I had a loose primer foul up my time on the range today. I didnt discover the rotten little gremlin in my lower until I got home.  I was trying some new Adcom ammo today.  Before shooting some, I fired a mag of some surplus XM193.  My rifle loves this stuff and has never had a problem with it in over 1000 rounds.  I then put in a mag of the Adcom and started having trouble almost right away.  I could fire a round, the empty would eject and a fresh round would chamber.  But then I couldnt pull the trigger.  I thought that it wasnt going into battery, so I tried the forward assist.  It worked a few times, but it didnt really seem to move the BC.  The only real cure was for me to pull back the bolt a third of the way and then release it.  Only then could I pull the trigger and fire the chambered round.  I switched back to the XM193 and continued to experience this problem, but much less.  I thought it was because this is hotter ammo.  I broke down the rifle twice and checked the chamber, the bolt, BC and gas rings.  Each time it got better, but then it would start again.  I fired about 210 rounds (150 XM193 and 60 of Adcom).  My last mag was a 30 rounder full of Adcom, which I hesitantly loaded into the mag well.  To my surprise I was able to fire the entire mag with only having to pull the bolt back twice.

I thought about what might be causing this problem all the way home.  I knew the hammer was being cocked and it appeared that the BC was going into battery, but I wasnt sure.  I figured either I had something stuck behind the chamber lugs or my problem was in the trigger itself.  Once I got home I tore right into the rifle again.  The lower and FCG looked OK.  Still, I gave the lower a shot of Gun Scrubber and took another look.  And there it was.  Looking right at me and wedged to the side of the front of my RRA NM trigger group was a black sooty Primer Gremlin.  I got out the hemostat and pulled the litte sucker out.  Now it all made sense.  No wonder I was able to pull the trigger every time I pulled the bolt.  It was because I always tilted the rifle down to do it.  Each time I did this, the primer got out of the way of the trigger mechanism and I was able to pull it with out a problem.  The rest of the time the primer was jammed under the front of the trigger mechanism and wouldnt let it move to release the hammer.

I examined the primer closely and it looked more like the ones from the surplus XM193 than the ones from the Adcom.  It did not look deformed in any way, so I guess it wasnt seated right and just fell out after firing.  I also suspect that it was only coincidence that it worked better with the XM193 than the Adcom during the range session.  Or it could be because the XM193 was hotter and it bounced the primer out from under the trigger mechanism more than the Adcom did.

Any way, thats my story and I hope someone learns something from it.

little stuff like that can drive you nuts!

I was at the range again today and experienced another primer related problem.  I started with a 30 round mag of XM193 without any problems.  I followed with a 20 round mag of Adcom with zero problems.  I then put in a 30 round mag of Adcom and thats where the trouble started.  After the first few rounds, the bolt was having trouble closing on the Adcom rounds and when it did, it turned into a single shot.  It would short stroke and not load the next round.  It ran better with the XM193 ammo, but still short stroked once in a while.  I left the range scrathing my head.

After spending some quality time with the wife (dinner and a movie), I began researching the problem here and in my books.  I finally looked down the carrier key tube looking for a piece of Q tip or pipe cleaner and guess what I found.  Why yes, you are correct....ANOTHER STINKING PRIMER!!!  It was jammed in there tight too.  I tried to dislodge it with a thin nail, but it would not budge!  I finally got serious and carefully drilled it with my dremel tool until it fell out.  

Boy was I pissed!  I never had any trouble with this rifle until I started using the Adcom ammo.  I'm going back to strictly XM193 and Black Hills ammo.  I'll use up what Adcom I have left on my .223 bolt gun.  BTW, I buy my XM193 loose in 500 round cans at the gun show.  It looks gunky, but always works and has never thrown primers into my action.  Even after 1000 rounds of it.

Ran 240 rounds of Adcom today in my Colt m-4 with no problems whatsoever.

I'm not going to defend any manufacturer.

ANY manufacturer can have a primer back out.
ANY manufacturer can have a squib
ANY manufacturer can have  a hang fire

Why the hell do you think they teach you how to deal with it in the military?

We've had the same problems with SBMC (Squires Bingham Manufacturing Company) 5.56mm ammo back in the Philippines.  The primer would fall off the case.  A friend had to change his gas tube because the primer got lodged in the gas tube.

I know that many people have had good results with the Adcom stuff, but I seem to be having problems with it.  Maybe I got a bad batch, I dont know.  What I do know is that I do not want to risk another primer jammed in the gas key or the gas tube for that matter.  

If it matters, my rifle is an SBRed Bushy lower with RRA internals matched to a CMMG M4 upper with an M16 BCG and RRA gas rings.  All of my mags have the Magpul no tilt followers and have been 100 % reliable.  This combo has run perfectly for over 1000 rounds with XM193 55 grn and Black Hills 55 grn.  I even had a few lower powered rounds run through and it always cycled properly even with weak stuff.  This is a first time I have ever had a problem and I can trace it directly to type of ammo I was using at the time.  Especially since I have the tiny little pieces of evidence that I pulled out of my gun to prove it.

