Full house .357 Magnum loads

I'm getting 1430fps from 15gr of 2400 under a 160gr hardcast bullet (gas checked). 6" barrel GP100.
1850 fps in a 18" Marlin.

I shot a dozen 200gr hardcast bullets with 10.5gr 2400 and the cases were a little sticky in the revolver and wouldn't cycle in the lever.

W296 didn't perform in my loads contrary to all the books.
 
"...manual lists 16gr of 2400 as the minimum load..." Alliant's site shows 17.5 of 2400, at 1409 fps, as the max load for a 125 grain jacketed bullet. For some daft reason, they tested the load in a 10" barrel though.
 
I have to load me up some 147's or 158's for my Coonan... I love the sound a loud gunfire and the sight of flying brass in the morning..
 
125 grain bullets over full magnum powder charges will likely result in flamecutting of your topstrap in a very, very short time. Too bad I didn't know any better then, so my 686 exhibited some flamecut after about 50 rounds.

My GP100 which has never tasted such 125 grain bullet loads and it still is flamecut-free after hundreds of magnum shots. Experts say that the FC will not hurt the revolver and will stop by itself after a certain depth...but still I don't like the idea.

If you want a satisfying full power magnum, try 15 grains 2400 under 158 grains JHP, regular WSP primer. Got that recipe from handloads.com.
I have been cautioned by one of the moderators in another forum to shoot this stiff load only with Ruger firearms.

I normally load Speer 158 grain JHP bullets over 14 grains 2400 and it is a very comfortable and accurate load to shoot, usually 3 shots in less than 2 inches at 15 meters, standing two-handed hold, firing double action from my GP100. Haven't chrono'd it but should be over 1,300 fps.


Is it the 125gr bullets that cause the flame cutting or is it the full magnum powder charges?

If I were to use 158gr will that eliminate the FC?

I bought H110, should I switch to something a little tamer like Blue Dot?
 
the flame-cutting is in fact the effect of sandblasting with unburnt powder.
it looks like this: http://1.bp.########.com/_XCkTSf0swcQ/R2TL4K22l3I/AAAAAAAABEQ/yrD-yJzo4Vk/s1600-h/flamecutting.jpg
or this: http://pages.sbcglobal.net/eickpm/flame_cut1.jpg

Heavier bullets generate higher initial pressure which is conducive to better powder combustion.
Conversely lighter ones cause more partially burnt particles to blow through the cylinder gap and erode the strap. The associated higher powder loads aren't helping either.

You could use a faster powder with 125gr bullets
 
the flame-cutting is in fact the effect of sandblasting with unburnt powder.
it looks like this: http://1.bp.########.com/_XCkTSf0swcQ/R2TL4K22l3I/AAAAAAAABEQ/yrD-yJzo4Vk/s1600-h/flamecutting.jpg
or this: http://pages.sbcglobal.net/eickpm/flame_cut1.jpg

Heavier bullets generate higher initial pressure which is conducive to better powder combustion.
Conversely lighter ones cause more partially burnt particles to blow through the cylinder gap and erode the strap. The associated higher powder loads aren't helping either.

You could use a faster powder with 125gr bullets

Soooo many theories! Nothing like shooting in general and reloading, in particular, to produce no end of theories, most of which can't be proven.
Anything that hits the strap, has to escape between cylinder and forcing cone. There is a great variation in revolvers, even from the factory, in the gap between cylinder and forcing cone. Result, wide gap, more burning on the strap. I doubt if the great majority of revolver owners bother to measure the gap. If their strap is cutting, presto, it's because of the bullet/the powder/the primer or anything except the real reason, wide gap.
In the real world, heat cutting of the strap is not a great deal. Many 357 or 44 mag revolvers have been shot a tremendous number of times, and strap is still good.
A 125 grain bullet cutting the strap worse than a 158 grain, is one of the weakest theories I have ever heard.
It seems to be accepted theory that it is unburned powder that burns the strap. A good revolver has a gap in the order of .005". Please explain how powder could be reduced in size to get through that narrow gap, and still be unburned.
Hot burning gases erodes the throat of a rifle barrel and hot burning gases erode a strap on a revolver.
Use whatever powder and bullet you like, and shoot your gun.
I get the impression that great numbers of handloaders out there spend so much time worrying about some new theory they've just read, that they can't enjoy shooting.
 
OP, please forgive me for hitching a ride on this thread it's great, but... I'm preparing to purchase a few boxes of 357 to lay in a good supply for reloading.
I'm in AB so one of our sponsor's in Western Canada who could supply me with some Winchester ammo would be preferable. I've had a looksee but am not having luck finding it in quanitity.
Or is there another brand which is advised?
 
Please explain how powder could be reduced in size to get through that narrow gap, and still be unburned.

Smokeless powder burns only on the surface of the granules, flakes or cylinders (http://en.wikipedia.org/wiki/Smokeless_powder)

Therefore at some point the powder kernels will be small enough to be forced through the gap.
The longer it takes to burn (as in less pressure, as in slower powder), the longer they stay at a size the can be blown out and hit the strap.
No big deal.
My 357mag has over 2000 rounds and no marks on the strap. But then again, I only shoot heavy bullets.

edit: spoke too soon. I looked through a magnifying glass and there is a slight erosion band.
 
Unique is faster burning than is 2400.
Unique has an excellent reputation for accuracy, but for full power loads in the 357, something like 2400, or the slower burning H110/W296 is much better.
My advice is to shoot any powder you want and any bullet, while not giving the slightest thought, as to which may be harder on your gun strap.
 
I had a good look at my 27-2 and despite an ultra tight gap there is still a fine sharp flame cut on the bottom of the topstrap. Either way, on an N frame I can't believe that this will be an issue as it would take a real deep cut to weaken this gun. Either way 16 gr of 2400 behind a 125 jsp is wickedly accurate....
 
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