Home Forums Reloading Big Game Rifles IMR4350 vs H4350

I'm going to be hunting elk at tree-line soon. The bullet cartridge combination I've chosen would have been IMR4350 written all over it before I started reading about temp sensitivity.

So I've bought a few pounds of H4350. Then prairie dog shooting and a lot of other things got in the way. so I'm hoping to gather information to quicken my testing...

First looking at manuals, there's fewer H4350 loads in manuals it seems. Second the newest Nosler manual says IMR4350 is the most accurate powder in this combination.

I understand that H4350 is a little slower but Hodgen reloading site has less H4350 than IMR4350 and it's loaded to a way lower pressure.

Does H4350 have red hair? Is it as good as IMR4350?

For those of you that use this powder, is it as accurate as the IMR version? Can you get the same or similar velocity?

Thanks

What cartridge and bullet?

Years past I shot scads of IMR4350 and still shoot some. It was the first powder that brought the temperature issue to light for me.

Sometime ago I switched to H4350 and have not used much else in the 30/06 since then...and strictly with 165 gr bullets. Far as I can tell one is as accurate as the other.

Yes I get the same velocities with both powders; usually around 2900 fps with H4350.

A buddyy knocked off a bull elk in the San Juans in 30 degree temperatures at around 500 yards,after shooting his 30/06 all summer back here with a max load of IMR4350 in temps of 80-90 degrees.

Go figure.

40-60 foster swing in my 300wsm with imr4350. 25-degrees to 80-degrees.

I would worry if was shooting 500 yards but out to what most of my shots are it is not a big deal.

[quote=Bugger
Second the newest Nosler manual says IMR4350 is the most accurate powder in this combination.
[/quote]

But that doesn't mean it will be the most accurate in your rifle. It's quite possible H4350 will be more accurate in your rifle.

Bugger,

Both IMR4350 and H4350 vary slightly in burn-rate from lot to lot, but overall I've been using exactly the same charges as IMR4350 since starting to use H4350 at least 15 years ago, with very similar results in both accuracy and velocity in cartridges from the .243 Winchester to .375 H&H.

The "way lower pressure" you noticed on the Hodgdon site is probably due to some loads being tested with copper-crusher rather than piezo-electronic equipment. CUP (Copper Units of Pressure) aren't the same as PSI (Pounds per Square Inch): 50,000 CUP is approximately equal to 60,000 PSI in most bolt-action cartridges.

I've killed a BUNCH of big game with loads using IMR4350, much of it in relatively cold weather, with no problems out to 300 yards or so. If you don't intend to shoot much farther I wouldn't worry about it much. But H4350 does result in more consistent velocities in cold weather, so leaves only the increased density of colder air as a factor consider on longer shots.

When I was experimenting with a 25/06, I could load a couple of grains more of H4350 than IMR4350. Some bullets grouped better with one powder over the other, you just have to shoot them to see.

I actually switched from imr 4350 to h4350 as a price and availability issue. And yeah, this was before the 6.5 Creedmore, and the swarm of guys who will use nothing else in it.

Nowadays I can find either A4350 or imr 4350 at least a couple of places that I frequent. But to use them I'd need to work up different loads. If I'm gonna work up new loads I wanna go forward rather than backwards. I wanna try the 4451 Enduron stuff.

Easy for a guy to overthink some of this stuff. Use what you can find, and enjoy the trigger time...

Worst powder that I've used for temp sensitivity is RL22. It's also THE most accurate powder i have found in a couple of rifles. Gotta say that I tend to stick on what works and don't care to experiment as much anymore. If I could find h4350 I'd never try the enduron stuff. Most of the newer generation powders just don't mean anything to me.

I shot imr 4350 in my 243 for years. A great powder. I had a poi change with this powder below 20 degrees,although some of it was due to denser,colder air. I switched to h4350 and did not notice the poi problem nearly as much.It really is temp resistant. Probably 3000 to 3500 rounds on these 2 powders,at all temperatures. Both are very accurate. If you are not hunting in really cold temps,you will never know the difference.

thanks. That makes me feel much better.

bugger, someone asked what cartridge and bullet. Care to fill us in? As for your question about H4350 being a "red headed stepchild", no it is not. It's damn good stuff. It's just hard as hell to find in these parts. I run across IMR4350 in every LGS I visit. My long time elk load used IMR4350 with a 250gr. pill. It worked wonders on elk. I develop loads in the winter time for my elk rifles, so temp sensitivity isn't an issue. Let us know what cartridge and bullet you intend to load up and we can help more...

