1 Attachment(s)
Home Made Mold with Spiral Lube Groove
I posted a variation of this over on the "British Miltaria" Forum and thought you might find it interesting.
Here's another option for the cheapskate and/or guy who likes a challenge. With this process you can make a wide variety of molds with nothing more than drills and taps, using old (and cheap) Lee molds, and a bolt you can buy from the hardware store. Here's what I did:
1. Make the Mold - Drill out an old Lee Mold (I used a 9mm double mold) with a 37/64" drill. This happens to be my Cadet Carbine's bore size (0.578"), so the untapped part will "ride the bore". Tap the mold to your desired depth with a 5/8" NC bottoming tap. This will create sharply pointed grooves to a 0.625" depth in the mold;
Attachment 149278
3. Make a Sizer - drill a 1 1/4 NF bolt in stages to 15mm, then cut it off to about 1 1/2". 15mm = 0.5906. Which is about 0.003" greater than my groove size (perfect for cast bullets).
http://www.pridham.ca/Sizer.jpg
4. Cast Some Bullets - get the Alloy and Mold HOT! The narrow pointy grooves are tougher than usual to fill. cast a few, and after cooling apply the Lee Alox.
http://www.pridham.ca/Cast_Bullet_Views.jpg
5. Size the Bullets - same process as for the Lee sizers. Borrow a large sizing "pin" from another sizer kit, and run them through.
http://www.pridham.ca/Lubed_Bullet.jpg
6. Load and Shoot
My mold produces bullets as shown that weigh a sized and lubed ~480gr when cast from wheelweights, and are ~0.725" long, so stabilize nicely in the slow twist of my Cadet Carbine. Yes - I could just buy a 0.590" mold and save the effort, and yes, the bolt, old mold, tap and drills cost something (and the drills are a bit difficult to find), but I made my own custom mold and can apply the process to other bore sizes that match available taps such as the 5/16" (0.312"). The spiral, continous lube grooves are an oddity, but holds the lube well and the accuracy seems unchanged (this is not a MOA gun).
Guys Please! and an update
Glad to hear that my post was appreciated, but sheesh, a girl could get a big head!
A couple of things have come up on reflection:
- I made an elementary mistake when I said that a 8mm tap would make a 0.323" mold. In fact it would make a 0.315" mold which is the standard 8mm bore, not groove size
- I did up another Snider mold (0.590") from a Lee 0.575", mold and found it much easier, and of better (more concentric) quality than the one I did up from a 9mm mold. The nose shape was as original and was a better profile.
Here is a list of standard taps. The diameters listed reflect the outside diameter of the bullet that will drop. The points will be thin and sharp, so sizing down at least 0.010" would be advisable. The depth of the grooves on the tap vary, but are from about 0.050" - 0.080" for the sizes that would be commonly used for bullets (0.280 - 0.460), so you could choose a tap and selectively size down from 0.010-0.050" and be ok.
Here's a list of commonly available taps. In most cases you need a bottoming tap, but for the smaller sizes you might get away with a standard. I have added some quick thoughts on where they could be applied. Not all taps might be the same. Further, although tough, you could conceivably turn a standard tap down a bit on a lathe for custom fit and/or for less sizing to do.
Imperial
1/4-28 (0.250) - good for 22 cal and 6mm
5/16-18 (0.3125) - good for 31 cal and down
5/16-24 (0.3125)
3/8-16 (0.375) - good for 0.338 to 9mm
3/8-24 (0.375)
7/16-14 (0.4375) - good for 10mm, 44 cal
7/16-20 (0.4375)
1/2-13 (0.500) - good for 11mm, 45 cal
1/2-20 (0.500)
9/16-12 (0.5625)
9/16-18 (0.5625)
5/8-11 (0.625)
Metric
6 x 1 (0.236) - good for 22 cal
7 x 1 (0.276) - good for 6mm - 270
8 x 1.25 (0.315) - good for 31 cal and down
9 x 1.25 (0.354) - 8mm-9mm
10 x 1.5 (0.394)
11 x 1.5 (0.433) - 10mm - 44 cal
12 x 1.75 (0.472) - 45 cal
14 x 2 (0.551)
16 x 2 (0.630)