Home Forums Hunting & Shooting AR and Tactical Rifles DPMS AR15 DCM Barrel Problems

Carolyn will run/swim all the way over, and get on a bike and whoop up on ya...... think an AR could survive the saltwater swim portion?

After I tell her what you're saying online, I'll think she'll be whooping up on your sorry Butt!

You started it!

Jerry;
Did you get the problem solved? My offer still stands.

Dave McGrath

Jerry;
Don't know if your still having problems or not but I
had one of my DPMS barrels out to the range today for some chronographing and grouping before I begin my winter loading of about 4000 rounds.
The bullet that had the most powder behind it was the Sierra 60 grain HP. My favorite bullet for 200 yd. shooting. The charges tested were as high as 26.3 grains of Reloader 15. Thats a case full of medium burning rate powder without having excessive port pressure. More powder and slower burning rate equals more port pressure. As I reported before, no signs of chamber pressure, no cartridge rim damage in fact no problems at all with groups of one inch and a couple of others, even a little less. Range was 100 yards with no wind.
LC-90 brass, Remington 7 1/2 BR primer.
I also tested loads with Varget. No problems there either. Groups were the same but RE15 had the lowest s.d. of the two powders and higher velocity.
My gas port diameter is .0995". Bolt and carrier of unknown origin bought from Sherluk Marketing back in the late 90's.

Then to complete my day at the range on a happy note, no copper fouling in the bore! It don't get any better than that! $176.00 barrel at Midway USA product number 550-750!!!!!!!!!Dealers and C&R holders get them for even less!!!!!! I'm a happy man!!!!!

Dave McGrath

Hi Guys:

Sorry it has been so long since you all heard from me, but I haven't had a chance to shoot the AR since my last post. Holidays, hunting ETC. have kept me from the range. Today though 12/29, we got out to my buddy John's for some dove hunting, and an opportunity to shoot a couple 35 Whelens, in preparation for a buffalo hunt in Kansas next month, that also gave me a chance to shoot the AR, here's the results: No cronograph, as the sun wouldn't cooperate, clouds etc. I set the gas tube @1.5 turns as was recommended, fired a round with 25 grains of Varget/69 Sierra, and promptly tore the rim off. I then set the gas tube @1/2 turn fired the next Varget round, and the action didn't operate. So I opened up the gas tube to 3/4 turn, and fired the next round, which operated properly. I then went on to fire 22 more rounds with 4 different powder charges, and I had no more problems. 25 grains of Varget/69 Sierra put 5 in a group all touching, with one rim tear off a little outside of the group, and the one that didn't operate the action a little off that one. I then fired 25.5 grains of Varget/69 Sierra, not as good a group, I also fired a couple different loads with 748, but they were just miserable. Looks like you all may have been right about the gas port. I think the problem may be solved, but I won't know for sure until I shoot it again, and shoot some hot loads thru it for testing. I'll let you all know.

Happy New Year

Jerry

Jerry

Now if the gas tube solves it somewhat, then its time for a brand new extractor, as you've probably sorta wrecked that one a bit now ripping enough rims off.
It may still be a bad chamber though.... gas tube solved some issues, but not all. Would be nice to know how fast bare 69s with 25.0(a real standard load) are running though..

Jeff

Jeff: I will run some 69's/25 Varget over the crono in a week or 2 and let you know the results. I fired another 22 rounds thru it on New Years, and didn't have a problem.. My only angst here, I had to buy an aditional piece of equipment, in order to make this barrel work. It does look like it wll be accurate, more testing will tell.

Jerry

Jerry

Don't feel too bad, I"ve had Pac Nor barrels that don't shoot 90s that I use well at all, though they'll shoot everything else.... sometimes a gas tube is a cheap investment.....
Not that it should be like that, but each barrel is a beast unto itself. Nope PN would not replace my tubes and I don't expect them too, not when it shoots everything else in knots. It just goes on our NTIT guns...

Jeff

Jerry,
September 2007 American
Rifleman magazine has an article on the 223 chamber vs the 5.56 Nato chamber. You might want to look this one over real close.
whelennut