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rrob692326
04-03-2017, 03:58 AM
I have a problem with a nei mehanite bullet mold as it produces a finned boolit. There is nothing on the mold faces .when I'm casting, but I can see the space between the blocks when held up to the light. It appears that the mold is resting on the base of the mold pins but I am not sure. Can I drive out the mold pins stone the mold faces perfectly flat and drive back the mold pins for a cure? I had the mold for quite a while but never had an opportunity to use it until recently so I feel like I'd be wrong letting Joel at Nei have it for doing a bad job now. I appreciate any and all solutions you can offer. It is a custom one of kind odd ball caliber and not easily replaced because of the extremely large boolit.
Thank you
RR

Devon
04-03-2017, 08:22 AM
I would try driving the pins a bit deeper in the blocks first.

ioon44
04-03-2017, 09:23 AM
You might try casting at a cooler temperature to stop the fins.

Bent Ramrod
04-03-2017, 10:10 AM
Check the mould half with the locating holes to make sure the holes are not peened over around their circumference. This happens when the blocks are carelessly slammed together in casting. If it exists, insert an appropriately sized drill into the holes from the outside and twirl it by hand until you can feel that the peened edge is removed.

If you still see daylight between the halves, put the mould half with the locating pins face up on a bench block, and, with a brass punch, give each pin a tap until you can feel the blocks move slightly in a lateral direction when held together and wiggled. Check the fit of the halves for daylight. Most of the time, there will be none.

Then turn the pinned half face down, with the pins protruding through appropriate holes in the bench block, and give each pin one tap each with the punch, testing the fit with the other block until the lateral motion just goes away.

You should then have a mould that fits together properly with no space between the blocks.

You can check the faces with a straight edge. I've seen very few moulds with dished or warped faces that had to be lapped down. They were all very old and most showed signs of abuse.

rrob692326
04-09-2017, 02:55 AM
Thanks for your help

TexasGrunt
04-09-2017, 05:20 PM
Check the mould half with the locating holes to make sure the holes are not peened over around their circumference. This happens when the blocks are carelessly slammed together in casting. If it exists, insert an appropriately sized drill into the holes from the outside and twirl it by hand until you can feel that the peened edge is removed.

If you still see daylight between the halves, put the mould half with the locating pins face up on a bench block, and, with a brass punch, give each pin a tap until you can feel the blocks move slightly in a lateral direction when held together and wiggled. Check the fit of the halves for daylight. Most of the time, there will be none.

Then turn the pinned half face down, with the pins protruding through appropriate holes in the bench block, and give each pin one tap each with the punch, testing the fit with the other block until the lateral motion just goes away.

You should then have a mould that fits together properly with no space between the blocks.

You can check the faces with a straight edge. I've seen very few moulds with dished or warped faces that had to be lapped down. They were all very old and most showed signs of abuse.

That should be a sticky.

robg
04-18-2017, 11:02 AM
I've got a rcbs mold that Finns boolits if you don't let the lead swirl into it .it might help.