More 6.8mm SPC mis-firing

[Hopalong7]

     We've talked about this on several occasions, but the problem just won't go away.  Summer a year ago somebody started a thread about this subject and I related an experience my huntin' buddy was having at the time.  He had bought two G-2 carbines with the 23" G-2 barrel in 6.8mm SPC for his grandsons to learn to deer hunt.  He bought a couple of boxes of Hornady 110gr ammo and took them to the range.  Miss-fires occured....one carbine pretty bad...one occasionally.  He got on the horn with both Hornady and TC.  Both acknowledged there had been some problems...TC suggested switching ammo(they suggested Hornady...opps),  Hornady said they had made some changes and sent new ammo.  They tried a few and they fired...maybe the problem is fixed.  Nope....fast forward one deer season and pretty much the same thing occurs.  Back on the horn with TC.  This time he gets a knowledgeable tech rep who understands the deal and immediately offers to send a bunch of new parts if he could get them installed.  My buddy replies that would be no problem because he has this buddy who is a total Contender looney and can fix anything(volunteering you know who).  He gets the parts, gathers up the rifles and comes to my cave.  Now I have exactly zero G-2's and all I know about them is that inside they aren't anything like a real Contender.
    First we checked the breech/barrel gap.....007" on both rifles.  Next we remove the barrels and extractors and checked headspacing on several different boxes of the Hornady ammo.  First rifle chambers up exactly flush with the end of the barrel, the second actually protrudes ever so slightly. I don't have a good intrument to measure this with but when I put a little steel ruler across the end of the brass I could get about .002" between ruler and barrel.  From a headspacing veiwpoint, both should have fired IMO.  All brass showed a fairly light primer indent.  We installed new extractor springs and per the tech's instructions, bent them "forward" meaning to put a bigger curve in the little spring in order for more presure upward by the extractor.  Next we installed new firing pins, springs and bushing.  Then we installed a new hammer spring with a supplied washer to put over the strut before the sping(effectively pre-loading the spring slightly).  The washer, according to the rep was not a TC deal but was his own little fix.  It was 1/16" or so thick.  Reassembled everything and it went Bang!!! Several times....a twenty round box(total) for both rifles.  The primer hits were noticeably better.  Maybe it's cured...only a  lot of time and shootin' will tell.  I was, along with Hornady, ready to pass it off as a headspace problem totally, but maybe not. 
     
 

[Preacherman]

My experience with the 6.8 misfires in a TC carbine barrel and a 12" MGM has all came down to not having it shut completly My is an Contender not a G2 make sure to close it hard and no hammer spur hope this helps.
Preacherman
ACTS 10:13

[DEACONLLB]

I have had the same problem with 6.8 in the Encore with ssa ammo first 8 out of box only 5 fired all had a good dent in primmer so is this an on  going problem with the 6.8 cal? I compaired the dents in my 7-30 waters barrel and the dent in 6.8 seem to be deeper.
Deaconllb

[243dave]

Like preacherman said take off the hammer extension first(if you have it on,weak hammer spring). 2nd-try different ammo. 3rd-rule out improper headspacing. 4th-replace the hammer spring. I wonder if some ammo makers use a thicker primer cup for the 6.8 like they do for 223 ammo made for a AR-15. There are probably some more things to try but thats where I'd start.  Dave

[Hopalong7]

     Preacher,  Yep, I agree, a lot of Contender problems are simply not closing the door firmly, although in the G-2, from what little I've handled them, it does not seem to be as crucial.  Anyway, in this case, it was the first thing I suggested, and the hammer extension was #2.  Neither seemed to make any difference.
     DEACONLLB, The primer strikes in both carbines was not heavy, but appeared to me that it should have been sufficient to fire the round.  The primer strikes WERE noticeably heavier after the new parts were installed and NO mis-fires occured.  Second hits on the mis-fired rounds produced nothing, even after the new parts were installed.
     243dave,  You pretty much nailed our procedure A-Z.  It "seems" that the hammer spring and maybe the washer was the answer, if, indeed we have cured the problem.
     Conclusion(so far)- It seems to me to be a rifle problem and not caliber or ammo specific.  OK....so why is it the 6.8 more than others
     Thanks for the input, guys.  Walt

[243dave]

I do wonder if some of the ammo companies use a harder primer cup in the 6.8 ammo. If I had a 6.8 and had problems after I ruled out head space problems, I'd install a new after-market(not factory but a stronger one) hammer spring.  Dave

[Hopalong7]

      243dave,  I think basically, that's what the TC rep was telling us with the little washer trick.  Obvisously he couldn't reccomend an after market spring so he came up with the washer trick and did say that it was not a "TC deal".

[DEACONLLB]

I have no hammer extension and this frame shot well with other barrels but it could be a weak hammer spring but I lean to bad ammo. Will do some more tests.
Deaconllb

[Lanny]

I have a 14" contender barrel ....6.8 rem that I reload for and have never had a misfire with this round
I`ll have to agree with the hard primers in commercial ammunition.....Just my opinion........

[JW/OK]

It is my understanding that SSA manufacturers 6.8 ammo with two different primers. You don't want the commercial primers for Contenders.
 A friend of mine ordered 6.8 Ammo from them that had the hard primers and they wouldn't fire in my G2. He sent them back and they sent replacements and we had no problems with the second batch of ammo.

[valvesinmyhead]

I use factory Hornady 110gr ammo in my T/C barreled Encore Prohunter and have NO misfires in 5-600 rounds. Two WT Does , 1 crow and, a few prairie doggies.

[DEACONLLB]

I did some more testing today, I removed the 6.8 barrel from the frame and put it on a new pro hunter first 2 fired then the one that had a big dent would not, shot 2more and they worked tried the one that snapped 4 times and would not fire so it has to be the ammo I put another barrel on the frame that the 6.8 was on to start with,the one where I first noticed the problem and it shot every time so I think it best to go with a name brand like winchester or remington and not something like SSA. The dent in the one that would not fire is way deeper than any of my other rounds and still will not go off.

Deaconllb