Join Date: Feb 2009
Location: Gloucester, Virginia
I spoke to JES after he rebored and rechambered a 223 Handi to 350 L. He used the same cutters to cut the bore as he does any 357 Magnum. He used a SAAMI spec 350L reamer that cut a .356 or .357 throat. I can't remember which it was. That's why he only recommended firing factory ammo in it.
As to the toughness of .358" bullets, remember the 180gr Hornady SSPB is .358 so I would say that some of them may be too tough but not all of them are. Even the .358 200gr Rem RN expanded very well for me when fired around 1800fps in my 357 Max.
I reload and shoot 348 Win, 358 Win, 6.5 Grendel, 30-06 Springfield, 300 BLK, 44 Mag, 357 Maximum, 9mm, 45 ACP, 45 Colt, 225 Win and 35 Rem