.357 Question

[eddiememphis]

I have a box of 125gr XTPs I got for free when I bought some dies.

Every manual I have (Hodgdon, Lyman and Hornady) says to load them at 1.590". In order to get the crimp centered in the cannelure, they come in at 1.570".

I am planning on using up the last of my Titegroup. Hodgdon says 6.8- 7.5 grains will get me 36.5k to 41.2k CUP with 45k CUP being max for the round.

How much will .020" increase the pressure? I was planning on using 7 grains.

 

[RKRCPA]

You're fine, go for it.

 

[Walkalong]

In order to get the crimp centered in the cannelure, they come in at 1.570".

Then use that OAL.

How much will .020" increase the pressure?

Some, but you should be fine. It's a big volume case, and you are not at max. If you are concerned, start at 6.8 Grs instead of 7.0 Grs. Load a couple, shoot them, get velocities, go from there.

 

[2ndtimer]

Probably the last powder I would choose for 125 gr JHP in .357 Magnum, but you should be quite safe at 7.0 gr, even with the slightly deep seating.

 

[.38 Special]

How much will .020" increase the pressure?

12.7 PSI.

(Seriously, there's nothing at all to worry about here.)

 

[Bazoo]

I would load them to the cannelure, and be comfortable with your suggested load.

 

[lordpaxman]

Every manual I have (Hodgdon, Lyman and Hornady) says to load them at 1.590". In order to get the crimp centered in the cannelure, they come in at 1.570".

How long are your cases? It could be part of the .020 difference. Crimp to the cannelure. If you were loading 9mm, .020 is a lot to reduce COL for TG, not so much for .357 but I’d still start at 6.8.

 

[ms6852]

In a jacketed bullet, the cannelure is there to maintain the jacket in place. So if you are not happy with your OAL you have the option to crimp else where. Otherwise you are good to go.

 

[Random 8]

Load them to the cannelure. I would actually reduce that TG charge at least to the starting, although you should be safe at 7. You're not making a hot-rod load, so why go hot? TG reduces well.

I'd like your odds of finding a good load even better with some .38 SPL brass/loads.

I played with some TG at starting loads with various bullets in .38 and .357 cast bullets. You might be pleasantly surprised with your results. I got very fine accuracy, clean, low recoil loads with little flash.

The 125 XTP is also a lot of fun at maximum velocity over H110. Best shot out of a rifle, as you may be getting into flame cutting territory with a revolver.

 

[mdi]

I started reloading in the mid '80s, waaaay pre web. I figgered the crimp grooves and cannelures were located for a reason and used that as the crimp location. Still do, never a problem

 

[eddiememphis]

How long are your cases?

1.280"

I finally got around to it today. 7.0 grains of Titegroup takes up very little space in the case.



I got out my very scientific depth tool (a pen) to see how much room there was.





Looks like plenty of room to avoid a high pressure situation, not that I was anticipating one.

I was hoping someone had a formula or computer program that could easily spit out the information- .020" deeper will equal X increase in pressure.

 

[eddiememphis]

The 125 XTP is also a lot of fun at maximum velocity over H110. Best shot out of a rifle, as you may be getting into flame cutting territory with a revolver.

I am going to make a few of those as well. I really enjoy the 158 XTPs over H110, both in the revolvers and the Marlin 1894CP.

 

[IWAC]

I am going to make a few of those as well. I really enjoy the 158 XTPs over H110, both in the revolvers and the Marlin 1894CP.

View attachment 1243206

Hoo boy! That's some flash! Not nearly as big as my late Bro-in-Law's 357/2400/155 gr. load, tho! I was never curious enough to ask what it was, but his flash was Beach Ball size (at high Noon, no less). Good thing he was shooting a Ruger Blackhawk!

 

[fxvr5]

In a jacketed bullet, the cannelure is there to maintain the jacket in place.

On revolver bullets, the cannelure helps achieve accurate, consistent crimping.

Source: Hornady 11th edition Handbook of cartridge reloading. page 55.

 

[Frulk]

If you can pull the trigger as fast as Jerry Miculek you’d be able to weld with that gun.

 

[fxvr5]

I was hoping someone had a formula or computer program that could easily spit out the information- .020" deeper will equal X increase in pressure.

Quickload estimates that going from 1.590 to 1.570 with 7.0 grains of Titegroup and your 125 grain XTP will raise pressure by 1,083 psi.

 

[OS/N]

I don't worry over the OAL or seating depth much for revolver ammo as long its not too long. Just start at the 10% under max load and work your way up until your groups land in nice groups at the correct elevation. Bullet speed if too high will spread your groups out and give you flyers with 125s but it will give you the most energy or stopping power if that's what your after. Seating in the groove is suggested to give consistant pressures.

Tight group is a little fast for heavy magnum loads IMO - one of the blues on up to 2400 would be my preference and something more bulky would give you more consistant speeds. The harder you want to push the slower the powder you want to use. Faster powders are fine for lighter target loads that you want to load more ammo per lbs of powder with (tightgroup, 231, AA5, & etc...). 5 to 10% below max charge usually gives the best accuracy for me. A tenth of a grain variation in fast powder weights at magnum pressures gives more variation in pressure than the bulkier slower magnum powders that fill the case do.

 

[eddiememphis]

Quickload estimates that going from 1.590 to 1.570 with 7.0 grains of Titegroup and your 125 grain XTP will raise pressure by 1,083 psi.

Thank you- exactly what I was looking for.

 

[Random 8]

I am going to make a few of those as well. I really enjoy the 158 XTPs over H110, both in the revolvers and the Marlin 1894CP.

View attachment 1243206

Out of my 20" barrel Henry, the 125s are akin to a 7.62x39 Vmax on soft targets. From the wife's 3" carry piece, they are terrifying. Like setting off an M80 and about 15 cadweld charges in the palm of your hand. Good fun!