how big should I cast

[chemist308]

Just a quick question. How far over the size my bore slugs at should I be casting? Although this question was mainly asked with a semi-auto in mind, I'm also curious to answer for revolvers and bolt action rifles...

[MT Gianni]

I try to size at least 0.001 over my bore or revolver throat size. I am not really concerned if that # is 0.003 if it chambers OK.

[RobS]

It is usually .001 to .002 for rifle and auto pistols and for a revolver it depends on the cylinder throats. This is general of course.

[Shiloh]

Do they chamber?? Some sixes are limited by what will chamber. I run my oversize .30's at
.004. They chamber and shoot wonderfully. Some have posted here to size to fit the throat.

This has worked well for me.

Shiloh

[Bret4207]

I don't believe there's a real answer to that question. You have to cast and then size (if needed) to what the gun and load want. It's another "depends on" question. I like to see my raw castings drop at exactly the size I need, but a larger boolit is always better than a smaller one.

Sizing to the throat or as large as the gun will accept works well in many guns.

[GBertolet]

I have found along with many others that larger bullets usually shoot better. How much larger depends on how big will chamber, how big the bullets drop from the mold and what's reliable chambering. If unsized will chamber you can tumble lube unsized if you wish, which is great. I know I'm splitting hairs here, but a tighter fitting round is more in alignment with the bore than a loose fitting round lying at the bottom of the chamber being able to rattle. This applies to rifle ammo also. I like .453 in the 45ACP, .432 in the 44 Mag and 356.5 in the 9MM, for example. As good reloading practice would dictate, If you are at or near max loading, and change anything, drop back a little on the powder charge and work back up.

[Crash_Corrigan]

I have a Browning M-35 that will malfunction after about 20 rounds if I size my boolits at .356. It just blows smoke everywhere and soots up the casings and fouls the chamber and the inner workings of the wepon something awful.

However if I use the same boolit and powder charge and up the diameter to .358 and then run the completed round through a Lee FCD all is well. :bigsmyl2:

Accuracy is outstanding and the gun will shoot hundreds and hundreds of round prior to needing cleaning.

Some say that the FCD will mess with the diameter of the lead boolit. Hooray. I know it works for me. :cbpour:

I use the FCD on my rounds for my M-1 and these babies are only neck sized prior to loading with a Lee expansion die just prior to insertion of the boolit. :-P

Some people can knock and revile Lee but I find his products inexpensive and well engineered unless you are talking about his Loadmaster press which is a ***.[smilie=p:

[1Shirt]

My rifles are all female and all have their own personalities as far as size of blt goes. Some shoot best .001 over, a larger percentage best at .002. and have a couple that with heavy blts shoot best at .003 over. Trial and error is what keeps me on the quest for the best accuracy with each one.
1Shirt!

[JD Yellowhammer]

I think the folks trying to help here are misunderstanding your question--you're asking about casting and they're talking about sizing (what sizing dia. will shoot best).

As I understand it, you want to know how far down you can size a cast bullet. For instance, if your rifle has a bore of .377, and you're going to size your bullets to .378, how big should you cast: .379, .380, etc.?

As it happens, I need to know the same thing (and those are the diameters I'm concerned with). So I hope someone will chime in.

[Ricochet]

JD, there have been a number of threads discussing that. Here's a recent one about the effects of sizing and how much can be done:
http://castboolits.gunloads.com/showthread.php?t=68004

[JD Yellowhammer]

Thanks, Ricochet! Just what I needed!

[Bret4207]

You're at the mercy of your alloy and mould as far as how fat the boolit drops.

[Ricochet]

That's pretty much it, but you can make them a little fatter by "Beagling." Problem there is gas check shanks get fatter, too.