Remington 1858

[dingus]

the 45 acp head space on there case mouth they sit in the chamber the same amount sticking out as a 45 sch will maby a bit less.
as and example the saa colts you see in 45 acp the only thing that stops the 45 acp from moveing forwards is the chamber throat.
i know on the conversion cylinders for the 1858s theres a plate that fits over the back with a fireing pin. so even if theres no space for rims on the 45 acp cylinders then just get a milling machine guy to make reseses on each chamber for the rims.
are you certin theres no rim recesses there already ?
in any case to get what you want some machineing work will be needed as you say most conversion cylinders are 45 colt.
you could get a 45 colt one and make tiny washers that fill the rim recesses part way up so only 455 brass will work as it has a thiner rim.
i have seen that done up here. its legal because once the area where the rims goes is part way filled then the 45 colt rims will stick up to much to put the backing plate on the cylinder. makeing 45 colt unuseable in the gun.
theres more than one way to go about this.
filling the rim area is abit of a pain but once the spacers are in place the thiner 455 rimed cases will work and you can even thin the rims on the longer 45 sch cases so you can then use them to.

 

[SIGP2101]

the 45 acp head space on there case mouth they sit in the chamber the same amount sticking out as a 45 sch will maby a bit less.
as and example the saa colts you see in 45 acp the only thing that stops the 45 acp from moveing forwards is the chamber throat.
i know on the conversion cylinders for the 1858s theres a plate that fits over the back with a fireing pin. so even if theres no space for rims on the 45 acp cylinders then just get a milling machine guy to make reseses on each chamber for the rims.

I can do that myself but my concern is if the rims will interfere with each other - overlap. Chambers being too close.

are you certin theres no rim recesses there already ?

I think no, judging from various pics on Internet.

in any case to get what you want some machineing work will be needed as you say most conversion cylinders are 45 colt.
you could get a 45 colt one and make tiny washers that fill the rim recesses part way up so only 455 brass will work as it has a thiner rim.
i have seen that done up here. its legal because once the area where the rims goes is part way filled then the 45 colt rims will stick up to much to put the backing plate on the cylinder. makeing 45 colt unuseable in the gun.
theres more than one way to go about this.
filling the rim area is abit of a pain but once the spacers are in place the thiner 455 rimed cases will work and you can even thin the rims on the longer 45 sch cases so you can then use them to.

Definitelly another option to think about.

Thanks