Bullet Sizing for 45 Colt Blackhawk w/ .453" Throats

[Racer X]

I am considering buying either the RCBS 270 SAA or 255 SWC for my Blackhawk. I understand these moulds cast on the large side, as high as .456" - .457".

My question is, would sizing bullets down to .452"-.453" be too much sizing?

[outdoorfan]

No, and the 270-SAA drops them at around .454.

[rockrat]

I wouldn't think so. I size some undersize boolits for my 45-70 (.457") down and use in my 450 bushmaster and they shoot very well.

Shamless plug here. I have a RCBS 270 SAA that I would part with. I could cast a few out of WW's and check as cast dia for you, if you are interested. PM me if you are interested.

[RobS]

I had both RCBS molds and the 45-270-SAA cast out right at .454 and the RCBS 45-255-SWC (Keith) cast out at .455. You won't have any problems sizing down. If you want a .453 sizing die you can hone out a .452 or have our forum member, buckshot, make you a custom one. His work is really good and the cost is just a few dollars more than a RCBS die.

The 270 grain SWC is a good design and shot well for me from the revolvers to 50 yards, however I found that a LFN design worked better for my purposes in both the revolver and lever action.

Here is a pic of the Keith/SWC bullets:
RCBS 45-255, BRP 45 2.1 redesign of the 45-270-SAA, 45 2.1 design of the 454424 (the last two are lubed 270 and 255's.
http://i612.photobucket.com/albums/tt206/RobS01/RCBS45-255vsBRP454-283.jpg

Here is a pic of the difference between the RCBS 45-270-SAA and the BRP redesign 45 2.1 design
RCBS on the Left and 45 2.1 on the right
http://i612.photobucket.com/albums/tt206/RobS01/RCBSleftBRP4521right.jpg

And finally the bullet that I designed and is now cataloged over at www.accuratemolds.com
45-300B
http://i612.photobucket.com/albums/tt206/RobS01/45-300B-D.png

[missionary5155]

Greetings
I have 2 Ruger 45´s and I size both of them throat + .001. They both shoot accurately with the oversized boolits and I have no leading problems. I use mainly the Lee 265 grain flat RN over 17-19 grains of 2400. When I am back up next time I am going to put my new 270 grain to the test and will size those throat + .001.
I guess I do all my revolvers that same way.

[outdoorfan]

I am considering buying either the RCBS 270 SAA or 255 SWC for my Blackhawk. I understand these moulds cast on the large side, as high as .456" - .457".

My question is, would sizing bullets down to .452"-.453" be too much sizing?


Also remember to take into account the sizing of a soft bullet (if you decide to use one) due to case neck tension when seating the bullets. If you do use a soft 8-10 bhn alloy, then being a couple thousandths over cylinder throat dimesions should be about perfect when you're actually ready to fire the darn things.

[HangFireW8]

I am considering buying either the RCBS 270 SAA or 255 SWC for my Blackhawk. I understand these moulds cast on the large side, as high as .456" - .457".

For reference, my new 454-270-SAA drops WW+ a little tin right in between .4540 to .4545.

-HF