Thermoset plastic bullets?


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tweakkkk
January 4, 2009, 10:55 PM
I have a relative who is selling some off a few firearms, a Chinese SKS, some deer rifles in everything from .243 to .30-06, and some handguns.

I've been keeping my eyes open for a .223 carbine to replace my .22lr plinker, since it's old and the barrel is almost unusable. I was going to use .22 pellets with the .223 primer pockets drilled out for magnum or shotgun primers for plinking, since I only get to the range every once in a while, and rarely hunt.

I know people use wax and glue bullets all the time to shoot in centerfire pistols and rifles. I'm a hobbyist and I've molded plastic parts for things using ABS granules... what I wondered is why not use them in a bullet mold?

ABS and other thermoset plastics can be bought in granules (tiny pellets) that melt easily and set hard. I have 9 pounds of the stuff left... I think they would easily make much more consistent bullets than hot glue or wax. You could probably seat to a correct OAL to feed in a semi (though you'd obviously still have to operate the bolt by hand)

If this could be done, it would make easy plinking with plastic bullets and primers. I wouldn't need to find a .223, I could buy up that SKS, or another long gun which would be great. My neighbor has an amazing reloading setup that he'd gladly let me use, since I let him use my workshop for his woodworking projects. I just don't want to go ruin any of his molds or dies experimenting with this if the experience reloaders here don't think it's a good idea.

I know I ask crazy things here, but I'm a "what if" kind of guy. If it's been done before it's just not fun!

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Grassman
January 4, 2009, 11:03 PM
Maybe more possible in handgun loads, as your rifle accuracy would be bad at best......

tweakkkk
January 5, 2009, 12:38 AM
Of course the accuracy just wouldn't be there for more than 15 yards with such light bullets, but that's enough for backyard plinking. The great thing about thermoplastics is that you can experiment with different weights and hardness. For lube you could probably just spray them with silicone, or hell, rain-x.

Or I suppose you could weight it with other things. At a show I saw these subcaliber cores in a polymer carrier (like a sabot, but it doesn't separate until it hits) -- The ones I saw were marketed for varmint shooting, so you could use low-power loads for .308 or 7.62x39 and tackle critters at 100 yards or so. Only ever saw em the once, so I'm not sure if they were successful.

jaimeshawn3
January 5, 2009, 12:48 AM
Very interesting idea. I think that there was a pistol load that was plastic with a steel or lead BB to give it some weight. Also I think there was a East German training load (for SKS/AK47) that was hollow steel with a plastic filler - the steel helped the bullet stand the pressure from the hot gases, and the force from the rifling. Soft lead bullets will tear from the rifling, at rifle velocities and pressures and so I'd guess un-protected plastics might too.... You might try buying the copper tracer bullet jackets from http://hi-techammo.com/ in Colorado and filling them up with plastic.... I just checked and they are out of stock. Anyone have another source of 30cal tracer jackets?

GP100man
January 5, 2009, 12:55 AM
get a lee 2 cavity mold , under $20
& soot it up & give it a try !!!

i have some 209 powered 44 gloolits.
dogs don`t like em !!!!

GP100man

tweakkkk
January 5, 2009, 01:49 AM
<<Soft lead bullets will tear from the rifling, at rifle velocities and pressures and so I'd guess un-protected plastics might too....>>>>

We're talking about using only a large primer here, no powder. I don't even want to think about the mess if you loaded powder behind a glue bullet...



I would go pick up a mold and try it... but I don't have a centerfire rifle anymore! I had a hand-me-down Remington in 7-08 but gifted it away a few years ago... regretting it at the moment.

RyanM
January 5, 2009, 02:06 AM
I'm not sure if a primer packs enough juice to get a hard plastic bullet all the way out of a rifle barrel. With rubber bullets, they tend to just give the bullet one good kick, and then it goes the rest of the way out just from that. Through a long rifle barrel, you'd probably have a vacuum pulling the bullet back after about 6" of travel, which would slow it down a lot.

A shotgun primer might do the job though, especially if you cast spherical bullets rather than bullet-shaped ones, to reduce engraving force.

You could also try to make "cat sneeze" loads with appropriately sized lead balls, and just enough fast burning pistol powder to get the ball out at enough velocity to punch paper. Those work best in straightwall cartridges, so you can seat the ball way down in the case, against the powder.

tweakkkk
January 5, 2009, 02:52 AM
<<Through a long rifle barrel, you'd probably have a vacuum pulling the bullet back after about 6" of travel, which would slow it down a lot.>>

This might be true. Workarounds?

If it's an option for a given caliber, I suppose you could use a slightly undersized mold. A .308 (normal .30) in a 7.62x39 or .303 might help this.

Use a drill press to drill a hole through the center of each bullet? A paper gas check/wad behind the bullet would get it moving, and the hole would prevent the vacuum from ruining velocity.

People say that they get wax to fire from their rifles. I wonder how strong the effect is? A 16" carbine might not have it so bad as compared to a 24" target rifle.

There are also plastics of varying hardness... and I suppose if you had a composite thermoplastic with hot glue, it would give the bullet extra weight and elasticity.

rcmodel
January 5, 2009, 01:39 PM
Wax & glue stick practice bullets have been successful through the years because they are cheap & very simple.

Thermoset plastic bullets would not be.

First, you would need a method to melt the plastic.
Then, you would need a method to inject the stuff into a bullet mold under pressure in order to get a complete fill.

Do you have a tiny Injection Molding machine?

rcmodel

Grump
January 6, 2009, 12:20 AM
I've seen plenty of training rounds in .308 that were molded white plastic from just forward of the metal web (either screw-in or snap-on), with the bullet being part of the whole assembly. Thinner sections at what would be the case mouth allowed separation when fired.

Think they had 2-3 grains of pistol powder in there, too.

I believe they would probably work fine. Might be easier to mold them by cutting oversize lengths and squishing them in the hot mold, oozing the excess out.

Just a few thoughts.

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