Since I just went through making 7.62x41 case I thought I'd publish the procedure used.

Started with a quantity of Win. and RP .257 Roberts cases.These cases were an acumulation from cases that had split necks out of my cousin's rifle.

Sawed them to length in a trim die filed them uniformly and deburred them while in the die.

Sized them in a .375x41 die

Trimmed the case length to 1.642"

deburred Inside and outside of neck

Turned the necks to a wall thickness of .012".

Full length resized them so they fit nicely in both 7.62x41 IMP rifles. The overall case length changed to about 1.632".

Annealed in bread pan with 1/2" of water.*

Loaded; 150gr. FMJ, Golden West Bullet. 31gr WCC844 (335), WLR,

Fired at range in a Mod. 200 with a Shaw barrel.Surprisingly good accuracy for a GW bullet.Achieved about 90% form. Case length reduced to about 1.625.

Lost NO cases during process or shooting.
* Annealing these shorty cases in water is more difficult than the longer cases as the water draws off the heat quicker.
I hope some of you find this helpfull. roger

I'm curious about the ballistics of this little cartridge???

quote:

Originally posted by El Deguello:
I'm curious about the ballistics of this little cartridge???

BW BT BM PT PW CASE Primer DATE Comments
150gr. psp 4198 31gr. CCI Mag. 2/16/1989 Good not Max.
" " " 29gr. Various " "
" " 3031 33 " " 3/16/1989 Accurate not max.
100gr plinker speer 4198 32gr " " 6/6/1989 NG Near Max.
" " " 3031 24gr. " " 08/30/89 OK
110gr 4198 20Gr. " " " OK
150gr. psp 3031 34gr. " " 03/17/89 near MAX. accurate
110gr. Speer 8208 33gr " " 02/20/90 not max. accurate
123gr .310dia. pfmj REM. 680 25gr " " 04/21/90 Accurate not max.
150gr. psp 680 27gr " " 7/90 NG NEAR MAX ?
" " 8208 29gr. " Win Mag " NG
125gr. psp 4198 34gr. " " " not max shows promise
110gr. rn 4198 34gr. " " " not max. looks good
180gr. psp. 3031 32.5gr " " 06/01/91 Good show
!80gr RN 8208 33gr " " 03/06/92 Rn don't feed, great, close to MAX.
!80gr RN 4198 27.5gr. " " 03/06/92 Good, feed problem
!80gr RN 8208 30gr. " " " Great " "
!80gr RN 3031 32.5 " " " " " "
110gr RN 680 20Gr. " " ": Cotton pack OK Sooty
123gr. .310dia. pfmj 4759 20gr. " " 04/30/93 Mild accurate
150gr. Mil 8208 34.5gr. " " " OK not max.
!80gr. psp. BW36 32gr. " " " great but dirty
150 gr. psp REM. Acc2200 29gr. FC.270 " 02/15/99 2B fire formed Not hot, accurate
125gr. psp REM. h110 25.5 mixed " 02/18/99 Ok Mild
150 gr. " REM. cavim 30 FC.270 " 11/09/99 flat primers looks like poor head space. 3" group at 50 yds.
180gr. RN 8208 30gr. " " 3" group at 50 yds. not max. bad feed
150gr. psp REM. BW36 36gr. " 11/19/99 2000fps accurate mild sooty
" " " 4198 29gr. wcc84 " " 2330fps. OK Clean Mild
" FN " " " " " " 2360fps.1" grp. at 50 yds mild clean
165GR. psp. Speer " " " " " MAX. 2320fps 2" group at 50 yds.
170gr. FN " " " " " " 2310fps. near max. 2" grp 50 yds.
180gr r n ? 8208 30.5gr. fc 270 " 04/09/00 MAX Accurate
110 rn speer 2200 29 WCC54 " " not max., accurate2347 to 2356 fps
123gr fmj .310 dia. " " " " " not max., accurate1971 to2081 fps
100 gr. plinker speer " " " " " 2189 to 2359 stinks
150gr. r n REM. " " " " " not max accurate 2152 to 2192 hot barrel
