted February 17, 2011 I have a stock DPMS 308 upper with a chrome plated bolt. I am going to add a side mounted (right side as I am left handed) charging handle. I was wondering what other modifications to the upper could or need to be made to accurize it? Since I will be getting machine work done on it I might as well get it all done at once. What about the BCG? In adding the addition reciprocating mass of the charging handle I intend to have the BCG lightened at least the same amount. Should I have it lightened more? The stock barrel I plan to shoot until I wear it out then replace with a better one. I will be having the barrel threaded and a sure fire compensator mounted. I am toying with the idea of fluting the barrel. For weight reduction and cooling efficiency. I have heard pros and cons of fluting. Any opinions? The last thing is a +20 to +30 scope riser as I plan to shoot this out to 1000 Yards (more often around 800 - 850). Thoughts? Robert Hi Robert! As for accuracy, the first thing I'd be looking to do is have your machinist re-crown to 11 degrees. That is usually the best accuracy enhancement you can make to a factory gun. Request he indicates the bore to .0003-.0005. That's a little intense, but if your taking the gun out to a grand, every little bit will help. I'd definitely add a 20 MOA riser. Every little bit of up elevation is more you have left in turret. I'm personally in the middle on fluting, i go either way. I like the weight savings, but I usually prefer a lighter profile over fluting, but that's just me. You right on having it done while the barrel is already out. Might be a good idea to have it cryo'd or otherwise stress relieved after fluting. Congrats on getting into the big AR's, they are a lot of fun! --KJ Link to comment Share on other sites More sharing options...
will marshall Posted March 23, 2011 Share Posted March 23, 2011 (edited) Trade it in for an OBR;) As far as getting the DPMS to shoot out to 1000 meters, almost all of that is barrel and if your barrel is free floated(which it is). You might want to consider just having someone rebarrel it with preferably a kreiger, or at least a fulton armory one(around 400 dollars). Why mess around with the stock sub standard barrel? You can buy a better one for your purposes instead of recrowning, cryoing etc. Other than that reload your own ammo and you might make it. Past 800 the 308 cartridge,especially out of an autoloader is not ideal. Of course it can be done, but much easier by bolt actions and cheaper to. And significantly easier by different cartridges. The stock DPMS is the bees knees at 600 or so. Especially considering I can buy 3 for the price of one OBR, LMT etc. Edited March 23, 2011 by will marshall Link to comment Share on other sites More sharing options...
Mike P Posted March 23, 2011 Share Posted March 23, 2011 Trade it in for an OBR;) As far as getting the DPMS to shoot out to 1000 meters, almost all of that is barrel and if your barrel is free floated(which it is). You might want to consider just having someone rebarrel it with preferably a kreiger, or at least a fulton armory one(around 400 dollars). Why mess around with the stock sub standard barrel? You can buy a better one for your purposes instead of recrowning, cryoing etc. Other than that reload your own ammo and you might make it. Past 800 the 308 cartridge,especially out of an autoloader is not ideal. Of course it can be done, but much easier by bolt actions and cheaper to. And significantly easier by different cartridges. The stock DPMS is the bees knees at 600 or so. Especially considering I can buy 3 for the price of one OBR, LMT etc. I'd be interested in what it is specifically that makes a DPMS stock barrel sub standard? Link to comment Share on other sites More sharing options...
