Powder coating as an 'up sizing' measure? (coat thickness)

[cpileri]

Does anyone think adding a powder coat to bring up the diameter of a bullet is a viable choice?

it would be in lieu of paperpatching, to properly size a bullet.

I suppose I would need to knwo how thick each coat is, right?

Is there a list of how thick each color or type/brand of PC woudl add to bullet diameter?

Thx,
C-

[meicalnissyen]

[cpileri]

Photo of dog does indeed show up!

C-

[sdcitizen]

It seems most coatings go on around a thousandth thick, I did try at one time heating the boolits until they were too hot to hold, and then rolled them in powder, it went on almost 4 thousandths thick, and when I sized them (microband), it wiped the grooves completely off the boolit, it was perfectly smooth sided and all the coating was still intact.

[cpileri]

Hmm. So if I am looking for a few thousandths, i'd need more than one coat...
C-

[BT8850]

This thread got me thinking . . . . How well do you think it would work taking the a LEE 125g 2r 9mm boolit and, powder coat it fairly heavily, size .358 or .359 instead of my regular .356, and shoot it out of .357mag? I don't currently load for the .357 but would like to start and if I already have a mold that I could use it would definitely teeter the scales

[rsrocket1]

What size are your 9mm boolits dropping at out of the mold? It might be close to .357 already. My 356-120-TC drop at .3575 and when powder coating, they wind up at .359 - .3595 so I could easily shoot them in my .357, but I use my 358-158-RF for that gun.

If your boolits are dropping at .356, you could beagle the mold for when you want thicker boolits. A couple of pieces of tape is cheaper than a new mold.

[petroid]

My 355-120TC drops at .358 and I PC/Hi-Tek coat so its a no-brainer to cast, coat, size to .358 for the 38spl. I have used the C312-185-1R as cast, coated, and sized to .315 for a Mosin that slugs at .313 and it shoots 1" 50yd groups at 1500fps with iron sights.

[Smoke4320]

If you are ES Spraying the bullets you will get approx. 1.5 to 2 Mil thickness per coat.. I have never tried more than 2 coats. It is worth a try to do a small batch and test the results .
I can say I have taken a 457 bullet that was coated to approx. 461 and sized it all the way down to 454 without any coating coming off

[BT8850]

rsrocket1, it's been a while since I cast with it but If I remember they DO drop right at .356. I looked into the 'beagle' method (i'm pretty new to casting, i'd never heard of it) and it looks like an awesome idea, I will have to give it a try

petroid, thanks for sharing, i'm glad to hear that it works! Sounds like the 'pc up-sizing' method works very well. Do you notice any accuracy differences between your pc up sized 120TC boolits for the 38spc vs ones from molds that were 'designed' for the 38/357?

smoke4320, indeed I am am es powder coating and am very pleased with the results, and have noticed also that you can size a pc'd boolit down pretty far without it damaging the coating, its very impressive!!

[popper]

it would be in lieu of paperpatching, to properly size a bullet. I assume HV rifle. PP is about 3 Mils so you could be close without sizing.

[petroid]

petroid, thanks for sharing, i'm glad to hear that it works! Sounds like the 'pc up-sizing' method works very well. Do you notice any accuracy differences between your pc up sized 120TC boolits for the 38spc vs ones from molds that were 'designed' for the 38/357?

Alas, I don't load 38 just did it for a friend and haven't gotten a range report yet

[bangerjim]

I have a 9mm NLG mold that drops ~357.

1. I can drop/size/coat/size and get a perfect 356 for my 9mm's.

2. I can drop/coat/size to 358 and get perfect slugs for my 38SPL's.

Yes it works, but I have never done it more that one coat. Never had the need.

I use both BBDT (thicker and not completely uniform) and ESPC (.002 total add and very uniform).

If you are an accuracy stickler, remember tumble coating is not uniform and multi-coats can add undeterminable unbalance and/or trajectory deviation to your projectile.

"Upsizing" works for my simple plinking needs. Your mileage may vary.

banger

[popper]

Sized then coated & WD some PB for the MG 30/30 last nite. 0.311 went to 0.313 avg, as the rough surface is difficult to get a good measure. Also noted, ASBBDT (really low humidity yesterday so it worked great with HF red) the bases came out really bad. Very lumpy, not nice & smooth like the cut sprue should be. I did tap to drop excess powder. ESPC doesn't do this, spraying base last coat - before cooking. This is a slightly rebated base design & the edges are very good, just cratered base. This is really for a hardness test, size then coat, WD vs post sizing. I just cooked base down on NS foil. Also have to check neck tension when loading, may resize the case or boolit. Oh, trying to push these to the 1800 fps range.

[bangerjim]

If you DT and sit on NSAF, the base should take on the texture of the foil they are sitting on. Mine are flat and smooth, unless the foil is old and wrinkly! With your rebated base, the powder must not have touched the foil and took on whatever shape it melted in........... looks like. Should shoot just fine.....I would let 'em rip!

banger

[oldpapps]

I use the 'Shak-n-bake' coating method, sometimes with and sometimes with out AirSoft balls.

During my experimentation when I started, I tried coating with warm to the touch, not burning hot, lead. I got a very heavy powder cover. When baked/cured, the powder flowed to the base (down). The as-cast measurement was .3115-.312 inches. The heavy coat measurement runs .3205 to .322 inches.

The coating looked great, other than the skirt. I attempted to push them through my .311 LEE sizing DIE. This didn't work well at all, too big. The coating held great but the lead sheared.



Although I have not done the tests, from all indications, two or more 'Shak-n-bake' coating should build the thickness, diameter of the bullet. My concern would be the possibility of high pressure scooting around/threw a very thick coating, the coating is almost rubbery, hard but with some flex. Only tests would prove this one way or the other.

Good luck,

OSOK

[xacex]

I tried some lee 309-170 boolits, but after coating the darn things would not chamber in my 308 due to the coating on the bore ride section. However, all is not lost because they are the perfect size for the 54R now.

[popper]

Banger - I think the excess powder didn't drop off the base, piled up underneath & cooked ( I cooked for one hour & temp was good). Sprue cut was clean, no nubbies. When sprayed, not much of the base gets coated, flows out under the weight of the boolit. Don't know if it's bad or not, just different. Probably will affect accuracy as the base isn't 'flat' anymore.

[bangerjim]

popper - I have had severe base PC flash early on in my "messing around". The size die took it all off, but at times would expose lead at the very bottom groove where it was chipped off. Back in the pot!

Wicking of liquid PC could occur under the boolit base. Cooking for an hour is significantly longer than the required 10 min (per all the directions) and will keep the coating liquid much longer than normal, so it could wick under there.

All my bases are nice and smooth when DT'ing because the NSAF they sit on is smooth. I do not spray or coat the bases when ESPC'ing as I can justify no gain for the extra work. ( One does not gain any protection from any grease on the bases of standard lubed boolits and, after all, PC is just another form of lube for the SIDES of the boolits.) If gas cutting is happening at the higher velocities, one should seriously look into using a metal gas check and not rely on PC for barrel protection. I do on all my 223's and 30's for full load rifle velocities. For plinkers (22lr-ish loads) I do not use GC's and have never had any leading problems.

Have fun out there!

banger

[popper]

banger - My original post here was about the up-sizing. This is a test boolit http://castboolits.gunloads.com/show...ase-experiment , post #17. The base needs to be good for accuracy, inspection with a 20x mag shows bad faults. Just noticed this time the bases came out poor for my testing, FYI. I H.T. for toughness.
Hollowpoint is doing a rebated BT base mould which is drawing some interest also.