Lee Loader

Very nice work Mac.

I thought I would throw this C.I.P. drawing up to show a little understood and underappreciated fact about the 7.5x55 Swiss. While it is loaded both commercially and privately with a .308 bullet, GP11 ammunition uses a 7.78mm (.306 bullet). The Swiss barrel has a nominal 7.77 mm groove and 7.51 mm land diameter. The allowable barrel wear by Swiss miltary standards was 7.56 for the lands. The .309 Lee cast I am using are .003 over groove size. My K31 barrel was air gauged as 7.54. It came with the armourer's signed certificate to this effect. Dies size for a .308 diameter bullet so even if I could find a .306 projectile I would need to modify a resizing die to provide proper neck tension.

I have a mould that would do the job nicely .

So finally got out to range. The results. Sorry for picture. I was in a hurry. Shooting all at 50 meters. Blustery wind.
IMR 4227 Lee 309-150, PRVI brass full sized, trimmed. Pan lubed, WW water quenched and gas checked. OAL 2.650. No crimp. All powder charges trickled up on a digital scale. Two fouling shots to warm up barrel.

26.5 grains
Hi 2025 fps (not sure why this shot was so far off the rest at this charge.)
Low 1971
SD 21.5

27.0
Hi 2029
Low 2009
SD 8.0

27.5
Hi 2086
Low 2045
SD 14.0

28.0
Hi 2091
Low 2067
SD 11.0

The wind was making keeping a steady rest a challenge and I jerked a few shots.. Seems the 28.0 grain loading worked best but I will load up a box and confirm these results. Again I couldn't detect any signs of leading.