A friend of mine just got a whole bunch of powder for nothing.
the containers are marked "Ammo Mart 33 rifle powder" theres a sticker on the containers that says "use 4198 load data"
my question is do i use the data for H4198 or IMR4198 ?
both are similar but not interchangeable.
any info?
thanks
That powder, is pretty old stuff. I just used the last of mine last summer.
I used it exclusively in my 223 Remington and 257 Maxi.
4198, was the old Dupont IMR powder. IMR, stands for Improved Military Rifle.
It was intended to be a small rifle cartridge powder that developed high pressures and burned cleanly in a small center fire case.
The #33 powder, is a left over lot of powder that was used by a company, such as Winchester or IVI Canada to load military cartridges. Tom Higginson and I talked a lot about this powder and I helped him develop the loads they used to hand out in a printed newspaper form with their sales of powders.
The loads I helped to develop were for the 223 Rem and the 218 Bee.
His specs were for 218 Bee, 222 Rem, 223 Rem, 222mag, 225 Win, 22-250, 25-20 and the 256 Win.
Very good powder, I wish there was more available but some of the new powders are just as good or better.
If you can find a first edition Hornady or 45th edition Lyman reloading manual, you will find 4198 specs.
I compared the tables in the 47th edition of Lymans book with the 45th edition and the IMR 4198 specs are identical.
This powder, works best with magnum primers. It also has a very narrow working range. Minimum and maximum loads are very close together, no more than one or two grains, even in the largest cases listed.
I liked it in the 223Rem because it was consistent from -40C to +30C.
My favorite load was 20.5 grains #33 over a small rifle magnum primer and a 55gr bullet.
This load was close to maximum in my rifle and my old hunting partner, used to use 20.0 grains on the nose.
I will mention again, this powder has a very tight range in any cartridge it is useful for.
Be extremely careful. As you approach max capacities with this powder, pressures spike with even a tenth of a grain to way beyond what you want. Accuracy wanes quickly as pressures approach max.
I can honestly say, this is one powder that is load sensetive when compared to accuracy.
Minimum loads, which are usually very accurate, may not be good with this powder.
To tell the truth, there was no difference in velocity between 20.0 and 21.0 grains in my rifle.
Both loads delivered an average of 2980fps at +20C temps but the extra half grain I used in my pet load delivered more consistent accuracy through all temperature ranges, down to -40C.
I can't stress enough how close the loading capacity range is. BE CAREFUL when you work up a load for any rifle you wish to use it in.
