Home Forums Hunting & Shooting Ask The Gunwriters IMR 4320?

Rummaging through my stash, I found a jug of IMR 4320 that I don't remember buying (probably 15 years ago), and I certainly don't remember loading anything with it.

What does IMR 4320 do well? 223, 30 cal? Anyone have any pet loads for this stuff?

I know the 06 likes it with a 150 grain bullet. My experience with it is usually in long action cases but have heard it works well in 308 length cases also. Think that just about anything you would use imr 4064 on it would use 4320 with a little adjusting.

I like it in 308 and in 8X57 Mausers of various flavors.

I used it a lot when R 15 was scarce. IMO it works just as well.

4320 can be tricky. I won't go on here with my extensive experience with it....instead, I recommend you google up Norma Burn Rate Chart. In my opinion, the best chart available to us handloaders, in that it rates powders in two areas, relative velocity AND relative pressure. I'm not aware that any other burn chart does this. When you look at the chart you will note that 4320 is on the faster side of 4895, right down near 3031. And that reflects my own experiences. All the other charts have it up around H380 pretty close to W760. And, with light for caliber bullets, it most likely is. But when you start going off the rez with heavier bullets and changing bore diameters, you will see some amazing velocity progressions on your chronograph. It's an excellent powder, just respect it.

It’s the only powder I use for the 300 Savage. Works good in the 17 Remington too.

I use it for 22-250, .223 . It is a pretty versatile powder in many cartridges.

My favorite in the 17 Remington and the 35 Whelen.

Worked great in my 243 with 62gr varmint grenades

Think of IMR 4895 that meters like ball powder, you might have to add half a grain more to equal 4895/4064 loads.

That’s diff from my experience. 4895 is ‘slower’ burning than 3031
And 4320 is ‘slower’ burning than 4320 > but faster burning than 4350.

I used 4320 in the 35 Whelen w/200 & 220 (?) gr bullets. It did exceptionally well.

J D Jones said to me in the 80s that 4320 was THE powder for the Whelen

I know, - diff interpretations. I’ve never read that 4320 was so close to 3031.

I recommend that You compare powder burn rate charts for yourself.
I know what I’ve seen/experienced.
Go slow in making your decision.


Jerry

Great choice for the 338-06, so I am not surprised it works well in the Whelen as well.

I have a 243 that would not group worth a flip until i tried some 4320 with 100gr Solid Bases. Presto, tiny groups. Never know til you try it.

Works great in my Remington 7600 35 Whelen

I don't remember the author ( gun writer) who published it, but I remember reading it on one of the websites..

When Varget was scarce, 4320 was recommended as a viable replacement..
it was available, was close to the same burn rate as Varget, to the tune of stating one could start off with starting loads of the two powders interchangeably...

IIRCm the site was like the 6BR web site....

I've found it pretty darn accurate and not real finicky, like most of the older IMR powder lines...

burn rates for 4064, 4895, and 4320 are pretty darn close...4320 being the slower of the three...

it shines real good in the 22.250, 243, 260, 7/08 from personal experience...

in the 223 with heavier bullets is a darn good choice also....

Used it in .22-250, .308, .30-06 without problem. Sometimes faster, sometimes slower than IMR-4064.

Tried it recently in .375 Ruger and got evidence of excess pressure at what were supposed to be starting charge weights.

I have not reloaded in a long time, but I liked 4320 in 7mm mag with 130 grain Sierras

Yep ! That’s how DuPont, IMR, has always listed the burn rate since I started handloading
in 1975.

Jerry

Another IMR powder that has withstood the test of time, versatile while delivering good performance without surprises. Tho I am using spiffy new powders in my 35 Whelen and 300 Savage, they are not delivering superior performance in any real meaningful way. Maybe it should be re-introduced as 4320Creedmore to give it a little buzz. It deserves more attention than it is getting.

Jack Oconner used it and liked it in 06 size cases.
IT meters much nicer than 4064 and the results are very similar.
I also like it in the 308, and would try it in others also.

It proved to be a diamond in the rough for my daughters Rem Model 7 .260, it was very accurate with a Sierra 120gr Pro Hunter in her rifle.


Her Remington 700 SPS .260 also loved the IMR4320 with the Sierra 120gr Pro Hunter