View Full Version : I need help from you guys

05-12-2010, 02:29 PM
I have a .380 mold coming from Lee in 100 gr bullets.My question is why do jacket
bullets in the same weight have different powder loads then lead.

I have a lb of Alliant Unique powder & can't find a chart for .380 100gr cast
but I can for 100gr jacket.

My Lyman 49th book is all jacket bullets in that cal & I can't find anything on
the net.Can I load my 100gr cast bullet the same powder loat as my jacket


05-12-2010, 02:38 PM
Start with the minimum load for the J bullet and work up. If no min. load is given, deduct 5% from the listed load and work up. with that powder/bullet I'd start at 3.8-4.1 and work up in .1gr increments until it shot well, hit the velocity I wanted, or gave me pressure signs.

05-12-2010, 02:45 PM
Always work up but you will most likely find a cast boolit can use MORE powder then jacketed. Less friction.

05-12-2010, 02:59 PM
I think it is due to the the fact that most people don't cast their own so the manufactureres don't bother to test them or list info.

05-12-2010, 04:21 PM
I just happened to have a copy of Lyman 41 on my desk and it tells me 4.5/Unique and 95 grain cast in the .380. The velocity is 970 fps. 4.8/Unique is the load for the 95 grain jacketed.

05-12-2010, 05:12 PM
Lyman #47 is a fairly comprehensive manual for cast bullets. You might wish to see if you can find a used copy. Lyman #47 gives 10 recipes for the 380ACP and a 100gr lead bullet.

Here's the Unique data for the 100gr lead:
Unique 2.4grs start 777fps 9,900cup
Unique 3.1grs max 1001fps 15,700cup

Here's the Unique data for the 92gr lead:
Unique 3.1grs start 755fps 11,800cup
Unique 3.7grs max 920fps 16,000cup

Use caution when loading small-capacity cartridges like the 380ACP. Pressures rise quickly as powder charges increase. Hope this helps, good luck.

05-12-2010, 05:20 PM
sagacious thanks I will get that book.Thank's to the rest on this input.

05-12-2010, 08:05 PM
44man nails it. Lead-tin alloys are used in high speed engine bearings because the have
very low friction against lubed steel. You will be safe using a jbullet load with the same wt or
close boolit. In many cases you will find lower loading data for boolits, but when they print the
pressures you will see that they chickened out and used a very low pressure for these cast
boolit loads. Apparently even the powder companies don't really understand boolits!

When they run the loads up to the same pressure you will find that you can burn
more powder and get more velocity with a boolit than a jboolit at the same pressure.

Low friction.


05-12-2010, 09:10 PM
I loaded 3.8 grains & this gun shot more accurate than it ever did with factory loads.My Lee
mold is kicking out .556 boolits so I'm not sizing.I have not slugged the bore but I'm going
to just to see.

This is my first hand gun loading & casting & I love doing this in this cal.I don't use much
lead or powder.I can't wait to cast more.

05-13-2010, 07:07 AM
Best to learn early on that cast has it's own set of rules. Cast and jacketed are apples and oranges. They both go boom, both hit the target, but there it ends. A lead alloy boolit has a completely different pressure curve/powder burn than jacketed, among other things.

Also- always remember most of the big powder companies consider casters the red headed step children of the hobby. For every caster there might be 5-10K other guys loading jacketed.