Is there any real world difference between the IMR and H powders.

I am thinking about starting my load work up with 4350 and 4831 for the 30-06, along with CCI 200 and Fed 215 primers, new winchester brass.

Thanks, John

30-06 likes both H4350 and IMR 4350. There is a small differance in burn rate between them. I have not used 4831 in 30-06 but quite a few people do and have good results.

The IMR powders are a bit faster then the Hodgdon. The Hodgdon powders are also part of their "extreem" line and are claimed to be more resistant to temp variations and are available in "short cut" form that meters better in a powder measure.

H 4350 is a bit slower than IMR 4350. Moreover, in every instance where I've tried the two, I've found that, with max loads of each -- the max load of H 4350 will be a grain or two heavier than the max load of IMR 4350 -- H 4350 gives me either higher velocity or better accuracy or both.

H 4350 is likely to be the best possible powder for many loads in the 30-06, or so it has been for me anyway.

The old H4350 was slower than the IMR4350.

The new H4350 Extreme powder is faster than IMR4350 in the latest lots I have tried.
H4350 Extreme is very close to AA4350 but also a little bit faster than that one too.

New H4350 Extreme is probably the most versatile and best powder available for the .30-06, and the .375 Wby, and the ...

In the .375 Wby, I have seen about 2 fps/degree F temperature sensitivity with IMR4350, but with H4350 Extreme it was 0.5 fps/degree F. RL-15 was 1 fps/degree F in the .375 Wby, in my limited experience.

I use H4350 in my 243. It is very good but I have 2 issues with it.

1. It is no more extreme than any other single base powder I have tried. In winter (England so not really cold, maybe 48 or so) it gives 3,140fps with 85gr bullets (generaly within 5fps shot after shot) and in summer at 70 it is 3,225fps. This is no problem other than it's no better than any other single base powder without all the marketing hoopla.

2. It's much dirtier than the Viht powders I generaly use.

quote:

Originally posted by Ropes:
Is there any real world difference between the IMR and H powders.

I am thinking about starting my load work up with 4350 and 4831 for the 30-06, along with CCI 200 and Fed 215 primers, new winchester brass.

Thanks, John

The IMR and H- powders fall side by side on the burn rate charts in many cases but not all. This implied but don't prove that in some cases they are exactly identical. Until Hodgdon comes out and says they are I think it's a potentially grevious error to use the data for one as the same for another similar sounding powder.

Ropes,

I have found that the IMR is a little faster than the H powders and that the (for what it's worth) the H powders meter & measure a little bit better than the IMR (especially the Short Cut (SC designated) powder). Also we cannot get IMR powders here in Europe so I exclusively use the H powders.

I have had great results with either IMR/H 4350 & 4831 in the 30/06 and consider these are excellent powder choices for 165 & 180 grain bullets in this cartidge. While I'm sure everyone has their favorites try 60.0 grs. of H-4831 with a 165 gr. Nosler Partion and you should be pleased with the results.

One benefit of H-4831 in the 06 case is that you cannot (normally) stuff enough into the case to get into serious pressure issues - IMO.

Also every rifle is law unto itself - the Reloading manuals consitantly state H-4350 gives more veleocity with 165 & 180 grainers. I get more velocity (& better accuracy) from H-4831 in my .30/06.

I just did some testing this past winter comparing the two powders in a 243 and a 338 WM. In both cases H4350 was faster - need to reduce loads one grain or so for the same velocity as the IMR version. IMR loads tested at temperatures down to 4 below showed up to 150 fps velocity loss - drop offs were 100 plus at 38 degrees compared to 80 degree days. H4350 velocities did not degrade with temp.

quote:

Originally posted by 2manyguns:
I just did some testing this past winter comparing the two powders in a 243 and a 338 WM. In both cases H4350 was faster - need to reduce loads one grain or so for the same velocity as the IMR version. IMR loads tested at temperatures down to 4 below showed up to 150 fps velocity loss - drop offs were 100 plus at 38 degrees compared to 80 degree days. H4350 velocities did not degrade with temp.

2manyguns,
Your handle would fit me too.
Your experience is the same as mine.
I think you must be working with the NEW H4350 EXTREME.

It is faster than the OLD H4350.

Nowadays we have to specify "H4350 EXTREME" versus "OLD H4350" if we are talking H4350.

Right?

quote:

Originally posted by RIP:

Nowadays we have to specify "H4350 EXTREME" versus "OLD H4350" if we are talking H4350.

Right?

This may be right.

The H 4350 I'm using is from some years ago.

In the case of 4831, all the H 4831 I've heard about is slower than IMR 4831. So a max load of H 4831 may be too hot if you were to substitute the same amount of IMR 4831.

Ropes,yes there is a real world differance between them when you get to max loads. I ran into this in old reloading books that my pop had laying around but mostly with the IMR vs H4831 powders. IT was extreme enough to BLOW primer pockets on newer cases.Dont confuse the two. I shoot both but I know Hodgdon bought out IMR a few mohths ago so I stocked up on the old IMR-4350. I hate it when companys verge especially when they were opponents because they jack up the prices!

H-4350 flows better through a powder measure too.

I can tell you from experience IMR4831 is definitly hotter than H4831---DO NOT USE LOAD DATA INTERCHANGABLY

The Sierra reloading book from about 25 years ago didn't indicate which manufacturer--just showed 4831 --- I poped primers right and left until I got wiser and pulled the rest of that bunch apart.

For a while I switched to 4350 but now I use only H4831sc in my 25-06

I'm with the guys that have the short cut 4350/extreme being faster than I 4350--that's they way it is with my powder lots. About 50 fps faster for the H over the I.

I use the H4350, too in my 06's. Seems they all like 58.5 gr with a 165 Interlock a LOT.

quote:

Originally posted by kraky:
I'm with the guys that have the short cut 4350/extreme being faster than I 4350--that's they way it is with my powder lots. About 50 fps faster for the H over the I.

LE270 and kraky,
Thanks.
H4350 Extreme is faster than OLD H4350, I agree.

OLD H4350 was slower than IMR-4350.
H4350 Extreme is faster than IMR-4350.

Not much change with H4831 Extreme (long cut or SC) versus the OLD H4831. They are all slower than IMR-4831, as pointed out above. I agree.