undersized bullets

[12DMAX]

How far under throat dia can a bullet be and one still expect good results? .001 .0005?
Tom

[Iron Mike Golf]

We need more information. Are you asking about revolvers? How does throat diameter compare to groove diameter? What do you mean by "good results"? Is that hunting accuracy at 25 yds (say a 2 inch group)? How much leading is a good result for you? None, or is a mild scrubbing with a wet brush after shooting 50 rounds OK?

edited to add:

OK, just saw your post about your .45 Colt BH, so I will assume it's that one. You got .449 Groove dia and .452 throats. As long as you stay above .450 or so, your accuracy will be OK. You are gonna get some leading, though if you shoot, say, a .451 diameter. It might not be bad. It depends on your load. You are probably going to give up some accuracy because the gases blowing by until the bullet seals the bore are going to erode the base a bit.

You could find loads you are real happy with for accuracy and don't mind the elbow grease for lead clean up.

[12DMAX]

Ironmike, reason i ask is i have been having trouble with leading/accuracy and ASSUMED the bullet caster sent me .452 bullets but after spending some time at the bench last night they very from .451 to 452. with some .4505

[Char-Gar]

Years ago, Elmer Keith wrote that bullets .001 undersize for the cylinder throats were just fine for 38/357. Move up to the 44s and 45s and he bumped that number up to .002.

He of course was talking about alloys that were soft enough to obdurate under the pressure of the load. Most over the counter cast bullets are far to hard to obdurate under anything but the most godzilla of Pressures. I suspect your problem will be found in bullets to hard and not bullets to small.

[mdi]

If bullets are too small for the throats, you'll get leading at the cylinder throats. From everything I read and my limited experience, a snug fit (interferience fit) to mebbe .001" smaller works best...

[Bret4207]

I kinda like the snug fit idea too. But, it also depends on the load, alloy and individual gun, some being far more forgiving than others.

[fast ronnie]

i just traded for 90# of 158 lswc for a mdel 64 smith. I started to size them tonight with my new latesmith star die and found the castings before sizing were running about.3565 to just over .357 at the smallest measurement. Is there any way to possibly swage these up, or is there another answer? There is no possibility of recasting these, as the gentleman no longer casts. Maybe I just have 90# of casting material?

[Wise Owl]

A little bit of a drift from the OP's question Eh.

[fast ronnie]

I know it isn't exactly the topic of this thread. I'm new to the forum and don't yet know how to start a thread that would answer my question, so I typed in undersized boolits in the search box. That's the reason for it being on this thread. If you have any suggestions, I'd appreciate hearing them. i haven't done any casting myself, and am not familiar with some of the things that can be done. Please forgive my ignorance on this. I did not intend to derail the thread, only looking for information. If you could steer me to another thread more appropriate?

[MtGun44]

Look at the sticky on revolver accuracy.

In general, spend a bunch of time reading stickies. They were put there because they are
important threads to understand and learn from.

Bill

[44man]

I firmly do not believe in "BUMP UP", fit first. I find groove size works fine to .002" over.
Once you expand to obturate you will slump the entire boolit. That soft and the boolit will skid the rifling.