Checking New Mold How Long to Wait?

[Themoose]

Forgive me for asking, but I couldn't find the answers using search..probably my fault but could someone help me to understand a couple of issues with evaluating a new mold? I have already slugged my bore and know it is .366, but I want to see what the new mould will produce and if it needs "beagling"... I plan on lube sizing and will have a sizer die made once I get the mold figured out.

1. How long should I wait before determining what size the mould actually throws?

2. Does the diameter change with age as the bullets harden?

3. Water quenched or air? Does it make a difference in diameter? again when should I measure

I plan on using wheel weight alloy for 9mm Markov... thinking of running around 900-1000 fps.

Thanks for your help folks.

Kindest regards,

Themoose

[runfiverun]

super good questions.
it also sounds like you do things in steps similar to how I do them.

an alloy with antimony will grow over time [so will one with copper]
it will also have some spring back after being sized.

just make some boolits and measure them when they are cooled off.
you need to size down.
so a mold that isn't throwing @.367 right off isn't gonna be much help to you.
stuff like our loved ww alloy isn't gonna give enough growth to matter, [or even accurately measurable with your calipers] so waiting 10 days is only gonna make them older, maybe .0005 larger, and a bit harder.

[44man]

I water drop mine and they do grow with time. Smaller boolits grow less though so you want large enough from the mold as Runfiverun stated and you might only get to .001 or .0005 in the end.
My .476" boolits can reach .478" with time but the 30 cal is much less.
Measure after casting so you know the mold, size soon and let them age. WD will change faster then air cooled and will be harder too.
For anything 9mm I would WD.

[Themoose]

Thanks to both of you for the info...Looks like a good week to do some casting...Nor' Easter on the way...good time to add to the inventory... Thanks again.

TheMoose

[adam_mac84]

Will check back for more replies. I just started casting 9mm with WW. Mold is throwing 0.004 over size. Going to try a few more today to see if there was some error that I made int he process. Growing from there would be bad newz

[Themoose]

Pressure cast water quenched measuring .366-.367 weighing 101-101.5 gr...No "beagling" just cleaned the mold out of the box, pre-heated and lubed... nice sharp edges...

[44man]

Will check back for more replies. I just started casting 9mm with WW. Mold is throwing 0.004 over size. Going to try a few more today to see if there was some error that I made int he process. Growing from there would be bad newz
Be OK, size soon and they will not get large enough to worry about. Always better larger, can't add if needed, You can size again.

[Wayne Smith]

Sounds like you are planning on shooting as cast. If your sizes agree you are good to go, but most boolits require some sizing. Even the boolits from a multicavity mold aren't all exactly the same diameter, and sizing also guarantees roundness (of course, so does your barrel!). If you don't have one consider investing a little in a Lee size die if you are only casting for one caliber.

[Themoose]

Wayne,

I do plan on running thru one of my Lyman lube sizers... I agree with you about them varying or being out of round... I was just trying to figure out if the bullet as cast would do for sizing without beagling the mold... I will have to get a custome sizing die made... Lee doesn't make one in .367 that I am aware of if I went with a push thru.. in my earlier post I mentioned that I have a blank die for the Lyman that I can have made up to whatever dimension I need. Saying all that, I will probably try some that I hand lube with soft lube and some tumble type lube just to see what I get... but more than likely I will lube-size them the way I do with other centerfire I cast for.

[BCB]

Not exactly sure what mold you are going to use, but I use the Lee 365-95-1R for my Makarov…

It drops from the mold at 0.368” with WW…

So that would give you plenty of boolit to size if need be. I shoot mine as cast lubed with LLA…

Winchester 540, HP-38 and Unique have worked quite well to get a tad over or under 900 fps…

I am not sure what firearm you are going to shoot them from, but I wonder if one needs to be so concerned with all you mention. Maybe so with a really good shooter, but I don’t know that the Makarov would fall into that category. I use mine just for plinking and then at ranges around 15 yards, mostly less…

Good-luck…BCB

[Shiloh]

2) Yes they can "Grow" I have picked up about .0003. You need a mike and mine took two weeks.
3) Water quench. If it's wet, it isn't hot. An old blacksmith shop rule that works for cast boolits.

Wheel weights cut with range scrap and water hardened should be plenty. Every gun is different.
I use 50/50 WW/Range Lead water dropped for rifle boolits gaschecked up to 2000fps as fast as I have gone.
Need it harder?? use WW or ad linotype metal. Water dropping helps a lot.

Shiloh

[Yodogsandman]

Pressure cast water quenched measuring .366-.367 weighing 101-101.5 gr...No "beagling" just cleaned the mold out of the box, pre-heated and lubed... nice sharp edges...

This is as my Lyman mold drops them, without water quenching at .3665". I use COWW's and shoot them without sizing, tumble lubed with a very thin coat of Lee Liquid Alox. Using a full dose of AA#5, they shoot right where I aim.

[rl69]

Thank you verry helpful thread

[Gee_Wizz01]

If your bore is .366 and the boolits drop from .366 to .3675 I would just give a light coat LLA and forego the sizing. Just load and shoot. I have the Lee Mak mold and a group buy TC mold which drop at 366 and I just use LLA and shoot. With my Russian PM and my friends East German PM they both shoot 2" groups at 15 yds using AA 5, BE, Unique and 231. My theory is try the easiest way first. If I can get away without sizing I am happy. I can TL 500 boolits in 15 minutes. If I must size I try a push thru first and my Lyman 451 is the last resort.

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