By Jeff Brown
In 2018 my family and I travelled to the USA for a four week vacation and whilst visiting a friend in Indiana I was introduced to poly coating (PC) of cast lead alloy bullets. I had been aware for many years of practice of powder coating and oven baking a synthetic coating on to bullets but had not seen it done or partaken it shooting of cast alloy projectiles treated in this manner. Upon arriving home some testing was done with great success but with one thing and another the experiments were put on the back burner until recently when a CBA member posted a record 400 13X score in competition using PCd bullets. This enormous achievement piqued my interest once more. Time to try this again I mused and being a sucker for punishment I elected to conduct the experiments using my Martini .310 Cadet.
There is no shortage of material available online demonstrating and explaining the PC process so I will not bore you with extensive details and advice. In short I small out of powder coating paint powder is dumped into a plastic container with the recycling mark '5' (polypropylene), clean cast bullets are then added and swirled or gently tossed around until the static created by the plastic container makes the powder cling evenly to the bullets. Standard practice for many users is to add airsoft BBs to the container also to generate more static and act as a bit of a buffer between bullets. I use the BB method but can't say for sure if the little plastic balls contribute anything meaningful but find it comforting to know they most likely reduce any lead on lead contact. Full coverage is achieved in short order (1-2 minutes) and bullets can then be removed (I use needle nose pliers previously dipped in the powder also) and stood up a baking tray coverd by a silicon baking mat. The silicon mat is a MUST as once the paint is baked it adheres to metal surfaces in a fashion that is hard to imagine. For the baking process I have a toast oven I previously used for heat treating bullets and this is set to 400F, the temperature at which the bullets are baked at for 20 minutes. Once baked and cooled the bullets are ready to shoot. It is worth noting at this point that the bullets are 100% coated including the based so essentially fully encapulated. Gas checks may be applied before or after depending on personal preference.
In 2018 my family and I travelled to the USA for a four week vacation and whilst visiting a friend in Indiana I was introduced to poly coating (PC) of cast lead alloy bullets. I had been aware for many years of practice of powder coating and oven baking a synthetic coating on to bullets but had not seen it done or partaken it shooting of cast alloy projectiles treated in this manner. Upon arriving home some testing was done with great success but with one thing and another the experiments were put on the back burner until recently when a CBA member posted a record 400 13X score in competition using PCd bullets. This enormous achievement piqued my interest once more. Time to try this again I mused and being a sucker for punishment I elected to conduct the experiments using my Martini .310 Cadet.
There is no shortage of material available online demonstrating and explaining the PC process so I will not bore you with extensive details and advice. In short I small out of powder coating paint powder is dumped into a plastic container with the recycling mark '5' (polypropylene), clean cast bullets are then added and swirled or gently tossed around until the static created by the plastic container makes the powder cling evenly to the bullets. Standard practice for many users is to add airsoft BBs to the container also to generate more static and act as a bit of a buffer between bullets. I use the BB method but can't say for sure if the little plastic balls contribute anything meaningful but find it comforting to know they most likely reduce any lead on lead contact. Full coverage is achieved in short order (1-2 minutes) and bullets can then be removed (I use needle nose pliers previously dipped in the powder also) and stood up a baking tray coverd by a silicon baking mat. The silicon mat is a MUST as once the paint is baked it adheres to metal surfaces in a fashion that is hard to imagine. For the baking process I have a toast oven I previously used for heat treating bullets and this is set to 400F, the temperature at which the bullets are baked at for 20 minutes. Once baked and cooled the bullets are ready to shoot. It is worth noting at this point that the bullets are 100% coated including the based so essentially fully encapulated. Gas checks may be applied before or after depending on personal preference.
Eastwood powder coating paints are widely recommended by experiences PC coaters.
The poly coating adheres to bullets remarkably so and whilst it may be scratched with a sharp object I have seen countless photos of fired bullets recovered with the coating still in tact. Indeed, it is possible to squash the bullet with a hammer or in a vice and have the coating adhere to the lead alloy in its entirety. I took a pair of bullets and pounded them flat on an anvil using an engineer's hammer and the coating stayed stuck the alloy.
PC coating adds, in my experience, 0.002 inch to the girth of a bullet. My .310 bullets measure nominal .308/.320 (320-120 pattern) and .312/.323 (323-125 pattern) so a PC treatment bringings them up to .310/.322 and .314/.325 respectively. The larger bullet often requires the heel to be run into a .314 sizing die just to squeeze the heel down a shade. On the subject of which, PC coated bullets take to sizing well and can be run through traditional base first and nose first dies with great results.
How do they shoot in the old Cadet? Easily as well as traditional lubed bullets and quite possibly a little better. Shooting at 50m/55y with open sights my rifle will group into an inch when I do my bit. Recently I shot a 10 shot group where 8 where in an inch, 5 in on hole and a couple of wide shots operator induced. A further bonus is due to the slick nature of the gloss finish paint I use there is a small velocity increase. I have yet to clock the Cadet loads but my .32-20 suppressor load averages 1030fps with lubed bullets and 1060fps with PC bullets.
How do they shoot in the old Cadet? Easily as well as traditional lubed bullets and quite possibly a little better. Shooting at 50m/55y with open sights my rifle will group into an inch when I do my bit. Recently I shot a 10 shot group where 8 where in an inch, 5 in on hole and a couple of wide shots operator induced. A further bonus is due to the slick nature of the gloss finish paint I use there is a small velocity increase. I have yet to clock the Cadet loads but my .32-20 suppressor load averages 1030fps with lubed bullets and 1060fps with PC bullets.
I am sold on PCd bullets for my Cadet at the very least. Further experiments I need to run for all my other cartridges and bullet patterns but progress thus far is very encouraging. Aside from looking cool the bullets are tidier to handle as there is no exposed lead and for cartridges the likes of the .310 Cadet that require outside lubricated bullets the advantage of no messy expose lubricant is a real bonus. More to come.
