Proper bullet size when powder coating

[chaplaincolby]

I searched the forums but didn't find an answer to my question, so if my question has been asked just direct me to to the previous post. My question is, I understand that traditional lubed cast bullets should be sized .001-.002 over groove diameter. Does the same rule apply to powder coated? If so, should the size be measured before or after coating? If not, then what should the final bullet size be after coating.

[farmerjim]

Coat and then size exactly as you would a lubed bullet. Measure size after sizing. .001 to.002 over grove.

[runfiverun]

like Jim said, same fitment as non coated.

[KenH]

Yes, size should be measured AFTER coating.

[djgoings]

I'd like to ask a question that expands on this thread. I recently took some 158 grain SWC cast bullets, sized them to .358, then powder coated them. After powder coating I measured the "new diameter at .362/3. I also measured the OAL of the bullet. I then sized down to .358. The OAL of the bullet had increased by about .004" or so. Doesn't this mean that the powder coated bullet is being extruded when sized down to .358. I remember some old timers telling me years ago that you never want to have to size down more than .002" or the "deformed" bullet will hurt accuracy.

[OS OK]

What method do you use to PC those casts?

Most of us here get an overall increase in diameter of <.003" . . . an actual coating thickness of .0015".

[Smoke4320]

I'd like to ask a question that expands on this thread. I recently took some 158 grain SWC cast bullets, sized them to .358, then powder coated them. After powder coating I measured the "new diameter at .362/3. I also measured the OAL of the bullet. I then sized down to .358. The OAL of the bullet had increased by about .004" or so. Doesn't this mean that the powder coated bullet is being extruded when sized down to .358. I remember some old timers telling me years ago that you never want to have to size down more than .002" or the "deformed" bullet will hurt accuracy.

when "Squishing it down" the excess lead has to go somewhere,so it goes the only direction left ..Its grows in length ..
it will always do that ..
now you are working up your load for accuracy so there is no issue
if you tried to compare a perfectly cast (to the correct size) to begin with load to one you had just sized down .004 without the work up yes you may see a difference in accuracy ..
same as comparing the lubed to pc load without the accuracy work up FOR EACH ..

[runfiverun]

guess what happens to it when you pull the trigger?

it gets shorter and fatter then longer and skinnier.
sometimes it tries to change into a cylinder shape.

[Smoke4320]

Changlings ?

[djgoings]

I used the shake n bake method with Sherwin Williams gloss black PC.
What method do you use to PC those casts?

Most of us here get an overall increase in diameter of <.003" . . . an actual coating thickness of .0015".

[dverna]

guess what happens to it when you pull the trigger?

it gets shorter and fatter then longer and skinnier.
sometimes it tries to change into a cylinder shape.

Shape shifters

[w5pv]

I just ran about a hundred or so through the sizer that already was coated off hand at about 20-25 yards the shot group was at aprox three inches

[chaplaincolby]

Thanks guys for a good answer to my question.

[Motor]

I'm finding that powder coating is much like casting itself as far as what to do and when goes. You do whatever you want to achieve the results that you need.

Yes for the most part its cast, coat, size. But I currently cast, size, coat for one application and for another I cast and coat only. This is to achieve particular diameters. The cast, size, coat one is simply because I'm too stubborn and cheap to buy another size die. :)

BTW: I shake and bake HF Red and usually get less than .002" diameter gain. .004" to .005" is a LOT !!!!!

Motor

[fredj338]

I also size to the final dia after PC. It is still a lead bullet after all, just diff type of surface lube.

[fredj338]

I'd like to ask a question that expands on this thread. I recently took some 158 grain SWC cast bullets, sized them to .358, then powder coated them. After powder coating I measured the "new diameter at .362/3. I also measured the OAL of the bullet. I then sized down to .358. The OAL of the bullet had increased by about .004" or so. Doesn't this mean that the powder coated bullet is being extruded when sized down to .358. I remember some old timers telling me years ago that you never want to have to size down more than .002" or the "deformed" bullet will hurt accuracy.

You realize how small of an increase that is right? Not even worth the time to measure it.
I used to size 0.459" bullets down to .0452" for heavy 45colt loads, they shot great.

[Kevinkd]

So for my H&K 9mm I originally sized to .357 (PC boolits that is) and I would get the occasional non-chamber. Just a little too big. So I sized to .356 and they shoot amazing. With 4gr of universal, one guy put ten in about 3.5" off my rest at 25 yds. Much better than I can do LOL... Also no leading or any issues - holes were nice clean, no tumbling etc.

Just my .02