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Loaded DPMS question...


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As I'm in the process of collecting parts for a custom 308 build, I tally up the price, and consistently wind up between $2200-2900 or so at the end of the day (net including optics).  This is with all the bells whistles I'm looking for on this particular build.  Of course, my main focus here is accuracy, and using the highest quality parts I can, while still aiming to keep the price as low as possible.  

 

So, I see prices for a DPMS 308 platform around $1500.  Doesn't look like anything special.  No bells, no whistles.  Yet, I know many of you shoot them (with minor mods) and get great accuracy and reliability.  Am I wasting my money?  Is DPMS a gamble, sometimes you buy a shooter, sometimes not?  Just trying to separate the wheat from the chaff (or, the Larue OBRs from the DPMSs, as it were).

 

DRD

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I can honestly say I've never saved by building.... Nor have I changed a part after it was built.

I own a LaRue OBR and a PWS MK214, and while they are worlds apart in end use both are built well. Do I think my PWS can hang with the LaRue consistent accuracy? Not even close. But then again I wouldn't volunteer running around with the LaRue where as the PWS is much better served there.

Could you buy an off the shelf DPMS and have it shoot like my OBR? It's possible. I consistently get .375-.5 inch 5 shot groups prone off a bipod at 100yds.

Remember, if you can't do your part, your not measuring the capabilities of the rifles, but of the man with weapon system.

Now that I've rambled, I will not buy any rifles off the shelf, unless it's like my LaRue where I know it can out perform me.

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edgecrusher,

 

You wrote: "I consistently get .375-.5 inch 5 shot groups prone off a bipod at 100yds"  - with which rifle? 

Do any of your builds get the same performance as your OBR?

Is the main reason you wouldn't want to run with the OBR due to it's weight, or do you have durability concerns?

How much does the OBR weight, btw - and do you know anything in comparison about the Predatobr?

I'm just writing this out of my insatiable curiosity.  I'm still building mine.  It may not be cheaper, but I don't have to lay out all the money at once.

DRD

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Definitely with Edge on this one. You don't really build a rifle in order to save money (so to speak). You're usually building it to get exactly what you want right out of the gate. When you buy the off-the-shelf rifles, you're going to slowly (or quickly) start swapping out parts to get what you want anyway. Every rifle that I build usually has a specific purpose, or a specific look that I'm going for. And, like Edge said, I usually don't need to change any parts once I get them together.

 

Oh, and the OBR/SR25/AR-10 SASS style rifles can get up into the teens (in weight) pretty easily once they're dressed out with glass and a bipod (no...not the Elite Iron one either)...especially with full 20 round mags.

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DRD, slow down and read the post bud, lol.

Yes, I get those groups with the OBR.

No, I never had any issues with any ammo or mag ever with my OBR.

I wouldn't run and gun with it because it's a 20" barrel with a PRS stock, and with glass and a 20 rd pmag she dresses out at a guesstimated 14lbs.

I haven't started my 308 build yet, but it will be an sbr, so what do you want me to compare it to? I guess what I'm asking, is should I compare it to my LaRue? It'll be about 8-9 lbs dressed out, and seeing as it's an sbr that may be an iron sight only rifle, there is no accuracy comparison you can really make. I have a few tools, each have a different job. They can all achieve the same result, but some at better at certain things.

What are you trying to achieve? What's the end use of your rifle ? I ask because I'm not sure how to help you. Will it be multi purpose? Will it be a SASS?

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Thanks.  Breathing....

LOL

I'm interested in two different builds.  One, I've started.  It's more modeled after the OBR.  20" heavier barrel, precision, long range, PRS stock.  Will have glass, bipod, etc. I am using Si Defense Receivers for this build

 

The other (that I haven't started yet) will be 16-18", standard profile, lighter weight, with a retractable stock (battle utility stock).  I'm looking to spend quite a bit less on this build.  Thinking of a Bison or BWH/Rainier barrel, DPMS upper, Tactical machining lower.

