Crimping pistol boolits with H110 still necessary in a single shot?

[Ed K]

My understanding of the purpose of the crimp on a pistol boolit is:


To keep the boolits from pulling under recoil, affecting OAL and ultimately tying up the action.
In the case of slow powders (e.g. H110 & WW296) allowing the case to develop pressure for good ignition before the boolit can move forward by constraining the case volume.


If one was to load a pistol boolit in a single shot, could advancing the nose of the boolit such that it engraves the rifling serve as an adequate substitute for purpose #2 above (provided the throat is sufficiantly short - perhaps even cut for this specific purpose)? My thinking is the displacement of boolit metal by engaging the throat/bore and the accompanying swaging would allow quite a bit of pressure to build - unlike the effective gross "freebore" of a revolver throat/forcing cone.

My primary reason for doing this would be to load to a slightly longer OAL than would otherwise be necessary if the crimp groove must be utilized.

[powderburnerr]

I was just reading handloader today and they were talking ablot that very thing. the crimp is to raise pressure , not necessaryly to hold the bullet , although cast is harder to hold than jacketed,... if you engraved the rifling you may accomplish the same thing , have to try it and see if it is enough to give you a clean burn...........Dean

[MtGun44]

Tight case neck tension is as or more important than the crimp for getting powders like
H110/W296 to burn well.

Bill

[mike in co]

Tight case neck tension is as or more important than the crimp for getting powders like
H110/W296 to burn well.

Bill

ok...but as he pointed out, single shot( no cylinder gap) and the ability to engrave form the start.

it would seem the trial and error is the answer.....keep trying larger harder boolits to get the burn ?

mike in co

[44man]

It takes a LOT of crimp to effect burn, full profile like.454 factory loads but that will ruin most cast boolits. I made many experiments with zero crimp, shooting single shot from revolvers, to full profile and nothing was worth the effort. Even case tension was the key to accuracy. I determined only enough crimp is needed in the revolver to hold boolits under recoil.
I would still keep tension good but I don't think a crimp is needed with a single shot. With neck tension I don't even think jamming the boolit into the rifling is needed but sure would not hurt anything. I would work it like a rifle and try different seating depths.
I think the .454 Jacketed load has so much crimp because of the SR primer. Poor ignition, they need all the help they can get.
I get perfect ignition with the .44 and .45 using a standard LP primer and only enough crimp to resist recoil.
Just try to crimp a Lee boolit hard with the tiny crimp grooves. Yet they shoot like crazy.

[Green Frog]

FWIW, powders like H-110 are routinely used in single shot rifles with breech seating... BUT you will have the bullet firmly seated in the rifling to provide resistance for that initial burn. I'm not sure your idea of an uncrimped but long seated bullet will give you enough push against the rifling to get that necessary initial resistance before the bullet begins to move, especially with a jacketed or very hard cast bullet.

I guess the next question is, "Why do you want to do this anyway?" Are you looking for an increase in performance potential, a gentler way to load and save brass, or what?

Froggie

[Ed K]

I guess the next question is, "Why do you want to do this anyway?"

I don't mind talking about that:


Accuracy: I generally load all of my rifles 0.000-0.025" off the lands. If I'm using ball powder in a pistol case, am I tied to the use of the crimp groove which results in a much greater jump?
Safety: I plan to load 45 Colt cases to approx 32Kpsi/Ruger levels. It would be nice if these did not fit into my USFA Colt clone and S&W 625 due to OAL.
Performance: a distant third but could come into play.

Probably about in that order. It's just an idea, a concept that popped into my head. Of course I could buy yet another custom mold to accomplish much of this :wink:

[gasboffer]

I shoot lots of cast in TC's. Never crimp any of them, just remove the bell in the casemouth. Seat the bullet to just touch the lands or be just off them.
Have shot some really good groups from a rest.
Clyde

[C A Plater]

In shooting H110 in a .44 mag Contender barrel over a chronograph I noticed the SD was significantly lower along with extreme spread. Velocity average was about the same.
YMMV

[badgeredd]

In my T/C Contender, I have found I get better accuracy with a crimped boolit (H110/W296) over a non crimped boolit. I do load the boolit I use to engrave the rifling a bit. I use a taper crimp since it seems to give me more consistent loads over a roll crimp. I've experimented quite a bit with the boolit/case combination which is a heavy 35 caliber boolit and the 357 Mag case.

Honestly, I would think that a mild crimp in combination with neck tension and boolit engraving would allow enough pressure for a consistent powder burn, but experimentation will give the real answer for your gun.

Edd