MP HP Alloy mold testing

burbank.jung

Active Member
What us your opinion on proceeding with a MP 9-125, 38-125, 40-160, and 45-200 HP test using the following alloys?

.22lr lead, .22lr plus 2% tin, pellet lead, pellet plus 2% tin, JHP/FMJ core range scrap, JHP/FMJ core range scrap plus 2%, placing a plastic ball in each if the hollow points. Does it benefit me to add over 2% tin? What has been your test results?
 

Spindrift

Well-Known Member
I did some subsonic expansion testing the other day, using the MP 360-180 Penta-point, with 8,5grs Vihta N32c in the .35 Whelen. I used my default BHN 14-15 alloy, it expanded well in a 4- inch stack of wet paper. And grouped at an inch at 60m.

IMG_20230114_103452533.jpgIMG_20230113_132007301.jpg

I've done some expansion testing with my alloys, and .30- cal MP designs in the thread below, I think you could extrapolate some observations. I'd use the .22lr bullets, and use around 1% tin.

 

CWLONGSHOT

Well-Known Member
I havent tested all yet.

But my MP 380 & 45 with largest HP pins both preformed well With 30:1 ( about 8 bhn) Alloy & 900 ( 380) & 800 fps.

My MP 40/160 likes 20:1 alloy @ 1300 in 10mm.
While my NOE 181 with large pins becomes a lead ball that fast. @ 1000 in 40 its a nice exp bullet W20:1.

I like 20:1 for average HP & 1200 fps. Adj from there.
 

Winelover

North Central Arkansas
What us your opinion on proceeding with a MP 9-125, 38-125, 40-160, and 45-200 HP test using the following alloys?

.22lr lead, .22lr plus 2% tin, pellet lead, pellet plus 2% tin, JHP/FMJ core range scrap, JHP/FMJ core range scrap plus 2%, placing a plastic ball in each if the hollow points. Does it benefit me to add over 2% tin? What has been your test results?
Only, when using lead/tin alloys.............. 16-1, 20-1, 30-1 etc.

IMO, HP alloy should be easily duplicated. Not a hodgepodge of relative unknowns.

I use 20-1 or 3-1 pure to lino.............depending on caliber and expected velocity. Easily duplicated.

I also like gas checks on the softer alloys that HP's require.
 
  • Like
Reactions: Ian