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Discussion Starter #1
Let me ask this straight out, so I've covered all the possibilities. What would cause a new 336SS 30-30 to back out primers .011”, stick cases and even just blow the heads off of them with factory or normal (for my 336C & XLR) to medium power hand loads ? But still get really good groups with my handloads.

Just want to cover all the options before sending it back.
 

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Have you tried factory shells? Where did you purchase the rifle? And do they have a gunsmith. If all else fails, Paducah Shooters in KY treated me great...
 

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I'm a little slow..

You lost me after the backed out primers?
What do you mean by 'blow the heads off of them'?

If I'm hearing you correctly, it sounds like some serious excessive headspace going on there..

I would send it back for sure!!!
 

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mainecat said:
I'm a little slow..

You lost me after the backed out primers?
What do you mean by 'blow the heads off of them'?

If I'm hearing you correctly, it sounds like some serious excessive headspace going on there..

I would send it back for sure!!!
I agree definatley dont shoot it anymore and send it back. do they not test fire these anymore? ::)
 

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Discussion Starter #5


I use 35 grs of 748 behind a 150gr Rem in the 336C with no problem. With 34grains, I can cover the group with a dime at 50yds with this new gun, but I have to go down to 33.8 to prevent backed out primers and stuck cases. I thought I'd try varget at 33.3 up to 34.0. This was the first shot of the day with brass that was on it's 2nd reload, this one didn't have any resistance on extraction. It was like the head was compleatly seperated on fireing. The other two rounds had backed out primers and bulging cases, so I stoped there. The boxs of (factory) 150 Rems & 170 Wins that I used first a few weeks ago had some backed out primers too.

If someone test fired it or even "cycled" it they would have found out that the lever was never smoothed on the inside. I found that out the first time I cycled it and thought I had sliced the back of my fingers. The clerk suggested I send it back, but after waiting 3 months for them to start shipping them from the new factory I figured I'd just smooth it out myself.

BTW, Rear sight was only half way on when I took it out of the box. No way anybody checked this rifle before it left the factory.
 

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Wow I cant believe they would send out a rifle with such a headspace problem(I'm guessing). Someone on here posted they were sending out "kit" rifles now and I believe they may have been right.
 

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Either your reloads are dangerously too hot or it's a headspace issue with the rifle..

I would try narrowing it down first..

I'm not fimiliar with your reloads, but I will say that just because they're ok to use in one rifle doesn't mean it's safe to use in another..
It also sounds like you're working your way down rather than starting low then working your way up..

Backed out primers are also a sign of low pressure loads..
This might be the case with the factory loads..

Before sending back the rifle, check the headspace, buy or make yourself a go nogo headspace gauge or have a smith check it..
 

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The head spacing might be the problem. Have you checked your scale for accuracy? Maybe your putting in too much powder. Usually the primers are flattened out when over pressured.
 

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In light of the catastrophic case failure pictured above, I would think that the brass that held together would show pressure ring signs in the area that the subject case separated. If you have chamber issues, both the factory and the twice loaded brass should show similar pressure markings and indicators.

I also would be interested in learning what your OAL measurements for this rifle indicated. How far are you jumping the bullet to the rifling? CP.
 

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There is something seriously wrong with those reloads.
 

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Bad handloads can not cause backed out primers. If you're getting backed out primers on a firearm that has proper headspace, or the headspace is not a tinge out of spec, it means that the ammunition is not at the optimum operating pressure for the brass/gun, and the brass can not expand to the chambers full dimensions. What happens is when you fire a gun, the primer backs out first to fill in the gap between the bolt face and the head of the case, and then the rest of the brass expands back taking up that slack created by the primer backing out. If the rounds are under pressured then the brass can not expand to take up that slack. If you're getting backed out primers and getting case head separations on a RIMMED case, you have SERIOUS headspace issues!
 

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Discussion Starter #12
34.5 of Varget is Hogdon's max, my others work best right there.
I started with 33.3 and blew the head off of one and stuck the other two.
36 is max for 748, but I'm popping primers & sticking cases over 33.5. Very very accurate though !
Also backed out most primers on a box of factory 150 & 170's with signs of pressure.