I will shoot it again next week with only XM193 and Black Hills.  If this happens again, I will certainly post it here.

Same thing happened to me with that British SS109 ammo a few months back. Poor cycling for me to begin with, and then a blown primer got stuck under the trigger, had to punch out the FCG to find it.

I've had a primer come out of military issued 1983 LC M193 a few years back, it jammed up in the carrier real good. Only time it has happened with mil crimped ammo for me . It was in one of my NM service rifle uppers and not my issue M16A2.

Quoted: I've had a primer come out of military issued 1983 LC M193 a few years back, it jammed up in the carrier real good. Only time it has happened with mil crimped ammo for me . It was in one of my NM service rifle uppers and not my issue M16A2.

Could just as easily have happened in any of your guns.
I've had it happen myself, just high pressure rounds, that's all.

Doesn't mean it will happen in every firearm.

Mark

I went through 350 rounds of ADCOM Saturday. I didn't experience one problem. What was the lot number of your ADCOM? (it's printed on the inside of the lid)

My Lot # is AML99M010-002.  I am using a the buffer that came with my RRA 6 position stock.  The barrel is an M4 14.5" with an A2 FH.  The barrel and chamber are both chromed.

What do the cartridge cases look like? Any indication of over-pressure? Flattening of the lettering or primer that did not come out, Indentations of the ejector hole.

Wrecktech, I compared spent cases from both the Adcom and the XM193 and they both look fine and exactly the same.  I can see nothing abnormal.  

Quoted: Wrecktech, I compared spent cases from both the Adcom and the XM193 and they both look fine and exactly the same.  I can see nothing abnormal.

Not being familiar with the Adcom, is that .223 Rem ammo? Check this thread: HERE for pictures of the case heads with and without pressure marks. Compare the case heads with unfired cases. While I doubt Rock River would put a .223 chamber in a 14.5" barrel, the tolerances might be a bit tight. Do you have the ability to measure the fired cases?

I'm having similiar problems refer to www.ar15.com/forums/topic.html?b=3&f=16&t=253108&page=2 and www.ar15.com/forums/topic.html?b=3&f=66&t=253950

I will be taking my rifle apart tonight. But for you guys who were having ADCOM firing issues, but shot other ammo fine. Why would a loose primer affect the adcom only and not other ammo you fired?

(Please excuse the potentially newbie questions, i'm familiar with firearms but don't know a lot about troubleshooting stuff beyond the basics)

Its very easy to find out what round the primer came from. Adcom primers are silver and xm193 is gold. I have fired approx 500 rounds of adcom now through 5 different guns with no problems.  16 bushmaster, 14.5 bushmaster M4 brought to 16" with FS, 20" 1/7 colt, 16 RRA, 20" 1/9 bushmaster SSHBAR.

Well guys, I'm really confused now.  Before I go into details, let me answer a few questions first.

Tweak, I have to admit that I'm not sure how to tell the difference between an H Buffer and a regular one.  Wreckteck, my upper is a CMMG and not a RRA.  Also, I dont have the tools to measure fired cases and my cases still look OK when compared to the pics from your post.  Fiend, you are not alone and I feel your pain. Agcsy, after carefull examination and some cleaning and even some filing for verification, I have to admit that the offending primers are indeed GOLD while the Adcom primers are  SILVER.  Which would mean that they came from my can of inexpensive and loose gunshow XM193.  

Do you guys understand why am so confused now?  The problems only manifested themselves WHILE fireing mags of Adcom, which I did only AFTER fireing a mag of XM193.  Can it be that the rifle only SEEMED to run better with the XM193 after the problems started because even with a primer jammed in the gas key, the XM193 was still hot enough to make the rifle work while the milder Adcom could not?  Can it be that the quality of my cheap XM193 is slipping because of the apparant dwindling supply?  I have seen date stamps on it from 00 thu 04 all from the same can.  At this point I dont know.  The only thing I can think of is to go out again and try the Adcom again WITHOUT the XM193.  I will also shoot it with some Black Hills for comparison.  I will try to sneak out of work early someday this week and hit the range.  I'll let you guys know what happens.  Thanks for all the responses and help.