I get as technical as the next shooter on the bench, but moving away from the bench and into the hunting fields, I think IMR 4350 will do everything you would ask H4350 to do. I like both powders and use both for me and others, but for my personal rifles, the IMR flavor has always shot a little better, so I use it. My 30/06 is a classic rifle, so I thought it would be cool to go with a classic load of 57 grains of IMR 4350 under a 165 grain bullet. It shoots well every time with no surprises. Here in the desert, I sight in as late in the fall as I can, but it's still 80 plus degrees much of the time. This past November, I took a mule deer on a morning that my truck read 16 degrees. I don't know if I lost velocity or not, and it was only a 200 yard shot, but that bullet landed exactly where I wanted it to go. That piece of brass went back in my pocket, and it will get some more IMR 4350. I say pick what shoots best, and go hunt.

Yeah, groups 1/4" smaller make a big difference on elk.

I'm in the same boat shooting IMR 4350 in both of my elk rifles. I sight in in rural San Diego County at about 4000 Ft of elevation and somewhere around 75 degrees. It will be close to 90 today. We hunt at 7800 Ft on average in Colorado at around 25 degrees any morning or evening.

One of my younger, very technical shooting friends who thinks you need a ballistic program to pull a trigger was terribly worried about the climatic differences. I explained to him that I'm the biggest source of inconsistency in the field shooting and that he was full of crap..... but feel free to run the numbers and let me know.

When he figured the difference it was .2 of an inch at 400 yards and I assured him that even though I've always thought my marksmanship is stellar - that I wiggle a heck of a lot more than that at 400 from a field rest. Last year at 550 yards my 2 shot group was middle of elk vitals with all that inconsistent powder, elevation, and barometric pressure working against me..... funny how those bullets keep hitting where the crosshairs meet hide.

FWIW, I went to CO and dropped a nice Mulie with a 270 and 52.0/IMR4350 under a 150 Partition. Seems that was max in that 700, 24" bbl. Range 275 yds, stopped just short of exiting the ham/hide after punched just to the side of the throat, head on.

Chrono'd 2850 mv - it was enough.......

Whatever you use, KNOW the POI/POA, and use a proper bullet.

No animal will know the difference.....

That said, in the 6.5s, alot of folks use "H" and it's reported to give about 75 more fps.

I found the difference in poi to be 1\2 m.o.a. at 200yds in the cold winter weather. This would make no difference to most big game hunters. It did make a difference to me, because that .5 at 200 grew dramatically on a coyote at 500 to 600yds. Enough to easily miss it.And since killing those little varmits is my job, I went to the more temp stable H4350. Air density is still an issue,but powder is not.

Yeah, that's the major advantage of cold-stable powders: You don't have to compensate for TWO effects of cold, just denser atmosphere.

On really cold days calling, I leave a couple of shells in my pants pocket. If I have to shoot a ways, I slide one of the warm ones in. Still have cold barrel, dense air, ect. Indecently, the leica geovid HD b s have been very accurate on giving me the correct clicks in extreme weather conditions,elevations,and angles. fww.

My first rifle in the early 60's was a Mauser 98 7.92x57. I only shot perhaps twenty rounds in it before the Sharon 6mm Remington arrived dad did the rebarrel and I bought a Herters C grade varmint stock. The IMR 4350 with 75 grain (both Speer and Sierra) bullets would shoot 1/4" groups. Thus the love affair with 6mm Remington and IMR 4350. Since then I've used that powder in many cartridges. I bought it in 8 lb containers.

I'm looking at 30-06 with Partitions for a cow elk tag in WY. I'm using lighter than normal (for me) bullets because I'm also loading for my son and I'm concerned on how he handles recoil. I will bring 3 ea 06's along. They all shoot under 1MOA with IMR 4350. When hunting out of state I normally bring a spare rifle. I often do so in state if away from home.

Since I live a little over 1,000 feet in elevation and am sighting in at 70 degrees. Plus, We will be hunting at tree line, perhaps 11,000 feet. At that elevation temperature could vary greatly, I think.

While shooting will likely be close range, I want to eliminate as much variables as possible. And in case I miss there's always "The sun got in my eyes and the rocks I was standing on moved about the same time as I was stung by something, and I heard a rattle that sounded like a timber rattler just behind me and...

Ive had better luck with IMR 4350 for 30-06 165 loads. H4350 seems to do better with 180's accuracy wise. IMR4831 for velocity behind the 180's.