Powder coating and lead hardness ?

[waydeo]

I'm wondering should I use soft lead or my alloy for powder burners when using powder coating for best results? 
Pros/ cons  ?

[Back_Roads]

 I use pure lead sometimes lubed, no need to PC IMO Sizing to a properly prepared bore is key.

[Firewalker]

I'm wondering should I use soft lead or my alloy for powder burners when using powder coating for best results? 
Pros/ cons  ?

It makes no difference if the lead is Lyman #2 or dead soft when powdercoating. The PC will be the only thing being engraved by the rifling.

I aim for a cast slug to be exactly bore size so that it will travel throughout the bore with no pressure. Then I PC one coat with one of the good powders like Carolina Blue.

Run them through a sizer that leaves them 1-2 thou oversize an shoot them.

I have not found any advantage to PC for airguns personally.

[cosmic]

Until you get into big bores !!

[rsterne]

David, typical rifling is 0.003-0.004" deep (per side).... How thick is the Powder Coating if the lands never extrude or engrave the lead?....

Bob

[avator]

Does that powder coating leave anything in the barrel to be concerned with?

[waydeo]

 Not that I've seen .My powder burners are  easy to clean.

[Firewalker]

David, typical rifling is 0.003-0.004" deep (per side).... How thick is the Powder Coating if the lands never extrude or engrave the lead?....

Bob

Bob, have you powder coated before? The PC is just 1-2 thou, the slug/pellet deforms or flows but the actual engraving is in the PC.

I guess if you had long and flat boolits, the hardness would come into play but I see no difference in speeds with pellets and little difference in speeds with the tiny .22 and .25 slugs I shoot.

[Firewalker]

Does that powder coating leave anything in the barrel to be concerned with?

Interesting question Bill. Castboolits has a youge thread about just that topic. My take is, no.

The PC is essentially plastic, no adders, clay, or hard bits, it's baked at 400°F for 20 minutes so it can handle some heat and it permanently bonds to the lead and I do mean, permanently.

I think it leaves little to no fouling but a rough bore will still foul. A well polished bore will stay clean.

[Firewalker]

Until you get into big bores !!

Agreed! I shoot only PC boolits in my .357/9mm Chalenger and they are cast with Lyman #2 and sized .002 over bore (lands).

[rsterne]

Nope, haven't powdercoated, but if the coating is only 1-2 thou, then the lead must be deforming when passing through the rifling.... I just couldn't understand how the hardness had no effect.... 

Bob

[Greg_E]

Bob, the most I've seen is a 0.004 gain in diameter from PC. I think that the lead still needs to be soft because it does still get formed by the rifling. Recovered rounds from rubber mulch indicate this to me, at least through my bulldog. I have not tried to recover anything from my Hammer, too much power for me to want to try and stop, 200 foot pounds is my limit.

[EdinGa]

I've spent several years hanging with PB guys that cast. I've gained a wealth of knowledge from them. They used traditional lube until powder coating gained popularity. They switched and now they powder coat everything from linotype to pure lead. In the case of PBs powder coat prevents gas cutting and subsequent lead fouling in bores. I've pushed powder coated boolits up to 2100 fps and they still had fully coated bases when I recovered them.


I powder coat my cast pellets and slugs for a few reasons. First off, it's simply part of my process when casting. I also like it because it looks good and it provides a barrier between my hands and lead. I've also used powder coat to add a thou or two to undersized projectiles. If something I cast is the correct diameter or too large, I powder coat and then resize.

[rkr]

Nope, haven't powdercoated, but if the coating is only 1-2 thou, then the lead must be deforming when passing through the rifling.... I just couldn't understand how the hardness had no effect.... 

Bob

Yes, it's 1-2 thou and lead hardness will have an effect. You could double coat if you wanted to use hard bullets. For airguns you gain about 10 fps with PC and barrel cleaning is a thing of past. Accuracy does not seem to be affected but I have not shot PC coated bullets extensively yet. One problem I do have is that the PC flows down a bit when in the oven and that sometimes leaves an edge or rim at the base of the BT bullets that are standing up. I've been removing that with pencil sharpener but that does not provide perfect results so I need to experiment to find a better fix for that. With plain base bullets that rim is removed when sizing base first.

[Back_Roads]

 I may add PC to my lead free ammo experiments, after sizing and size again after PC. as these alloys, solutions do tend to load harder even sized correctly.

[Firewalker]

Nope, haven't powdercoated, but if the coating is only 1-2 thou, then the lead must be deforming when passing through the rifling.... I just couldn't understand how the hardness had no effect.... 

Bob

Bob, I've already addressed that, there is deformation under the PC bit it's minimal in small calibers. The lead itself does not have to take on sharp shoulders and the .002 offset x2 is .004 so it fills the grooves.

I'm sure larger calibers provide much more mass to deform and need consideration but I have not found that to be the case with my. 357 boolits shown above.

[rkr]

Nope, haven't powdercoated, but if the coating is only 1-2 thou, then the lead must be deforming when passing through the rifling.... I just couldn't understand how the hardness had no effect.... 

Bob

Bob, I've already addressed that, there is deformation under the PC bit it's minimal in small calibers. The lead itself does not have to take on sharp shoulders and the .002 offset x2 is .004 so it fills the grooves.

I'm sure larger calibers provide much more mass to deform and need consideration but I have not found that to be the case with my. 357 boolits shown above.

In .257 it's more like 0.001-0.002 increase in bullet diameter, definitely not 0.004. I need to measure it next time I coat.

Edit, it's about 0.0015" increase in diameter, 0.03-0.04mm.

[rsterne]

Well a .257 is that size on the grooves, and only 0.250" on the lands, so that is a 0.007" difference, not 0.003".... The hardness still has to make a difference, particularly in the chambering effort.... unless the chamber is so long the nose doesn't really engage it....

Bob

[waydeo]

Just a thought ,can someone that powder coats slugs recover some slugs shot with pure lead and alloyed slugs to look to see how they shoot. I don't have a pcp that shoots slugs yet.

[EdinGa]

Just a thought ,can someone that powder coats slugs recover some slugs shot with pure lead and alloyed slugs to look to see how they shoot. I don't have a pcp that shoots slugs yet.

I only cast air rifle slugs with pure lead. I can try to recover one that's been powder coated over the weekend.