sandog

I appreciate all the replies, especially your's, survivalshop. Most everyone else suspects the FCG, I will say again: I did not even go near the engagement notches, and only gave the other parts mentioned a few seconds buffing with a felt bob and polishing compound. What I did do that was stupid was letting the bolt/carrier slam forward on a hand fed round. And believing someone else who told me that Winchester primers were some of the hardest and least sensitive out there. I guess that might have been true back when they still had nickel cups. I have used Winchester LR primers in my R-25 in .243 for 500 rounds now, and have not had a problem, but with the .243 I don't recall ever letting the bolt forward on a round that was already in the chamber, no magazine present to slow the bolt. The trigger in the DPMS .308 is functioning fine, no doubles, hammer following, etc. I am getting 1000 rounds of primed (Mil-Spec primers) Lake City 7.62 brass next week, and when it comes time to reload it, I will be using CCI #34 or 250 primers.

Whoops, got one photo in there twice and couldn't seem to be able to edit it out.

Safety was on. I fired another 100 rounds today with no problems. I'm now using CCI 250 Primers instead of the Winchester LR, and was using a 10 round PMag, As explained earlier,when shooting last week end, the 25 round PMag was way too long for the bench, I started hand chambering the SST rounds and let the bolt slam forward that way. I checked a few of the CCI primed rounds today after letting the bolt slam home on them. I extracted the loaded rounds out of the chamber and looked at the primer. I could hardly see where the firing pin left an imprint on the primer. I did not have any of the Winchester primed rounds on hand today but will do the same test to some of those next time out. Group was shot with Hornady FMJ, I forgot to write that on the target. 300 yard gong is just below the top of the hill at the end of my range:

I did some searches on slamfires and primer sensitivity, and there were references to problems with the newer brass cup Winchester primers in service rifles. Federal seem to be the most sensitive, with Winchester a close second. Least sensitive were CCI. There is no debris in my firing pin channel, I did not enlarge the holes in my receiver ( pins are still very tight!), no high primers. One thing I remembered from the shooting session last Saturday was: I had been loading 5 rounds into the magazine to fire groups with each powder charge, but the only magazine I had was a 25 round Magpul Pmag. Way too long to shoot from the bench. I was having trouble raising my shooting rest up enough to clear the long magazine. When I finished shooting the 150 FMJ's, and started shooting some 165 SST's I had loaded, I quit using the magazine and started hand chambering the round. I don't remember easing the bolt forward, so was probably letting it slam forward by pushing the bolt release. This would incur more bolt velocity as the bolt was not having to strip the round from the chamber on it's way forward. I will not do that again. Don't know what I was thinking. Yesterday I purchased some CCI 250 magnum primers, which I will use until I can get a supply of CCI #34's. I also picked up a 10 round PMag for shooting form the bench. https://thefiringline.com/forums/showthread.php?t=461475 http://www.m4carbine.net/archive/index.php/t-12741.html https://en.wikipedia.org/wiki/Slamfire http://m14forum.com/ammunition/51719-federal-210m-primers-m-1a-slamfire-risk-2.html

Yes, as soon as I can afford it, I am getting rid of that stock trigger ( and getting a F.F. handguard, and heavier buffer spring and adjustable gas block to tone down the excessive gas). I had to do something to the stock trigger as it was the worst trigger I've ever ran across. I am not offended by any of the suggestions given out, I posted this on here to get other's opinions. I spent maybe all of 3 seconds with the felt bob on the pivot holes in the trigger and hammer, I doubt I enlarged them or even smoothed them, if at all. I heard about smoothing the holes to eliminate friction from manufacturing burrs from Patrick Sweeney. The trigger has functioned fine for 200 rounds, just when I hit the bolt release and the bolt slammed home did it fire. I've considered all the things mentioned as possible causes. There was no obstruction in the firing pin channel as someone else mentioned. I would think that debris in the channel would impede the firing pin movement and cause light strikes, not unintentional ones. Primers were seated to the bottom of the pocket with an RCBS hand tool, and checked twice before loading. Trigger was function tested after polishing. This is my first .308 AR, but I have had a dozen in 5.56mm, not counting ones issued in the Army. I've fired probably 10,000 rounds in those. I do have a Remington R-25 in .243, shot it for close to 2 years now. It is essentially the same rifle, being made by DPMS. It also had a less than stellar trigger, I smoothed /lightened it as well, before I could afford the CMC trigger it now has, and it has always fired the same Winchester primers that I was using in the .308 last Saturday.

