IMR 4227 load data for 357 mag

alanshaffer2000 · July 21, 2014, 08:29 PM

New to reloading and wondering why IMR 4227 (not to be confused with H4227) load data for 357 mag. using 158 gr. SWC is not listed in Hodgdon or IMR official load data, but IS listed in Lymans (#358665).

I'm ready to reload my first batch of 357's, but not willing to lose a finger or damage firearm by not following the manufacturer guidelines. Planning to start @ 12.5 gr. and move up to 15gr. Am I in safe territory here?

My firearm is GP100 6"

http://www.imrpowder.com/data/handgun/357mag.php
http://www.hodgdonreloading.com/

Thanks.

res45 · July 21, 2014, 08:50 PM

I find around 14.5 grs. of IMR-4227 to be an excellent load using 158 gr. SWC in plain base or gas check versions. I've shot this load for years in my Ruger Blackhawk.

BOOMST1CK · July 21, 2014, 10:34 PM

I really like using 14 gr of 4227 under a 158 gr berrysbullets FP, good target round.

coldbeer · July 22, 2014, 04:57 PM

There's so many different bullets they can't list them all. If you use the data given in this thread and your previous one you'll be OK. You'd have to work really hard to blow up a GP100 with IMR 4227 anyway. It's a slow powder and I don't think you could fit enough of it in a case since max loads are already compressed pretty good.

Nick_C_S · July 22, 2014, 05:09 PM

Quote:

. . . but not willing to lose a finger or damage firearm by not following the manufacturer guidelines.

A good approach to have, to be certain.

In this case - with IMR 4227 - you've got such a slow powder there that you have "headroom" for days of margin of error. It would actually be hard to load it up to the point of gun damage. Of course, I'm not suggesting that you try. My only point is that you're dealing with one of the most forgiving pistol powders out there.

Now about using it for loading up a lead SWC - I wouldn't. I just think it's too much powder for anything other than a true jacketed bullet. But that's just me and my opinion. I have no doubt plenty of posts are soon to follow with notions to the contrary.

coldbeer · July 22, 2014, 05:29 PM

My target load for 158 grain plain base lswc bullets is 6.7 grains of hs6. This is a very mild and accurate load in my 8 3/8" 686, but I understand finding a vertain powder isn't easy these days and you have to work with what you have.

I'm pretty sure IMR 4227 and h4227 are the same powder.

Nick_C_S · July 22, 2014, 06:06 PM

Quote:

My target load for 158 grain plain base lswc bullets is 6.7 grains of hs6. This is a very mild and accurate load in my 8 3/8" 686.

With a 158g LSWC, I ran 7.6g HS-6:

963 fps S&W 686 3" bbl
1036 fps S&W 686 4" bbl
1072 fps S&W 686 8-3/8" bbl

But . . . the round was so filthy that I discontinued loading it. HS-6 is notoriously dirty when it's underloaded. And to load it up to the point where it would burn clean, would probably mean dealing with leading issues. So I discontinued it. I can only imagine how it runs down at 6.7g's.

I have since moved to Unique - 6.4g. It runs clean, uses less powder, and I have a touch more velocity (but not too much for lead):

1034 fps S&W 686 3" bbl
1098 fps S&W 686 4" bbl
(Did not chrono through my 8-3/8" bbl. - figure about 1125 fps)

This is an excellent 158g LSWC loading for 357 Mag.

I do run HS-6 at 9.2g's with a jacketed 158; and it's clean burner.

coldbeer · July 22, 2014, 06:34 PM

I really wish I could find some unique. I'd cherish it.

Nick_C_S · July 22, 2014, 07:44 PM

Quote:

I really wish I could find some Unique. I'd cherish it.

Perhaps no powder is more versatile in 357 Mag than Unique.

I'm sitting on about 1-2/3 lb of it. That'll suit me for at least a year. The pound in use, I bought about a year ago. The unopened pound, I bought a couple months back. I could have gotten more, but chose to do the cool thing and leave them for others' to purchase. I have what I need.

Now, if I could just find some Bullseye and/or W231/HP-38. Last time I saw W231/HP-38 on an LGS shelf was just before the shortages (Nov./'12). I had a little over a pound at the time, and didn't see a need to get more. Boy, that was a mistake.

alanshaffer2000 · July 22, 2014, 09:32 PM

Thank you all. I will let you know how it turns out.

buck460XVR · July 22, 2014, 09:44 PM

Quote:

Originally posted by alanshaffer2000:

New to reloading and wondering why IMR 4227 (not to be confused with H4227) load data for 357 mag. using 158 gr. SWC is not listed in Hodgdon or IMR official load data, but IS listed in Lymans (#358665).

I'm ready to reload my first batch of 357's, but not willing to lose a finger or damage firearm by not following the manufacturer guidelines. Planning to start @ 12.5 gr. and move up to 15gr. Am I in safe territory here?

My firearm is GP100 6"

The "new" IMR4227 is just the "old" H4227 rebranded. If you look at the rifle section for .357 in the Hodgdon web site load data you'll see the powder charges listed are exactly the same for IMR4227 and H4227 with a 158 jacketed. Velocities and pressure listed are exactly the same also. This and a e-mail reply from Hodgdon tell me it's the same powder.

That said, in the .357 rifle section they give a recipe for H4227 and a 158 SWC. Min is 10.5, max is 11.5. Most manuals give same max loads for rifles and revolvers in handgun calibers.

rclark · July 23, 2014, 11:29 AM

I tested IMR 4227 from 10.2g to 14.0g under 158g SWC. Didn't mark any load tested as particularly accurate. Maybe you'll run onto a load you like

. Just remember to use a Magnum primer (say CCI-550) with the powder for best results. Your good to go.

