Lee C312-155-2R plain base conversion

[Castloader]

So, I got my hands on one of the new 6-cavity LEE C312-155-2R molds and set about modding it to plain base for PCing. Here's what I did:


I drilled out a 1" thick chunk of steel (happens to be 301 stainless but that's just I have a bunch) with a 5/16" drill bit (.310" with my caliper, very conveniently) This acts as a bit guide when reaming out the mold.


I chucked the bit backwards in my lathe and turned a shoulder into the butt end that matches the diameter of the gas check shank - .285"


I cut some crude reaming flutes into the shank near this new shoulder.


I added a depth stop collar to the bit to make sure I don't cut too deep.


That's it!


To ream the gas check shank out of the mold I do the following:


1) Remove the sprue plate and stop screws from the top of the mold
2) Carefully align the mold halves and clamp in my vise. I don't haul down on the jaws, just firm pressure. I don't want to smoosh the aluminum and ruin the mold.
3) Insert the drill bit shank backwards into the steel block
4) Align the bit shank into a cavity (the shoulder on the bit makes sure the bit is centered and the block as well)
5) Clamp the steel block onto the mold so it cannot shift. Now I know the hole in the steel block is centered on the cavity
6) Flip the bit around add some cutting fluid, and slowly and BY HAND spin the drill bit cutting into the cavity.
7) Clear chips with a Q-tip frequently.
6) As soon as I feel the bit catch a little, (meaning the gas check portion is almost gone) I remove the bit, clear chips and flip it around and ream the cavity out with the crude reamer. The depth stop ensures that I don't touch the lube groove.
7) When the bit spins freely, remove the steel block and using a razor blade, scrape the top of the mold flat to remove any burrs created by the cutting.


THAT'S IT! It looks pretty good. Once the bit is created, it takes a couple minutes per cavity to convert. The reamer function probably could be skipped with the cutting end of the bit used by itself and the stop collar adjusted for that side. Since I have the reamer, I use it, but it would probably work just great without.
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Here's what it looks like halfway through. PB on the right, GC on the left.
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Cheer's!

[JonB_in_Glencoe]

excellent !

[Artful]

Geee, well thought out - accurate and easy to replicate - Thank you for sharing

[Elkins45]

Lee makes a six cavity rifle mold now? Am I out of touch or is this a group buy?

[Castloader]

Lee makes a six cavity rifle mold now? Am I out of touch or is this a group buy?
yes, they make this mold now. It's a little hard to find since it's so new, I had to get it on eBay. Midway doesn't list it yet and a couple other do, but not in stock yet. I paid like 37.99 plus a little shipping.

I found it because I email Lee asking them to make this mold in a 6-cavity. Lo and behold they replied that they already have it and gave me the P/N which is: 90741

http://www.ebay.com/itm/like/231583340901?item=231583340901&vectorid=229466&rmvSB=true

I bought it from this guy. No issues

[RoyEllis]

http://www.titanreloading.com/molds/bullet-molds/762-x-39-303-b-8mm/lee-6-cav-mold-c3121552r
Titan Reloading (a site sponsor) has it in stock right now.

[W.R.Buchanan]

Ditto on Titan!

Randy

[Leatherhead Bullets]

Nice! Let's see some coated and a range report please!!! I have been thinking of this myself.

Thanks

[kbstenberg]

Question on point #6 With what did you hold the bit to both turn it and cut the GC.?

[Castloader]

Question on point #6 With what did you hold the bit to both turn it and cut the GC.?

I have an old keyless drill chuck that works great as a handle.

[Castloader]

Nice! Let's see some coated and a range report please!!! I have been thinking of this myself.

Thanks
I'll post that as soon as I can. I have a slightly unique way of coating as well that is probably 90% as good as using a gun but I tumble coat. I'll also post that as soon as I make some. Probably will be a few days, work is crazy right now.

[borg]

Plus 5 on Titan, where I got mine.
Have you cast any yet?
Just wondering what the weight is.

[2wheelDuke]

It looks good. Makes me want to give this a try myself. Problem is that I don't have access to a lathe right now. I bought one a couple years back, but I loaned it to my dad, and he's 12 hours away.

I just got one of these molds from Titan last week. I haven't had time to clean it or put any lead in it just yet.

I also got one of their new 55gr .225 molds. I got the 2 cav to see how they do. A $20 mold is a good candidate to test out the conversion.

[Castloader]

It looks good. Makes me want to give this a try myself. Problem is that I don't have access to a lathe right now. I bought one a couple years back, but I loaned it to my dad, and he's 12 hours away.

I just got one of these molds from Titan last week. I haven't had time to clean it or put any lead in it just yet.

I also got one of their new 55gr .225 molds. I got the 2 cav to see how they do. A $20 mold is a good candidate to test out the conversion.

