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H4350 vs. IMR4350

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24 November 2003, 06:26
tlp335
H4350 vs. IMR4350
Are the burn rate of these two powders similar? I am trying to work up a load for a 280 Ackley and have been very happy with H4350 in other calibers but the load data I have found is for IMR4350. Could I use the IMR data for the H4350? I am fully aware of pressure signs to watch out for, but for a starting load, are the 2 interchangible? Thanks
24 November 2003, 06:46
Bigdaddytacp
quote:
Originally posted by tlp335:
Are the burn rate of these two powders similar? I am trying to work up a load for a 280 Ackley and have been very happy with H4350 in other calibers but the load data I have found is for IMR4350. Could I use the IMR data for the H4350? I am fully aware of pressure signs to watch out for, but for a starting load, are the 2 interchangible? Thanks
..FOR A STARTING LOAD the two are interchangable....according to the load/cartridge they do vary a little in burn rate/pressure at the upper end but not enough to worry about for starters and working up....IMR is listed on a few burn rate list as just barely faster than H......and a couple percent difference in weight/volumne......not much difference and no more than you might find in Lot to Lot variances in either powder......good luck and good shooting-loading!!
24 November 2003, 08:46
tlp335
Thanks Bigdaddy. That is pretty much what I though, but I just wanted to check. Thanks again!
24 November 2003, 09:00
R Flowers
Good advice from Bigdaddy. I find more and more uses for H 4350, it is good powder.

R F
24 November 2003, 09:02
kraky
I have a can of each and from what my chrono tells me they have been real identical in making velocity. H 4350 has not been showing me a slower velocity. I would have to think pressure has been real identical too. BUT you have to remember that these are two individual lots and it's possible that lots can vary by 5%--so maybe my IMr is a hair slow and my H is a hair fast. At any rate for my purposes I would not load H4350 with any more grains than I4350 as some data suggests.
24 November 2003, 09:39
Canadian reloarder
Hi tlp335. I've used these two powders quite a bit in my 300Win mag, 25/06, and in my 270Win. I've always found H 4350 to be about 2grs slower than IMR4350. In fact I've found it to be between IMR4350 & IMR4831. A very useful powder in a variety of calibers.
24 November 2003, 13:31
ricciardelli
Faster to slower:
176 IMR-4350
177 H-4350
178 S-365
179 TU-7000
180 N-550
181 AA-4350
24 November 2003, 13:52
4bambam
ric--posted the order=imr4350 than h-4350, you can usually use 1-2 more grs of h-4350. Imr will show more signs of pressure faster before you reach the higher vel. with that powder. Imr 4831 and Imr 7828 are also excellent in that cal. [Wink]
24 November 2003, 14:15
mjolnir2thor
Been using IMR4350 in my .257 Wby Accumark for years. Loaded at 3300 fps as per the Hornady manual (58.8 gr) for a 87 SP bullet, I've gotten a best grouping of .5 MOA at 100 yards. [Smile]