Hammer was in the cocked position ready to fire again. No shavings in the FCG or in the firing pin channel, I took out the firing pin and cleaned the channel when I first got the rifle. Suppose I could have missed a high primer but not likely, as I said I check them all after priming and again going into the loading block before powder charging. I polished the trigger and installed the red JP trigger and disconnect spring when I first got it, and have fired about 200 rounds the last few weekends. I did not polish the pin holes in the receiver, only holes in the trigger and hammer, and only very lightly.c Gonna try harder primers when I load again.

That's great that the Armalite has a firing pin return spring. Too bad I don't own one. An AR-10 that is. I do own an Armalite 5.56mm.

No, without a jig or fixture I know to not do anything to the engagement notches. I did a light polish on the big shelf atop the trigger and the pin holes and sides around the holes with jeweler's rouge on a felt Bob. I switched trigger and disconnect or springs for red JP springs, but kept the stock hammer spring in there. About 200 rounds through it with no other problems, all my hand loads, no factory.

Yesterday I was shooting my Oracle .308 and had a slam fire. I have been shooting since I was 12, 45 years ago, and enlisted in the Army in 1975. I've shot a few rounds through self loading rifles. But this slamfire was a first for me. I was using Hornady brass, Winchester LR primers and W748 powder under Hornady 150 gr. FMJ bullets. I was certain that all primers were seated below flush, I check twice before charging with powder. I was under the impression that Winchester was a harder primer, but an aerospace engineer friend told me the Winchesters were very hard when they still used a nickel cup, but since switching over to a brass one they are now one of the softest. I went to several stores yesterday looking for CCI #34 primers but there were none to be had. My friend told me he has dissected various primers, and to him the CCI 250 mag primer is essentially the same as the #34. I will try some of those until some of the #34's are in stock here. I might add that the round fired when I hit the bolt release to start off another 5 round string. I would think the bolt velocity would not be any more than if the bolt was cycling from a previous shot. The DPMS rifles do seem to have tighter chambers than others I've fired. I have had no chambering problems in my .308 when sizing with a regular Full length die. Another friend, who bought a 5.56mm Oracle when I bought mine, was having problems with the bolt seating fully using brass that he full length sized. ( and O.A.L. was correct.) I checked the rounds he loaded in my L.E. Wilson cartridge gauge, and all inserted fully, no tightness. His is the first semi-auto rifle I've seen that might actually need a small base sizer. So far, I have swapped out the factory stock and grip for a Magpul ACS and Moe+ grip, Got the trigger down from 7 1/2 pounds and gritty to 5 pounds and smooth, a Troy Medieval muzzle brake, and added an ambi safety, Norgon ambi mag release, P.O.F. Rattler ambi charging handle to make it more "Lefty friendly". Next up will be some Troy or Samson BUIS, an adjustable low profile gas block, heavy buffer and spring, and an Apex F.F. tube, and eventually a better aftermarket trigger that doesn't have a mile of pretravel. Still trying to decide about an optic to replace the cheap 2-7x shotgun scope that on there now just so I can have some sights to get out and shoot it. Thinking about getting a Leupold VX-R 3-9x with Ballistic FireDot. I was shooting Hornady 150 FMJ's in Hornady brass with W748 powder, and Winchester LR primers. I had started another 5 shot string and hit the bolt release to chamber a round. The carbine fired when the bolt slammed forward. It was angled down and to the right when it firedslightly in relation to the target frame, and just missed hitting the tripod my chronograph was sitting on.

Thanks all. Unforgiven, the scope is a long eye relief Nikon 2.5-8x BDC Force Encore. The big gun store here has had NO powder for the last few months, but the little mom and pop store has a few dozen different powders, mostly Hodgdon. The guy got 30 pounds of Varget alone, and it was all gone in a day. I bought some H-380, Benchmark, Varget and BLC2. The Benchmark is only suggested for 55 and 60 grain bullets in the .243, but the other 3 I'll try in the Remington R-25. Also bought some Nosler 80 grain Varmint Ballistic Tips.

pics of the Mini:

Thanks, 98Z5V. I wish I had an M1A though. That is just a Mini-14 in the pic.

The H-4831 SC didn't do so well. Accuracy was good, velocity was on the lower end to reliably cycle the action ( 2800 fps.) but the recoil seemed harsh. The recoil shooting the medium powders like 4895 and 4064 is almost nonexistent, like shooting a .223. With the 4831 it was more like .308 recoil, so I stopped shooting those loads and pulled the rest when I got home. I finally settled on 36.0 grains of IMR-4895 with the Hornady 87 grain V-Max, velocity was just under 3000 fps. and accuracy sub inch at 100. I want to try some different bullets like the Nosler Varmeggedon or Sierra varmint line, would like to get under 3/4 groups for a varmint load.

That looks nice. I'll contact them.

Yes, I'd never use the lever, and cutting it off would simplify installation. The "stubby" mag looks to be out of stock, but I'll have to get a couple when I can find some.