Today's 300 Win Mag experiment H4350 vs IMR4350

[Float Pilot]

Rilfe: Rem M700 XCR tactical 26 inch bbl, 1 in 10 twist.
Bullet: 168 grain Speer Gold Match BTHP
Brass: WW Virgin
Primer: Winchester LR mag.
Temp: 20 degrees F.
Range Cond: 100 yards, flat light on snow


73.0 grains, IMR 4350= 3,190 fps, ES 10 fps and a 0.48 inch group

73.0 grains, H 4350 = 3,120 fps, ES 40 fps and a 1.5 inch group.

The difference in group size really surprised me....

Too bad, since I am almost out of IMR 4350 and have two can of H4350....

[MontanaRifleman]

Rilfe: Rem M700 XCR tactical 26 inch bbl, 1 in 10 twist.
Bullet: 168 grain Speer Gold Match BTHP
Brass: WW Virgin
Primer: Winchester LR mag.
Temp: 20 degrees F.
Range Cond: 100 yards, flat light on snow


73.0 grains, IMR 4350= 3,190 fps, ES 10 fps and a 0.48 inch group

73.0 grains, H 4350 = 3,120 fps, ES 40 fps and a 1.5 inch group.

The difference in group size really surprised me....

Too bad, since I am almost out of IMR 4350 and have two can of H4350....

Interesting results... Ya gotta like a .48" group and a 10 fps ES.

Thanks for sharing

H4350 is a good powder, no doubt you will find a good use for it.

[Jmurman]

Thanks for that post. Quite a difference between IMR and H!

Your ES of 10 is very impressive.

Only 20°? Heck, you'll be in shirt sleeves before you know it

[marshall]

Too bad, since I am almost out of IMR 4350 and have two can of H4350....

No worries Float Pilot. The powders are very close. I'm thinking you can bump the charge a few tenths at a time and match the velocity. You may have the results you desire.

[marshall]

Hogdons web site shows the following data:

168gr HPBT IMR 4350 72.5gr @ 3089fps developing 61,300 PSI

168gr HPBT H-4350 70.0gr @ 3034fps developing 51,000 CUP

Converting PSI to Cup is a bit complicated. This article is interesting reading and shows the correlation.


http://www.shootingsoftware.com/ftp/psicuparticle2.pdf


The above reading has a chart representing 54000 CUP and 64000 PSI as MAX charges for the 300 WM. It appears that Hogdons data is under max based on those numbers. I think this will allow you to tune up the H-4350 charge you tested to match the velocity of the IMR4350.

Our rifles and cartridges being totally different perhaps the same logic applies. My rifle shoots equally well with 300gr Game Kings loaded over RL-15, RL-19 or H-4350 when tweaked for 2650fps.