bore and cylinder throat questions

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I have four Ruger revolvers I am looking to get setup for cast bullets and to accurize as best I can. I have slugged the throats and bore of each and the data as follows,

Ruger new model Blackhawk 6.5" stainless .357 magnum. I have had this one a long time and it has some rounds through it
bore .3580
cylinder
1 .3592
2 .3592
3 .3594
4 .3593
5 .3594
6 .3592

Ruger Bisley Blackhawk 4 5/8" stainless .45 colt new and unfired except for factory
bore .4505
cylinder
1 .4523
2 .4518
3 .4520
4 .4523
5 .4520
6 .4522

Ruger Bisley Blackhawk 4 5/8" stainless .45 colt I have 500 or so rounds through this one.mostly informal plinking
bore .4508
cylinder
1 .4522
2 .4522
3 .4522
4 .4522
5 .4522
6 .4522

Ruger Bisley Old Model Vaquero 4" case colored/blued .45 colt bought used unfired by me.
bore .4513
cylinder
1 .4520
2 .4522
3 .4515
4 .4520
5 .4515
6 .4514

I think these numbers are probably pretty good for out of the box guns. the two stainless .45's probably have a bore restriction?

What size should i size my boolits? hopefully I can run the same load/components in all three .45's.
Thanks

 

[DeletedMember275]

I would size the .357 bullets to .358", personally. The .45 Colts, well, I'd have to do some fire lapping and throat reaming on them before I worried about best accuracy. Once that was done, I'd size bullets at .452".

 

[Chuck 100 yd]

Normally cast bullets are sized to fit the cylinder throats. If they are a couple thousands larger than the groove diameter they should be fine.
That said, every gun is a rule unto itself and only experimenting with different loads can tell you just what is best.
I tend to work with just one gun at a time.
None you listed seem to be way out of spec and should give satisfactory results depending on your expectations. None of them are precision target guns after all.

 

[[email protected]]

The .357 will most likely do well with no changes. The stainless .45 that has been shot has even throats and should do well except for the bore restriction. The other two may have trouble shooting the same poi on all holes in the cylinder I worry. I guess I could shoot them and find out. If it isn't too bad just have it addressed as I send them for action work, though that may be a bit.

 

[NikA]

Unless you have a thread choke, all your throats are smaller than your groove diameter. I would see if .452" cast bullets will chamber, and if they do I wouldn't worry about it. All your variation is within .001", which could be noise in your measurement method.