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Posted: 2/5/2008 2:45:18 PM EDT
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I have a new DPMS LR-260 and I feel I finally found a good load. I'd like to experiment with an adjustable gas block because my load is pretty hot and the primers are really flowing. I'm afraid I'll start piercing the primers in the summertime. Is it a simple job to change gas blocks that can be performed by a home gunsmith rookie? I have changed barrels and messed with alot of Savages, O3A3's and Stolle Panda bench guns. That's about my experience. How about the JP adjustable gas block from DPMS in .936 diameter? Is there a better brand out there? Thanks, Dale McClure |
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True - true unrelated. I hope you're not implying that an adjustable gas block will have any affect on a too-hot load. Changing a gas block is relatively easy; remove any muzzle device so you can slip the gas block off the end of the barrel, loosen whatever is holding the current gas block in place (taper pins, set screws, etc.), slide out the block and gas tube, drive out roll pin, remove gas tube, insert and pin into new block, reinstall, attach. I don't know what DPMS uses to attach the LR-260s gas block, but it looks like a set screw setup. If your barrel is .936 at the gas block, the JP parts are nice quality. But again, don't try to "game" hot loads by playing with the gas system. A blown case is not good. Take care, C97 |
He might be implying that is rifle is over gassed as many AR's are. That's why Tubbs came out with his carrier weight. |
| i use the jp gas block on my .308. my .308 shows primer flow as well. best idea is to use a cws, chrony your loads, and check for case sep signs before each loading. ive had decent brass life by only setting the shoulders back .003" from fireformed. im gonna chrony my loads again this summer, with cci benchrests/lapua brass this time, to get a better idea if the firing pin hole is oversized. |
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Thanks fellas. I guess I'm just used to running hot from my 6PPC BR days? I have checked and set my headspace to .003 to .004. A factory loaded R-P round was .015 headspacehock.gif. I use Norma brass because some of the R-P I used at first the primer would darn near fall out because it was so loose. That's on once fired commercial R-P hunting load brass. We never used CCI primers in benchrest because they were too hard. I guess it's now time to use them in the .260? I had it in my mind that an adjustable gas block would do the same as an adjustable gas plug on an M-1 Garand? You know, set it to just enough to cycle a new round so the Op rod doesn't beat the rifle up with hot commercial hunting loads. I'm starting to catch on. Thanks to all who have offered help. The last time I messed with these black things was in the USMC in 1969. They took our M-14's away against our will. We hated the black rifles. I'm now enjoying the new technology that 38 years makes. So far, I like it. Dale |
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The adjustable gas will give you a wider range of loads that correctly cycle your rifle as well as the opportunity to turn down the gas on an over gassed gun. However, it is probably not safe to run loads in a rifle that are flowing the primers as you say. If you mean the primers are flowing out of the primer pocket and not just into a loose firing pin hole, you are really at the upper end of the pressure curve and might want to back it off a bit. I think that is more of what folks are suggesting. Get the adjustable gas if you want one, but it won't cure your overpressure problem. Only dropping the charge a few grains will. -David Edgewood, NM |
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