IMR4350 vs. H4350

[skiutah02]

Did see a few threads on this but they were quite dated.

Pulled the trigger too quickly on a recent order. What thinking I was ordering H4350, but instead ordered IMR4350.

My bad, my fault. Unfortunately ordered 10 lbs.

How close are they? I have not developed a load for the 6.5-284, but H4350 was suggested as the powder to use by someone who I trust.

Yes, I can do load development with this powder, but with the barrel life really don't want to waste time/material/money if I should just cut my losses and wait for the H4350.

Drew

 

[Lapua40X]

Frankly, I'd prefer the IMR4350 for its wider range of load options when compared to the range for H4350

 

[Steve Blair]

I've had good results with both H430 and IMR 4350. Accurate 4350, too. All three are in the right burning range for a lot of cartridges.

 

[2506]

All the 4350s are close in burn rate with H being just very slightly faster than IMR or AA. Do a work up and you will be fine.

 

[fdshuster]

I've been told (can't prove it by me) that IMR will be a little more temperature sensitive, unlike the Hodgdon extreme powders. Bought 2 cans of IMR 4350 for a new 6.5x47L build, then heard the claims that pressures would increase with warmer temps. Just bought 2# of H4350, so will do some comparisons.

 

[skiutah02]

Thanks for the replies. When I get going on my 6.5-284 project (need to finish up some FTR matches), I'll update what I find out. Drew

 

[CaptainMal]

In smaller cases, like Dasher, it's not good. IMR seems to take up more space and is a bit slower. In larger cases the differences don't seem to be as much. My experience in larger cases seems to find the IMR to be a bit faster.

There are many here that seem passionately against IMR powders. Don't know if that's because they are so "old" or what. Hodgdon, Alliant and VihtaVuori seem to be more "in" for a variety of myths.

Try it and see. I tried it in my 6.5 AI and it worked. Rel. 22 just seemed to work better and I settled on it. Most of my larger and standard cartridges work well with IMR 4350. It could be the one powder you need if you could only use one.

 

[243DH]

Imr4350 is good powder, shoots accurately but is pretty dirty compared to h4350. I have found that in my one rifle i shoot it in that velocity swings 65 fps in 90*-60*. My h4350 load in that rifle swings 35fps in 90*-35* change. I had 5 rifles that used h4350 and my supply started to dry up of it. I found 8 lbs of imr4350 and worked up a substitute load. It shoots very good and gets same speed, just more temp sensitive. Once that 8 lb is gone i will return to h4350 for all rifles.

 

[rvn1968]

The Graf burn rate chart ranks them one after the other.Followed by Alliant reloader 17 and then Accurate Arms 4350.

 

[schumi]

My prone rifle in 6.5x284 loves 49.5gr of IMR4350 under a Sierra 142. But my hunting rifle with 140SSTs prefers 50.8gr of RL22. I have tried H4350 and run it occasionally in my prone gun and my 6.5x47. I agree with 243DH, the H4350 is much, much less temperature sensitive.