Bullet Sizing for Win 1873 in .45 Colt

[justindad]

I have a new Win 1873 in .45 Colt and 79 freshly cast boolits from an RCBS 45-230-CM mold (COWW, fluxed with root kill for ~0.1%Cu, plus 1%Sn). I’ve never shot a lever action, let alone loaded for one. I’m going to use the AA#5 load data in the Lyman Cast Handbook #4.
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Do I size the boolits to fit the grooves or to fit the chamber?

[Larry Gibson]

I shoot a lot of the Lee 452-230-TC bullets out of mt Uberti 1873 Winchester 45 Colt. I mostly load them over Bullseye or 700X for 1050 fps. Accuracy is excellent with the bullets sized at .454 (as cast) or at .452 with no apparent difference when targeted at 100 yards. I also shoot a lot of Lee 452-200-RFs over the same powders for 1200 fps. Again, no apparent difference betwee bullets sized .454 and .452.

[Randy Bohannon]

My newer Win.92 takes a .456” bullet and shoots very good. 45 Colt chambers in lever guns are big sloppy affairs so the fattest bullet that will chamber is desireable.

[justindad]

Thank you guys!

[fordwannabe]

I was doing load development this weekend in my custom Marlin .452 shot a 6 inch group at 25 yards. Same bullets, same powder charges shot 1 ragged hole when sized .453. Each gun will let you know what it likes and what it doesnt.

[BLAHUT]

Get some ( creosafe ) from brownells and do a chamber cast and stare there ? I use pure lead and a tad oversized bullets in my rifles at about 1200 FPS ? Very accurate...

[freakonaleash]

Slug the barrel. I shoot .001- .002 over groove size most of the time.

[DAVIDMAGNUM]

Slug the barrel. I shoot .001- .002 over groove size most of the time.

I have no experience with Uberti 1873s in 45 Colt. After a few years of struggle I gave up on my 1892 Japchester in 45 Colt. The bore was .450, but the chamber was LARGE. I could thumb seat .460 bullets deep into fired cases. I tried so many things to get this rifle to shoot well at 100 yards. One attempt was neck sizing brass with a 45 Colt die. The result was cases with a pronounced neck.
To make a long story short, I sent it off for gender reassignment surgery. It is now chambered in 44WCF and is very accurate.
Okay , I feel better. Please excuse my rant.

[gwpercle]

I have a new Win 1873 in .45 Colt and 79 freshly cast boolits from an RCBS 45-230-CM mold (COWW, fluxed with root kill for ~0.1%Cu, plus 1%Sn). I’ve never shot a lever action, let alone loaded for one. I’m going to use the AA#5 load data in the Lyman Cast Handbook #4.
*
Do I size the boolits to fit the grooves or to fit the chamber?

The round has to chamber ... no chamber - no shoot .
Idealy +.001" - .002" over groove diameter and the round will still chamber and shoot accurately .
If Not ... it's back to the drawing board for Plan B .

I have read of so many 45 Colt / model 92 Win. horror stories that if I ever get one it will be in 44-40 , 38-40 or even 32-20 ...but never in 45 Colt !

Good Luck , Load Safe
Gary