My 'goto' load is 5.0g of Red Dot under 158g SWC for around 1019fps.

T. O'Heir · July 23, 2014, 03:35 PM

It's on the site for a 140. Not being listed for other bullet weights usually means they didn't run any tests.
There's lots of data in my Lyman book. Jacketed or cast matters. It shows 9.5 to 15.0 for a cast 158 with a gas check. 11.5 to 15.0 for a jacketed.
Use the IMR data. IMR is owned by Hodgdon.

sig220mwxxxx · July 24, 2014, 04:58 PM

I have good results using imr 4227 for my 357 magnum. I however do not use the 158 gr bullets but instead 180 gr swc gas checked bullets. In fact I use imr 4227 for 44 special and 45 colt and get good results for all three. Like others have said it is a slower burning powder and as such yields good velocities. I have done this purposely so as to try and cut down the number of powders I have. I must admit though that I have a supply of win 296 that also works for these three. It seems to kick a little sharper so I chose the imr as my usual with the 296 to be used as a reserve when needed.

July 21, 2014, 08:29 PM	#1
alanshaffer2000 Junior Member Join Date: July 4, 2014 Posts: 10	IMR 4227 load data for 357 mag New to reloading and wondering why IMR 4227 (not to be confused with H4227) load data for 357 mag. using 158 gr. SWC is not listed in Hodgdon or IMR official load data, but IS listed in Lymans (#358665). I'm ready to reload my first batch of 357's, but not willing to lose a finger or damage firearm by not following the manufacturer guidelines. Planning to start @ 12.5 gr. and move up to 15gr. Am I in safe territory here? My firearm is GP100 6" http://www.imrpowder.com/data/handgun/357mag.php http://www.hodgdonreloading.com/ Thanks.

July 22, 2014, 05:29 PM	#6
coldbeer Junior member Join Date: February 21, 2012 Location: Woodhaven MI Posts: 477	My target load for 158 grain plain base lswc bullets is 6.7 grains of hs6. This is a very mild and accurate load in my 8 3/8" 686, but I understand finding a vertain powder isn't easy these days and you have to work with what you have. I'm pretty sure IMR 4227 and h4227 are the same powder. Last edited by coldbeer; July 22, 2014 at 05:44 PM.

July 23, 2014, 11:29 AM	#12
rclark Senior Member Join Date: February 12, 2009 Location: Butte, MT Posts: 2,650	I tested IMR 4227 from 10.2g to 14.0g under 158g SWC. Didn't mark any load tested as particularly accurate. Maybe you'll run onto a load you like . Just remember to use a Magnum primer (say CCI-550) with the powder for best results. Your good to go. My 'goto' load is 5.0g of Red Dot under 158g SWC for around 1019fps. __________________ A clinger and deplorable, MAGA, and life NRA member. When guns are outlawed, only outlaws will have guns. Single Action .45 Colt (Sometimes colloquially referred to by its alias as the .45 'Long' Colt or .45LC). Don't leave home without it. That said, the .44Spec is right up their too... but the .45 Colt is still the king.

July 21, 2014, 08:50 PM	#2
res45 Senior Member Join Date: September 15, 2007 Location: NC Posts: 753	I find around 14.5 grs. of IMR-4227 to be an excellent load using 158 gr. SWC in plain base or gas check versions. I've shot this load for years in my Ruger Blackhawk.

July 21, 2014, 10:34 PM	#3
BOOMST1CK Senior Member Join Date: January 9, 2014 Posts: 117	I really like using 14 gr of 4227 under a 158 gr berrysbullets FP, good target round.

July 22, 2014, 04:57 PM	#4
coldbeer Junior member Join Date: February 21, 2012 Location: Woodhaven MI Posts: 477	There's so many different bullets they can't list them all. If you use the data given in this thread and your previous one you'll be OK. You'd have to work really hard to blow up a GP100 with IMR 4227 anyway. It's a slow powder and I don't think you could fit enough of it in a case since max loads are already compressed pretty good.

July 22, 2014, 06:34 PM	#8
coldbeer Junior member Join Date: February 21, 2012 Location: Woodhaven MI Posts: 477	I really wish I could find some unique. I'd cherish it.

July 22, 2014, 09:32 PM	#10
alanshaffer2000 Junior Member Join Date: July 4, 2014 Posts: 10	Thank you all. I will let you know how it turns out.

July 23, 2014, 03:35 PM	#13
T. O'Heir Senior Member Join Date: February 13, 2002 Location: Canada Posts: 12,453	It's on the site for a 140. Not being listed for other bullet weights usually means they didn't run any tests. There's lots of data in my Lyman book. Jacketed or cast matters. It shows 9.5 to 15.0 for a cast 158 with a gas check. 11.5 to 15.0 for a jacketed. Use the IMR data. IMR is owned by Hodgdon.

July 24, 2014, 04:58 PM	#14
sig220mwxxxx Senior Member Join Date: April 16, 2011 Location: Marshall, Texas Posts: 104	I have good results using imr 4227 for my 357 magnum. I however do not use the 158 gr bullets but instead 180 gr swc gas checked bullets. In fact I use imr 4227 for 44 special and 45 colt and get good results for all three. Like others have said it is a slower burning powder and as such yields good velocities. I have done this purposely so as to try and cut down the number of powders I have. I must admit though that I have a supply of win 296 that also works for these three. It seems to kick a little sharper so I chose the imr as my usual with the 296 to be used as a reserve when needed.