smokshwn Posted March 23, 2011 Share Posted March 23, 2011 (edited) Trade it in for an OBR;) As far as getting the DPMS to shoot out to 1000 meters, almost all of that is barrel and if your barrel is free floated(which it is). You might want to consider just having someone rebarrel it with preferably a kreiger, or at least a fulton armory one(around 400 dollars). Why mess around with the stock sub standard barrel? You can buy a better one for your purposes instead of recrowning, cryoing etc. Other than that reload your own ammo and you might make it. Past 800 the 308 cartridge,especially out of an autoloader is not ideal. Of course it can be done, but much easier by bolt actions and cheaper to. And significantly easier by different cartridges. The stock DPMS is the bees knees at 600 or so. Especially considering I can buy 3 for the price of one OBR, LMT etc. I'd be interested in what it is specifically that makes a DPMS stock barrel sub standard? Or specifically how a bolt gun manages to be ballistically superior than an auto.... Or why getting to 1000 is almost all barrel rather than ballistics and bullet choice..... To the original poster, there are many things that can be done to coax a little better performance out of any particular platform of gun. However sometimes it is worth it to see what the gun can do as is, evaluate its performance and then determine which modifications are appropriate for any shortcomings. You may find that you need the extra 20moa, mine does not. You can lighten the bolt a bit to reduce recoil but make sure you don't go crazy with the mill. The DPMS 308 have by and large been very solid performers right out of the box. I have one that is excellent and I have a buddy who has both a .308 and .260 that were both excellent shooters bone stock. As a matter of fact my barrel is sub MOA with either factory match ammo or handloads. I would stick with the heavier loadings, 175 or 178 gr 308 match loadings from Southwest Ammo, Black Hills Ammo, Cor Bon, Hornady, or Federal. With respect to fluting....it does very little of the functions that the internet myths claim, however it does look bitchin! Shoot the gun a little and wring it out, then start with the mods. My bet is you will be very happy. Edited March 23, 2011 by smokshwn Link to comment Share on other sites More sharing options...
dskinsler83 Posted March 23, 2011 Share Posted March 23, 2011 My LR-308 does require the 20 MOA riser but depending on your scope choice you may or may not need it. I hand load 175gr SMK and get pretty good accuracy but I built my LR-308 and had a 20" Rock Creek single point cut rifled barrel w/ 1:11.25" twist rate and a rifle length gas system for more efficient burn. The 18" barrel is 1:10 which will shoot 168s great but don't let anyone tell u it won't shoot 175s or larger till u try it out of your gun! All guns are diff. The DPMS barrels are good quality and shoot well if seasons good. My opinion is look at the new DPMS 20" rifle length gas port barrel that is fluted and threaded already as a replacement for the 18". I think they run $200? You can reach 1k with the factory gun though so it's up to you and how you want it done. Link to comment Share on other sites More sharing options...
rstimpfling Posted March 23, 2011 Author Share Posted March 23, 2011 (edited) I have the 24" barrel. My thought was to work with that. I am sure the gun will out shoot me initially. Once I get comfortable shooting the gun then I can replace the barrel. Building one of these is expensive. I am not cutting corners but I think the barrel I have should get me through the first year of shooting. I was also thinking of somehow putting in a method to shut off the gas so the gun would shoot as a single shot. That has tactical as well as accuracy considerations. I plan on using the 175gr SMK in a custom load for this gun. I will start working up the load once I get closer to completing the gun. I am curious to know what powder you use. Robert Edited March 23, 2011 by rstimpfling Link to comment Share on other sites More sharing options...
smokshwn Posted March 23, 2011 Share Posted March 23, 2011 Robert, My gun started as a an LR308 with the 24" bull barrel. I don't have my initial velocities on hand but when I first got the gun bone stock it shot well under MOA. The stock stainless barrels are very good barrels. Yes, there are better barrels out there, Schneider, Krieger, Broughton, Bartlein, etc but IMO the DPMS barrels are very good. I had the barrel cut down to 18" and turned down to a .750 diameter to cut a bunch of weight off the gun. It still shoots just as well and I can easily get 2550-2600 fps with the 175's. That's still supersonic passing 1000 (1190fps for me @ 4000 ft elevation). By and large Varget is probably the most popular powder but many guys get very good results from RL15 & Ramshot Tac. The new Hodgon/Hornady Super Performance powder is also an option, but it has only been available for a short time and there isn't much data out there for it. .308 Loads Link to comment Share on other sites More sharing options...
dskinsler83 Posted March 23, 2011 Share Posted March 23, 2011 I use IMR 4064 @ 41gr and it's super sonic at 1000 so is the new IMR 8208 and it's a very accurate versital powder. I use Winchester brass and wolf large rifle primers. I hvnt quite dialed in the 8208 load but the 4064 is a shooter. I also hve used R15 which is used in some military match grade 308 ammo. All are good choice, the trick is to find what "your" gun likes. I agree that stock DPMS bill barrels are accurate. Link to comment Share on other sites More sharing options...
