hogwylde

The ammo in question was some MILSURP 308 ammo I inherited. Cases were stamped TZ 79, TZ80, TZ81. I've since learned that this is surplus Israeli ammo that is prone to case failure. Inspection of the cases from that shooting session showed multiple case "ruptures" and one with the entire primer face missing. I'm not sure which particular case caused the steel DPMS style magazine to dump it's guts. It bent the base plate and "ejected" the mag spring/follower/remaining rounds onto the bench. Straightened the base plate, re-assembled the magazine and it (the magazine) functions fine. I've since junked all that crap ammo and have been using PMC Bronze and ATI for range sessions. NO indications of case bulging or any other abnormalities with the brass. I haven't had the opportunity to check anything on gun since the last range trip with the groups all over the place. I'm curious about the no name muzzle brake I installed right after I got this thing. I want to re-install the factory flash hider and see if things get better............

Now that I have over 1000 rounds through my DEF-10, it runs like a top. No short stroking or FF or any other "function" problems. Now..........it seems like I can't hit the side of a barn. Took it out for a 3-gun match. Thought I had it zeroed a while back, found I was hitting high and to the right (200 yds, 12in high, 4in right when I went back to the range and checked the zero). Walked my group down where I wanted it and went to a match the next day. Now, I'm shooting 12 inches low! I remember one of my 5 shot groups looked like a 6 inch vertical string, and all my groups (@ 200 yds) are about 6 inches at best. I'm using 147g ball ammo. I get the same thing with 168 match ammo. Groups that are 6+ inches and no consistency. I'm thinking this thing should shoot better groups and not vary day to day where is hits. I did have a primer failure a while back when breaking this thing in. Blew the bottom and guts out of my magazine. Stopped shooting, inspected everything for bulging/obstructed bore/anything unusual....found nothing. I've had no problems with function of this rifle now, but I'm concerned that maybe the barrel might be loose or the upper cracked or something allowing the barrel to wiggle around relative to the scope? Anything I should check that I haven't already mentioned?

Has anyone else noticed that when the gun fires, the charging handle come back and almost hits the person firing it in the face?

I got my DEF-10 last October. The receiver is marked "Armalite AR-10A" and the serial number. It has the Armalite logo, but nothing else and nothing to indicate that it's the DEF-10 model.

I've been looking around at various sites for accessories. Lot's of places have parts/accessories that fit "DPMS pattern" rifles. My AR10a takes PMAGS and DPMS style magazines, what other parts can I reasonably expect to work/fit? Charging handles, BCG's, hand guards, stocks, etc. I'd really like a new charging handle....maybe even a NiB bolt carrier with the Armalite bolt in it, but I don't want to play the maybe it will/maybe it won't fit game. Any good guidance or is everyone in the same boat I am?

Armalites new AR10 VSR (Versatile Sporting Rifle) comes with an 18" black cerakoted barrel. So does the new AR10 TAC18. Call them up and order a replacement barrel for one or the other. That should solve your problem.

How can this be a new or unknown issue?? There is a warning on page 47 of the Armalite AR-10 owners manual that specifically warns you not to do this..... "CAUTION: ONLY INSERT THE BOLT INTO THE CARRIER FAR ENOUGH TO INSERT THE CAM PIN. IF YOU INSERT THE BOLT TOO DEEPLY WITHOUT THE CAM PIN IN PLACE, THE BOLT RING MAY JAM IN THE BACK OF THE CARRIER. IF THIS HAPPENS, YOU MAY NEED TO WIGGLE THE BOLT TO REMOVE IT. IN SOME CASES, IT MIGHT REQUIRE DRIVING THE BOLT FORWARD WITH A BRASS ROD, DESTROYING THE BOLT RING. ONCE THE CAM PIN IS IN PLACE, THE BOLT CAN'T BE PUSHED FAR ENOUGH INTO THE CARRIER TO CAUSE A PROBLEM."

Do Armalites normally come with McFarland one piece rings or standard 3 piece rings? I get the impression from their website that the McFarland is standard issue for AR10's.

I've got 160 rounds thru it now. Now that I realize I'm limp wristing this thing, I'll put the H3 buffer back in it and see how it runs of the PMC stuff.

