94 headspace problem

[walks with gun]

A few years ago I inherited my grandads old .32win 94 rifle. I've taken a few deer with it in the last three years but noticed the primers are backing out a little. What's considerd excessive headspacing. I can't afford to put alot of money in it right now but hate to retire it. Only factory loads through it and it shoots great.

[walks with gun]

I probably should of said my .32 is an old nickle steel 94 made in 1907.

[J Miller]

I don't know the exact head space specs for a 94 but in recent years here on the forum there's been quite a few people mention primers backing out with factory ammo. I've had it happen as well and don't worry about it.
What's happening is when you fire the cartridge the primer's own pressure causes it to back out of the case, then as the pressures build up the case will back up and re-seat the primer. If the pressure is low it won't reseat the primer and you have the condition you described.

I'd take it to a gunsmith to verify the head space. There is a source of over sized locking bolts for the pre-64s but I can't remember who it is right now.

Joe

[earlmck]

If you are only going to use factory ammo I wouldn't worry about a little excess headspace in this moderate-pressure round. All the excess headspace is going to do is reduce the expected brass life a bit, and that won't bother you if you don't reload it.

However, if you plan on reloading, don't want to spend $ getting it fixed right, I'd do my loading so I ended up headspaced on the shoulder rather than the rim. (I think you have enough shoulder to do that OK). To do this I'd prefer to start with new brass, make a normal load except that I'd seat the bullet a little too long so it jammed in the rifling and was hard to chamber. After this first shot, where it is essentially "headspaced" on the bullet, I'd load normally to standard case length, but make sure never to full-length size so completely that I set the shoulder back.

Anyway, that's how el-cheapskate Earl would do things. Yeah, I have an old m92 25-20 that gets this treatment, and a 700 Remington 30-06 also. Someday I'll probably get 'em taken care of when I run out of better places to put the $.

[Griff]

The Winchester mdl 94 headspaces on the cartridge rim. So it's a really simple operation to check... get yourself some of that "Plasti-gage" used in the auto industry for measuring crank and connecting rod clearances. Put on the back of the case, and close the bolt. Compare the width of the crushed plastic tape against the package it comes in... presto-chango, your headspace. Here's what I understand acceptable is; .001-.003, great; .003-.005, ok, .005-.007, acceptable; over .007, might need work, depending on how much over.

The headspace on the Winchester 94 is adjusted by the thickness of the locking lug face. Some are marked with the thickness over standard on the back side. I have one that's .005... and have one gun that I could possibly use it in.

Another culprit can be rim thickness. Thinner than spec rims can give indications of excessive headspace.

However, if your rifle measures in the .002-.007 range you could still get primers backing out. And not due to excessive headspace... but rather due to LOW pressure. Your cartridge is slightly smaller than the chamber, when the firing pin moves forward it may just be pushing the cartridge forward enough that upon combustion, the case swells enough to hold the case in place, and leaves space for the primer to back out, as the cartridge isn't hot enough to push back against the bolt face and flatten the primer.

Here're the SAAMI specs for case and chamber:

30-30Dimensions.JPG

Hope that helps.

[Chuck 100 yd]

Griff said it all.Joe said it too,so I don`t have to.
And age has nothing to do with it. A new .30-30 will do the same thing and the head space can be right in spec.

I adjust my dies to head space on the shoulder like earlmck
said.

[Nath]

Don't worry about it It's when the primers start falling out the case you got a problem

nath.

[Pisgah]

Primers backing out is almost always a low-pressure sign and not an excess-headspace sign. To check to see if it could be part of excess headspace, examine for incipient case head separation. Straighten a paperclip and make a small right-angle bend on one end. Insert the "hook" end in to a fired case all the way to the end, then feel for a "catch" in the case wall just above the bottom, indicating an incipient crack in the brass. If you don't feel it, the headspace is OK. If you do feel it, the problem can be addressed (if you handload) by neck-sizing only.

[sullkat]

Not to high-jack this thread but I have the same issue, I measured the primer backing out .011, I put a feeler gage .012 between the lockblock and the bolt and it moved the bolt forward to snug it up.
Now my question is the blocks are sold in .005-.010 and .015 should I go with .005 or go ahead and get .010?
TIA

[Hobie]

Since your question has been answered let me congratulate you on a fine keepsake!

[KCSO]

IF the headspce is really off and IF yu don't want to put a lot into a fix here is a cheap solution that has worked well here.

Pull the barrel and solder a piece of shim stock to the breech face to correct the headspace and then re cut the extractor groove. I have one that has went over 1000 rounds that way with no problems. Otherwise you turn off 1 thread and re cut the chamber.

[pokey]

Since your question has been answered let me congratulate you on a fine keepsake!

me too.

[JBledsoe]

.

Me three.

[walks with gun]

Thanks guy's, next trip to town I'll grab some gauge material and check it out. I have plenty of other rifles to hunt with but this was grandads and I still like packin it around. My 16 year old daughter thinks it's the coolest cartridge rifle in the safe.

[earlmck]

Don't worry about it It's when the primers start falling out the case you got a problem

nath.

I'm pretty close to Nath's opinion. Many of the old levers have a little excess headspace, but it isn't a problem if you are using factory ammo and aren't worried about getting a bunch of reloads out of your case. The fact that the primer pooches out visibly shows that the case did not do very much of the type stretching back in the head area that can produce the head-separations.

And if you want a quick and dirty way to see how much excess headspace you have, take a new case, seat a used primer about half-way in so it still pooches out a ways, and chamber this baby. Case length guage will show the difference in length measured to the cartridge base and to the primer base. On these rifles with quite a bit of excess (where you aren't trying to detect the difference between .003 and .005) this gets you a pretty good idea.

[Malamute]

If you do the gauge thing, check the thickness of the rim of the shell you use. You can't assume the ammo is exacly on spec (and there is a range of size allowed in the spec), which may be as much of what you're seeing as anything. My local gunsmith mentioned that most factory ammo was NOT very tight as far as headspace, most was loose, and most chambers were a bit lose in various dimensions.

I've gone thru this on a couple rifles, and finally decided that unless it was grossly out of spec, it simply wasnt an issue. One thing the makes it more noticable, the ejectors on Winchester 94's hold the shell forward in the chamber, and the rounds arent very high pressure for the most part, meaning the shell is doing exactly what it's supposed to, holding the pressure IN the chamber, not making bolt thrust. The shell is doing this well enough that the shell isnt even seating back against the bolt face and reseating the primer, as happens in most rifle cartridges. Think about that for a moment, the bolt thrust isnt overcoming the ejector spring pressure well enough to reseat the primer. There will ALWAYS be some clearance between the chamber and bolt face that's what "headspace" is. Room for the cartridge to fit in the chamber. There is an range of allowable size, in both chamber and cartridge, there simply has to be for the cartridge to fit in the chamber and for it it to function. Your gun can be well within spec, and still have enough room for the primer to back out a little, as the ammo isnt perfect as to headspace dimensions (rim thickness in the case of rimmed shells). It just isnt practical to make "perfect" ammo or guns, hence the size range of both thats allowed in the industry, as well as the fudge factor that seems to have creeped in over time on ammo. Check factory ammo with a cartridge headspace gauge and you'll know what I mean. Much of it is a bit loose. My 'smith showed me on various cartridges, it was quite interesting. He said most reloading dies also sized a bit more than required, all meaning to make the ammo work in the variety if guns chambers, but not neccesarily the best for utmost accuracy. The reason many fiddle with their dies to get best results, and still be entirely reliable.