Well, here's my first attempt at reloading full bore .357 Magnum.

[flip180]

I went out this morning to try out some .357 handloads that I pu together last night. I was using Winchester cases, Winchester small pistol primers, Remington 158gr. SJHP's and 14.1 grains of 2400 with a light crimp. I was shooting these out of my 6.5 inch stainless Blackhawk. I was also using a Pro-Digital chonograph to chrono the loads. The velocities were optained by shooting a ten round string approx ten feet from the barrel. Here they are.

Hi-1429 fps
Lo-1359 fps
Avg-1393 fps
Es-70 fps
Sd-24 fps

There were no signs of overpressure. The primers were rounded and extraction was easy with no sticky cases. Recoil was manageable and the report wasn't very loud at all. There were litterally no signs of unburnt powder or residue on the gun. My Lee manual calls for 14.1 grains as a starting charge with 1436 fps being what was listed. Where to go from here? From what I saw from lack of signs of overpressure, I think I have room to go up a little. Will my crimp or should I increase it a little when going up with a higher powder charge?

Thanks, Flip.

 

[The Bushmaster]

2400 requires a stiff crimp to burn completely. With that said...How accurate were they?

Lyman and Sierra manuals show 15 grains of 2400 as a maximum charge with a 158 grain bullet...

 

[Ben Shepherd]

I run 14.2 as my standard 158 jacketed 357 load. I've found it accurate in over a dozen 357s. Try it again with a firm crimp. Your ES and SD numbers should come down a bit.

Unless you blackhawk is a lot different than my blackhawks, you should find that load easily capable of a 5 shot group holding at or under 1 inch at 25 yards.

If you're after speed, yes you should have room. But there's really no reason to. I went faster, and found accuracy dropping off a bit. Not much, but noticeable.

 

[flip180]

I really didn't shoot too much for accuracy as much as just feeling it out. The manual calls for a minimum OAL of 1.580 for that load but in order to seat the bullet to the crimping groove, I had to go down to about 1.570 OAL. I'll tighten up the crimp and maybe have another go at it next week when I get some time off. Any other suggestions?

Thanks, Flip.

 

[kostner]

Skeeter Skelton would have been proud. He used cast bullets with G/Cs. You are running with good company.

 

[earplug]

I would not change the crimp, unless you had some bullets backing out due to recoil.
You have to judge what is a heavy crimp, You need a heavier crimp on lead bullets then you do on jacketed.

Since your getting a clean burn on your powder charge, your load is in the sweet spot for that combination of bullet and powder.
Your brass will last longer if you can avoid excessive crimping. The more you work the brass the faster it will split.

 

[Ben Shepherd]

Earplug-I'm not trying to bash or start an argument, but I'd darn near bet a steak dinner that if flip adds just a touch more crimp his ES and SD numbers will come down.

He may lose 1-2 loadings on the other end of the brass life span, but it's a price I'd be willing to(and do) pay for a better load.

 

[The Bushmaster]

A firm crimp gentlemen. A firm crimp...

 

[Walkalong]

Yep.

 

[earplug]

Not trying to start a argument on a crimp I can't see.
We don't have a crimp-O-meter to measure a firm or light crimp, just a chrono to measure velocity.

 

[Ben Shepherd]

Exactly. Given the good burn characteristics he has, his chrono is telling me that, barring one chamber being different from the others in his gun causing the high ES numbers, that just a touch more crimp would be the cats meow.

 

[flip180]

Thanks everyone!

Exaclty how much more do you think is needed provied the bullets don't jump crimp? Should I try a medium crimp next or go full on heavy? Other than a narrowing of the ES and SD, will there be any other differances in velocities and pressure signs with the same charge? I was very surprised on how clean it burned. I have a thing called the revolver thumb. I shoot thumbs forward. The thumb nail of my left hand always becomes blackened or greyed when I shoot revolvers due to the gasses comming out from the cylinder gap. My thumb as clean as it was before I started shooting. I know that's not scientific but that was a surprise to me.

Thanks, Flip

 

[Hutch]

You might also consider going to a magnum primer, as well as the crimp.

 

[Ben Shepherd]

A touch more. IME 2400 needs right on the line between moderate and heavy, squarely at firm. But as earplug posted we don't have a crimp-o-meter here.

Your definitions of moderate and heavy may differ from mine.

From the numbers you posted, whatever your crimp is at right now, just a touch more. Between an 1/16 and 1/8 of a turn on the die probably. If your crimping and seating in the same step, don't forget you'll need to re-adjust your seating stem.

 

[flip180]

I'm using a Lee crimp die set up 1/2 turn for a light crimp. It calls for one full turn for a heavy crimp.

Flip.

 

[GP100man]

just take a bullet & case nuttin else &( sacrefice) it .
seat the bullet to the groove & back out the seater then start screwin the die down a 1/4 turn at the time ,i promise you`ll see the difference!!!!!!!!

GP100man

 

[ArchAngelCD]

flip180,
I also use a Lee FCD and I use at least a 3/4 turn for the crimp and sometimes more. Most slower burning powder like W296/H110, 2400 and AA#9 will give you better results with a heavy crimp. It give the powder time to burn before the bullet started down the barrel and you end up with slightly higher velocities too.

All in all not bad results at all. Looks like you are on your way to a good load which will be even better with a little tweaking. You will know when you get it just right when the accuracy is right on...