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Posted: 9/12/2015 10:35:35 AM EDT
| I just got the dpms 308 sportical from walmart during their sale. Ive heard it has some problems areas as far as quality goes, what should upgrade to make it more reliable? |
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The gas block needs to be replaced with a steel one. Aluminum gas block + CLGS + .308 = major gas leakage and eventual short-stroke malf's.
I've seen it over and over again, even on RLGS .308's with the 6061 blocks, even when bedded. There is simply too much pressure and heat, coefficient of thermal expansion on steel and aluminum is totally different, and you get major leakage. I'm not making this up. I've seen it on several DPMS carbines with aluminum blocks. CLGS/.308 has port pressure that is far higher than the design parameters of the original AR10 as well. |
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Thanks for the info guys, I plan getting a new stock and handguard here soon , just go to find one i like thats not to expensive... "...There is simply too much pressure and heat, coefficient of thermal expansion on steel and aluminum is totally different, and you get major leakage." So basically the aluminum heats up and expands faster than the steel, causing a gap between the two metals and leaks from there? |
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Quoted:
The gas block needs to be replaced with a steel one. Aluminum gas block + CLGS + .308 = major gas leakage and eventual short-stroke malf's. I've seen it over and over again, even on RLGS .308's with the 6061 blocks, even when bedded. There is simply too much pressure and heat, coefficient of thermal expansion on steel and aluminum is totally different, and you get major leakage. I'm not making this up. I've seen it on several DPMS carbines with aluminum blocks. CLGS/.308 has port pressure that is far higher than the design parameters of the original AR10 as well. Any recommendations on gasblock? |
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For those that doubt me. Here's an aluminum LR-308 gas block taken off of a RLGS/20" .308 barrel. This is the block they used on the DPMS .223 Lo-Pro Classic, the first LR-308 rifle and Carbine. It's 6061 aluminum.
I have personally done experiments with 7075 T6 gas blocks on 5.56 MLGS, and they still failed, even when JB Welded on. Slapped on a steel gas block, no problems. This gas block was replaced with a steel one, and the gun now runs like a raped ape. It was short-stroking before I replaced it, same thing I saw happen on the Lo-pro Classic many years ago, and every other aluminum gas block except from JP on a RLGS. JP's 8 screw clamp-on 7075 T6 block, when used on RLGS and sealed with LT-271 (rated to 500 F). 
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Quoted:
Any recommendations on gasblock? Quoted:
Quoted:
The gas block needs to be replaced with a steel one. Aluminum gas block + CLGS + .308 = major gas leakage and eventual short-stroke malf's. I've seen it over and over again, even on RLGS .308's with the 6061 blocks, even when bedded. There is simply too much pressure and heat, coefficient of thermal expansion on steel and aluminum is totally different, and you get major leakage. I'm not making this up. I've seen it on several DPMS carbines with aluminum blocks. CLGS/.308 has port pressure that is far higher than the design parameters of the original AR10 as well. Any recommendations on gasblock? Any steel gas block that is the correct ID and fits your needs. I've had to hand-fit a few gas blocks, but most are pretty straightforward. Alignment of the ports is critical. We're seeing a lot of people just mounting them up to the barrel's shoulder, and then wonder why their rifle short-strokes, stove-pipes, and doesn't work. |
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