You could probably take a drill bit to a machine shop and have them do it for almost nothing. It would take them 5 minutes. Or have your dad do it and mail it to you. Just make sure it's the right diameter. 5 divided by 16 is .3125 but mine measures .310 which is what I want. I imagine the actual sizes of different bits will vary some.

[Castloader]

Plus 5 on Titan, where I got mine.
Have you cast any yet?
Just wondering what the weight is.

Probably will this afternoon. I'll post as soon as I have.

[Castloader]

I had a few minutes today and cast a few.
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This is one of the better ones
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[Castloader]

I need to polish the cavities, weights are spread a bit from 155 to 158 grains based on a sample of about 15. Most are 155 or 156. It looks like the cavities I cut first are not as good as the last few. Polishing should help a lot. All very shootable, but I probably wouldn't win a bench rest competition with them. I'm making them for close range blasting so should be perfect for that.

[Castloader]

Actually, I may not polish the cavities. After powder coating and sizing, they look great. Now to see if I can get to the range anytime soon...
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[borg]

wait a minute, the Lee C312-155-2R weighs 155 gr already.
What mold do you have?

[Castloader]

My tumble method of powder-coating:
Rule: no skin contact from the time they fall out of the mold until they come out of the oven with a coat of powder.

These bullets are coated in Mirror Black by PBTB

1)I tumble in the powder for at least 10 minutes, an hour is better.
2)I put on nitrile gloves and coat my gloved hands in powder. I fish the boolits out of the powder and put them tip DOWN into a plastic block that once held factory .40 S&W ammo. The block has been coated in loose powder as well. This keeps powder from rubbing off the boolits
3)I shake and tap the block to remove clumped powder
4)I put a sheet of non-stick aluminum foil on top of the boolit bases
5)I put the oven tray on top of that.
6)With one hand above and one below in a sandwich, I flip it all upside down.
7)The boolits drop base-down onto the non-stick foil.
8)I tease the block around so the boolits are evenly spaced
9)I blow a gentle puff to remove loose powder that has fallen into the foil. This helps eliminate flashing
10)I remove the plastic tray(s) and slip the oven tray into the oven at 400 degrees being careful not to knock the boolits over.
11)Ten minutes later I remove from the oven and place in front of a fan
12)I run the boolits through a sizing die lubed very lightly with non-scented hand sanitizer. Helps eliminate sticking and galling the new coat of powder. It will harden up later with the lead, so I like to size immediately.

I I can bake and size a batch of 100 boolits in a 10 minute cycle. They look almost as good as gun-coated boolits, but are fast like tumble-coated.

[Castloader]

wait a minute, the Lee C312-155-2R weighs 155 gr already.
What mold do you have?
Well, they do with Lee's recommended lead mix PLUS a gas check AND lube. I skip the lube and don't use a gas check, but add a little lead where the gas check would be and a thin coat of powder. I guess it comes out in the wash. Some were more like 156. Either way, they'll do for my porpoises. :veryconfu

[Mk42gunner]

wait a minute, the Lee C312-155-2R weighs 155 gr already.
What mold do you have?
I'm going to say it is alloy variation. I don't think I have ever had a mold drop the specified weight boolit. But then the only molds that I was even close to the specified alloy was when I cast a few round balls out of sorta pure lead.

Robert

[Castloader]

After coating 25, there are
8 in the 155gr range
9 - 156gr
5 - 57 gr
2 -158gr
1 - 159gr

I guess the cavity polishing would probably help that a little. I had some issues with flashing for a sec while casting and may have grabbed a couple oversize ones. I wasn't trying to be too precise.

[MauiDoug]

I'm new to CastBoolits - never heard of powder coating. What are the advantages - does it replace conventional lubing for single shot pistols, or is it used in HD revolvers, rifles or what?

[Mytmousemalibu]

I'm new to CastBoolits - never heard of powder coating. What are the advantages - does it replace conventional lubing for single shot pistols, or is it used in HD revolvers, rifles or what?

Welcome to the forum! Powder coating is the new age replacement for traditional & tumble lubing of bullets. As long as your bullet specs for size, hardness of alloy, etc, as you would for a standard lubed bullet, you can essentially shoot PC'd bullets in any firearm you can run a cast projectile in. You could run a PC'd round ball in a flintlock if you wanted to. All the common rule of cast bullets apply, your just replacing the lube with super slick PC. The big advantage is no leading of your bores! Also no sticky, messy lubes, on your bullets, dies, other reloading gear. You can use cheap push-through sizers like the Lee's, no lubrisizer. There's a lot of nice advantages.

[JonB_in_Glencoe]

I'm new to CastBoolits - never heard of powder coating. What are the advantages - does it replace conventional lubing for single shot pistols, or is it used in HD revolvers, rifles or what?
let the reading begin
http://castboolits.gunloads.com/forumdisplay.php?184-Coatings-and-Alternatives