bunsen27 Posted March 23, 2011 Share Posted March 23, 2011 I concur with the previous posts that the stock DPMS barrel is quite good and perfectly acceptable for most applications. I've had my 24" bull barreled LR-308 for about 3 weeks. I have ~300 rounds through it, and it already has two LR competions under it's belt. I did not do any load development initially (due to time constraints) nor barrel seasoning (I don't believe in the Tooth fairy either). I just used my M1A load of 168gr Nos HPBT over 41.3gr of IMR-4895 at 2.800 OAL. Accuracy was 0.75-1.00MOA. This past weekend I finally had some time and wanted to see exactly how good the rifle could shoot. Here are my load development targets from the local indoor 100yd range: I think my stock DPMS barrel REALLY likes 43.0gr-43.5gr of Varget under a 175gr Nos HPBT. I did upgrade my rifle with a Magpul PRS, JP VTac handguard, JP trigger, JP adjustable gas block, and JP/Benny Cooley Comp. It sports a Vortex Viper PST 6-24x. If you haven't done so already I'd invest in a top quality trigger for your lower. Without that determining your rifles true accuaracy capabilities could be impaired. I prefer JP triggers others prefer Geissele. Both are top quality IMO. Link to comment Share on other sites More sharing options...
Mr.Kirk Posted March 23, 2011 Share Posted March 23, 2011 +1 on re-cutting the crown and then spend the money on bullets. If you are shooting F-class you don't want to fool w/ a compensator. In fact if you aren't planning to do any born identity type of stuff, then you shouldn't need the comp for a heavy barrel as they tend to mess up your accuracy. Many folks would reccomend against fluting the barrel as it is possible to imprint on the bore. Also, you don't want it to be lighter if you don't want to run and gun w/ it. DPMS is hit or miss on the barrels. I've shot 2 of their barrels and they have been good, but they are no Kreiger or Braughton and that's just reality. It's plenty good enough to get going and should be competitive in mid-range for sure. You are right in sticking w/ the 175s if you plan to reach 1k. The side charger tapped into the bolt carrier doesn't mess things up balance wise. My gunsmith shoots an AR-10 in 6XC w/the same set up and it is perfect. Untill you let it hit your fingers. You might also want to look at RL-17, it makes good velocity (couple minutes higher impact than varget) and accuracy in similar cartriges and IMR 8208XBR it is like Varget but more temp stable and more of a PITA for finding a good load. Link to comment Share on other sites More sharing options...
dskinsler83 Posted April 7, 2011 Share Posted April 7, 2011 I've wondered this and wanna see what y'all think. What if you put an adjustable gas block on the ar10 so youncan turn it off and use it for more precise single shots? Yes or no? Link to comment Share on other sites More sharing options...
rstimpfling Posted April 7, 2011 Author Share Posted April 7, 2011 I was thinking the exact same thing. Shut off the gas and manually operate the bolt. Does that increase the accuracy of the gun? If you need multiple shots then turn the gas on and deal with the reduction in accuracy. Does that make sense? Robert Link to comment Share on other sites More sharing options...
smokshwn Posted April 7, 2011 Share Posted April 7, 2011 Assuming the shooter uses the same fundamentals for each shot, one shot with the gas on and one with it off, the mechanical accuracy will be the same. Link to comment Share on other sites More sharing options...
Biloxi23 Posted April 7, 2011 Share Posted April 7, 2011 I have used an adjustable gas block on my LR308m and it didn't make any difference. I have a 24" cryo'd stailess barrel, JP trigger, steel upper, hard chromed bolt and high rise integral rail. With Federal 168 grain GMM my 10 shot average in 68 degrees was 2652, elevation just above sea level. With the 24" stainless bull barrel and the steel upper receiver, I can see the rounds impact on steel plates between 250 and 350 yards. AT 350 yardes max, I cannot see any difference with the 175 grain Match Kings. Link to comment Share on other sites More sharing options...
Mr.Kirk Posted April 25, 2011 Share Posted April 25, 2011 That's what was done on the REPR rifles and it supposedly has a positive effect on accuracy. I can tell you that if you have a crappy bolt carrier "from a popular sidecharger upper manufacturer" that causes single shot activity, you will not get better accuracy. Only oily crap blown back into your eyes. Link to comment Share on other sites More sharing options...