110gr. rnsp ? " " wcc84 " " 11/4" grp. 2184 to 2292 pleasant
110gr. fmj Rem. " " " " " 2270 To 2356 acc. nice plinker
100gr. plnker speer 4198 30gr. fc270 fed mag 12/01/00 2446-2575 NG
110gr. fmj. REM. 4198 30gr. wcc54 " " 2441-2544 pleasant super group 100yds.
123gr. .310dia. fmj ? 2230 C 29.5gr. WCC84 fed mag 10/09/02 Super 1858-1938 fps. Mild
" " " " " win.270 " " 1/2"grp. 1816-2000 fps. ?
" " " " " WCC54 " " ok cronograf spooky
" " " " " Front270 " " ok cronograf spooky 1" grp
" " " " " Mixed " " 1780- 1873
1 to 47 were Douglas Supreme barrel
150gr. fmjBT GW Turk 28gr. SL42 WLR 07/17/08 oal= 2.50" ,Shaw barrel, fire form, 2200 fps. Avg., good fire form load
160gr cast gas chk 7625 11gr. .257 rp " " oal= 2.320", Shaw barrel, 1462fps. Avg., fair fire form.
150gr. fmjBT GW " 10.2 gr. SL-42 " " oal=2.500", 1390 fps. Avg.Shaw barrel, Too Mild not a great fireform
168gr. " " Turk 27.5gr. .257 rp " 07/30/08
" " " 2015 28.9gr. SL-42 " " oal= 2.555", Shaw barrel, 2075 fps.avg. , mild , accurate out to 200yds. Great fire form
110gr. plycrb ? IMR4198 30.7 " 34 08/04/08 OAL= 2.350" , 2658 to 2696fps. Scope way off
150gr. BT-sp gw IMR4198 29gr. SL42 34 08/04/08 oal= 2.505"2360 to 2391 fps., good once hot
150gr. FMJ mil IMR4198 29gr. SL42 34 08/04/08 oal= 2.540", 2359 2392 fps., 3 shot 3/4" group at 50 yds. Not max.
148.6gr. sp ? IMR4198 29gr. SL42 34 08/04/08 oal=2.435", 2354 to 2395 fps. NG.
148.6gr. sp wcc846 36.2gr. 257rp 34 " oal=25.33", 2385 to 2410 fps. ,mild, soot, so-so
150gr. btsp GW wcc846 36.2gr. 257rp 34 " oal= 2.472", 2380 to 2395 fps., 3 shot 1/2" group at 50 yds.
150gr. fmj ? wcc846 36.2gr. 257rp 34 " Oal= 2.580", 2297 to2376 fps., 3 shot 3/4" group at 50 yds.
150gr. BTsp ? DP74 33.7gr. SL-42 34 " oal= 2.440", 2284 to 2310 fps., 4 shot 5/8" group at 50yds.
148.6gr. sp ? DP74 33.7gr. .257rp 34 " oal=2.470" , 2284 to 2325 fps. 1 1/2" group at 50 yds.
110gr. carb ? 2015 22.5gr. " " 09/17/08 oal=2.140", 1613 to 1657 Fps., Too mild, not great, UBP
150gr. Plated Berrey " " " " " oal=2.300", 1590 to 1649 fps. OK , UBP. Too mild
110gr Carbine 1625-1650 fps. Great
150gr. plated berrey Blue dot 12.5gr. SL 42 34 10/01/08 oal=2.297", mild, 1495 to 1565 fps., shows promise
" " " " 13.5gr " " " oal= 2.297", mild, 1512 to 1613FPS., not bad
!50gr. FMJ GW wcc844 34gr. FC.308 " " 2365 to 2400 NFG
168gr. fmj bt ? " " " " " oal=2.558", 2261 to 2320 fps.
174gr. cast gas chk 2200 26gr. SL 42 34 04/07/09 oal=2.418", 1607 to 1727 fps. Mild, clean, barks, DEADLY. Douglas barrel
177gr. " " " " " " " oal=2.410", 1659 to 1773 fps., some soot, barks, 1 1/2" group at 5o yds.DB*
174gr. " " 2015 24.5gr., .257RP #34 " oal=2.425", 1524 to 1602 fps., soot. UBP., NG., DB*
177gr. " " " " " " " oal=2.415", 1538 to 1667 fps. NOT GREAT douglas barrel*
194gr. Gas Chk 2 dia. 2200 26gr. SL 42 " " oal=2.474", 1710 to 1784 fps. Little soot, 4 shot 1/2" group at 50 yds.DB*
201gr " " 2015 24.5gr., .275RP #34 " oal=2.540", 1506 to 1563 fps., 1" group at 50yds.,DB*
194gr. " " " " " " " oal=2.465", 1528 to 1568 FPS., 3/4" group at 50yds. DB*

I'm not sure how good this will come out but see what happens. roger

Thanks