Author Topic: sizing enigma... (Read 740 times)

myronman3 · « **on:** April 06, 2005, 12:30:39 PM »

ok. had my lyman sizer in the garage over the fall. sized some bullets with the sizing die and they measured .430 . i moved it inside, and recenly sized some bullets. they are all coming out at .431 ; same die used.
i have an idea as to why, i dont know if it is right. i am keeping it to myself so as not to polute the ideas.
anyone have any idea as to why there is a variance?

jhalcott · « **Reply #1 on:** April 06, 2005, 03:28:39 PM »

if your using the same alloy you need to heat your garage.or thin out your alloy with a little more tin.

myronman3 · « **Reply #2 on:** April 06, 2005, 03:59:23 PM »

the only question i have as to alloy is to my way of thinking, it shouldnt matter, once they are run through the sizer they should all come out the same size, right? i know different alloys will drop from the mold at different sizes, i would think the sizer makes them all the same.

Nobade · « **Reply #3 on:** April 07, 2005, 02:16:28 PM »

Two thoughts. One is bullet alloy; high antimony alloys have more springback than straight lead or lead/tin. They will come out of the sizer larger even though they went through the same size hole. The other thought is, are you sure your mic is in cal? Could it possibly not be reading correctly? Always good to check your instruments before anything else.

myronman3 · « **Reply #4 on:** April 07, 2005, 04:46:55 PM »

the mic is right on. the first bullets i did fit my freedom arms. my second batch didnt. i got out the mic and discovered the difference in sizing.

the only thing i can think of is the difference in temperature from out there and here might have made the sizing die size smaller. your idea about the alloy may hold some water, i am mixing in heavier amounts of wheel weights with my bullets now.

MGySgt · « **Reply #5 on:** April 08, 2005, 02:01:49 PM »

If you check some of the older Lyman Cast Bullet book you will see a chart that gives you the as cast sizer and after sizing size with different alloy.

You do state you are using more WW now in yor mix - A harder bullet will give more spring back after sizing then a softer one will.

anachronism · « **Reply #6 on:** April 08, 2005, 04:18:56 PM »

Quote from: Nobade

Two thoughts. One is bullet alloy; high antimony alloys have more springback than straight lead or lead/tin. They will come out of the sizer larger even though they went through the same size hole. The other thought is, are you sure your mic is in cal? Could it possibly not be reading correctly? Always good to check your instruments before anything else.

I'm voting for springback too. The same thing has happened to me, and this was all I could figure out at the time.

Bob

jgalar · « **Reply #7 on:** April 08, 2005, 05:08:33 PM »

I would suspect your change in alloy. You can always measure the internal portion of your sizing die at the different temperature ranges to determine or eliminate that as the problem. You can use telescoping gauges or small hole gauges with your micrometer.
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