Original Low Wall 32-20 pressure question

[Htom_servo]

I picked up an original Winchester 1885 low wall made in 1888 in 32-20. I'm currently loading 115 grain bullets over 17 grains of FFg goex or about the same triple 7 with a .030 wad. does anyone know the pressure of 32-20 black powder? I am also looking at loading smokeless in this action. specifically HP-38 which I have on hand. hodgdon load data says starting load at 3.2gr for a pressure of 11,100 CUP, looking up the triple 7 load data from hodgdon 18 grains they put at 12100 CUP. I know there is more going on then just the peak pressure but would that load of HP-38 be OK for a low wall rifle. I plan to mostly stick with black powder but am working on a poor accuracy problem and want to avoid black powder fouling before I decide if I want to have a barrel liner installed.
Thanks for any info.

[M-Tecs]

https://loaddata.com/articles/PDF/32...%20(Rifle).pdf

http://www.assra.com/cgi-bin/yabb/Ya...num=1269380330

http://castboolits.gunloads.com/show...ssure-Concerns

https://winchestercollector.org/foru...cf-model-1873/

http://www.assra.com/cgi-bin/yabb/Ya...num=1198805027

[Htom_servo]

Thanks for the info M-Tecs. its deferentially pointing me in the right direction. I'm always happy to read and learn anything I can.

[M-Tecs]

Your low wall will have the older black powder era firing pin size. The ones I looked at have been .125 but I have read claims that the early used even larger firing pins??? With the .125" and pistol primers I would not go over 25K in a Hi-Wall or Low Wall. Since your are not close to that pressure just info.

[Outpost75]

Some of my .32-20 firing data might be helpful.


Factory .32-20 Ammunition in Rifle and Revolver
Ammunition Description___________Colt Police Positive 5”_____Savage Sporter 25”

Rem-UMC 100-grain lead
Kleanbore “Dogbone” box 1930s______898, 44 Sd, 116 ES________1302, 15 SD, 38 ES

Peters 100-grain softpoint
Kings Mills, Ohio 1940s______________870, 28, 71______________1150, 44, 137

WRA 100-grain lead
Red & yellow box 1950s_____________854, 33, 87_______________1263, 18, 53

W-W 100-grain lead
Rounded primer, yellow box, 1970s____800, 11, 31______________1241, 9, 22

W-W 100-grain lead
Flat primer, white box, 1990s_________778, 27, 69_______________1172, 18, 65

R-P 100-grain lead
Bridgeport, CT 1970s________________780, 24, 67_______________1181, 17, 52

R-P 100-grain lead
Lonoke, AR current production________716, 21, 55_______________1140, 12, 35

Column Mean by Gun_______________5” Revolver______________25” Rifle
Average Velocity of Factory Loads_____814 fps._________________1207 fps



Group 1 Standard Pressure Loads for Rifle or Revolver

Bullet, Little Dandy#, Pdr. Chg.____Colt Police Positive 5”______Savage Sporter 25”

Remington .311” 100-grain JSP____930 fps, 16 Sd, 45 ES________1230 fps, 26 Sd, 79 ES
LD#4, 4.9 grains AutoComp

Accurate 31-105T
LD#1, 3.2 grains TiteGroup_________858 fps, 22 Sd, 61 Es_______1133 fps, 30 Sd, 67 ES
LD#4, 3.2 grains Bullseye__________861 fps, 19 Sd, 47ES________1173 fps, 18 Sd, 54 ES
LD#3, 4.5 grains AutoComp________912 fps, 19 Sd, 53 ES _______1260 fps, 21 Sd, 55 ES
LD#4, 4.9 grains AutoComp________ 943 fps, 32 Sd, 71 ES_______1315 fps, 32 Sd, 118 ES
LD#10, 7.5 grains Alliant #2400_____991 fps, 24 Sd, 65 ES_______1348, 29 Sd, 69 ES DO NOT EXCEED!
LD#13, 10.0 grains IMR4227_______985 fps, 25 Sd, 61ES________1280 fps, 53 Sd, 176 ES
LD#17, 13 grains IMR4198________974 fps, 21 Sd, 94 ES________1326 fps, 46 Sd, 138 ES

Accurate 31-114D

LD#3, 3.0 grains Bullseye_________741 fps, 35 Sd, 92 ES________1041 fps, 26 SD, 78 ES
LD#4, 3.2 grains Bullsye__________861 fps, 20 Sd, 54 ES________1173 fps, 18 Sd, 52 ES
LD#13, 10.0 grains IMR4227______962 fps, 27 Sd, 62 ES_______1268 fps, 62Sd, 224ES
LD#15, 11.5 grains IMR4198______777 fps, 43 Sd, 101ES_______1248 fps, 36 Sd, 114 ES

[Htom_servo]

Your low wall will have the older black powder era firing pin size. The ones I looked at have been .125 but I have read claims that the early used even larger firing pins??? With the .125" and pistol primers I would not go over 25K in a Hi-Wall or Low Wall. Since your are not close to that pressure just info.

cool thanks for the info in the firing pin. off hand i think its the .125 but will double check and read up. as for pressure i'm likely to stay as low as i can, i'm always a little paranoid about pressure.

also thanks for the numbers Outpost75. especially as i was looking at both those molds just yesterday. definitely got some thinking to do and probably some powder to go pick up.

[uscra112]

For some years now I've used 12,500 psi as the maximum pressure that black powder can generate, when estimating loads in Quickload. Forgotten now where I got that - maybe from the now-defunct site that Ulrich Bretscher maintained. I know of no actual pressure test data from any stateside experimenter. According to a source I just consulted, SAAMI lists 16,000 psi as max for the .32-20 cartridge.

Working backwards in QL, a 1200 fps MV from a 24" barrel with the 3118 bullet in the .32-20 cartridge, selecting powders in the 4227 speed range, the pressure would only be about 8500 psi area. This is very much off-the-cuff, so make of it what you will. But I think I must revisit the 12,500 number.