IMR 4320 is not a powder I see much mention of. I found a one pound can of this powder in the powder cabinet, must have been there for a lot of years. Opened the can up the factory seal was still there and when opened the alcohol smell was strong.
I loaded up 25 rounds using 40 grains of 4320, and 25 rounds with 41 grains, with the 208 grain cast bullet from the Mountain Mold I had made for the Winchester 95 , 30-06.
It took a few rounds to determine this load was shooting way high. Once I got the Lyman reciever sight adjusted for this load, the load proved itself to be reasonably accurate.
It struck me as being odd that there is so little mention of IMR 4320 being used. I think I'll buy a couple more cans just to find out how accurate I can get this powder/bullet combination.
Do any of you all use IMR 4320 for any of your reloading?
Jim

Hi Jim,

I use IMR 4320 in my 356 Win. and it shoots as well at higher velocity(2200 fps or so) as my IMR 4350 loads do at lower velocity(1800 fps). Groups have hovered at around 1.25" at 50-60 yards, but I haven't tweaked it that much. Like you, I have wondered why nearly no one uses this powder. I think it is ideal for 356/358 Win. loads. It's somewhat slow burning, fills the case nicely and seems to shoot well. Also, I have read of 6.5 Mannlicher and Swede shooters getting good results from IMR 4320 in their military Mausers, which suprised them.. I don't think many people try this powder, and they may have missed a good bet.

Been using 4320 in both my sweed, and a 7x57, and found it to be a very consistant powder, and heat and cold seems to have very little effect on loaded ammunition.

Lee L.

I should add that I have used IMR 4320 with the 210 Gr. Beartooth LFNGC with excellent results and very little leading. It seems to be cast bullet friendly.

Gents,

Excellent powder, consistant and versitile. My read is that it was designed to be a 30 caliber match powder, probably because of this consistancy and easy metering.

As far as versitility, I have used this powder in 6.5 swede, 300 Savage, 308 Win, 358 Win, 30-06 SPRG, and 350 Rem Mag. All loads show acceptable accuracy, but the 140 grain partition in 6.5mm really did shine.

I also have heard that Remington used it for the factory load in the 350 Rem Mag, and I have been able to duplicate that load, to the same point of impact, at least.

It was my first medium powder, and for awhile my only, and now that I am overgrown with medium powders, I use it less, but I will always have some on hand. It just has a quality about it that I like.

Good shooting, fellows.

Steve