IMR 4227 in 357 Magnum

[mstreddy]

Roval,
I'm shooting Berry's Plated currently, but I've shot other 357 Mag loads with the Xtremes. I don't know the actual velocity as I don't own a chronograph, but according to the Lyman book the Max charge of 17 grs of 4227 gave 1345fps. The Xtremes I've used, 158 gr, over a 12 gr charge of 2400 should be around the 1100fps mark. Lyman has 11.4gr @ 1024 and max of 15.5 @ 1344.

From Berry's FAQ page -

We guarantee our Standard Bullets to handle velocities up to 1,250 fps, and up to 1,500 fps for the bullets designated as TP (thick plated).

According to Xtreme's Load info page:

Our Copper Plated Bullets can be run at mid-range jacketed velocities or higher end lead velocities. We recommend keeping velocities to less than 1500 FPS (Feet Per Second) and using only a light taper crimp

Any velocities over 1200 FPS we recommend either our Heavy Plate Concave Base or Hollow Point products for superior accuracy. We recommend keeping velocities to less than 1500 FPS (Feet Per Second) and using only a light taper crimp

Can anyone suggest a formula for figuring out velocity, given the load data? Or is a Chronograph the only way to get that?

 

[roval]

thanks mstreddy I looked at my lyman 49th and I found the 158 grain hornady jhp information.

My bullet type was different but I'll try the load recommendations with a 158 swc if the max load of 16.1 was 1249 fps for the JHP then it should be good. i'll probably go to less than max anyway. i'll chrono the load once I work it up.

is imr 4227 now h4227? that's the only data I found on IMRs site.

I can always order different bullets but I still have about 700 of the 158 xtreme swc.

 

[mstreddy]

Roval,
There was thread here talking about I/H 4227. IIRC - and don't quote me on this --- One of them was discontinued and then they renamed the other one with the "old" name. I'll see if I can dig up that thread for further clarification.

OK, here it is..

THE new IMR4227 is the old H4227 renamed. The old IMR4227 is now discontinued. So there is only one now being currently produced. Old H4227 and newer IMR4227 data is what you want.

Here is the whole thread.