About to be flamed...

[Yellowseven]

I am trying to find info on how load data is influenced by powdercoating vs traditional lube. I am particularily interested in using cast bullet data vs jacketed data. Also, I am interested in info about sizing. I know their are different opinions about .0005 to .001 under vs over throat diameter. Does this change in pc bullets? Also, what about hardness? Does one need to continue to match hardness with chamber pressure?

I attempted to use the seach function, but what ever terms I put in I get no results. I think it is an issue with the tapatalk app I use to view the forum.

Can anyone point me in the right direction?

Kind regards.

Sent from my SM-G925V using Tapatalk

[runfiverun]

lets see.
no.
yes.ish you can use a slightly softer alloy but why go through all the trouble.
you still need fitment but it isn't as absolutely critical you have a little wiggle room.

lets see.
lead is slicker than copper, and P/C is slicker than lead.
so you'll probably have to raise your load about 3% to compensate.


oh and your mold is too hot.

[res45]

The only thing I have found is that with a particular 9mm bullet with a RN profile it needed to be seated slightly deeper to compensate for the thickness of the coating vs. the same bullet without coating. Since all my bullets cast slightly oversize to begin with I size them to the desired diameter after coating. Can't think of any issues I've had with coated bullet in both rifles and handguns other than slight changes in seating depths an in the majority of cases with the bullets profiles I use it's never an issues anyways.

Bullets do appear to be a bit frosted so just back the temps down a bit,they should shoot fine and take the coating with no issues. I use 50/50 for my 9mm and 45 ACP bullet and PC them an have no leading issues. My 9mm is running around 1150 and the 45 at just over 1K fps.

[charles1990]

People make this waaaayyyy too hard, especially in revolvers.

Buy a good plain base mold.
Run your melt hot enough to fill out the mold. (I like frosted boolits)
Tumble coat them and bake them.
Load em up as is (no sizing).
Shoot em up.
They will shoot better than you can.

My 329 44 magnum, New Service 44 special, New Service Match 45 colt, Officer's Model Matches in 32 and 38 ALL
work just fine with these easy, non smoking boolits with Trail Boss, Unique and HS-6.

Shooting is fun ----- even more fun when KISS is employed.

[HABCAN]

^^^^^^^^^^^^^^^^+1!!!

[sergeant69]

i guess i do it wrong too. i PC because my 405 gr 45-70s are just too dam hard to push thru my star and take too many pumps to fill the grooves. took the fun out of it. so i turn on the convection oven, dump some slugs onto a wire mesh on a pan, stick em in the oven and when after they are warm to the touch take em out and dump em into my cool whip bowl that has a lot of Smokes clear powder in it (no BBs) shake for a minute or three, when the temp hits 400-425 (oven temp gage verified) dump em onto a wire mesh over a diff pan to collect the excess powder (they are COATED) now, put the wire mesh over the original pan and bake em for 15-20 minutes (i watch for the powder to start to melt and hold em at that temp) then remove and cool. they go thru the sizer like budda and come out "sized" to .460, gas checked, lubed (yes the reservoir still has lube in it ) and with a thick coat of PC. i practiced PCing with some 40, 45acp, and 44 slugs the right way ie: BBs, shake off excess powder etc and had to PC 2-3 times to get a good coat. now its one shot, no BBs, no picking up each bullet with tongs or gloves etc. for ME anyways, the wrong way works. the pre heat method i saw a version of on u tube. wasn't my idea.

[fredj338]

I find my load data doesn't really change. The PC or HT is just a lube, you still need proper fit. It is still a softer lead bullet vs most plate & certainly jacketed. So lead data is appropriate. My PC or HT loads are about 20fps faster than conventional lubed. That is within margin of error for chrono & testing conditions, so I call it the same.

[Yellowseven]

Fred,

May I ask what you consider proper fit?

I have read so many different thing, from both respected members of the casting community, and published data. Many time the published data says, .0005 to .0015 over cyclinder throat diameter, so that the bullets are swedged down and it ensures obturation.

However,
other published resources say it should be .0005 to .0015 under so that bullets are bumped up to obturate. And that sizing over throat diameter leads to cylinder end shakes and refuce the life of the gun.

Aldo, thank you for you reply. It was helpgul.

Sean



Sent from my SM-G925V using Tapatalk

[runfiverun]

never under size.
you can get away with groove size in a fixed breach system.
but in a cylinder throat to a barrel throat you fit to the cylinder throat.
unless you have a serious over diameter mismatch between the two you won't be wrong.
if you do have a serious mis-match you either fix the problem or shoot copper wrapped.

[bbogue1]

i guess i do it wrong too. i PC because my 405 gr 45-70s are just too dam hard to push thru my star and take too many pumps to fill the grooves. took the fun out of it. so i turn on the convection oven, dump some slugs onto a wire mesh on a pan, stick em in the oven and when after they are warm to the touch take em out and dump em into my cool whip bowl that has a lot of Smokes clear powder in it (no BBs) shake for a minute or three, when the temp hits 400-425 (oven temp gage verified) dump em onto a wire mesh over a diff pan to collect the excess powder (they are COATED) now, put the wire mesh over the original pan and bake em for 15-20 minutes (i watch for the powder to start to melt and hold em at that temp) then remove and cool. they go thru the sizer like budda and come out "sized" to .460, gas checked, lubed (yes the reservoir still has lube in it ) and with a thick coat of PC. i practiced PCing with some 40, 45acp, and 44 slugs the right way ie: BBs, shake off excess powder etc and had to PC 2-3 times to get a good coat. now its one shot, no BBs, no picking up each bullet with tongs or gloves etc. for ME anyways, the wrong way works. the pre heat method i saw a version of on u tube. wasn't my idea.

Your PC process is Very close to what I do. PCing has had no obvious effect on load. I preheat up to 20 seconds, Cool Whip swirl, dump out onto a screen and sort loose powder from bullets, gently tap the botom of the screen then tip the screen so the coated bullets will roll a little. I pour them all into an 8X8 baking pan with a copper mat (Yoshi brand) and bake 400 degrees for 12 minutes. Bullets removed from oven and dumped out of pan into water. Pan allowed to cool, baked powder scraped off the mat with a putty knife and it is ready for another batch. Sizing? No problem some are a bit fatter than others so they take a bit more effort, but, my landlords 7 year old son loves sizing bullets.