The official Mike Bellm's

Bellm TCs


TC Contender, G2, Encore/ProHunter Performance Center

 


   
   
   
   


By seating bullets out in Magnum cases you create the same case capacity as a .357 MAXimum with the bullet seated deep in the case at revolver spec overall cartridge length.
This image was appropriated from a Reloaders Nest forum for the benefit of .357 Mag shooters wanting more performance from break open guns. If the originator of this image has any objection to its use here, please let us know.

At the standard overall cartridge length for the .357 Remington Maximum nearly all of the bullet shank is stuffed into the case.

In the TC and other single shot break open guns, overall cartridge length is basically meaningless. You can seat bullets WAY out and safely load published revolver spec loads for the .357 MAXimum in .357 MAGnum cases.


All .357 MAGnum barrels made before the early 1990's had a VERY short, abrupt cone that does NOT permit seating bullets out. These barrels can and should at least be rethroated with a long, cylindrical throat that will permit seating bullets well out of the case.

All SAAMI .357 Magnum chambers from the early 1990's on have the .4" long forcing cone chamber.

See the drawings on this page:
Forcing cone chambers


Note that with even a 180 gr. bullet, the base of the bullet is about 1/8" past the mouth of the case before it even contacts the front end of the cone.

There is ample room to seat the bullet way out and add the approx. .3" of capacity that is the difference in case length between a MAGnum and a MAXimum case.

In the closed breech TC and H&R guns it makes absolutely NO sense whatever to stuff all that bullet shank down into the case wasting all that case capacity.

Then from an accuracy standpoint, getting closer to the riflings reduces the horrendous amount of bullet jump to the riflings that is the norm with all revolver spec ammo shot in the forcing cone chambers.

Best accuracy will be obtained with bullets with the longest full diameter shank seated way out of the case. Best of all are the wide flat nosed 180 and 200 gr. cast lead gas checked bullets. These minimize the distance over which powder is blown AROUND the bullet BEFORE it can even seal off the bore at the nose.

Many die hard cast lead bullet shooters swear these flat nose bullets kill as well or better than the best jacketed bullets in this application.

Again, look at the chamber casts...... most bullets are in total "free flight" for about 1/8" of travel, during which powder is blown completely AROUND the bullet and into the bore before the bullet nose seals off the bore.

SAAMI pressures for the .357 Maximum are set at about 48,000 psi.
The MAG and MAX are only a few thousandths larger in diameter than a .223 Rem. with a maximum pressure MUCH higher than this.

Thus, even in the Contender, you can run the pressure up to the same level as a .223 Rem. ..... very safely!

I routinely take pressures in the .357 Rem. Maximum case up to the point of a slight cratering of the primer, then back off just below the level where the cratering first starts to appear. Ie, the same as they appear shooting standard, factory .223 Rem. ammo.


While you cannot duplicate the potentials of the .357 MAXimum case with bullets seated way out of the case using .357 MAGnum case, you CAN duplicate the published SAAMI revolver spec .357 MAXimum loads in all of the loading manuals.
My advice is this.
While there is a shortage of .357 Rem. MAXimum brass, shoot the .357 MAGnum barrels as they are with MAGnum cases, then when you obtain a supply of .357 MAXimum brass or loaded ammo, rechamber to .357 MAXimum.

There is one caveat to shooting .357 MAXimum loads in MAGnum cases, and that is the difference in case wall thickness back at the head of the case.
I had always assumed the cases were the same except for the length. I recently learned that Remington did increase the thickness of the .357 Maximum case to better handle the higher pressures of the Max.

It can be presumed that the MAGnum cases loaded with .357 MAXimum loads are more prone to separations or other case failures related to the thinner construction of the MAGnum cases.

However, tests I ran with loads even hotter than book maximum for the MAX in .357 MAGnum cases fired from a Contender showed no signs whatever of any potential failure.

My thought is that with the price and availability of .357 MAGnum brass, one can either afford potential case losses or stop a bit short of full .357 MAXimum book loads.


But the bottom line is you can dramatically increase the performance of .357 Magnum ammo fired in the break open guns!


 

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