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So, picked up a Win 94 in 32WS, and bought an RCBS 32-170-FN mold for it. Loaded ten rounds using ~8.3gr Unique and WLR primers in brand new Hornady brass. Chrono showed 1264 fps avg ES 40 SD 15. Question about the primer, the strike looked deep and hard, and the primer was backed out of the case enough to easily see and feel. I'd think a hot load, but it seems like a pretty mild load of Unique. Any suggestions as to why the primer looks like it does?
If it were a rimless case, I'd say that:
1:You have excessive headspace
2: Your pressure was not high enough to obturate the case and it is getting pushed forward by pressure in the primer pocket, thus collapsing the case's shoulder to some extent and thus shrinking the case.
3: But, and this a big BUT, your rimed 32 Special case does not suffer from that malady (either squib loads or full power loads) and the backed out primers indicate excessive head space in your rifle.
While this is an issue, you can work around it by fire forming your cases to the chamber and head spacing on the case's shoulder as if it were a rimless cartridge. I do this in two Marlin 1903 rifles in calibre 30/30 and it works fine.
PS. The fact that your case was pushed forward and then not returned by chamber pressure would seem to indicate you are shooting a fairly light load. Increased pressure will overcome the high pressure in your primer pocket and push the case back against the bolt, but the fact still remains that your rifle is suffering from excessive headspace as it really shouldn't be forward like that in the chamber. It's good that you found out now and that now you can take steps in your reloading technique to get around it.
try a neck size die only but you may not have problem after they are once fired . New brass is just that new ,and many times are not uniform
Thanks, that does make sense. Had time after dinner to take a few measurements. New cases were 1.470" from the datum, a few fired were 1.485", 1.486", 1.488". Looking at SAAMI the specs are 1.497"-.015. Does it appear the new cases were sized too short? The fired cases are right at the minimum spec. Does it still look like too much head space, or were my cases just too small to begin?
This phenomenon has been covered on this forum many times. Sounds fairly normal and probably not indicating excessive headspace.
Lighter charge- lower pressure. The primer fires and backs out of the primer pocket and pushes the cartridge forward to its headspace limit, the ignited charge builds pressure, the case wall temporarily sticks to the sides of the chamber, the pressure doesn't exceed the tensile strength of the case, the case stays forward, the pressure drops, the primer remains slightly popped out.
Heavier charge- higher pressure. The primer fires and backs out of the primer pocket and pushes the cartridge forward to its headspace limit, the ignited charge builds pressure, the case wall temporarily sticks to the sides of the chamber, the pressure does exceed the tensile strength of the case, the case stretches rearward and the case head is pushed against the bolt face, the pressure drops, the primer has been fully re-seated.
Thanks, I've only been loading cast in rifle for a few months, really new to lighter charge lower pressure rounds. It was just a bit counterintuitive to see the primers like that given my past experience with only high pressure rounds.
Yes, it's counterintuitive but happens with most cartridges and guns to some degree as it's very difficult to maintain absolute zero headspace with any action or cartridge. And if headspace is too tight or less than zero it can impede reliable function.
Even with higher pressure, jacketed bullet loads in bolt guns, the residual evidence of some headspace (like a popped out primer) is hidden as the primers are re-seated during the firing cycle.
The RCBS Cast Bullet Manual number 1, shows that boolit in the 32 Special with a starting load of 8.5 grains of Unique @ 1168 and a maximum load of 10.5 grains @ 1468 fps.
Bump that 8.3 grain load up a bit and it should be fine.
My regular load for both 30-30 and 32 special with 170 gr. FN boolit , is 10 grains of Unique.
Gary
Thanks Gary, I'll bump it up a bit. The Lyman book lists 8.0 - 10.0 gr Unique so I was trying to start low. I've got some room to play.
That happens with light loads! Normal....... nothing to worry about unless your brass is really used. Beef e'm up & see if they don't stay put.
I shoot a lot of light loads in my 30-30 and backed out primers are normal
If your rifle is headspaced correctly, the rim will keep the case from going forward as that is its designed purpose and there will be no protruding primers. That's one of the advantages of a rimed case for light loads. If excessive headspace is present; well yes, the case will be pushed forward and a backed out primer is the evidence if a light load is fired.
I load for three 30/30s and a 32 Special currently. The two Marlin 1903 rifles (circa 1905) have slight headspace issues (common in these earlier Marlins it seems) and primers will back out with light loads as all have attested to above. The Winchester 94 carbine (circa 1953) and the Model 64 rifle (circa 1941) are headspaced correctly and no matter how light the load, the primers will not back out because the case is not allowed to go forward due to the rim no matter what the pressure differential is between the primer pocket and powder in the case. My 30/40 Krag is also headspaced correctly for its rimmed round and I have never seen a protruding primer for it, not even when shooting the absolute minimum loads with Bullseye powder and a 32 (.314 diameter) calibre hollow base wad cutter boolit for indoor range use. Protruding primers are not normal for a rimed case unless the rifle is out of spec.
Rimless bottle neck cases are a different animal and will eventually shrink between the head and the shoulder from light loads due to that differential in pressures and while the rifle's chamber may be spot on for headspace, the cases are no longer in spec after a few light loads and will exhibit a primer above the base of the head after a few squib loads. Shrinkage will continue with additional firings until a point is reached where the extractor will not let the case move further forward. That's normal for rimless cases and low pressure loads.
If in doubt, a trip to a gunsmith who has headspace gauges for any of the 30/30 based rounds chambered in the Model 94 Winchester will verify or dispel any suspicion you may have about your rifle's headspace.
You have a small headspace problem. Almost all 94s have the same problem to some extent. http://www.wisnersinc.com/web_layout...hester/94.html sell over sized locking bolts in .005,.010 and ,015" oversize if you want to tighten it up. I have found with most lever guns that if you get the headspace as tight as a bolt gun then they have a little problem with the lever sticking after firing. You can use a pore mans headspace gauge by putting masking tape on the bottom of a sized case and building it up till the lever just closes all the way then measure the thickness of the layers of masking tape. Most 94s will be about .008" ( two layers )but I have had more than one come in that was over .020". Factory ammo for the 30-30 is loaded to about 42,000 psi which in most cases will not stretch the brass to keep the base against the breach block. If there is any head space the primer will back out to touch the breach. This does not happen with higher pressures like in a 30-06 where the brass will stretch and keep the primer flush with the base.
The head space on your rifle does not mean it is unsafe. If the primer is moving out more than .010" then you might consider having it looked at. Almost every 94 I have checked will close on a "no go"gauge.
Get your headspace checked so you know if it's good or not.
That said, you are not having a problem and are not seeing any indication of an unsafe firearm. That load is very close to what I use for paper punching and what you are seeing is a low pressure load. What's happening is there is not enough thrust from powder ignition to force the case rim against the bolt face, but there is enough to push the primer against the bolt.
No big deal, have fun!