High pressure signs in a TC Contender

[Bigeasy]

A couple of days ago, I bought a used TC Contender, old style frame (1974) with a 14 inch factory .223 heavy barrel.  Figured it might make a fun woodchuck gun this summer in the fields of PA.  Anyway, I got a chance to fire it for the first time today.  I only brought some old 55 grain FMJ UltraMax reloads to try.  I am not sure what the load is in them, but they have been 100% reliable and accurate in several of my AR's and heavy barrel bolt actions.

After firing, I noted it was hard to open the action, but the empty casings slid easily out of the chamber.  Upon closer inspection, I noticed the center of the primers (where the firing pin hits) was raised above the surface of the rest of the primer.  I believe it was these raised portions that were causing the difficulty in opening the action as they were dragging across the breach face as the gun was opened.  After 4 shots, with 3 of 4 primers showing this condition, I stopped firing.

High pressure might be a first guess, but these loads have been fine in half a dozen other rifles I own.  Headspace issue?, over size firing pin hole, allowing primer flow?, primers too soft for this particular gun?.  I am not familiar with the Contender, so I was wondering if anyone had any suggestions, or similar problems with these guns, or any thing particular to the Contender I should be aware of.  I have not yet had a chance to do any real digging yet to figure out the problem.  Thanks

Larry

[spruce]

Just a thought here.

If you developed the loads in one of your AR's (with a 5.56mm chamber) they may be on the warm side for a .223 chamber.

Maybe not hot enough to show any apparent pressure signs in your bolt guns, but perhaps warm enough to "spring" the less strong Contender action?

I'd probably try a few rounds of factory .223 and see what they look like.

[Mikey]

Big:  those be pressure signs alright, no bout adoubt it, especially that primer.

Spruce:  I thought it was the other way around, that the 223 is a higher pressure round than the 5.56, as the 308 is a higher pressure round than the 7.62x51.

Big:  one thing I noticed in your pictures is that it appears you are/were using mil-surp brass, as the crosshairs within a circle on the case head indicate.  This brass is normally/usually thicker at the web and handloads to commercially rated pressures in mil-surp/mil-spec brass often give you higher pressure signs as the brass is thicker and there is less room to expand, so to speak, except out both ends.  

I think I remember reading somewhere that to avoid the higher pressure signs when using mil-surp brass you need to reduce your powder charge by a grain or two - I don't know what that will do to the velocity or accuracy of the round when reloaded this way but your Contender is a finely made handgun with absolute minimal tolerances and what works in one rifle (especially with a semi-auto military chamber) may not work in the Contender.

I think your problem stems from the use of mil-spec/mil-surp brass.  If you are going to continue to use that type of brass for reloading you may wish to resduce your powder charge by a bit (one grain or two).  If I recall correctly, and that's one big 'if', I believe that amount of powder reduction does not affect the round much at all.  HTH.
 

[Lloyd Smale]

Allmost looks more to me like the primers were backing out. there not really flattened like a high pressure load will do. My guess is the company doing the reloading used some brass that was a bit used and had loose primer pockets or when they swadged the pockets they got a bit carried away.

[coyotejoe]

I'm with Lloyd in that it doesn't look like primer flow from high pressure. My guess it that your new/used Contender has a very light hammer fall and is bouncing away from the firing pin. With nothing to hold the pin forward a soft primer cup will flow back into the pin hole. If you went to loads with a harder primer it probably would misfire. I'd suggest you replace the hammer spring and try again.

[Blackhawker]

Bigeasy;
I've been through this over and over and know EXACTLY what you're talking about with the primer material flattening and almost creeping (forming) back into the hole in which your firing pin passes, hence making it hard to near impossible to open the action.  I was working up some loads for my 38-55 the other day and finally got to some hot enough loads in which the primers started cratering and forming back into and around the firing pin.  In the case of what I had the other day, it was reaching too high of pressures that caused the problem.  However, about two years ago I ran across a bad batch of CCI primers.  In fact, some of the primers actually blew holes right out the back side.  I posted a thread on this matter and I'll post the link if I can find it so you can see the details.

