Shooting boolits larger than the cylinder throats

[T-Bird]

I have 2 44 mag revolvers, one a mod 29-6, and a Uberti Callahan. Both have cylinder throats less than .429, but not by much. I haven't measured them. I shoot .429 boolits, and both do very well. I have a single shot rifle that likes .430. For simplicity I want to just load .430 boolits. My load is 10gr AA#5 under 429421 for 950-1000fps out of the revolvers.My alloy is COWW. This is nowhere near a max load, so other than probably increasing the pressure in the cylinder somewhat by shooting the larger boolit, am I causing harm or added wear and tear to the revolvers if I do this?

[gnostic]

You may have to load your handguns with a mallet...

[Dusty Bannister]

You may have to load your handguns with a mallet...

This is not entirely true. The throat is smaller than the chamber area of the cylinder and generally you can shoot whatever size bullet that will easily chamber and extract, or fall out of the cylinder of it's own weight. Some feel a tight throat will introduce leading.

Increasing the bullet diameter by .001" is not likely to create any problem with chambering unless you have a tight chamber like a contender carbine. Then it can be a problem. Better to just try it and see if it freely chambers and falls out of it's own weight.

[TCFAN]

My superblack hawk has .430-.431 throats and it shoots my .433 boolits very well.

[Walkingwolf]

Guns built for jacket bullets/FMJ tend to have throats slightly bigger than bore size. Guns built for cast bullets have bore size a little bigger. As long as the gun does not lead the bullet will swage to size through the throat. I have two GP100's that are this way, both are very accurate, and both do not lead. The only problem is bullets cannot be seated past the throat. My Smith model 21 the bore is large enough to seat bullets to 44 mag length/Keith style loads.

[Outpost75]

I shoot .430 bullets in my S&W Model 544 Texas Commemorative .44-40 which has .429 throats and accuracy is wonderful.

[scattershot]

If you’re worried about the pressure, don’t. I once fired a .452bullet through a .429 barrel with no damage. Kicked like a mule, but no damage. ( long story, involving a mismarked barrel).

[Hannibal]

I have 2 44 mag revolvers, one a mod 29-6, and a Uberti Callahan. Both have cylinder throats less than .429, but not by much. I haven't measured them. I shoot .429 boolits, and both do very well. I have a single shot rifle that likes .430. For simplicity I want to just load .430 boolits. My load is 10gr AA#5 under 429421 for 950-1000fps out of the revolvers.My alloy is COWW. This is nowhere near a max load, so other than probably increasing the pressure in the cylinder somewhat by shooting the larger boolit, am I causing harm or added wear and tear to the revolvers if I do this?

Your statement confuses me. You need to know the diameter of your throats. It really does not matter what size your bullets are when you load them, by the time they travel thru those cylinder throats, that will determine their diameter.
If all you are concerned about is shooting .430 bullets thru 2 revolvers that you have been shooting .429 bullets through, I would be surprised if this causes you any trouble.

If you have not measured your sized bullets with a micrometer, it's quite likely your .429" and .430" bullets aren't what you think they are, anyway. Particularly if they have sat around a few weeks after sizing.

Not sure if this all helps or not. Bottom line is, you won't know for certain until you shoot them and see what the target tells you.

[T-Bird]

I'm not going to worry about it. A .430 will chamber, and fall out freely from both revolvers. I know the throats will swage them. I have done this some already, just wanted to be sure I wasn't doing one of those "never do that" things. They shoot fine at .430 as far as accuracy goes, chrono says maybe a little slower than .429 but I guess that makes sense if they are being swaged a little more. But if this even exists, it's not much but my sample size is small. I have noticed no leading. Thanks everyone.