archeratlrg
Well-Known Member
Where are you still finding it? Haven't seen any on shelves for years. Looking to pick up a few lbs of it.
DuPont IMR 4320, IMR 4350, IMR4227
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It is the most accurate powder out of my 350 Rem Mag using 225 grain bullets. It meters like a dream too for being an extruded powder. First I've heard they discontinued it. Darn shame it works really well in my 224 Valkyrie as well using 80+ grain bullets. I was going to try it in my 6mm arc as well but might have to hoard the rest for my 350.
65WSM
Well-Known Member
From Ken Water's Pet Loads. He said more IMR 4320 has been used in the .220 Swift than any other powder. That was written before plastic tipped bullets, all 16 twist varmint bullets were flat based hollow points or lead points and light for caliber 40, 45 and 50 gr. The good news is that Sierra and Hornady still make some of these bullets and they are relatively inexpensive. IMR 4320 is temperature sensitive. If you zero the day of the hunt, and adjust as temperatures changes through the day, you will be pleased with this single based powder. I have had success with the Ackley .22-250, Swift and my own wildcat based on small rifle primers for a similar case volume. Double based powders will outperform this old timer for velocity and consistency, but IMR 4320 is well suited for high capacity .224 varmint cartridges with 40-50 gr bullets.
Derfman
Member
Old powder, although it is usable and might be reliable, does degrade over time and might not perform as listed in the old data. Where and how it's stored…temperature and humidity…type of container…matters more than the age of the powder…from what I have read. I think your powder container might have rusted, indicating some higher humidity storage. If you sniff it and it doesn't have a strong odor of ammonia,it's probably OK.
Brian Litz studied the effect of humidity and moisture content of gunpowder and the results were very surprising.
If you start low, and work up a load like you normally would, I think you'll be fine, and if anything, you'll come in a bit slower than what's shown in the older books.
I have other older manuals with more data; so holler if you need it.
Brian Litz studied the effect of humidity and moisture content of gunpowder and the results were very surprising.
If you start low, and work up a load like you normally would, I think you'll be fine, and if anything, you'll come in a bit slower than what's shown in the older books.
I have other older manuals with more data; so holler if you need it.
From looking over the reloading data it seems like the IMR 4350 powder is a very close match to the 4320. It is readily available and it is extremely accurate in my experience and my rifles from 22-250, 7mm Rem Mag, and 300 WM. If you're ever in a pinch it should work fine for most of the calibers that the 4320 works with. Overlapping calibers and similar uses may be why they discontinued it possibly in the first place.
antelopedundee
Well-Known Member
Looking at burn rate charts IMR4320 is close or identical to Varget, Win748, Reloder 15 or VV N140.
You are correct. I was going by the reloading data that was provided earlier in this thread. It's a faster burning powder and that would explain the slightly higher velocity from the 4350 in the heavier bullets.
Volume/case fill is going to be different
antelopedundee
Well-Known Member
True, but I expect that's mostly personal preference. I tend to choose powders that mostly fill the case.
I've been reloading for over 50 years. IMR 4320 has been my goto powder for most of that time.
I use it in my 22/250, 270, 308, 30/06, 300 WSM, and even in my 45/70's. My old Mentor taught me about it years ago. He hunted all over the World and it was his favorite powder.
Bob Forker that wrote about reloading for G&A for years, in his March 2004 article stated that it was the most accurate powder for the 300 WSM, 62 gr behind the 150-grain Swift Scirocco at 3240 MV. Hard to believe they are discontinuing making it. Good thing I stocked up on it, Will be a little more stingy
about loading it up for friends.
I use it in my 22/250, 270, 308, 30/06, 300 WSM, and even in my 45/70's. My old Mentor taught me about it years ago. He hunted all over the World and it was his favorite powder.
Bob Forker that wrote about reloading for G&A for years, in his March 2004 article stated that it was the most accurate powder for the 300 WSM, 62 gr behind the 150-grain Swift Scirocco at 3240 MV. Hard to believe they are discontinuing making it. Good thing I stocked up on it, Will be a little more stingy
about loading it up for friends.
memtb
Well-Known Member
antelopedundee
Well-Known Member
If my fave powder isn't available I find something else rather than look at the empty cases and wish. I don't know when it was decided to drop IMR430, but stock up if/while you can. If enough folks contact Hodgdon maybe they'll reconsider. They did do an about face on the Eduron line so there's that. I do have a saved Hodgdon burn rate chart from April, 2001, and I don't see it there.Empty case….is wasted space!memtb
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BigEnuffToBurnDiesel
New Member
I have used IMR 4350 almost exclusively in .22-250, .300 Savage, .30-06 and .300wm for 35 years and always had great results. Only recently have i branched out to try other powders in various calibers.
In reality you don't have to look any farther back than many of the current reloading manuals, Nosler 9, Lyman 49, and the Hodgdon reloading site all currently list load data for IMR 4320. If however you want to go back in history and compare loads the 1974 Sierra loading manual also lists IMR 4320. I have used IMR 4320 since I started loading back in 1973. I used it for my 308/7.62 and 30-06 match ammo reloads, and still will until my supplies run out. I have found that IMR 4350 is a good substitute.
