380 Auto with Win 231/H-38

[burket]

I may reload 380 auto later. I was researching the loads on Hodgdon, and see what I consider a question.

The starting powder load for a 90gr JHP bullet is higher (at 3.2 gr) that for both of the heavier bullets listed (both 95 and 100 gr FMJ) which each have a starting load of 2.9gr of powder.

Lyman's 49th also has a similar listing.

for 90gr JacketHC (which I would think were very similar, if not the same as, JHP) and 95gr FMJ starting Win231 load is 2.1

while

for 115gr JHP starting Win231 load is 2.0

Is the heavier powder load due to the bullet type (JHP), rather than the bullet weight?

This premise is sort of eliminated by the Lyman entries. What am I missing?

I am confused by the heavier starting loads for a lighter weight bullet!

The COL's are also listed, and change with each bullet weight (not surprising!)

Hodgdon

90 GR. HDY JHP HP-38 .355" .955" 3.2 917 13,900 CUP 3.5 957 15,400 CUP

95 GR. SPR FMJ HP-38 .355" .970" 2.9 802 13,100 CUP 3.2 884 15,400 CUP

100 GR. HDY FMJ HP-38 .355" .980" 2.9 819 13,800 CUP 3.1 843 15,400 CUP

While Lyman's 49th has

90gr Jacketed HC OAL at .925

95 gr FMJ OAL at .900

115 gr JHP oal at .956

The OAL's seem all over the place for the same type of bullet

(90 gr JHP has either .955 or .925).

(95 gr FMJ has either .970 or .900).

Seems like a very large spread to me. Comments desired.

Thanks for any/all clarifications.

[noylj]

A lighter bullet will move easier for a given powder charge so pressure will be less, so charges tend to be higher.

A lighter bullet can be loaded so there is more free volume in the case, thus a given powder charge will produce less pressure, so charges tend to be higher.

The main caveat to this is that very light for caliber bullets (such as 80-100 grain 9mm/.38 bullets) may need to be seated deeper to get enough case/bullet tension to prevent bullet set back.

You, the reloader, have to determine what COL satisfies the needs of you gun.

You, the reloader, should start at the lowest starting load you can find by referencing several manuals. After all, you gun is not the same as the test guns in the manuals, so your max load may be different. Thus, for safety, always start with the lowest starting load.

Next, the .380 is just a small case that any powder charge error or bullet seating depth variation can cause large pressure variations. Thus, you must try to load to the longest COL that feeds and chambers in your gun and shows no bullet set-back after two or three cycles chambering.

.380 Auto Load Data

Bullet Weight Powder Weight Velocity Start/Max COL Power Factor

Hdy HP-XTP 90 231/HP38 2.9 850 Start 0.9650 77

Hdy HP-XTP 90 231/HP38 3.5 1050 Max 0.9650 95

JHP 90 231/HP38 3.5 957 Max 0.9550 86

Hdy HP-XTP 90 231/HP38 3.6 950 Max 0.9650 86

Speer FMJ 95 231/HP38 2.8 Start 0

FMJ 95 231/HP38 3.2 860 0.9840 82

JHP 95 231/HP38 3.2 884 Max 84

Speer FMJ 95 231/HP38 3.2 964 Max 92

Speer FMJ 95 231/HP38 3.2 1015 Max 96

FMJ 95 231/HP38 3.2 860 Max 82

Hdy FMJ-RN ENC 100 231/HP38 2.5 700 Start 0.9800 70

Hdy FMJ-RN ENC 100 231/HP38 2.6 700 Start 0.9800 70

FMJ 100 231/HP38 3.1 843 Max 0.9800 84

Hdy FMJ-RN ENC 100 231/HP38 3.3 900 Max 0.9800 90

Hdy FMJ 100 231/HP38 3.4 870 Max 87

Hdy FMJ-RN ENC 100 231/HP38 3.5 900 Max 0.9800 90

[chirpy]

I'm using 3.2 gr. of 231 with 95 gr. Zero bullets loaded to .964. This bullet has a flat, soft point. It is accurate and shoots nice in my LCP.

FWIW

Richard

[Hi-Power Jack]

A lighter bullet will move easier for a given powder charge so pressure will be less, so charges tend to be higher.

A lighter bullet can be loaded so there is more free volume in the case, thus a given powder charge will produce less pressure, so charges tend to be higher.

The main caveat to this is that very light for caliber bullets (such as 80-100 grain 9mm/.38 bullets) may need to be seated deeper to get enough case/bullet tension to prevent bullet set back.

You, the reloader, have to determine what COL satisfies the needs of you gun.

You, the reloader, should start at the lowest starting load you can find by referencing several manuals. After all, you gun is not the same as the test guns in the manuals, so your max load may be different. Thus, for safety, always start with the lowest starting load.

Next, the .380 is just a small case that any powder charge error or bullet seating depth variation can cause large pressure variations. Thus, you must try to load to the longest COL that feeds and chambers in your gun and shows no bullet set-back after two or three cycles chambering.

+1.

Noylj has hit in on the head - excellent explanation.

Start at the bottom, find your OAL and work up Very Slowly.

Good luck.

Jack