Primers backing out, .30/30 rifle

Marlin and Winchester lever actions are notorious for excessive sized chambers.

Is there a large expansion ring around the spent cartridge

Is the rifle new? If so, take it back to where you bought it from.

Is it accurate? Probably not.

The good news is, Marlins are quite strong and will usually work well under this condition and even shoot acceptably well.

If you're not going to handload and you're satisfied with its accuracy and the primers aren't pierced, don't worry about it.

By the way, Marlin lever actions, chambered in 30-30 Win, headspace on the rim so the only feasible cure for it, is to have the barrel set back and rechambered.

bearhunter
 
The majority of chambers are within acceptable headspace specifications but the majority of brass is manufactured under size and this is probably why you are experiencing what you are.

It is fairly normal.
 
guntech, you're probably right about the majority of chambers being within spec. I do feel they are on the max side of spec though. As for the ammunition being on the small side of spec you're probably correct on that as well. Not a great situation overall.

Andy you're absolutely correct about low pressure loads, but fat tony says he's useing factory ammunition, so I doubt that's the problem.

bearhunter
 
bearhunter said:
guntech, you're probably right about the majority of chambers being within spec. I do feel they are on the max side of spec though. As for the ammunition being on the small side of spec you're probably correct on that as well. Not a great situation overall.


bearhunter
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Exactly... the .22 Hornet is the worst example of this... the chambers pretty well all are within spec but even a custom chamber with minimum dimensions uses brass that is considerably under size and it always looks bulged. I have never seen .22 Hornet brass made to the correct specs.
 
How far backed out? If it's from a lower pressure load, it could simply be that the brass hasn't expanded lengthwise enough to re-seat the primers and conform to the chamber shape. Better question might be "are they loose when reprimed?" that definitely shows over pressuring. Most overdone loads in any of my levers tend to (if I didn't notice on firing them) show sticky extraction, but I've never yet seen a primer backed out, loose or worse blown out. They headspace off the rim and a lot of new unfired brass measures pretty short. Combined with generous chambering, as noted previously, some ammo simply has a maximum amount of space to fill when fired. Found that using a Lee factory crimp die and applying a heavy crimp really made hunting ammo behave a whole lot better both in accuracy and consistency in feeding not to mention probably a lot safer - no chance of bullet movement from recoil. And believe me, my .45-70 has a whole lot of that!
 
This has nothing to do with handloads. Thanks for the reply though. You say Lee Factory Crimp dies? is that a neck - sizing only die? - You see i bought a set up, it's RCBS .30/30 dies, that full length resize, my plan to get into reloading is a work in progress, I intend to get one of the Mastercraft benches and modify it slightly, Maybe I should get some of the neck sizing only dies, instead. :confused:

the federal site stated that the loads I was using have a mv of 2200 fps; in some of my reloading books, the spiciest loads for that caliber and with a 170 grain bullet are hovering around 2300 fps, so that's pretty much a full power load, as for the breech pressure that's a pretty good question I heard the .30/30 generates around 37-38,000 psi.
 
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Factory loads for the 30-30 tend to be a bit "soft" in my experience. I suspect that the Factories do this in deference to the many very old, less robust rifles chambered for this round. The backed out primer is almost certainly a sign of low pressure loads [factory or otherwise] and should disappear once you load to decent pressure levels. FWIW, I chronographed a whole slew of 170 grain loads for the 30-30, and instead of the 2200 fps advertised, most were in the 2015-2035 area. Pretty mild, but still doing the job after all these years. Regards, Eagleye.
 
The dimension that matters is that between the head of the cartridge case and the face of the bolt.
SAAMI spec. is maximum 0.006" IIRC.
If it's less than that, you will have to live with it or find a gunsmith that is willing to reduce it.

I do not believe that this excess headspace has no effect on accuracy.

