To increase bullet diameter

SIGP2101

SIGP2101

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Hi all

I need advice. I need to size (read bump up, increase diameter) my bullets. I do not have experience doing this and I do not know what equipment should I acquire. Can someone point out or list components needed for such requirement, and describe procedure. Please no acronyms. Keep in mind that I am casting my own and need to increase diameter not decrease.

Thanks
 
First time I have heard of this I have heard of the reverse, ie sizieing bullets down, but not up!!

What size bullet do you want to go to?
 
Adding linotype or monotype to your alloy will cast a larger diameter bullet.

You can also use a hollow base mould. When casting with this type of mould & using a relatively softalloy the bullet will "bump up" on firing.

I would also suggest that you obtain a copy of the "Lyman Cast Bullet Handbook". This book covers just about all aspects of bullet casting.

Rod. :wink:
 
If it is not a large increase and if the bullets are soft and if you have a properly fitting nose puch you can bump them up slightly in a standard lube-sizer.

If it is a significant increase you will need to make up a bumping die and nose punch--and use a hammer to do the job.

44Bore
 
If you're really desperate, I'm sure you could work up a punch arrangement with a proper-sized hole bored in a thick-enough piece of plate or rod, a nose-cavity in another piece, and a piece of rod that has been sharpened to use as a punch. You could center the bore over the nose-cavity block, drop an under-sized bullet into the bore, drop the punch in on top, and give the rod a smack with a hammer (or even squeeze it with a vise. Then, lift the bore piece off the nose cavity, and give it another shot to knock the bullet out. It's slow, but unless you want to adapt some sort of hydraulic-press to this operation, that's probably the next best thing to a proper swager.
 
Gibbs505 said:
First time I have heard of this I have heard of the reverse, ie sizieing bullets down, but not up!!

What size bullet do you want to go to?
Click to expand...

One swages bullets up to increase diameter, and draws bullet down to reduce diameter.

Ted
 
Thanks for all of your inputs.

I was hoping that something exist on the market that would enable you to swage bullets to desired size. I am trying to go from .379 to .381. It is not too much. I guess I will have to order custom size casting mould and fix problem that way, or invent something that I could patent, and get rich, maybe.
 
I don't actually know much about casting bullets and stuff, but assuming you could obtain the proper dies and press you could easily swage up or down .002"

Swaging could either be increasing or decreasing the diameter of the bullet. I think that in general, swaging is considered cold forming metal - usually with a die. I've swaged tubing through a die to decrease it's outer diameter. Drawing as I've heard it used could mean the same thing, but I've usually heard it used as lengthening or widening metal often while hot - like a blacksmith does.

Try looking at http://www.corbins.com/ I looked there a while ago when I was first thinking about making my own bullets.

What ever you decide to do, if it's going to be done accurately, it'll likely be expensive.
 
Corbin make/made bumping dies for jacketed bullets, with a step method of bumping involving a series of progressively larger dies for bumping in small increments IIRC....

IMHO, For cast bullets, it's a lot simpler to order custom sized molds and sizing dies from Lee.....

Custom Molds

We can produce custom bullet molds within certain limits. Please check out our custom services page for more information.

If you are interested in this service, please download both page 1 and page 2 of the following links.
Mold Design Mold Design Pg 1 383 KB
Mold Design 2 Mold Design Pg 2 250 KB
Click to expand...

Here is the link to the page....

http://www.leeprecision.com/cgi/catalog/browse.cgi?1129742890.2012=/html/catalog/bullmol1.html
 
Just get a regular casting mould and get it machined .0025 over. Then size as ususal.
This will be the cheapest way to obtain proper diameter bullet.

As for sizing them up, you are just looking for poor acuracy unless it is swaged with Corbin dies or the like. Too much sizing down is already detrimential to accuracy, imagine swaging them up as much as you are expecting.
 
SIGP2101 said:
I was hoping that something exist on the market that would enable you to swage bullets to desired size. I am trying to go from .379 to .381. It is not too much. I guess I will have to order custom size casting mould and fix problem that way, or invent something that I could patent, and get rich, maybe.
Click to expand...

I have a few 38-55's and a couple of 38-56's, none of which have the same internal demensions, but I use the standard Lyman 375248 in all of them.

When I need a .381 diameter bullet I bump up an 'as cast' 375248 to the proper diameter by placing a bullet in a .381 sizing die in my RCBS Lubesizer and work the ram up and down until the bullet fills out to .381. Actual bump dies are not required, in fact bump dies are normally made to bump a bullet nose up to slightly over bore diameter so that the nose is supported by the bore.

This method is also used by CBA members to work voids out of a cast bullet.

The largest standard die available was .379 so I made myself a suite, between .378 and .382, which meets all my needs in the various 38-55 and 38-56 rifles I have.

Such sizes are available from Stillman (http://www.sizingdie.com/index.htm) if you can't google them or make them.
 
Why not? said:
Gibbs505 said:
First time I have heard of this I have heard of the reverse, ie sizieing bullets down, but not up!!

What size bullet do you want to go to?
Click to expand...

One swages bullets up to increase diameter, and draws bullet down to reduce diameter.

Ted
Click to expand...

OK, I stand corrected!! :oops: :oops:

[Sweeps off hat and bows]
 
For a single cavity aluminium mould, I'd probably just lap the mould.

cast a few and put keyed brass rod or tubing in them before they harden, cover them in grinding paste and put them into the mould and use the rod to rotate the bullets in the mould till you've used all the bullets or the mould fully closes, then recast and measure the post lap cast size. Repeat till they drop from the mould the size you want.

You might want to keep grinding paste out of the lube bands though.

go slow, go easy and keep the rod vertical. I had to go .007 over for mine. .429 to .436 for my .442 RIC (thanks garmak)
 
One other possibility, which I have read about but haven't tried, would be to place a piece of aluminum foil between the mold blocks. After trimming the foil out of the bullet cavities you should be good to go. If more diameter is required, add another layer.
 
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