I am going to try indexing components to see if it helps accuracy. I have a 2 cavity mould. Any suggestions on marking cavities so I can 1) separate cavities and 2) consistently orient components during loading (and firing). I am considering making a small dimple in the nose area of the mould with my dremel tool. One dimple for cav 1 and 2 dimples for cav 2. Has anyone done this and is there a possibility of unbalancing the bullet with these marks? Should they go on the tip of the nose section, side of the nose section, etc? Any comments would be appreciated.
I would personally steer clear of the Dremel tool & instead use an automatic center punch (or manual if that's what you've got) because it's easier to control and less risk of it getting away from you.
All that's required is a light punch mark on the nose - I prefer further down the nose just because alignment accuracy can be a little better than if you're up toward the tip. Just be sure that you put it in an area that won't get sized and that's in an easy spot to see for your indexing chores.
Differenct cavities on some moulds can be significantly different. I think you'll find it pays dividends.
Best regards-
Sky C. Longmont, CO
Posts: 103 | Location: Colorado | Registered: 03 January 2003
I have used a needle file so one cavity has a little flashing near the tip. Lets me sort visually and thumbnail flicks it off. Do it just right and the nose punch takes it off.
Posts: 1570 | Location: Base of the Blue Ridge | Registered: 04 November 2002
I use the core of a .30 cal AP projectile for a punch. Makes a very small mark. One punch in one cavity, two punches in the other. I can differentiate between the two cavities and also orient the bullet throughout the processing and loading.
Despite what Lyman may tell you, there is a difference between the two cavities. When the mould is cold, there is probably no discernable dimensional differences. In casting, I always fill the same cavity first each time. With .30 cal bullets 170-210 grains, there is about 1/2 grain difference in the average weight between the two cavities, although both cavities will produce bullets with very uniform weights, usually +/- 0.1 grain. The difference has to be related to relative heat trasfer from the cavities.
leftoverdj has the correct approach. A needle file applied very lightly on the cavity edge about halfway up the ogive works great and shaves right off with the fingernail./beagle
quote:Originally posted by beagle: leftoverdj has the correct approach. A needle file applied very lightly on the cavity edge about halfway up the ogive works great and shaves right off with the fingernail./beagle
Myself I'm not going to add another step to the loading routine. Best way to mark a cavity is taking a 1/16th drill bit and putting a very small pimple on the ogive base near the forward engagement pt. This is done by turning the bit slowly by hand-- and does not increase bullet wt. Like I said-- a small pimple. The second cav can be marked same-- just well higher on that area for easy sorting, allowing orientation thru out the loading sequence.
Posts: 1529 | Location: Central Wisconsin | Registered: 01 March 2001