 

DRD

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I'd thought of that.  Doesn't that get a bit blasty that short?  You need about 18" to burn most 308 loads, no?  Anyway, I'd need to wait for the upcoming "Muzzle Device Test" to be completed so I know which brake is the "holy grail" to be pinned.  Any 14.5" barrels you'd recommend?  Or, will I need one cut down? Also, would a shorter barrel benefit more with a tighter twist? (1:10)

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I'd thought of that. Doesn't that get a bit blasty that short? You need about 18" to burn most 308 loads, no? Anyway, I'd need to wait for the upcoming "Muzzle Device Test" to be completed so I know which brake is the "holy grail" to be pinned. Any 14.5" barrels you'd recommend? Or, will I need one cut down? Also, would a shorter barrel benefit more with a tighter twist? (1:10)

My PWS with a heavy buffer is a great shooter, not bad at all, it has the PWS fsc30 brake I the end. I hate to "brake" it to you, but you not going to get a holy grail decision from the gents. I'm sure you'll get great feed back, as scientific as possible test, but I doubt they will dub one a holy grail piece. To hard to prove. I have shot the fsc30, a Surefire brake, and I couldn't tell you the difference. Robo has an AAC Brakeout that he snagged from me when he came to visit last. There's a good list going, but man, I'm glad I am not doing the study.

Back on topic. I can't personally attest to one over another, as I've only shot my PWS in that size. Rainier has their ultra match and a Noveske for sale in that size, but neither are going to be cheap, rather you're going to pay for their quality and they will be real shooters. I don't know if buy a cheap barrel, only to have it suck and have to replace it. Actually I feel that way about all my parts.

As for the powder burn, 14.5" will get you out to 550 yds easy, and if you're doing a 20" to go long, that for me is plenty. I know this, because I lost my last bet with 98z5v while visiting, shooting 550yds with a red dot on top of a 14.5" 5.56 gun he built.

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Here's the 16" build idea:

 

·         Tactical Machining Stripped Lower                                                                                   

·         DPMS  Assembled Upper Receiver                                                                                 

·         16” BHW Mid-Length Barrel with Polygonal Rifling 1:11                                              

·         MI SS Gen II FF 12” Handguard                                                                         

·         Brake: Go-gun Supercomp-XL / Griffin 7.62 Flash-comp  / Lantac Dragon                           

·         BCM Mod 4 Gunfighter Charging Handle                                                                          

·         BCG:  Shadow Ops (NiB)                                                                         

·         PXT Super Light Low-profile Adjustable Gas Block (.750)                                                 

·         Gas tube                                                                                                                            

·         Lower parts kit w/o tcg                                                                                                        

·         Geissele GS2 Trigger                                                                                                     

·         Grip – BCM Gunfighter mod 2                                                                                                  

·         Standard M4 or Battlelink Utility Stock                                                                                                         

·         Ambi Selector Switch                                                                                                          

·         Heavy Carbine Buffer & Spring                                                                                        

·         Carbine Buffer tube                                                                                                           

  •             45 degree offset iron sights                                                                                                
  •             Millett DMS-1 1-4x24                                                                              
  •             Burris P.E.P.R. QD mount      
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·         BCM Mod 4 Gunfighter Charging Handle

Consider a Mod 3 large latch if you like to charge with just the left palm or have optics near the charging handle.          

 

·         PXT Super Light Low-profile Adjustable Gas Block (.750)

   

Check out the SLR Rifleworks adjustable gas block. It's more expensive, but also looks better designed (and it seems that PXT has sporadic reviews - either great or terrible).

 

·         Heavy Carbine Buffer & Spring                                                                                        

·         Carbine Buffer tube

Do yourself a favor and go AR-10 pattern on the buffer system. A VLTOR A5 (or standard AR-10) receiver extension, AR-10 spring, and AR-15 H3 buffer costs the same (or less, when on sale) as JUST Slash's CAR-10 heavy buffer. That combination of parts has been proven reliable (AR-10, Knight's, and LMT rifles), and is similar to running the heavy buffer in a LR308 pattern gun. It also gives you the option of swapping cheap AR-15 buffers when tuning your gas block instead of $100+ ones. I've converted/will convert both my .308s to the VLTOR A5, 7-position receiver extensions for more adjustment.

Edited by FaRKle!
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The .308 achieves complete burn at 15.5"

After 16" there is very minimal increase in fps per inch of barrel.