Quoted: Well guys, I'm really confused now.  Before I go into details, let me answer a few questions first. Tweak, I have to admit that I'm not sure how to tell the difference between an H Buffer and a regular one.  Wreckteck, my upper is a CMMG and not a RRA.  Also, I dont have the tools to measure fired cases and my cases still look OK when compared to the pics from your post.  Fiend, you are not alone and I feel your pain. Agcsy, after carefull examination and some cleaning and even some filing for verification, I have to admit that the offending primers are indeed GOLD while the Adcom primers are  SILVER.  Which would mean that they came from my can of inexpensive and loose gunshow XM193.   Do you guys understand why am so confused now?  The problems only manifested themselves WHILE fireing mags of Adcom, which I did only AFTER fireing a mag of XM193.  Can it be that the rifle only SEEMED to run better with the XM193 after the problems started because even with a primer jammed in the gas key, the XM193 was still hot enough to make the rifle work while the milder Adcom could not?  Can it be that the quality of my cheap XM193 is slipping because of the apparant dwindling supply?  I have seen date stamps on it from 00 thu 04 all from the same can.  At this point I dont know.  The only thing I can think of is to go out again and try the Adcom again WITHOUT the XM193.  I will also shoot it with some Black Hills for comparison.  I will try to sneak out of work early someday this week and hit the range.  I'll let you guys know what happens.  Thanks for all the responses and help.

I thought the adcom was right up to spec speedwise and not any less hot then 193 [855 really]. Anyways thats what the chrony said according to one of the guys who posted here. I sure can't tell the difference. Since all 5 k rounds I bought are 99 dated and I pulled boxes from each shipment and fired them before Storing it in old SA 308 "cans" I can't say anything except the 99 year Adcom. I saw no sign of any primer problems and I policed all [well most of it anyways] my brass.

Primers falling out of primer pockets are usually caused by one of two problems, either overpressure or reloaded ammo that has oversized primer pockets.  Since XM193 has crimped primer pockets it is more likely caused by reloaded ammo of dubious quality.

Hi guys.  Here is my latest experience.  First I made sure the rifle, chamber and bore were completely clean and free of any debris.  I got to the range and first fired 20 rounds of Adcom from a proven 20 round Colt mag.  Round #16 blew out the primer and it jammed behind the chamber lugs preventing the bolt from closing.  I cleared it and fired the last 4 rounds.  I then broke down the rifle and made sure there was nothing else in there.  I then proceeded to fire 80 rounds of Black Hills 55 grain FMJ and another 20 rounds of thier 55 grain Soft Point.  I used the same mag thru the intire session.  I did not experience a single blown primer or any kind of malfunction.  So that makes 100 rounds of BH without any trouble and 20 ronds of Adcom with 1 blown primer.

I examined the primer after I got home.  I filed the finish down and found that although it has a silver finish, it is brass colored underneath.  It was the same color as the other 2 blown primers that I kept from the last 2 times.  I am now convinced that this batch of Adcom ammo is not going to work in my gun and it is the source of my blown primer troubles.  What a relief!

Quoted: Round #16 blew out the primer and it jammed behind the chamber lugs preventing the bolt from closing.  I cleared it and fired the last 4 rounds.  I then broke down the rifle and made sure there was nothing else in there.  I then proceeded to fire 80 rounds of Black Hills 55 grain FMJ and another 20 rounds of thier 55 grain Soft Point.  I used the same mag thru the intire session.  I did not experience a single blown primer or any kind of malfunction.  So that makes 100 rounds of BH without any trouble and 20 ronds of Adcom with 1 blown primer.

Do you have access to a chronograph to try both the Adcom and Black Hills ammo? Have you measured the freebore in you rifle?

Sorry WT, I dont have access to that equipment.

Quoted: Sorry WT, I dont have access to that equipment.

bummer! That could give us some really good info about the chamber and any differences in MV.

I have a 1000 rounds of the ADCOM and it is the same lot as the other Santino34.  I will take 100 rounds to the range on the 30th when I get my CAV-15 in.  I will report on the ammo when I get back.  I hope it is not the ammo because I was going to keep 500 for SHTF uses.  

I`ve fired a little over 400 rds. of the adco 62 gr stuff now and have only one problem a primer some how got jammed in the bolt on iits way back while ejecting a spent round jammed it up really good too, had to remove the stock to tap bolt forward so I could  remove the upper to get the primer out. Needless to say it was a big pain in the ass, not the kind of thing i`d want to happen in a SHTF situation.   Glad I had two AR`s at the range. -Todd

Quoted: did first you try tapping the muzzle (bore perpendicular to horizon) onto a piece of wood?

No can say that I did, I couldn`t even move the bolt forward using the bolt forward assist. -Todd

Today I fired 120 rounds of my favorite loose gun show XM193 without a single problem or blown primer.  I am now sure that it was only the Adcom blowing the primers.  As far as I can tell, it was not caused by the rifle.

Well, you all had me sort of worried about the adcom until I saw that most of your lots were '99.  I just bought 1k lot # AML02M010-005.  I am going to try it out this weekend and see what happens.

My Colt 20" H-Bar has been a blammin the '99 lot like there's no tomorrow!

Not one single problem.

I bought 5K!


---Woody---

I'm 1,500 rounds in to the 2000 I bought of Adcom(99,03,04) and have not had one problem out of Bushmaster 16"