You can find how much it actually is by inserting a primer in an otherwise empty case so that it stands proud by about 0.015" or enough that you can get it out of the shellholder, chamber it & close the bolt, then carefully remove it and measure the difference between the case length with and without primer.
 
fat tony said:
This has nothing to do with handloads. Thanks for the reply though. You say Lee Factory Crimp dies? is that a neck - sizing only die? - You see i bought a set up, it's RCBS .30/30 dies, that full length resize, my plan to get into reloading is a work in progress, I intend to get one of the Mastercraft benches and modify it slightly, Maybe I should get some of the neck sizing only dies, instead. :confused:

the federal site stated that the loads I was using have a mv of 2200 fps; in some of my reloading books, the spiciest loads for that caliber and with a 170 grain bullet are hovering around 2300 fps, so that's pretty much a full power load, as for the breech pressure that's a pretty good question I heard the .30/30 generates around 37-38,000 psi.
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Lee Factory Crimp die can be bought separately for pretty well any caliber and it does come with some of their die sets - the ones in the red rectangular box. I've never bought those sets so wound up buying the FCD by itself - they run around $12-$14. Nice thing about them is you don't need a cannelured bullet and trim length isn't very important - they'll make their own cannelure. Danger is in overcrimping - you'll wreck the brass. It's simply a split collet that you set the length for, lock it then feed your cartridges thru and crimp with their recommended 25# or so of weight on the handle. The Deluxe Lee die sets come with both a F/L resizing die and a neck sizing only die - I like the "dead center" bullet seating die. I've never measured any bottleneck finished cartridge loaded with their deluxe set that measured more than .001 runout and that's good enough for bench rest, let alone hunting ammo. Using your own cases, shot in your gun only, it's not hard to partial size with any decent dies - I do it for my 7mm and 300WM all the time to get rid of all the "slop" - headspacing off the belt requires a precise case fit or you get no life out of the brass and since starting to use an RCBS case gauge setup, I've seen how fast the case head can thin out ahead of the belt - sometimes 3 firings is pushing it. The above comments about real world velocities and man'f claims is very true - especially when it comes to lever gun ammo. Hornady's claimed velocities for their LeverEvolution ammo are real interesting as wella s a bit deceptive - they leave it up to you to notice that their compared velocities neglect to mention that they generally are using a lighter bullet than standard and Lord only know what barrel length they used. We've seen as much as 250 fps less than claimed in 22" barrels!
 
SAME here..marlin 336 30-30..factory and hand loads. Had it checked head space on older Marlin. Rifle will shoot with 170 grain into a coffee cup at at 100 yards wirh 4 power scope. Has not hurt accuracy.
 
Every 30-30 I have ever owned and 95% of 30-30 brass I find at the range has backed out primers due to the low pressure. The Case is not forced back hard enough against the bolt face to overcome the outward thrust that "sticks" it against the chamber walls.


Wasn't it a 30-30 AI that Acley fired out of a M94 with no locking lug at all and the bolt never moved back?
 
Republic of Alberta said:
Every 30-30 I have ever owned and 95% of 30-30 brass I find at the range has backed out primers due to the low pressure. The Case is not forced back hard enough against the bolt face to overcome the outward thrust that "sticks" it against the chamber walls.
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While I can't think of any way of proving it, I don't think that cases move or stretch lengthwise. Reason is that before the gunsmith adjusted for headspace, all my cases showed backed out primers regardless of how stiff the loads were. Some cratered when finding a maximum powder charge. Some factory cartridges.
Just plain logic tells us that in order to back out, the primer must first have some space to back out into. So this is the excess headspace.

Beware the poster's standards, for instance Buck45 is happy with a coffee cup sized group, while I want all the holes within 1/2" center-to-center. Gunsmith reducing headspace did have a big effect on improving accuracy. $73 at Gunco in Ottawa.
 
As has been noted, most 30/30 rifles will back the primer out with factory loads. Pressures are low, there is always some headspace (necessary for function with a rimmed case), and the the case sticks to the chamber walls sufficiently well to allow the primer to protrude.
The difference between a "go" gauge and a "no go" for a rimmed cartridge is .003" (go= .063 no go= .066). It is no unmcommon to find brass with a rim thickness well under .060" so there is a possibility of even .010 headspace even when things are within spec.
If handloading, it is possible to negate this by headspacing on the shoulder if you can once get the brass to fireform properly (advanced techniques which I will not go into here). Once the brass fits the chamber, headspace will remain fine as long as pressures are sufficient. The drawback is, pressure sufficient to maintain case dimensions are high enough that case stretching can start to rear it's ugly head in the rear locking lever guns.
The bottom line? If you are shooting factory loads, don't worry about it. If you are reloading, work toward headspacing on the shoulder.
A 30/30 AI (which I consider to be kind of a neat cartridge BTW) has a better shoulder for headspace purposes and will approximate 300 Savage ballistics if you are into reloading. Die costs are the only downside. Regards, Bill.
 
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