Loading .357.....need help

[shelpster66]

Hello all.....
Loaded up some .357 not that long ago and used the 158 gr jsp from Speer. Most of the information I got on this bullet weight made sense and I loaded up about 50 and used them without issue. I have not done a Chrono on them yet, but will tomorrow when I hit the range.
These were set with regular magnum brass, small pistol primer, WIN 296 ~15.5 gr of powder, and 158 gr Speer jsp.

The new load I am trying to put together is with Hornady 125gr XTP jacketed hollow points. The information on this is all over the place.

FIRST - I am shooting a S&W .357 Magnum Revolver with a 2" barrel. Can't find a great deal of data that supports that pistol.

What I loaded and shot with this size of bullet is this-
Magnum brass -(left over from Federal Hydroshoks)
Small Pistol Primer #100
WIN 296 @ 18.5gr
Hornady 125gr XTP #35710

I loaded just 10 if them to see how they held up. Well....there was quite a bit more BANG over the 158 gr I loaded. The primers were FLATTENED. I honestly couldn't believe it did that. I was well within range of what the book told me. This is where I start to get confused....and have subsequently held off loading any others until I get some input.
I have a small book that I bought from Midway that is just for loading the .357 cartridge. This book indicates the starting load for what I have is 16.9 @1250 vel and 20.3 max @1500 vel.
Hodgson loading data (online) says that the starting load is 21.0 @ 1881 vel and the MAX is 22.0 @ 1966 vel.
The Lee manual has no starting load data for this bullet but says to never exceed 18.5 @ 1800 vel..........

So I have no idea where to start or end with this. I was going off of the book I got from Midway because 21/22 grs is A LOT in that case......The primers are not magnum primers and them being as flat as a pancake concerns me.

Please tell me somebody has some information for me regarding this load. I want to load these XTP's but don't want to blow my F'ing hand off in the process.

Thanks,
Mike

 

[kenmack]

Re: Loading .357.....need help

Isn't that powder the same as H110? If it is, there are some peculiarities with it that deserve consideration. Namely, it is prone to detonation particularly with light loads. Hence, the narrow spread between min. and max. charges. I notice that the Midway info has a lower minimum than the Hodgdon's. H110 is also harder to ignite, and for the .44 mag that I load, a magnum primer is recommended. Other factors thought to contribute to detonation are lower volume powder fills and powder orientation in case. I am relatively new at reloading but have reported what I've found while researching for .44 mag. I hope I've given you some leads to pursue.

 

[kenmack]

Re: Loading .357.....need help

Hodgdon's 20012 Annual Manual uses a "Winchester SPM" primer. The article starting on page 56 states that W296 and H110 are the same.

 

[former naval person]

Re: Loading .357.....need help

296 is a bit slow for that light of a bullet and that short a barrel. 2400, Universal Clays, or Unique would probably serve you better. Universal is a much lower flash powder. JMHO

 

[Niles Coyote]

Re: Loading .357.....need help

An opinion and an idea. First my opinion, I think that powder is a little slow for such a short barrel and light bullet, it works great in my 6 and 10” barrels but a lot of it likely is being burned outside of the barrel... BOOM… Now for the idea. I am not familiar with the 125 XTP, but I know many of Hornady’s pistol bullets are on the large size. As is my 44 mag XTP are .430 rather than .429 if this is the case with the 125 XTP that could be the reason it is showing pressure.

lol, looks like a lot of answers before I entered mine.

 

[JGorski]

Re: Loading .357.....need help

Ive got no issues with 20grs 296 and 125 Win HPs, not really fun to shoot but no flattened primers or stuck cases.

 

[kenmack]

Re: Loading .357.....need help

JGorski, I think that if what I supposed was, in fact, the issue, then a "hotter" load, ie. a heavier charge such as your 20 gn, would solve the problem. I just didn't feel, with my lack of experience and familiarity with .357 loads, I could recommend that with any conviction. Likely, should the OP consult more and different reloading manuals, he would find the majority have a recommended minimum powder charge much higher than his load, and more closer in weight to the maximum suggested powder charges. In short, I concur with your observations.

 

[boone3380]

Re: Loading .357.....need help

If your S&W is a Model 19 or 66, you would be better off using the 158gr bullets. The 125s were know to cause forcing cone problems in the older pistols.

I have the same .357 book. Your exactly right in what you went by under the Hornady section of the book. If you go to the Winchester section, it says don't go less than 18.5gr with W296. Any further reduction in powder can cause dangerous pressures.

After all of that you should have still been good to go. That's why we test our loads. I use IMR4227 with .357 and .44 loads.

 

[JGorski]

Re: Loading .357.....need help

Did you get any stuck cases, if not I wouldnt worry about the load. Primers might be a little on the soft side.