Big Bore Posted April 25, 2011 Share Posted April 25, 2011 (edited) My LR 308 started as 24 inch gun which I had cut down to 21.5" and the diameter reduced to .750 and a Rolling Thunder compensator installed. It also has a carbon fiber handguard and the bolt has been lightened. I wanted this gun set up for heavy metal but have not got around to it. I do not have a 20moa base and don't need it, the Super Sniper has plenty of elevation adjustment. It is easily sub MOA with 168 grain Nosler CC's and shoots great to about 8-900 yards where it drops to sub sonic. I have not had the time to mess with the 175s but I intend to later this summer. I am running a JP gas block that I have adjusted so it barely cycles with the 168's. This seems to not beat the brass up as much. So, as far as mods? I would take it out and shoot it and see what it does. Why pull off a barrel that may perform quite well and let you get the hang of the long distance game. later on you can change out the barrel if need be. Why waste the money? Edited April 25, 2011 by Big Bore Link to comment Share on other sites More sharing options...
Wap wap Posted April 25, 2011 Share Posted April 25, 2011 best mod. I did to my AR10T was replace the stock with a CCA adjustable. Adjustable lengh of pull (17 in), cheek riser monopod, and recoil pad. Link to comment Share on other sites More sharing options...
blackstone Posted April 26, 2011 Share Posted April 26, 2011 Add a 20 MOA base if you intend to shoot to 1,000. I like the Accuracy International one piece 20 MOA base and rings. It is very rugged. A Magpul PRS stock is a huge improvement over the A2 for precision shooting. A good trigger is essential. I have tried all of them, I think. The Geissele Super Semi Automatic Enhanced is the best I have found thus far. These are modifications I've made on my AR10's. YMMV Link to comment Share on other sites More sharing options...
gose Posted April 26, 2011 Share Posted April 26, 2011 (edited) Havent had time to do much accuracy testing with my 24" DPMS, but with the 168 FGMMs it shot 5-shot groups just over an inch at 200. Need to take it out and shoot some 175s, but for what I'm going to use it for (Iron Man and coyotes) it seems more than adequate out of the box. 24" fluted LR308 w Miculek brake on Fulton lower with JP internals. NF 5.5-22x56 in 20 MOA Spuhr mount. Edited April 26, 2011 by gose Link to comment Share on other sites More sharing options...
SHinck82 Posted June 2, 2011 Share Posted June 2, 2011 (edited) I shoot an 18' OBR, I have not had access to 1000m range I have however shot sub-moa out to 800m. With Berger 155.5 and 44.8gr of IMR 8208 you will be pushing 2800fps and stay supersonic out to just past 1000m. THe biggest suggestion I can make for making shots out that far is make sure you have clear scope and enough elevation adjustment in the turret or enough MOA built in to the rails or mounts. Edited June 2, 2011 by SHinck82 Link to comment Share on other sites More sharing options...
TimBoettcher Posted June 21, 2011 Share Posted June 21, 2011 (edited) Trade it in for an OBR;) As far as getting the DPMS to shoot out to 1000 meters, almost all of that is barrel and if your barrel is free floated(which it is). You might want to consider just having someone rebarrel it with preferably a kreiger, or at least a fulton armory one(around 400 dollars). Why mess around with the stock sub standard barrel? You can buy a better one for your purposes instead of recrowning, cryoing etc. Other than that reload your own ammo and you might make it. Past 800 the 308 cartridge,especially out of an autoloader is not ideal. Of course it can be done, but much easier by bolt actions and cheaper to. And significantly easier by different cartridges. The stock DPMS is the bees knees at 600 or so. Especially considering I can buy 3 for the price of one OBR, LMT etc. This is a factory DPMS .308, 24" stainless fluted barrel... at 194 meters Edited June 21, 2011 by TimBoettcher Link to comment Share on other sites More sharing options...
Mr.Kirk Posted June 25, 2011 Share Posted June 25, 2011 (edited) Load development for 223 F-TR w/ Krieger BBL - 300 Yards (load development was on a rest) It will hold pretty good on the bipod Here's the 100 Yard zero on my 6.5x47L Braughton BBL Just sayin' You're gonna shoot that barrel out in a year or two. When you do, spend a little extra and get a Krieger. If you regret it, somebody will buy it from you. Edited June 25, 2011 by Mr.Kirk Link to comment Share on other sites More sharing options...
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