Mould adjustment

[tudor8055]

I have been working with a new Lyman mould 429667 RNFP. Trying to find a good load for a Lispys 44 special 4&5/8. My first load was Unique worked from 6.2 to 7.5 The 6.5 load was the best pattern. I had pretty bad lead deposits from about the barrel threads to the crown. I Fire lapped the gun and re tested the load. The pattern tightened and leading decreased as the charge went up. At this point 7.5 is the tightest pattern. I still have leading but it is minor in the forcing cone. I slugged the bore, .4295 Throats are .4305. Problem is bullets drop at .4285. This This may be the last New Lyman mould I buy as most of the new Lyman moulds I have purchased have been undersized. (wheel weights plus enough tin for fill out.)
Any way the point of this post is what to do. I figured nothing to loose as I have no other 44 with tight enough throats for this boolit. I was going to dimple the mould blocks so I went over to my shop to get a punch and hammer. As I was looking through my toolbox I found a Blue Point snap punch I forgot I had. Using the snap punch on the hardest setting I snapped a dimple on all four corners of one half and in the center top & bottom on the other. This did not do much so I snapped each dimple two more times.
Tried the mould out. Casting at 700-750 deg Mould came up to operation faster and cast better boolits at a cooler temp with no flashing. Boolits dropped at .4315. I believe if I go any larger I will get some flashing.
I have a .431 sizing die coming from lathsmith that I am certain will size at .431 as all other dies that came from lathsmith have been spot on so far.
The purpose of this post is just to document a method that was easy and worked. If you did not know the work had been done you would not even notice the dimples.
Only thing now is to see if it solves the problem in the gun.
Tudor

[DLCTEX]

I would keep a check on wear on the dimples to see if the small contact area will wear very fast.

[Catshooter]

Interesting. Keep us posted if you would.


Welcome to the forum tudor.


Cat

[Crash_Corrigan]

Ya can also beagle the mold with foil tape. Cut a narrow strip and apply it on the inside face of the molds at the ends and maybe a narrow piece between the cavities.

Apply to both sides of the mold and you will increase the diameter of the cast boolits and you can play with it up and down until you find a happy spot.

The foil tape stands up to casting pretty good but eventually may have to be replaced and if you tire of the mold you can remove the tape and sell an unaltered mold.....

[runfiverun]

it will, i shoot the 429421 in both my lipsies sized to 430 over 7,2 grs unique.
at least lyman is consistent, my 429667 4 cavity come in at 4285 ish also.
took me a week to lap it out to make 430.
it just scuffs the 430 size die now.