What, pray tell, is IMR 7383?? Is this new, or just a non-canister powder? (Don't see it on the IMR website....)

It is mil surp. from 50 cal spotter ammo. It has a realively slow burning rate,but faster than the 4350s and a low density so that ,for instance,you can't get enough of it into a 30-06 case to over load with a 165 gr. bullet.It looks like it should have mag. primers for ignition. In the 30-06 you get a good bit of unburned powder when you are loadin below 165gr. bullet or are not using a near compressed load. Paul, Ricochet, or myself can fill you in further if you like. So far some nice accuracy has been achieved. roger

Eldeguello, As Roger said, IMR 7383 is a .50cal. spotter powder that can be had for $4/lb. Before the old Shooters'Talk > Cast Bullets site disappeared, there was considerable discussion about using it with cast bullets and speculation that it was about the same "speed" as IMR 4064. Wrong!! We discovered that (a) the speed of different lots varied significantly; (b) extreme spreads and standard deviations in velocity were just too great for accurate CB shooting; and (c) that CB velocities and reduced charges of 7383 were "not a good thing" (to quote Martha Stewart). Thus, a new problem (or opportunity?) presented itself, namely what to do with ~7lb. of pseudo-4064? Roger, Ricochet, and I, among others, tried loading 7383 with jacketed bullets following published data for 4064 and found it didn't apply. By trial & error, we (separately) tried published recipes (starting charges) for IMR 4350 and cautiously worked up. Bingo! We discovered the stuff to be accurate, clean-burning, and consistent (low ES's & SD's), virtually a clone of 4350; i.e., as long as you stay a bit under max. 4350 loadings. The rest, as they say, is history. Hope this sheds some light on the subject. ...Maven



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I came up with IMR5010 for the big 50,and IMR4831.IMR 7383 is for a practice round,the,T249E2.

Thanks!

earlier thread with 83.3 gr / 92 gr = 90.5% density of H4350



11.9 gr / 13.5 gr = 88.1%, which is consistant with the earlier thread.

That is close enough.
I get the idea.
I am loading for .222, .223, .243, 25acp, .243Win, 257 Roberts AI, 6.5 jap, 6.5x55, 7x57mm, 32acp, 32sw, 32S&WLong, 32-20, 7.62x25mm, 30-30, 303Sav, .308, 30-06, 7.5 French, 7.5 Swiss, 7.62x39mm, 303Brit, 7.62x54R, 8x57mm, .380, 9x19mm, 9x23mm, 357 Sig, 38 sp, 357 mag, 38sw, 40sw, 10mm, 10.4mm, 44 mag, 45acp, 45Colt, 452/70, .410, 45/70, 20 ga, 16 ga, 12 ga, and 10 ga.

The good candidates are 243 and 257RAI with heavy bullets.
As few of those loads as I will ever shoot, I can use 4350.
If I get a 338 Lapua or 338 RUM and start feeding a powder hog at long distance target shooting, I would jump on 7383.

Hey, Clark!!!!!!!!
If you're loading all them catridges when do find time to burn some powder? roger

Roger and Maven, thanks for the info on this new stuff!

I had one of those 28s circa about 1910. This was in 1952. Could not hit a standing rabbit with it. Did get a quail once, but it wasn't the one I was shooting at. ?roger

I found it in "Cartridges of the world"By Frank C.Barns.Page 449,Cartridge,Cal 50,Practice,T249E2.110grs of IMR7383."OH NO DID I SAY 4383"I meant 7383 SORRY about that.