I have a Lyman 266673. 6.5mm 150gr GC.
I just started to PC it, and am having good results.
When I size it, before PCing, I noticed parts of the bands, don't show signs of being sized.
How would I go about enlarging just the bands????
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I have a Lyman 266673. 6.5mm 150gr GC.
I just started to PC it, and am having good results.
When I size it, before PCing, I noticed parts of the bands, don't show signs of being sized.
How would I go about enlarging just the bands????
Are part of the bands left unsized because the alignment pins need to be adjusted to shift the mold halves back into the correct relationship?
There are guides on how to use valve polishing compound to fix that.
Before permanently altering the mold. Check for alignment.
But if you are having good results then i wouldnt even sweat that.
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The boolets actually shoot good.
I'm just thinking if it will do as well in my other rifles, being that it is a little uneven.
The pins looks to be good. No parting lines on boolets.
You can lap the blocks to just enlarge the bands but its a little trickier. I prefer to do it all as this helps maintain concentricity or the grease grooves.
What you need to do is use a couple flat plates to impregnate the bullet / lapp with very fine compound. A very light smear on one steel plate and roll bullet between the 2 plates this only impregnates the tops of the bands. then work with a tapping motion back and forth in the cavity. For just truing up 800 grit, diamond paste, auto rubbing compound, flitz will all work.
Yes, that's the way. To rotate the bullet, drill a small hole in it and press in a Torx bit. this gives a positive drive that won't loosen up. You can usually make the lap expand a thou or two by pressing the bit in deeper.Quote:
Originally Posted by country gent
Rinse the excess compound off the charged bullet so it doesn't get trapped in the joint faces.
If you don't feel confident in your own abilities, Erik at Hollow Point Mold Service opens band diameters for a reasonable price.
I've done the same for the whole boolet.
Never tried it on just the bands.
Also this is a Lyman mold.
I've only done Lee molds.
I'll give it a try.
Thanks
Go slow and be patient and gentle and you will do fine. Normally it dosnt take a lot to true a bullet to round. I have found most valve grinding compounds to coarse for this job. ( when lapping valves the compound breaks down much faster to the finer grits). Watch the original moulds finish as you go and you may see the high low spots. Keep in mind lapping cuts all around on dia. so removing .0005 on a side is .001 on dia.
Work slow and carefully. checking often to see where your at, I have a lead pot going on the bench and heat mould and pour a few bullets when checking finish, size, and roundness. Takes a little longer to pre heat cast and cool but I know for sure right where Im at. I simply dip the blocks in the molten lead for a few mins until it no longer sticks to blocks and then pour a few good bullets 6-8 the other plus to this is if more is needed you have fresh bullets for a new lapp. This takes any expansion shrinkage into account when measuring the cooled bullets.
I lapped the bands larger on a lyman 429421. I rolled the lap bullets on a flat surface pressing down with a file to texture the drive bands then rolled them in 320 grit diamond powder spread on a plate. It started casting less than .429" and it's now .432".
Arrowhead Lapidary had the diamond reasonably priced.
Just leementing w a bullet enlarges everything. Anything you do not want enlarged needs to go. I had a few Lee molds that cast undersized. I would cast some bullets, linotype, they tend to come out bigger as it is. Then lathe off everything but the bands. If its gas checked, need to get rid of that shank or its murder to put them on later.
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Put the hard cast boolit in a drill and use a file or? to decrease the diameter of the gas check area before enlarging the bands