Home Forums Hunting & Shooting Ask The Gunwriters H4350 v IMR4350

I’ve always had great groups with IMR 4350, it’s hard to change when something works so well.

Very interesting thread. I've heard others say the H gives about 50-75 fps more than IMR.......

Regardless, I always used IMR as a go to for 243 and 270, though the latter had less speed than say H4831. I have had great accuracy with both. 1/4 MOA at 200 yds in a custom 260 with H, using Lapua.

Nice to see so many good options, since perhaps high volume shooters are using/hoarding....if not the ammo companies, IDK.

If you get any good load, have the POA/POI worked out, and enjoy. I doubt for field use the difference is material, but results vary.

Lastly, on that 4451 note by JB, I have always thought there is more potential speed in the 243 with slower powders yet than 4350. Is accuracy there, I have not tried, but 6mm Rem has some data (IIRC Nosler) using powders that are definitely slower burn rate than 4350 class. Small bores do like slow powders.

I changed to H in the past for the SC aspect, and hope for more speed. That said, IMR sure is a benchmark in many rounds.

bought imr4350 from a hoarders estate. he had 800lbs of it when he died. they were selling it for 15.00 a lb gave me a heck of a break on 125 lbs. i have used it in 06, 6mm and others .

John, just call me Ed, it's easier.

Thanks for the info. I've done some loading for my .243AI, mostly with IMR4831, Retumbo, and Re-26. I've read of folks having a lot of luck with H-4350/IMR4350 for accuracy, which is also my primary goal.

For the 6.5 x 280AI, I will take a look at the 4955 & 7977. I've seen a few 1lb jugs of 4955 around here, haven't seen the first one of 7977. Yet.

Ed

If you are persistent, it is out there. I dislike changing powders at this late stage.

bigwhoop,

I grew really weary of persistently looking for H4350, along with other stuff that appears briefly here and there. So I simplified my life and switched to 4451, though I'd already worked with 4451 enough to know the switch wouldn't be tough. So far it's taken trying 2-3 loads to match (or better) H4350 results in 7-8 rifles. Didn't even have to change the scope setting.

N2TRKYS,

Dunno how you're working up loads, but if you check Hodgdon's pressure-tested data, the vast majority of the time max listed loads for H4350 and IMR4350 produce just about the same velocity, though there are exceptions. Here are some examples from Hodgdon in various cartridge/bullet combos I've used both powder in over the years:


.243 Winchester 100-grain:
H4350 2973 fps
IMR4350 2958 fps

.30-06 165-grain:
H4350 2781 fps
IMR4350 2770 fps

.338 Win. Magnum 250-grain:
H4350 2637
IMR4350 2634 fps

.375 H&H 300-grain:
H4350 2645 fps
IMR4350 2478 fps

Ed,

In the 6.5-.280 AI I'd also be very tempted to try Reloder 26.

Just picked up a jug of it.

Thanks again!

Ed

whats the story on the scarcity of H4350?

Still in production now and then?

My primary contact at Hodgdon recently told me the H4350 shortage is mostly due to the popularity of the 6.5 Creedmoor. H4350 is considered its ideal powder.

I don't know why, but it just never seems to work out like that in my rifles. Maybe it's something I'm doing.

H-4350 always seemed to be about one grain behind the IMR and A-4350 in all my velocity test in 30-06 or greater size cases.

For those worried about IMR4350 and temperature sensitivity, re-read what Mule Deer said about what kind of extreme temperature variance is needed before affects are noticed. I use IMR4350 in a 6mm Rem and quit worrying about it (at least where I hunt anyway).

IMR4350 works well in several of my cartridges, most notably my 6.5x55.

Sakoluvr,

Good point, and it also might be pertinent to point out that while all the older IMR powders aren't considered temperature-resistant in the same was as the Hodgdon Extremes, temp-resistance also depends on some other factors, including load density and primer. I still use IMR4350 in a few loads, because I tested them and found they performed very well in cold.

Other IMR4350 loads, however, were definitely affected, the reason I switched to H4350 in them, and now IMR4451.

I am going to try R16 and R17 when I start working up 4350 substitute loads. Similar burn rate with usually higher velocity. Not a close match but in the ball park. But R16 is just as hard to come by at the moment as H4350. A max charge of R16 in the 25-06 and the Leheigh 85 grain chaos bullet will not be liked by Hogs at 3600 fps.

The 6.5x280AI sounds a lot like my 25-06 A!


7977 works really well for me.

JB confirmed my guess on the 6.5CM burning up all the H4350 The ideal powder, perhaps near ideal cartridge, for much of what is done in NA.

On the Swede target, curious what bullet weight?

JB - is the "Variance" due to temps in the IMR, due to expansion ratio? Or no trends?

TAG

IMR4350 was my first favorite powder (back then, 244/6mm Remington & 30-06). I think I've come close to running out. I'll be on the look out for 4451. Thanks for the thread.