Been using 4 grains 4227 +38 grains of eg swiss/OE 2F/3F under a lyman 375445 240grainer  for some time in a variery of leverguns and single shots with nothing much happening.   Just noticed my ammo box  the first 20 or so ejected like a semiauto rifle when flipping the finger lever and their primers were somewhat flat.  next 60 rounds they ejected more sedately, but the primers are raised.  Have heard of this with real low power loads but this load is not low power.  Ay ideas?

JLouis wrote on Mar 28^th, 2018 at 4:39pm:


Same here John. Raised primers say headspace issues to me.

Three decades ago, shot a Rolling Block and a Marlin 1893 carbine with a duplex load. The duplex load was SR 4759 and FFg, RCBS 37-250-FN with the gascheck shank machined out and a wad under the bullet. The cases were new W-W.

Resizing, I noticed a ridge along the line where the SR 4759 was and tested loads at the range.  There was .0015 case head expansion at this point on each case. 

Next tests were with straight SR 4759 and FFg in both the Rolling Block and the Marlin. Neither set of cases had the expanded ring on them. I quit the duplex loading and went to SR 4759 because I could not get a satisfactory answer for what was happening.

Some of the primers were flattened. This usually happens when the primer backs out slightly and then the case head is pushed back. The cases with flattened primers also ejected easily and the ones that the primers just backed out gripped the chamber wall tighter. It sounds like there was not enough pressure to push the case back with the tighter fitting cases.

Theres your problem LPs are shorter than RPs they are backing up in the primer pocket.

40 Rod

Never use pistol primers in a rifle case, the additional clearance is harmful to the breachface, especially the older softer versions. A high primer in a rimmed case is a sign of two or three things that may all be going on at the same time. First the rim may too thin, secondly the breach may be too wide and last the powder burn pressures are so low to not overcome the primer chamber pressure thus the protruding primer. If the protrusion is not over say 0.010 it is of no concern but too much over that figure then it is time to find thicker rimmed cases or correct breachspace. An easy fix for low pressure protrusions is to enlarge the flashhole ever so slightly till the primer pressures match the case's pressure, just be mindful to segregate the case's and never use them for high pressure loads which could be catastrophic.

I'm with Premod and Marlinguy both. I don't worry about a little primer protrusion in a rifle that's shot with low pressures. I've got a couple of 'em that do that. Some are from deep rim recess/thin rims, some are just plain low pressure. 
The worry you have is the sudden change- if it's from shooting the same in various rifles, separate 'em. And, if you want to see if it goes away permanently, just shoot a load that's a little higher in pressure and see if the problem stops. If it doesn't maybe you really do have a headspace condition. 
Either way, I avoid using pistol primers in my old rifles. Period.

Thanks all. Rifle primers it is and a few high pressure loads as well to check.  The wealth of shared knowledge and experience is awesome, and I am grateful.    BTW  the brass is and remains unsized for slip fit bp loads regardless of rifle, but i now realize chamber widths do vary and will segregate. I have read that the hepburns are very strong actions  well made from good steel, and this one not shot much-- bore is a mirror-- so I discounted excess headspace.