Dose anyone here uses Prvu-Partizan 22 Hornet brass? Just loaded and fired a 100/box of Win brass without checking the from/factory headspace of the brass. After fireing about 20rds the next seperated. Checked brass headspace and it was almost 70/1000" short for my chamber. If I had known I would have sized up to .25cal with a Lyman M die and then run throught the FL 22 Hornet die to set headspace. I have used Prvu-P in three other cases but not 22 Hornet.

Factory .22 Hornet is designed to headspace on the rim, not on the shoulder. If your rifle is properly within spec, it should not matter how far rearward the little shoulder of the Hornet case is, as the case will be held firmly to the rear of the chamber by the rim.

It would appear that your rifle has somewhat more clearance between the bolt face and the chamber face than is within spec, so you are having to headspace on the rather puny and very sloped shoulder of the brass. Sounds like you may either be forced to do the expansion/resizing operation you're talking about or set the barrel back to reset the headspace.

Yes it dose matter. When the case is fired with the shoulder back,the shoulder is going to move forward. Where is the case is going to find brass to go forward? Its going to thin the side of the case in front of the web. The gun is a TC Contender so I have to enlarge the brass as I can't cut back the barrel. Since I load on the light to normal side for the gun I could live with a lenghting of 25/1000" on first fireing but not 70/1000".

Nevermind...

New cases are going to lengthen some on first firing (.003 - .004) because as you point out, the case is undersize, being new. New cases are likely underspec. But once fireformed, there should be little or no case elongation. Not at normal hornet pressure anyway. I was using my hornet as a hunting rifle so needed as much performance as the little cartridge could deliver and this resulted in gradual case length growth until the case mouth reached the step at the end of the chamber and thats were the length stayed - I actually headspace on the cae mouth! Not all chambers will allow that. (Most won't).

FA,

quote:

If I had known I would have sized up to .25cal with a Lyman M die and then run throught the FL 22 Hornet die to set headspace.

Well, now you know.

Best,
GWB

quote:

Originally posted by Slowpoke Slim:
Nevermind...

Well, I tried. +1, Slowpoke, you pegged this one.

I think Fat_Albert is asking a question that is meaningful to him but that we are thinking along different lines, i.e. missing his point. He has a specific issue relevent to him.

Fat_Albert, if I may so bold as to attempt to provide some help, I think what might be happening is that you are using a case designed in very low pressure days in a very modern gun and you are wanting modern performance from it. That's OK but you may find your chamber pressure is too high for the case design. Might I suggest trying Lil'Gun and keeping the pressure below the industry standard of 43,000 CUP. Lil'Gun produces very good performance in the hornet at below 43,000 CUP. (Needless to say, you should only be neck sizing).

Something that will stretch hornet brass a lot is a fought chamber. Not just rough ib that it looks bad but in that it bids the case during firing. If that is happening and the chamber looks good then polishing it with fine steel wool on a wood dowel spun in an electric hand drill should polish it smooth. Another trick is to lube the loaded cases before firing. Not dripping with oil, just a finger wipe with some case lube. This will allow the case to settle back against the breach face while the chamber pressure is still low. I should point out that bolt face thrust is not an issue with the hornet. Try and see what happens. It works for me.

From Hodgdon web site

quote:

45 GR. BAR XBT
Hodgdon Lil'Gun 12.0gr 2641fps 35,700 CUP
Hodgdon Lil'Gun 13.0gr 2770fps 38,500 CUP

55 GR. HDY SP
Hodgdon Lil'Gun 12.0gr 2551fps 39,400 CUP
Hodgdon Lil'Gun 13.0gr 2652fps 42,900 CUP

Hope this helps.

It looks like I am the person that was all wrong. I had 3 phone call with Mike Bellm and he explained that all factory Contenders that are for rimed cases have excess headspace because they cut the rim inset to max SAAMI that is deeper than the rim of the case. This leaves the case sitting in a hole below the rear face of the barrel. On rimmed cases the headspace is the distance from the bottom of the rim inset to the face of the breach. On Contenders its the face of fireing pin bushing to the bottom of the rim inset. The distance between the rear of the barrel and the face has nothing to do with the headspace or lockup of the action. He explained that I need to have the back of the barrel face turned down 10/1000" so that the rear of the case will be sitting out of the inset 6/1000" insted of sitting in the hole 4/1000" as it is now. I then find the distance from the back of case to the firering pin bushing and then shim under the bushing that amount. No there is no problem with the case sticking out of the inset of the barrel. He said that the 99% of the rim can be sticking out of the rear barrel as the force of pressure is pushing on the side walls of the case and the rear of the case not on the outside face of the rim. There is no difference in strenght of 357 Mag pistol if the rim is inset or not in the ciylinder. The only Contender rimmed case that dosen't need the barrel cut back is the 45-70 as its base is larger than the bushing and only need shimed to take up the gap.