With the hope of not beating a topic to death, I ask for guidance. I have two lovely .44 Magnums: one a 29, one a 629 Classic. A .430 bullet will easily drop through the chamber throats of the 29, a .4295 (didn't have a .429) is a tight fit in those of the 629. I understand a cast bullet should match the throat diameter of the gun it's fired through. Would a .431 of around 15BHN be suitable for BOTH guns, or do you see it as too tight for the 629? I'd like to simplify logistics and expense if I can. For the time being, I'd be limited to commercial bullets, and am looking to load them to "mid-range" levels. Can anyone please advise?

Close enough. Try it and see what happens. I would expect you might be fine. I'd really like to know what the throats on the 29 really are though, my 629-2 is .433, and hates .431 bullets with an iridescent purple passion. You may only know by trial and error though. The guns won't be shy about telling you what they do and don't like.

Did you use jacketed bullets to check the throat sizing on both? How hard was the 629 to push thru? Was it noticeably hard, as in barely able to do it by hand?

Don't focus too hard on one factor over another on shooting lead bullets. It's more of an all of the above issue where you can usually defeat one failing by being resourceful in another area. Chamber throat size, bore size, forcing cone angle, bullet alloy hardness, load pressure, lube used, bullet design to include driving band, and more all go into seeing if your load works and you don't get leading. Add a little black magic, voodoo, or helping of luck and you will have mastered the art.

Besides, I've found where someone will swear a load won't be accurate, will lead like heck, and would be a waste only to find that in my gun it worked pretty good. And then in my other gun the guy was right.

Thanks for the replies! Bluedot, I used jacketed bullets. The Sierra .4295 would not budge through the throats even with pencil pressure. I'd say those throats are pretty snug! I've fired both Hornady .430's and the Sierra .4295's through the gun with no issues that were apparent. I, however, didn't max the loads out. The load data was out of the respective manufacturers' manuals.

The 629 throats sound nice & tight, kinda like my 686-6 throats, but unlike my 29-2 where a .429" JHP only stutters a bit before dropping thru. It sounds like you haven't bought the .431" bullets yet? My experience with cast bullets seems that they usually are slightly smaller than the advertised dia. BHN 15 should be good for a moderate load, of course other factors come to play with leading issues. I'd say start at a safepoint with your powder preference & workup to where you want to be & watch for signs of too much pressure &/or leading. Sometimes it's just got to be customized for you. 17.5 - 18.0grs of 2400 with a 240-250 LSWC is very accurate in my 29-2. (You didn't say what weight bullet you're looking at?)