I finally purchased a set of RCBS 357 mag dies and plan on reloading the 158 gr xtp bullet. I am looking for a velocity of around 1500 fps out of a 6" Ruger GP-100. What powder do you recommend to achieve this? Anybody have loads worked up?

I would consult a current Hornady reloading book. The XTP bullet has a different bearing surface and (I believe) jacket material than a standard bullet of the same weight, so different loading data must be used.
For a powder recommendation, I would say H 110 would fit the bill very well.

I'm a fan of W-W 296, but I question whether 1500f/s is possible in 6" of barrel. I use Hornady's 158 grain HP/XTP and 17.1 grains of 296 for an honest 1370f/s from a 6" 686.

H110 and Win. 296 are the SAME powder. It should be a good choice for a 357 Mag.

As long as you're not at a maximum load with a particular bullet, you should be OK interchanging loading data for jacketed bullets of the same weight. When you start pushing maximum loads, then each individual bullet type should be worked up cautiously looking for excess pressure signs.

quote:

Originally posted by Grumulkin:
H110 and Win. 296 are the SAME powder.

No, no they aren't!! The cautious observer will note that the flame produced by WW296 is blue, not orange like that of H110. Either way one cuts it, both are excellent powders as are 2400 and IMR 4227.

I was at the range yesterday in 30 degree weather shooting my new Taurus with 6" barrel.
16.0 of W296 with the hornady 158 was only clocking 1100 fps. It was accurate but I am a little disappointed in the speed. Most data from published loads seems to stop at about 16.7 of W296. I wouldn't push it too far over this.

I e-mailed Hodgdon several months ago about the H110/Win 296 question. They confirmed that they are the same powder.

Just like the IMR powder line, Hodgdon is now selling all Winchester brand powders.

Molar1,

I don't think 1500fps is possible with a 6" barrel. The fastest a 158gr XTP is 1591fps using 16.7gr H110, but that was with a 10" barrel. And that was in a WW case which usually has a bit more capacity than others. So you might get close...

Even VihtaVuori N105 powder will only get you 1490fps in a 7" barrel using the XTP bullet. Isn't that close enough?
I think a 158gr Speer would make it to 1500fps.

quote:

Originally posted by kraky:
I was at the range yesterday in 30 degree weather shooting my new Taurus with 6" barrel.
16.0 of W296 with the hornady 158 was only clocking 1100 fps. It was accurate but I am a little disappointed in the speed. Most data from published loads seems to stop at about 16.7 of W296. I wouldn't push it too far over this.

Kraky, In my book 16.0 of 296 is a starting load. Lyman's #46 cautions that reduced loads are not recommended by Winchester, and in fact list only the 17.1 grain charge. I know others specify different charges, but I'm loath to reduce slow burning powder charges in any case whatsoever. If you question your velocity, you must question your crimp too. A hard roll crimp is a must have with these slow burning powders.

With a 4" barrel, I can only get 1173 fps with 18 gr LIL'GUN and 158 gr.
That is like 1300 fps with a 6" revolver.

I think 1500 is possible with a 6" revolver, but the specter of sticky case looms.

I just visited the buffalo-bore site and they are reporting a velocity of 1400 fps with a 180 gr 357 load out of a 6" revolver. Has anyone tried this ammo and how are they achieving this velocity?

Buckshot-- I'm crossreferencing alot of websites. The data on Hodgdon says that 16.7 of 296==40,000 psi which is more than should be run through a medium frame revolver on a continuous basis. Also my Quickload says that is nearing the max. As does the Hornady reloading manual I have.
I'm a real avid rifle reloader and the revolver stuff is new to me. I can't believe there is this much difference between loads and actual results. I've made recent post here thinking maybe I should push to "above book" loads but everyone says don't do it and I guess there are far to many resources saying "dont" than "do".
I'll keep watching this post as well as others and keep gathering info. I can tell you this about shooting the 296....I'm surprised at how almost every shot I'm getting "burned in the face" by apparant gun powder flying around that is still being lit. Maybe this powder doesn't do worth a darn at 30 degrees. Maybe at 80 drgrees I'd see a jump of 200 fps???????
This revolver stuff seems to be more challenging than reloading my 5 weatherby calibers!!!!!!

kraky, It never hurts one to be cautious and it isn't my intent to steer you wrong. Others here say that 296 and H110 are one and the same, whereas I'm not so sure. Could be that some changes have been made as of late, and caution would be the order of the day.
If you are experiencing incomplete combustion with 296, I'd be looking at my crimp and primer. Just like with rifles, pistols require a magnum primer with heavy charges of slow burning powder. Pistols also demand a heavy roll crimp to ensure reliable ignition. You are in good company keeping within the reloading book suggestions. Best of luck with your reloading project.

I know they made the contender barrels in a 6" for a short while. It would be interesting to see if the totally enclosed contender would do lots better than a revolver for velocity. I may have to keep an eye on e-bay for a short barrelled .357 contender frame.

molar1: magnum handgun powders perform differently depending on the volume of the case. In other words, the best .44 Magnum powder may not be the best .357 powder. This is coupled with a slower burning powder needing longer barrel length to develop full velocity potential: burn rate geometry. The best performing powder that I have used in .357 Magnum is AA#9. Five or six years ago when Accurate boosted their pressure data to 40,000 CUP, they chronographed their loads in a S&W 686 with a 6" barrel. Velocity was slightly above 1600 FPS with AA#9 and the 158 gr. XTP. Back when load manuals used the original pressure spec for .357 Magnum, the highest velocity obtainable from a revolver rather than a pressure barrel was with Blue Dot. Since then, there were cases of lot to lot variation with Blue Dot and it has fallen from favor a bit. When pushing the envelope, the last thing you want is variations in pressure through chemistry or poor metering qualities. Example: guys that are pushing the velocity envelope in 10mm are claiming that 800-X is all the rage. Maybe, if you want to weigh every individual charge because 800-X is most likely the poorest metering handgun propellant on the market. Conversely, AA#9 is very dense and fine grained. It is slightly faster in burn rate than 296 or H-110 and better suited to the case capacity of the .357 Magnum. Ramshot Enforcer is very similar in burn rate and performance, but no one has yet developed data for the type of load you're looking for.

Another bonus: among .357 revolvers with 6" barrels, the GP-100 is most likely to chronograph the highest velocity.

Ramshot Enforcer and AA#9 are the same:
1) looks the same
2) smells the same
3) within 1% of same charge to loosen the primer pocket of 7.62x25mm brass with 110 gr bullet.

If anything can approach 800X in for 40sw and 10mm I would like to hear about it. I have pushed until the primers fall out and not get anything like 800X velocities with Power Pistol, 3N37, LONGSHOT, Blue Dot, N105, AA#9, Enforcer, STEEL, and H110.

The amount of power possible with a 357 mag, without stickey cases, is a function of the chamber compiance. The compliance for steel is always the same, so it is a funciton of chamber wall thickness.

As my buddy John Bercovitz wrote in 1991:
http://groups.google.com/group/rec.guns/browse_frm/thread/4bf75a94cd4d25ed

quote:

A really good illustration of this can be found when comparing the S&W
model 19 to the S&W model 27. Both guns are 357 magnum caliber and both
can take full-pressure loads without bursting. The model 27 has thick
chamber walls and the model 19 has thin chamber walls. Cartridge cases
which contained full-pressure loads are easily extracted from a model 27
but they have to be pounded out of a model 19. So manufacturers don't
manufacture full-pressure loads for the 357 magnums anymore. 8-(