To make a long story short of it, I was chasing my tail over this for about a year, blaming powders, inaccurate powder measures, a bad fitting T/C frame or barrel chamber, etc for the overpressures that caused primer deformations and failures.  There were times in which the primer material formed around my firing pin and literally grasped onto the firing pin, making it impossible to open the action.  If this happens, by the way, draw the hammer back and give it a second drop on the pin, that'll shake it loose of the jam-up.
.....anyway, after a year or so I decided to try some factory loads.  NO PRIMER DEFORMATION!  Then I tried some of my loads right after and got a jammed up action and deformed primers.  So I went home and loaded up some ammo with Federal primers.  The next time out I shot the CCI primed ammo, the Federal primed ammo and some factory ammo.  Guess what happened?  The only jam ups and primers that deformed or cratered were the CCI's.  
Lesson learned:  I don't load with CCI primers on my .223 T/C any longer.

Again, if I find the link of my post with this "saga", I'll post it.


Chris

[Blackhawker]

OK, I found the link.  It was really someone else's link referring to misfires in a T/C.  Anyway, there may be some other useful info on the thread to you and other T/C users that I came across as far as appearances of overpressures etc.  Sometimes, as you'll see in what I posted about my 30-30, bullet seating depth can cause problems too.  Anyway, it's around post #18 where I describe the resolution of the primer problem with the 223.

Hope this info may be helpful to you Bigeasy.

Link:
http://www.gboreloaded.com/forums/index.php/topic,183814.msg1098934663.html#msg1098934663

[spruce]

Mikey - The specs for the 5.56mm chamber are different than the specs for the .223 chamber.  The most significant difference as far as pressures are concerned is that the 5.56 has a longer throat than the civilian .223 chamber.

I believe it was around 1979 or 1980 when SAAMI first cautioned shooters that firing 5.56mm ammo in a civilian .223 chamber could cause higher pressures.

One caution I know of concerning .308/7.62 NATO is that the Spanish used a lower pressure loading in their CETME assault rifle and their converted M93 Mausers and it's not recommended that .308 or 7.62 NATO rounds are fired in these.

[Bigeasy]

OK, an update-

The UltraMax ammo is part of a batch from the early 1990's.  I acquired about 12 cases of it after my agency switched from reloaded ammo to factory new for practice due to liability reasons.  Always been good plinking ammo, but I do not know what primers are used.

Anyway, I hit the range today with NATO green tip, Federal Fusion, and Winchester white box ammo.  Everything shot fine, without the primer issues I was experiencing with the UltraMax stuff.  The Winchester FMJ stuff was grouping right at 1 inch at 100 yards from the bench, so I guess this gun is going to be a keeper.  Now I just have to work up a good load or two.

The last time I had a primer issue like this was using CCI primers in a .357 mag with max loads.  They would flow into the firing pin hole, but Federal and Remington primers would not using the same loads.

Thanks for the quick responses from everyone..

Larry

[JMeadows51]

I had an issue with my 221 Fireball. It was very hard to open and the primers were flattened out. This was with Remington factory ammo and my reloads.
This was in the early 80’s so I don’t know what load I had in them. I didn’t shoot it for many years because of this.
One day talking about this problem to a co-worker he told me to check the case length. I did that and found them to be too long.
The neck of the casing was being squeezed by the rifling and holding the bullet into the casing and it was causing excessive pressure buildup. I didn’t have any more problems after I started trimming my cases.
I don't know if this is the same problem or not.
just my .02

[Rutin2tin]

FWIW: The older Contenders are routinely difficult to open when firing potent cartridges.
That's why T/C changed over to the easy open option back around 1981. 
BTW: I have a 1979 .223 Super14, and I hear ya!

I'm not able examine Your mtys, so I'll reserve any comments on cartridge pressure.

[qwikrick]

I had primers do the same thing in my 223 contender.
first time I went to shoot it I just grabbed some rounds that I use in my mini 14 ( 55gr  norinco & some mil-surp ).
the thing was super hard to open & I thought that something was wrong with the barrel couse it was the only one that ever had this problem.
next time I shot it I got a 20 round box of 55gr PMC bronze and the thing worked perfect.

just my 2 cents.