Got a chance to run 100 rounds of 5 different groups of ammo today. The 175g PPU ran just fine, no hickups at all. The PMC 147g hickuped once, then ran the rest of the mag out. The Perfecta 147g short stroked the first 3 rounds. I switched to an H2 buffer and ran the rest of the mag out. Some 1979 Spanish NATO 7.62 hickuped a few rounds, then ran out the rest of the mag. Finally, some ZQI 147g. It hickuped a few, then I really grabbed the handguard and pressed the rifle into my shoulder and it ran like a raped ape the rest of the mag. So, it definately likes the heavier stuff. But, it's more expensive...harder to find....and NOT "milspec 7.62x51" that Armalite claims that their rifles are designed to run. Also, I'm wondering if I was causing part of the problem by not really grabbing the rifle and getting a nice FIRM hold into my shoulder. I guess you would say............the equalivent of "limp wristing" it? ??? It seems to like the H2 buffer also. Would it be ok to leave it in or should I work on providing a firmer resistance for the rifle to recoil against??

Didn't think it would. But, I was reading some info on adjustable gas blocks and it mentioned that "silencers and muzzle brakes" affect the gas pressure. I'm thinking that with the ambient temp @ 38 degrees and a fresh out of the box rifle equals sluggish bolt action. I cleaned/polished up all the sliding surfaces on the bolt carrier and I'm going to run this thing at an indoor range Sunday with a handfull of different ammo types and a dripping wet bolt to see how things go. Thanks everyone for your input.

OK.....getting ready to run 5 different brands of ammo thru this thing to see if it likes something else better. One question that I have......I changed out the flash hider for a Miculek style muzzle brake. Would this make any difference?

Yes, I did mean 7.62mm. I had a suggestion from someone that I could try a lighter buffer. The one I have is marked HB. I'm wondering if swapping out a couple of weights with a carbine buffer and reducing the weight an ounce or so might be worthwhile..................

Talked to Tim this morning at Armalite. He says to use a heavier bullet for the break in period. Something in the 155-175 weight range. I would have thought that M80 ball equilivalent rounds would be fine, but I guess not. My barrel is marked 1-11.25 as the twist rate. The gas key is tight, the gas block is tight and not canted, Gas rings in the bolt are good, no rubbing or wear found on anything except on the bottom of the charging handle from having to manually cycle the bolt 60 times. (the bottom has rub marks from dragging on the receiver.) I'm sure the 38 degree temperature MAY have had some effect also. It did on my M4 carbine. I was sighting in a new scope on it at the same time as breaking in the AR10. The M4 short stroked a whole magazine of TULA, but ran fine with 55 gr M193 5.56 ball. I've got some 1979 era Spanish NATO 7.65 that I'll try and also pick up something with a heavier bullet and see what happens. I run SLIP 2000 EWL lube in my M4 and that's what I used for the AR10. Should I run something lighter for the breaking in period or is what I'm using fine?

I just got myself a new DEF10 from Armalite (It says AR-10A on the side of the reciever). Had a chance today to take it out and run some rounds through it. I get 3 shots out of it before it turns into a single shot rifle. The next 57 shots out of 3 brand new PMAG SR20's are almost all singles. Ejects the spent cases into a neat pile about 5 feet out @ 4 o'clock, bolt closes on an empty chamber. Last shot out of each mag fails to lock the bolt back. (tells me that it's short stroking) I do get a few Failures to Feed with the round jammed into the chamber, but not completely. Feeds just fine when I pull the charging handle and let it fly home. I've been running an M-4 carbine for 3-gun for years now, so I know to run the bolt wet....it's not lacking for lube. I disassembled before firing to clean and lube. Nothing found out of order. I disassembled after firing and still nothing unusual. I'm running 147Gr PMC Bronze FMJ, not cheap junk Russian TULA. Am I missing something? Granted, it was 38 degrees today....but I don't think that had anything to do with anything. Don't tell me that PMC ammo is junk and 147Gr ball ammo doesn't work in these things. Someone point me in the right direction. I really don't want to send it back to Armalite.