  Of course that would depend on the powder , but pretty much correct & on the mark . I have tested loads side by side with my 16" & 20" HB's & while most data say there will be a 125 -150 fps difference with the shorter bbl. , with load development testing I have gotten down to 68 fps. loss with the shorter bbl . , which is not much of a loss , unless you are at the most extreme range of the 308 cartridge .

 

 I believe the 16" bbl. 308 is optimum for all around use , longer barrels have there use also , but more of a refined use . If its a weight issue , go light weight 16 " 

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Yup, those are the parts. You should be able to get the buffer and charging handle for much less during sales (Damage Industries usually has a 20-30% off coupon and has the buffer, Primary Arms and others usually have good sales on the BCM charging handles). The VLTOR tube can be had a bit cheaper too (I paid $40.40 shipped for my last one).

The SLR gas block has a coarser thread pitch and requires a larger degree of rotation per adjustment so it doesn't foul as easily and is easier to clear/set. You can also fully disassemble it and it can cut off the gas completely.

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Thanks for the recommendations.

 

What's the advantage of the Vltor tube over the DPMS? My M4 stock would be too short for it. Any idea if a Mission First Tactical Battle Utility or Minimalist stock is long enough for it?

It seems that Slash's heavy carbine buffer is over an ounce heavier than the H3.  In a 16" mid-length gas 308, wouldn't max recoil reduction be desired?

And, why would you ever need to completely shut off the gas in the SLR block?

 

DRD

Edited by D.R.D.
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Thanks for the recommendations.

 

What's the advantage of the Vltor tube over the DPMS? My M4 stock would be too short for it. Any idea if a Mission First Tactical Battle Utility or Minimalist stock is long enough for it?

It seems that Slash's heavy carbine buffer is over an ounce heavier than the H3.  In a 16" mid-length gas 308, wouldn't max recoil reduction be desired?

And, why would you ever need to completely shut off the gas in the SLR block?

 

DRD

I like the VLTOR A5 7 position tube because I use stocks that can close on the smallest position (ACS, EMOD, STR, ect). If your stock is too short internally to use the 7 position tube they also make a 6 position one, or you could get an AR-10 tube from Armalite.

The DPMS AR-15 carbine receiver extension is a compromise in a .308AR. Knight's found that the shorter receiver extension causes the action spring to get very close to binding when compressed.

The MFT minimalist will collapse fully on the 7 position VLTOR A5 receiver extension.

Slash's CAR-10 buffer ($99) is only .1oz heavier than the H3. The Car-10XH ($125) is about 1.1oz heavier than the H3. Spending money on that when you already have an adjustable gas block is just spending money to say that you have it...

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Awesome info.  Thank you all for clearing so much of this up.  It can certainly be confusing with all the options and misinformation out there.

 

So, now that that build is outlined, here are my specs for the one I started.  Any recommendations or suggestions are welcome!

 

Longer range / precision 308AR (500-1000m)

 

                                                                            

·  SI-Defense Billet Receivers                                                                                    

·  SI Defense Phosphate BCG                                                                                              

    20” .308 rifle-length heavy barrel (.936), threaded, 1:11.25    

 

 

·                  MI FF SS Gen II or  KeyMod 15 Handguard or Rainier Fortis Switch 14 Rail        

·                  R&D MRAD Muzzle Brake                                                                                                   

·  Geissele Hi-Speed DMR Trigger

·                  Grip BCM Gunfighter mod 2                                                                                               

·  Magpul PRS stock

·  TacOps-1 Charging Handle                                                                                       

·  SLR Sentry 9 or Syrac Gen II (.936) Adjustable low-profile Gas block

·  Rifle Length Gas tube

·  DPMS lower parts kit w/o tcg                                                                                                

·  DPMS upper parts (port cover, spring, forward assist)                                                        

·  DPMS Buffer tube                                                                                                                 

·  Slashs Heavy Buffer & Spring                                                                                             

·  Crusader Weaponry Permanent Dry Lube Rifle slipstream treatment

·  Cerakote finish

·  Harris HBMR Bipod 6-9 swivel-notch                                                          

·  ADM QD bipod mount                                                                                                

·  Bobro 20 MOA  QD Scope mount                                                                 

·  45 degree offset iron sights      

    Optic: TBD         

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