Home Forums Reloading Big Game Rifles IMR 4350

With the shortage of H4350 now if I bought an 8lb keg of IMR 4350 would really even notice a difference in preformance? Following printed data of course.

Nothing wrong with IMR 4350.I get good velocity and accuracy with it.I've used it with temps from the 20's to a 100 degrees without any issues that I could tell.I load around one grain less than what I would with H4350.

There's enough of a difference you will need to back off a bit and work up again. Your exact optimum load will probably be a little different, but it's not uncommon to settle on loads within a half grain (or an .06 sized case) when switching between H and IMR variants of 4350.

Don't forget about IMR-4451. It's the "new" 4350....kind of....

I have used Accurate 4350 for a long time. It is currently available locally. Not a bench rest shooter, but the game I have taken never complained.

I did a test on three 4350 powders all loaded the same with a 168gr Nosler Ballistic Tip out of one of my 30-06 rifles.All of them gave me very good groups.This is how they compared in my rifle.

58.0grs A-4350 - 2917fps - Best group
58.0grs IMR-4350 - 2911fps - 2nd best group
58.0grs H-4350 - 2890fps - Largest group of the three,but only about 1/4" larger

How many shots in each group?

How many groups of each combination?

I've used IMR-4350 for years in several calibers with great success. 257 Roberts/270 Win/6.5 Swede/7mm SAUM and 7RM. I tried H4350 in a couple of those claibers and never got the same accuracy as I did IMR 4350.

baldhunter,

Ran the same sort of test 2-3 years ago with the three 4350's, using a .257 Roberts with 100-grain Ballistic Tips:

45.0 IMR4350: 3083 fps, 1.35 inch groups
45.0 A4350: 2917, 1.88
45.0 H4350: 2985, 1.12

Powder batches, even of long-established powders like IMR4350, can vary some. Have seen Hodgdon data over the past 20+ years since the Australian H4350 "Extreme" appeared that sometimes showed IMR4350 as faster-burning, and sometimes showed H4350 as faster burning. No doubt this was because of the latest manufacturing lots.

Have also seen new powders vary considerably as well, especially when first introduced. This is because powders for handloaders are typically blended with previous batches, to result in a more consistent product, and when there hasn't been many batches produced yet, the powder can vary more even after blending. Here's one with IMR4451 when it was introduced a few years ago, using the same 100-grain Ballistic Tips in the same .257 Roberts, with the same brass and primers:

46.0 4451, lot 1: 3052, 1.49
46.0 4451, lot 2: 3104, 1.03

Should also note that all four powders shoot 100-grain Ballistic Tips more accurately when a little more powder is added, probably because published .257 Roberts data is pretty mild--even the +P, which is rated at 58,000 PSI average maximum. The powders burn more consistently at 60,000+. The same rifle shoots consistent sub-inch groups with both the 100-grain Ballistic Tip and Barnes TTSX with a little more 4451.

I just did a one time 3 shot group average just to get a feel on how the three compared loading them all the same.H-4350 is supposed to be the best at temperature extremes,but where I live,the temperatures I may encounter would be between upper 20's on the low end,40's and 50's most common and 100 degrees on the extreme high end so I'd be happy shooting any of the three.

I got a big jug of H-4350 back when you could, so not a problem for me.

If I was looking for an alternative, I think I'd try to get IMR 4451 instead of IMR 4350.

The Canadian Enduron series is reported to be nearly as temp stable as the Australian Extreme powders.

DF

DF,

Yes--with "nearly" being the operative word. In my tests the Extremes still generally are most consistent in varying temps, but while the Endurons vary a little more, it's generally around 25-30 fps at most.

Must also mention that IMR4350 is pretty temp-resistant when compressed, and used with magnum primers.

Would you prefer IMR-4451 over IMR-4350 if given the choice?

DF

"Must also mention that IMR4350 is pretty temp-resistant when compressed, and used with magnum primers."

Mule Deer,I do use magnum primers with IMR-4350.Since I also shoot a lot of the ball powders.I followed you're advice about using magnum primers with ball powders.I have found the Winchester and Federal magnum primers to work quite well in my 308Win,30-06 and 338-06.I was using Winchester Large Rifle Primers before switching to the magnum primers on my non-magnum rifles.I just really didn't see that much difference between the two Winchester primers.

DF,

Have pretty much switched to IMR4451, partly due to erratic availability of H4350, but have also gotten better accuracy with 4451 in most loads.

I've read that std. Winchester primers were hotter than most std. primers. So, maybe there isn't a big difference, WLR and WLRM.

Would appreciate input on that.

DF

That was kinda what I saw.I tried the standard in my 300WSM and there was maybe 15fps or difference in velocity between the two,so I just stayed with the magnum primer.Rifle seemed to group the same as well.

Depends on your performance expectations. I use imr powders for practicing. They are usually less expensive and very acceptable accuracy is achieved.

You won’t notice much difference unless you shoot year round in a extreme conditions. Save the extreme powders for hunting ammo.

DF,

Tests run maybe 20 years ago by A-Square and reported in their handloading manual indicated the WLR was was the hottest "standard" LR primer.

I’ve used the IMR 4350 for 40 plus years. Another Reloader recommended it when I was starting out. It works very well for me. It is hard for me to try something else when the old standby works so well.