Seth_AZ
10-07-2020, 12:19 PM
So I received the Rossi R92.
Having read of the issues with bore diameter from others, I tried some Hi-Tek coated, unsized bullets cast from the Lee 255gr FN mould. I brought 16 rounds with me to pick up the gun (it was at the range) and just fired it to try it out.
I got some pretty ferocious leading. The unsized raw bullets size out to around .454", so with the Hi-Tek they're a couple thousandths over.
I've borescoped and slugged the bore. I was getting measurements of around .454" (some measurements showed .4535" but my calipers probably aren't accurate enough for that to be authoritative).
Borescoping showed tons of horizontal tool marks all the way up the lands and grooves. At least when I slugged at the muzzle end and at the chamber end the measurements came out identical within the accuracy limitations of my caliper.
I think I'm going to roll some firelapping bullets using the LBT firelapping compound, then follow those up with some bullets rolled onto some JB Bore Compound as a finish polisher. I don't want to raise the bore diameter, but just knock down the toolmarks a bit and smooth it up. No jacketed rounds have been fired in the bore, so whatever burnishing effects jacketed bullets would have on the surface roughness of the bore have not been done. I'm thinking 10 firelapping bullets and maybe another 15 of the bullets with JB Bore Compound grit embedded in them. I'll clean it every 2 or 3 shots with the firelapping bullets, then do a final cleaning after I'm done firing all of these and slug and borescope it again and see what difference it makes.
As far as moulds go, the ones I use for .45 ACP drop around .452" or so, but I'm thinking if I cast these, then apply 2 or 3 coats of Hi-Tek, size using a .454" sizing die, then apply one more coat of Hi-Tek to the sized bullets, that should leave the bullets at around .455", which should be good. The Lee 255gr bullets I'll do the same to, but they'll be sized a bit more since the Hi-Tek on top of a .454" bullet will build up enough thickness to be sized down a lot in that die.
I'm still searching for info on what weight of bullets will be well stabilized by the slow 1:30" twist of the barrel. I haven't found anything definitve yet, but seeing reports of others showing 280-300+ grain bullets with adequate accuracy is encouring. I'd really like to shoot some lighter (200-215gr) bullets that I cast for my .45 ACP for general plinking, but I'd like to have the option to go with something heavier than 255gr if I decide to take this hunting. That said, anything I'd conceivably hunt (I'm not really a hunter) would probably be dropped authoritatively with a 255gr bullet, so I may not need to go any heavier.
Having read of the issues with bore diameter from others, I tried some Hi-Tek coated, unsized bullets cast from the Lee 255gr FN mould. I brought 16 rounds with me to pick up the gun (it was at the range) and just fired it to try it out.
I got some pretty ferocious leading. The unsized raw bullets size out to around .454", so with the Hi-Tek they're a couple thousandths over.
I've borescoped and slugged the bore. I was getting measurements of around .454" (some measurements showed .4535" but my calipers probably aren't accurate enough for that to be authoritative).
Borescoping showed tons of horizontal tool marks all the way up the lands and grooves. At least when I slugged at the muzzle end and at the chamber end the measurements came out identical within the accuracy limitations of my caliper.
I think I'm going to roll some firelapping bullets using the LBT firelapping compound, then follow those up with some bullets rolled onto some JB Bore Compound as a finish polisher. I don't want to raise the bore diameter, but just knock down the toolmarks a bit and smooth it up. No jacketed rounds have been fired in the bore, so whatever burnishing effects jacketed bullets would have on the surface roughness of the bore have not been done. I'm thinking 10 firelapping bullets and maybe another 15 of the bullets with JB Bore Compound grit embedded in them. I'll clean it every 2 or 3 shots with the firelapping bullets, then do a final cleaning after I'm done firing all of these and slug and borescope it again and see what difference it makes.
As far as moulds go, the ones I use for .45 ACP drop around .452" or so, but I'm thinking if I cast these, then apply 2 or 3 coats of Hi-Tek, size using a .454" sizing die, then apply one more coat of Hi-Tek to the sized bullets, that should leave the bullets at around .455", which should be good. The Lee 255gr bullets I'll do the same to, but they'll be sized a bit more since the Hi-Tek on top of a .454" bullet will build up enough thickness to be sized down a lot in that die.
I'm still searching for info on what weight of bullets will be well stabilized by the slow 1:30" twist of the barrel. I haven't found anything definitve yet, but seeing reports of others showing 280-300+ grain bullets with adequate accuracy is encouring. I'd really like to shoot some lighter (200-215gr) bullets that I cast for my .45 ACP for general plinking, but I'd like to have the option to go with something heavier than 255gr if I decide to take this hunting. That said, anything I'd conceivably hunt (I'm not really a hunter) would probably be dropped authoritatively with a 255gr bullet, so I may not need to go any heavier.