SR4756?

11 October 2003, 10:30

Gary D.

SR4756?

My local gunshop got in about 6 cans of the old Dupont sr 4756 and I was wondering what it's used for. I'm pretty sure it's used for rifle cast but don't know what caliber/bullets/amounts/etc. Thanx Gary D.

11 October 2003, 10:52

felix

If it is cheap, buy it all. A single base Herco in speed. Only very light rifle lead loads; medium pistol loads. Ultra clean burning. Very easy ignition. ... felix

11 October 2003, 10:58

Blackhawk44

Some uses I've found, 32ACP, 32Long, 9mm and sees most use in 32-20 revolver. Originally intended for shotshells. Very close to Herco in burn rate. I have never used for such. I believe it was Speer #9 that used 4756 in a lot of pistol rounds for remarkable speeds. BACK WAY OFF. Pressure testing was not a exact as today. Some of those loads can be way too warm. Also used in some rifle cast bullet loads. Really good for smaller capacity pistol rounds.

11 October 2003, 13:19

NotRicochet

Lots of the loads in older manuals were never tested for pressure. How they came up with the maximums, I have no idea.

12 October 2003, 02:17

Bug

I have it listed for shotshell, and pistol loads. I agree with Felix, if it's cheap enuff', buy it!>>>>>>>>>Bug.

12 October 2003, 04:17

Nathan Detroit

quote:
Originally posted by Blackhawk44:
Originally intended for shotshells. Very close to Herco in burn rate. I have never used for such. I believe it was Speer #9 that used 4756 in a lot of pistol rounds for remarkable speeds. BACK WAY OFF. Pressure testing was not a exact as today. Some of those loads can be way too warm. Also used in some rifle cast bullet loads. Really good for smaller capacity pistol rounds.

It was not Speer's #9 manual, but the #8. Manual #9 listed NO loads for SR-4756. SR-4756 did not re-appear until manual #10. Speer treated it as if it did not exist after the problems with the No. 8 loads came out. One of the culprit loads was 8.5 grains with a 158 SWC in the .38 Special. DuPont listed 8.9 grains as a 40,000 CPU maximum load in the .357 with the same 158 SWC. How much higher the pressures were in the shorter case is anyone's guess. Speer also listed 11.0 as the max load for the .357; WAY over the DuPont pressure tested maximum! I would go beyond the advice to cut way back on the #8 loads, and recommend that you ignore the 4756 data from Speer's #8 manual totally. The loads in Speer's manuals from #10 on are OK to use.

Ironically, the "SR" in the designation for 4756 and its faster sibling 7625 stands for "Sporting Rifle", even though they are primarily shotgun powders, with some handgun applications.

Nathan Detroit

[ 10-11-2003, 19:22: Message edited by: Nathan Detroit ]