Bullet flashing and my fix

[7br]

I have a new to me lyman 280412 single cavity mould. Started casting with it early Sunday and notice a lot of the bullets had flashing on the nose and more towards the handles than opposite the handles. I noticed that when the mould was in the handles, opposite the the handles, the blocks were tight, but closer to the handles, there was a gap about the thickness of two sheets of paper. I removed the blocks from the handles and held them together. Perfect fit. Beings that I do not have a grinder to releave the inside face of the handles, I removed a quarter inch from one side of the handle. Blocks close perfectly now.

The only problem is I cast about 50 before I noticed the gap and about 100 after the fix. All are mixed together. I can sort by flashing and base size, or I can melt them all and start over. I think I am going the remelt method.

Interesting side note. Base diameter before fix .288, after fix .283. Weight before fix 144gr, after fix 140gr.

[Ben]

Whenever a mold doesn't want to close properly, I'm always suspicious & look for interference in proper closure caused by the handles.

Ben

[runfiverun]

i borrowed a pair of single cavity molds, and only had 1 pair of single cav handles.
a bit of handle chopping, some grinding on the handles, as well as the prongs,and i now have two pairs.
but one of them can be used for both now.

[jhrosier]

I always close the blocks and hold the mould towards a light to check for gaps with a new-to-me mould.
I also pinch the block closed with my fingers and release pressure on the handles to make sure that the blocks are free to move a bit on the handles to self-align.

I have filed a couple of sets of large handles on the prongs to let them close with small blocks.

Since I have bought as many used Lyman moulds as new one recently, I check them closely.
One mould had burrs turned up around the alignment pin holes.
The blocks closed on the burrs and had a gap.
I ground the burrs off with a 3/8" round mounted stone, turned by hand.
There was still enough undamaged hole to keep the blocks properly aligned.

I make it a point to close the blocks gently to avoid damage and take a quick look at the faces of the blocks from time to time to spot particles stuck to the faces.

Jack