Powder Coated Bullets

Powder Coated Bullets

Powder coating can completely replace the copper or gilding-metal jacket on a bullet and works well on cast bullets. The powder coating is completely polymerized during the baking process and does not further melt when traveling down the bore, nor is it affected by the hot gases following behind. It adheres well to the bullet and is very durable and is will not flake off like some liquid polymer coated bullets, accepts being sized with no problems (you will want to flare case mouths slightly to avoid scraping powder coating off bullets during bullet seating step of loading). The powder coating completely covers the bullet, protecting it from hot gases and barrel friction and protects the bore from the lead, completely eliminating lead and copper fouling. The higher the gloss level for the powder coating the more “slick” it is or the less friction the coated bullet will have down the barrel. High gloss (95% gloss level) powder coated bullets will typically have faster velocities compared with jacketed bullets for the same powder level (~100 fps in rifles, ~50 fps in pistols, at 95% listed max load).

Traditional hardcast wax-lubricated lead bullets need the addition of tin, antimony or silver to the lead alloy to make the bullet harder to reduce lead fouling. The addition of gas checks further reduce lead fouling by protecting the base of the bullet from hot gases and allow for higher velocities. Richard Lee in his excellent reloading manual has a chapter dedicated to cast bullets and the calculation of maximum velocities for different bullet hardness alloys. This applies only to wax lubricated and gas checked cast bullets. Powder coated bullets act like a jacketed bullet and can use the same loading data as jacketed bullets up to a velocity of 3200 fps – Several people report to me that shooting my powder coated bullets in a 22-250 at 3400 fps results in a cloud of lead about 10 feet in front of the muzzle – the powder coating does not add structural strength to withstand centrifugal forces like a thicker gilding metal jacket can. In my experience the powder coating acts just like the jacket on a jacketed bullet. People who have used gas checked cast bullets are initially hesitant to use powder coated cast bullets without a gas check but are soon won over after trying them. It is more difficult to add a gas check after powder coating (the gas checks have to be tapped on with a mallet) and the gas check adds enough friction to negate the speed gains of the slick polymer coating without adding any more protection to the bullet. I have had several people report that even at rifle pressures they have observed no gas cutting on recovered powder coated bullets supporting the observation that no gas check is required on powder coated bullets. I do offer gas checks on 50BMG powder coated bullets but only for those customers who insist – I do not use them on my own 50BMG loads.

Soft lead (100%) has a Brinell Hardness (BNH) of 5. My bullets with 3% antimony have a BNH about 10-15 depending on whether they are air cooled or water quenched (tempered). This means that they are hard enough that they will deform a little but won’t slough off lead like a softer jacketed bullet and are not so hard that they would shatter when hitting hard bone. Large or dangerous game bullets would typically be tempered to make a harder bullet with less mushrooming and better penetration characteristics.

Powder Coating Process and Notes

I use the 95% gloss “Super Durable Wet” series of powder from Powderbuythepound.com. I typically shake bullets in a quart-sized Tupperware container with several tablespoons of powder. The bullets are strained out using fine mesh strainer and the powder recycled. The bullets are dumped in a pan then individually placed on a copper grill mat base-down, not touching each other, and baked at 450°F for 20 min (the powder coating requires 400°F for 10min at part mean temp to fully polymerize) in a large convection toaster oven and allowed to air cool or are water quenched depending on desired BNH rating (large or dangerous game bullets would typically be tempered to make a harder bullet with less mushrooming and better penetration characteristics). Bullets are then sized through a sizing die and packaged for delivery. Powders are meticulously kept separated as the colors will contaminate each other – surfaces are vacuumed during color changes and copper grill mats are dedicated for a specific color (copper grill mats will last for several years heavy use and are cut to fit in a baking sheet for use in the oven). Powder has a shelf life of about 1 year after which it does not cover very effectively, requiring two or more coats which reduces visual esthetic appeal and doubles or triples coating time and results in a splotchy-looking bullet. Bullets must be at least room temperature but not hot enough to melt the powder (i.e. comfortable to hold in your hand) when you shake them in the powder coating. My shop is unheated and at cold temps shaking does not build up enough electrostatic friction to have the powder coat adhere to the bullets. When my shop is cold (<50°F) I place bullets in a pan on top of the oven to warm enough to coat evenly and thickly when shaken in the powder. Upon request I will powder coat buckshot or round balls and use a dimpled silicone candy mat to keep the round balls separated on my baking sheet as either bullets or roundballs that touch each other will have the powder coating melted to each other and be locked together. The powder coating adheres less to the copper grill mat than a silicone mat. I use nitrile gloves when handling powdered bullets prior to baking and have found that pinching bullets while turning them a couple times while resting base-down in the baking tray I dump them into from the mesh strainer tends to even out the coating and fills in any holes in the powder coating from being jostled together while straining or dumping them out of the strainer – be careful not to touch the bullets with a wiping motion as that will remove the powder from the bullet and the powder won’t stick to that spot after that. My current favorite powder coat color is: Crystal Clear Super Durable High Gloss Clear – shows the natural lead color. The more I have used powder coated bullets the more I have liked them and the less I use jacketed bullets for hunting (I have been casting bullets for over 40 years but only tried powder coating bullets about 6 years ago).

Rob Davidson

11/5/2024

Robsbullets.com