Home Forums Hunting & Shooting Long Range Hunting IMR4350 Vs. H4350

Both powders will deliver supreme accuracy in that cartridge!

Them young boys on my deer lease say IMR 4350 is an old man’s powder

I've used IMR 4350 for years in my 270 with 130 grainers, my 257 Roberts with 90 grain X-bullets, and used it once in my 7 RM with 145 grain Speer Grand Slams. All 3 guns shot less than 1" groups and have good velocity so I've never bothered to experiment with H4350. The way I see it, if it works don't mess with it.

I don't buy imr-4350 at all anymore h-4350 for the win..mb

Two similarities. I prefer IMR 4198 over H 4198 because it produces slightly better accuracy and velocity for me, the same reasons I prefer IMR 4350 over H 4350. Almost the same thing with IMR 4895 and H 4895 except for ease of metering. They are horrible to meter but I crunch em anyway, even down to the little 17 IV. Been shooting some X terminator and it's perfectly luverly.

A4350 works for me. Like that brown can, but got a deal on Accurate 4350 and been liking it.

One of my favorite smells in reloading during my teenage years was cracking open a brown can of imr-4350 to load up another box of 30-06 ammo. Couldn't resist taking a quick wiff before commencing with the loading process. Switched to H4350 for better accuracy and speed compared to the IMR version, but when dispensing from the automatic Lyman PDS the long grains of IMR-4350 don't matter.

Years ago I compared IMR4350 to H4350 before it was changed to the Extreme line in my 7mag with 140gr bullets and the IMR4350 was about 100fps faster.I've used IMR4350,H4350 and Accurate4350.All three of these powders have given me good accuracy.Don't know,maybe it's changed over the years,but I've read a lot about Accurate4350 being the slowest velocity of the three.When I compared it in my 30-06 with 165gr bullets shooting all three powders loaded with the same charge,Accurate4350 gave me the highest velocity,followed closely was IMR4350 and around 30fps or so behind them was H4350.Did this same test recently in my 308 Norma Magnum using 180gr bullets and my results were different.H4350 gave me the highest velocity,followed close to it was Accurate4350 and the slowest by around 30fts was IMR4350.I know powders can change a little from lot to lot,temperature and humidity can affect it as well,but it has me thinking case fill and pressure also can affect the results of velocity.Temperature is not a big factor for me because it's usually somewhere between 30-80 degrees.As far as accuracy goes,all three have given me good results if loaded right.

This is a pretty astute observation.

I'm a tweener.

Old farts simply refer to it as 4350

You guys forgot about AA 4450

I use both. Just depends on how they shoot in different rifles. Temperature stability here isn’t too big a problem but It’s in the back of my mind. H4350 for my elk loads in 30/06 to be used in Colorado.

Some readers may be interested to know that when H 4350 (AR2209) was created in the 80's it was released with an advertised burning rate being 95% the burning rate if IMR4350 so was a touch faster.

If you like drooling over the past you might like to know I had mates who bought powder in 250 pound kegs. Aussies tend to reload and shoot a lot more than Americans because of no game laws, no hunting seasons or bag limits, no Wildlife departments and no snow country for most.

Ah, the old days, we called it.

Much of my load testing with old favorites of mine was with the IMR version. I've been trying the H version and I think as far as accuracy goes the H version is likely as good as the IMR. If you have lots of IMR, I'd suggest working with that powder.

I guess I'm considered old school...

Here are the results of a test I made of the three 4350 powders, which was published both as a magazine article and as Chapter 9 of The Big Book of Gun Gack II, "Different Batches of the 'Same' Powder," using a 24" barreled .257 Roberts. The loads were identical except for the powder, and I used 45.0 grains with the same cases and primers, and 100-grain Ballistic Tips seated to the same depth. And yes, they were during the same range session:

IMR 4350, 3083 fps.
A4350, 2917 fps.
H4350, 2980 fps.

Obviously this might vary with different manufacturing lots of the three powders. The best-grouping powder in that test was H4350, but that also could easily vary with other lots--and rifles.

Good info. However, as I've stated before, when you and others bring up examples like this, on these types of tests is the one that hits on the best node is going to shoot the best: It's always going to be about OCW. I'll bet if you drop the charge weight (to say 43.5gr's for example) on the IMR a bit, to get it closer to where the H is running, it would shoot just as accurately and consistently. In my experience IMR shoots damn well, but you have to develop loads in the fall or winter, where the temps are close to where they will be when you hunt.

With that being said, my favorite powder is H4350 because of it's consistency all year around. Loads with this powder are not affected by temperature change, like the other powders mentioned (IMR and AA). One reason why my competition ammo is loaded with H4350. I don't have to mess with it, and I know I can trust it, regardless of the temp. That adds a ton of confidence and peace of mind.

Have both IMR and Hodgdon in several different powders. I use one or the other to develop accuracy loads for a cartride/ bullet combination and stick with that load for that cartridge. There is a bit of burn rate difference between IMR and H in the same numbers in the past but they are close. Has been about the same as a lot change in powder. As always , when you change lots, you start the accuracy load development again with a back off and the back up.

Well said BSA. The powder vs powder velocity numbers is good solid information...the accuracy information means nothing.

i guess since i am 70 yrs. old its IMR 4350 and that`s great it does seem to shoot well in my 30-06 Winchester. great information ha-ha ,Pete53