I've cleaned it with Hoppes 9, Hoppes Elite Copper Terminator, Shooters Choice and even Gunslick Foaming Bore Cleaner.

I wonder if the barrel may be bored slightly undersized. I don't have any way to "slug" it though.
 

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Excessive headspace. Read my post up there. If this is happening with factory ammunnition and you're getting excessive pressure signs and backed out primers, it is excessive headspace. A bore a thousanths under what it should be, say it should be .308 in the grooves, but its .307 will not be enough to raise your pressures to dangerous levels even with factory ammunition. Do not put your life, fingers, and face at danger. Just send it back and get the problem rectified.
 

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Just thinking out loud, well sort of. A 30-30 headspaces on the rim, does a 30-30 headspace gauge also check the shoulder depth or just the rim thickness? I went to the Midway site and they sell a Forster no-go that only checks the rim. Your chamber might be too deep causing the head seperation.
 

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A 3030 headspaces on the rim and a primer backing out that much means the case is sticking in the chamber normally and the pressure is pushing the primer out at least the amount the headspace is out of spec.

You should be able to SEE if the 3030 case is too low by dropping a EMPTY resized case into the chamber and LOOKING at it. You should be able to see if the case has dropped below the level of the barrel face...the case rim should be even and flush with the extractor groove/barrel face and NOT below them.

OR the chamber was cut TOO deep allowing the case shoulder to move forward a little before it locks to the chamber walls THEN the rear of the case moves backward stretching beyond the metals fracture limit and separating...

Sounds like the barrel threads weren't registered correctly prior to cutting the hood and extractor notch or the bolt is totally screwed up.

I could be a combination of all the above and MORE.

In ANY EVENT...STOP SHOOTING IT AND SEND IT BACK.

The 3030 case isn't all that thick or strong and it doesn't take much out of spec screw ups to cause problems...like you're having.

How many reloads on that case anyway?? It doesn't look all that new.

There are ways to solve your problem, but I need a lot more info on your reloading practices and what length you seated the bullet to before I will suggest any.

LUCK
 

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186 Tmanbuckhunter said:
Excessive headspace. Read my post up there. If this is happening with factory ammunnition and you're getting excessive pressure signs and backed out primers, it is excessive headspace. A bore a thousanths under what it should be, say it should be .308 in the grooves, but its .307 will not be enough to raise your pressures to dangerous levels even with factory ammunition. Do not put your life, fingers, and face at danger. Just send it back and get the problem rectified.
Don't take any chances. Send it back! Body parts are hard to repair and cannot be replaced.
 

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Discussion Starter #18
For the heck of it and because there's nothing good on tv tonight, I thought I'd take it apart and pull out my WW trigger before sending it out. I've noticed that unlike my other 30-30's the bolt sticks out a little in the back. About .055", maybe a little bit more. So I removed the locking block and was able to push the bolt in till it's flush with the back. While holding it in by hand, I pushed the locking block up into place and dang if the bolt didn't push back out slightly.
 

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You should have about 0.070" plus or minus a bit that the bolt moves if it is pushed all the way up against the barrel face without the lever removed...that is the amount of "headspace" or room for the case rim...the bolt doesn't rest against the barrel face when it is fully closed, it rests at the point "the headspace distance" AWAY from the barrel face. That is why the breech bolt moves the bolt back' slightly". At rest closed the breech bolt holds the bolt in place at "the headspace distance".

You will also have a bit of slop in the finger lever before it starts moving the bolt backwards OR forwards.

Somewhere in the build process for that rifle all the tolerance variation stacked the wrong way...it happens in ANY manufacturing process. You might have gotten a "Friday"...hurry up, it's TGIF or "Monday"...still nursing a hangover...rifle.

LUCK
 

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Discussion Starter #20
Well it's heading out (with some sample cases) to get checked. Folks at the store are saying the same thing, looks like chamber's out of spec !
 
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