xtp's vs. standard jacket 357 mag?

[Gallahad]

I was looking up loads for 180gr. 357 loads, and (I know this must have been covered somewhere, but help me out) Hornadys xtp data is @ 300 fps slower (or more) than Lee's jacketed data for the same grain weight. Lee starts out at @1200fps, with jacketed 180's with h4227 and hornady's max load is 1050fps for that powder. I prefer the xtp for hunting, but am willing to switch bullets for the increase in speed. what gives?

[LaOtto222]

Loading data from different sources is often conflicting. It depends on how long the barrels are, whether it is a revolver vs test barrel, make of gun used, etc. I have a Lee 38 special die set and the data for the 38 special does not state what gun or barrel length was used. I think Lee lifts their data out of other peoples load data so the comparison is not valid because of all the factors involved. The data for Hornady 180 grain Silhouette bullet is the same for their 180 XTP bullet. Same for the 158 grain bullets. I have shot some XTP bullets and I used Hornady load data. I do not think that there is much difference between XTP bullet construction and most other bullets of similar construction (jacket thickness and core hardness). Is the amount of H4227 the same in both cases - Hornady and Lee? You should start low and work your way up. If shooting in a revolver watch for sticky cases. If you increase your load in .3 grain steps, you should find your best load. Do not try to make your 357 Mag into a 44 Mag. If you have not reached the max data and you run into sticky cases, back off .3 grains and call it good, but never exceed max listed loads. Sticky cases involves a little effort to push them out of the chambers. I have a S&W Model 66. It is a medium weight gun, so I shoot mid level 357 Mag loads in it. Shooting max level loads in it over an extended period would shoot it loose. If you have a Blackhawk or similar gun you can go for heavy loads. I would use Hornady data and not worry about it. A 180 grain bullet going 1000 fps will do the deed as long as you keep the range reasonable. Good Luck and Good Shooting

[buck460XVR]

In some calibers, the XTPs are a little bigger than other jacketed bullets(.44 for example, .430 compared to .429), but it is not true in .357. Some bullet profiles cause more drag than others also, but most of the time this is moot unless loading max.  I have yet to have my loads match listed velocities even when using identical components as listed in the manuals. Too many variables I assume, don't matter to me tho,  as I load for maximum accuracy as opposed to maximum velocity. My experience is that XTPs have always been accurate outta all my guns regardless of caliber.....and most loads listed in Hornady's manual are fairly conservative.

[Dand]

One of the best articles I've ever read had the title, Why Ballisticians (or Ballistics Experts) Get Gray".  Or something like that. It might be in the older Speer manuals or you might find it on line. It showed how widely varied results can come from the same load fired in different guns. You might want to try finding a copy.  I seem to remember there was a photo of a large number of 357 revolvers arranged in a circle. I found it really helped my perspective on selecting loads, what it takes to develop a generally safe load (say from a load book editor's view) and why its a really idea to be very careful in load development.  Really when I think about it, its pretty amazing how well we all do when it appears a lot of load manuals are developed using one or two guns.

HTH

Dan