Lyman 314299 diameter

[DanM]

I bought one of these from Midsouth, hoping it would work for my Enfields, but it casts only .312". I use a 1:40 tin/ww alloy for pistols, and then add a tablespoon of magnum shot to 20lb for rifle boolits and quench. This yields a very hard boolit that casts to full weight. I need a .313" boolit for my post war Fazarkley, and a .314+ for the Longbranch, so this mold won't work for either. I am thinking that some of yall are using this mold for Enfields with good results. What is the as cast diameter from your 314299 molds? Maybe I should send it back.

[sundog]

Dan, I have had one for quite awhile. It drops .314 and .303 forward of the front drive band with 50/50 ww/rangescrap. Very good design.

Have you thought about beagling it? Or lapping it?

[DanM]

Well, I have been lapping on it with mixed results. A very slow process with the Lyman mold compaired to lapping a Lee mold. This mold started casting at only .3115", and I have done six one minute lap and cast cycles, and only gotten it to .312" measured 90 degrees from the seam. This is with coarse valve compound. It is fatter when measured at the seam, more like
.315", so my lapping efforts have made it egg shaped. I need it to
'round out' to a full .314" in the sizer.

[Calamity Jake]

Beagle it, it should become more round and .315 to .316 90° to the seams

[DanM]

OK, I will try beagleing it next. Do you find that when lapping a mold, it enlarges faster at the seams than at 90 degrees away?

[leftiye]

Yep, The sides get lapped sooner, and also more than the bottoms of the cavity halves do. This is why a little lapping and a little beagling works so well. Beagling doesn't expand the width at all, just the depth.

[longbow]

DanM:

You got alomost exactly the same results I did!

I had borrowed a 314299 which dropped boolits at 0.311" body and 0.302" nose ~ small for my gun. I then bought my own mould and found it dropped boolits at 0.312" body and 0.303" nose so better but still small. My bore diameter is 0.303" and groove is 0.314" so I decided to do a bit of lapping.

I was very careful but still got the oval mould syndrome - a little bigger at the seams. It turned out at 0.315" at the body seam and and about o.314" at 90 derees to the seam with the nose at 0.305". I used thin foil to Beagle it and the boolits are just a little out of round but shoot well.

I would prefer nice round boolits but they are shooting pretty well so who can complain?

Yes, from what I have read and experienced with more than one mould, lapping tends to result in an oval mould slightly larger at the seams. There is an article here about correcting or avoiding that.

Longbow

[DanM]

When lapping I noticed that the compound would migrate over the gas check shank, and cause it to enlarge along with the rest of the boolit. I tried to keep the stuff off the shank with no success. After two laps, I noticed that checks were getting hard to seat. To correct this, the first thing I tried was to grind off the GC shank on the 'cherry' boolit, but that left a flange that was hard to remove. I chucked the boolit in a drill, spun it, and pushed a file against the GC shank to reduce the diameter so it would not cut in that area. Seemed to work. Likely this is old news, but I thought I would mention the technique since it is new to me.

[NVcurmudgeon]

My 314299, made in 2000, casts .314" X .303" using WW with or without 2% tin. That is perfect for my .303.

[Boomer Mikey]

When you make your lap:
Embed the compound into the drive bands by rolling between two steel plates and clean off any excess that isn't embedded into the drive bands. The lap should look like sandpaper... a smooth surface with grit glued to the surface. With iron molds you can use a little sulfur base cutting fluid to improve cutting action. In aluminum molds use kerosene or odorless mineral spirits to improve cutting. Keep the compound off the areas of the lap that you don't want enlarged in the mold cavity. If you pay attention to detail it's possible to enlarge any part of a cavity you want to... shank, drive bands, lower half of nose, etc. Embed the compound grit only into the area of the lap you want to change in the cavity. Rotate the lap in both directions for short periods and clean/flush the cavity often.

This requires patience in spades.

Lee-menting is a polishing/deburring process extra abrasive is OK as it's super fine.

Boomer :Fire: