Yeah, I think that's good advice to load it like 4064 and accept the usually resulting low velocity. If it punches holes in the paper, that's OK.

I'm going to load all my 7383 loads henceforth without compression. I plan to use Lee powder dippers. My RCBS Uniflow measure won't handle 7383 satisfactorily, due to the long grains. Not only does it shear grains and measure inconsistently, it bridges terribly in the small caliber powder spout and dumps half the charge on the floor. If using less than a case-filling charge, it can underload one and overload the next if not carefully checked.

All, I wish to respectfully disagree a bit with Linstrom re 7383 as IMR 4064. It isn't bad advice at all, since we've got to start somewhere with this oddball powder. However, in my experience with the .243Win., using 4064 data with 85 & 87gr. SP's didn't work well at all: Dirty cases, low velocity (36gr. -> 2,631fps. SD was 48) and so-so accuracy. I then loaded 7383 as IMR 4350, or almost 4350 since I couldn't get more than 43gr. in the cases (Remington) and seat the 87gr. BTSP's. With loads of 41gr 7383 to 43gr. 7383, I got 2,911fps; SD = 37 (41gr.) while 43gr. -> 3,099fps; SD = 28. I consider 43gr. to be MAX. since I don't need ~3,100fps to punch paper. 41.5gr. or 42gr. 7383 will give excellent accuracy (better than 1 m.o.a.) with less compression and pressure and @ 3,066fps. what's not to like? Btw, I don't use more than 42gr. of IMR 4350 either, as it isn't necessary.

After last week's discussion of 7383 as H 380 or IMR 4350, I decided to try 7383 in my 8mm Mau. (26" bbl.). Lyman #47's starting loads for both were 50gr. I normally use 48-49gr. IMR 4064 with 150gr. SP's, as it is a tack driver, especially with the 150gr. Sierra SP. Today I tested the 50gr. 7383 with standard primers (Fed. 210's) in neck-sized cases with 150gr. Hornady, Sierra & Speer SP's. Accuracy and clean-burning were about the same as with IMR 4064 (1 m.o.a.). Velocity was 2,449fps (n = 30); SD = 17, which is ~100fps slower than my 4064 load. On the other hand, Lyman #47 said 4350 should -> 2,347fps and H 380 2,570fps from either a 26" bbl. or a 23" bbl., it is impossible to determine which one(s) were used. My results put 7383 in the 8mm Mau. as slower than 4064 and H 380, but faster than 4350.(!) Lastly, I did 3 T-test's to check whether the Speer v. Hornady results, Speer v. Sierra results and Speer v. Sierra v. Hornady results were significantly different (with respect to velocity & SD) from each other: They were not (not even close)!. I.e., the differences were merely due to chance. One last point, 50gr. 7383 will quickly fill 8mm Mau. cases so some slight compression is necessary. Consider it as a Max. load because of the compression problem Linstrum mentioned and because you can't get more into the case. I seated my bullets (all) to 3.06" whereas they'd be 3.09" with IMR 4064. Btw, there were no pressure signs at all today (ambient temperature was 83 deg. F). ...Maven

Nice test result reporting,Paul. I was genuinely curious about the 50gr. load under commpression. This Wed. I'll be doing a lot of 8mm 7383 shooting up to 185gr bullets. Later depending on Wed. results the heavier bullets in 8mm w/7383 will go to the firing line. roger