Schuetzen FFFg powder, Remington 6 1/2 or  9 1/2 primer, barrel length (). All the powder I could get in the case & seat the bullet so it would chamber. All loads compressed.
25/20 wcf (22.5) 19.0g 98g Lyman 25720 1344 fps 21850 psi
30/30 wcf (24) 44.0g 176g Lyman 31141 1529 fps 21000 psi
32/20 wcf (21.5) 21.0g 115g Lyman 311316 1302 fps 11500 psi
32/20 wcf (21.5) 16.0g 155g Lyman 311466 995 fps 9400 psi
32 Win. Spcl (20) 46.0g 178 RCBS 321170FN 1417 fps 23350 psi
33 wcf (24) 65.0g 205g Lyman 338320 1611 fps 27550 psi
38/55 (2.125 case) (26.5) 47.0g 273g Lyman 375296 1334 fps 18750 psi
38/56 wcf (26.5) 56.0g 330g Accurate 38-325G 1336 fps 20600 psi
38/40 wcf (22.5) 37.0g 198g NEI 401200 1253 fps 7900 psi
Firing mechinism broke on the 44/40 so no additional data at this time.
Now to give some comparison data with smokeless. Same barrel & same bullet.
25/20 7.6g 4759 1562 fps 22550 psi
30/30 12.0g Trail Boss 1106 fps 25450 psi
30/30 15.5g 4759 1511 fps 12450 psi
32/20 5.5g Trail Boss 1124 fps 10450 psi
32/20 11.5g Lil 'Gun 1659 fps 14650 psi
32/20 12.0g IMR 4227 1510 fps 13050 psi
32/20 10.0g 2400 1474 fps 10800 psi
32/20 13.5g 300MP 1831 fps 17450 psi
32 spcl 15.6g 4759 1495 fps 17450 psi
33 wcf 23g 5744 1678 fps 21350 psi
38/40 9.5g Trail Boss 1277 fps 17000 psi
38/40 10.5g Unique 1428 fps 16400 psi
38/55 12.6g Trail Boss 1101 fps 19400 psi
38/55 19.6g 4759 1582 fps 24300 psi
38/56 25.6 Reloder 7 1458 fps 17150 psi
38/56 30.0 3031 1538 fps 23500 psi
38/56 22.0g 4759 1577 fps 29700 psi * May be to hot for older guns.
44/40 9.5g Trail Boss 1194 fps 13600 psi
44/40 25.0g Reloder 7 1354 fps 10300 psi
44/40 9.5g Unique 1286 fps 12200 psi
44/40 19.5g 4759 1494 fps 13350 psi
44/40 10.0g Power Pistol 1399 fps 14100 psi
I hope that this information will be found useful. As I stated earlier black powder is a very energy limited powder as opposed to the high energy of smokless (Trail Boss excluded). The low velocities & pressures of the rifle/pistol cartridges with black powder is due to a low charge to sectional density ratio.
Harry

  Yes, thank you!

"38/55 12.6g Trail Boss 1101 fps 19400 psi"


this is much lower pressure than Hodgdon data of a lower charge.What do you think is the difference?(I understand yours is psi and theirs CUP)Their 7g charge would be about 21000 psi 

also the 32-20 data has two bullet weights in the back powder data. whats the bullet weight in the smokeless data?

was your data from the Oehler 43 system. 

that's a bunch of work!
thanks 

Interesting that some 4759 loads have less pressure than black at the ~same velocity.

Trail Boss is an odd powder. 

It’s pretty high on any of the burn rate charts, but isn’t exactly predictable.

It’s also designed to be loaded loose.
My experience has been that once you start to compress it, the velocities get more erratic. Basically pressure swings. Almost like if you plug the holes, it can’t ignite.

If you look at the Lyman cast bullet manual, there is a lot of data for Trail Boss and cast bullets. The above loads for 38-55 are very similar in velocity with the same long version of the case. The charge weight is almost double what the Lyman loads are.

This is more or less what my experience has been. At some point around 95% fill, there is not much increase in velocity, and may decrease under compression.

To give an answer to the data. Hodgdon data was used to calibrate the 30/30 pressure barrel & it matches almost perfectly at 41000 psi. I have seen this difference in Trail Boss on other loadings. I have actually seen the pressures drop with increased powder charges. I basically only use Trail Boss in pistol cartridges in which it works reasonably well but not so well in rifle cartridges.
Harry

Duck_Rider wrote on Jun 30^th, 2023 at 8:51am:


it's a weird powder for sure.i use it in pistol quite a bit  and in a few modern rifles.I've had good luck in rifles .Surprisingly it worked very well in the 416 Rigby and 375 H&H.The 310 Cadet wasn't bad either but velocity too low with powder to base of bullet.

Duck_Rider wrote on Jun 30^th, 2023 at 9:17am:


thanks for the correction.i appreciate all the work you put into this.