Casting polymer boolits

[halodub]

After doing a quick search and going through the first few pages, I didn't see anything related to this, so I figured I would make a post about it. Has anyone here considered casting entirely polymer boolits? Not just polymer tipped, but full polymer boolits, like the high density polymer ones some companies are offering now. Is this something that would for sure have to be injection molded, or is it possible to cast a high-density polymer using traditional methods? I'm thinking something like the hard outer container of batteries that are used to house harsh chemicals, or something of similar weight that would result with a somewhat similar weights to traditional boolits without having to have some HUGE boolit that would make any of the benefits go out the window.

I noticed a few of these rounds are actually polymer-coated copper boolits instead of pure polymer, but just figured I would drop a thread in here and see if anyone has thought about this, or has any insight as to if it's possible or practical to research further.

[Rcmaveric]

I would imagine weight would be an issue. Polymers are strong and light weight. Its like using zinc or copper, those bullets have to be rather longer to equal the weight of a lead bullet. Method of cast would have depend on consistency or viscosity of base material in liquid form and the mold would depend on shrinkages. Probably a million other factors my feable mind cant comprehend. I am curious as to why you would want to? There are lead free casting materials all ready available.

[sqlbullet]

Density is the huge issue.

The most common high density polymer is HDPE. It is used for a wide variety of containers including batteries, harsh chemicals and oils, etc.

It's density is just below 1 g/cm^3. .93-.97 depending on a couple of factors.

Lead is 11.34 g/cm^3.

So a 9mm cast bullet that weighs 113.4 grains as cast from lead would weigh only 9.7 grains if cast from HDPE. It would have to be driven 4000 fps to deliver the same energy on target as the lead bullet at a sedate 1200 fps. And even then the momentum and taylor KO values would be small fractions of the lead bullet.

Such bullets do have a place and many of us here have cast them. The favored medium is hot melt glue, which can be found made from HDPE, though it is more commonly a poly vinyl acetate of some variety. Densities are similar. The bullets are useful for indoor practice as they can be propelled by just a primer and offer reasonable accuracy at living room distances. They can often be re-used two or three times as well. Due to the lack of energy and momentum it is easy to build a basic trap to stop them.

[Kestrel4k]

A couple years ago I messed about with those German 7.62x51 training rounds; an 11gr plastic bullet in a plastic case (was actually a one-piece injection molding), with a steel rim. They were reduced loads of an ostensibly fast-burning powder, filling up perhaps 1/3 - 1/2 of the case. They chronographed at ~3400 fps from a short rifle bbl and grouped ~2" @ 50 yds. Shot into moist dirt, they mushroomed heavily - I didn't check the retained wt, but I still have the recovered bullet & a little of the ammo. Was certainly a novelty & an interesting distraction - I have no doubt it would still be lethal up to moderate distances.

[halodub]

I was mostly considering these for practice use just to have an alternative to lead if need be; I saw a video that kind of sparked my interest about them. Biggest thing I was worried about was maintaining accuracy with a load like this, especially considering how light they would end up being. I appreciate the input, and will have to look into that hot glue method. Sounds like it might be right up my alley. Thanks again everyone :)

[Victor N TN]

Speer used to make a plastic "practice" round. It was a special case with a rubber / wax bullet. It was fire only by a primer.

This might not help. But it came to me while I was reading this thread. Good luck.

[wistlepig1]

Speer used to make a plastic "practice" round. It was a special case with a rubber / wax bullet. It was fire only by a primer.

This might not help. But it came to me while I was reading this thread. Good luck.

About 5 years ago I got some of the speer's [38] to do some New shooter training. They worked will a close range.

[PBaholic]

I made some plastic .38's out of 3/8" solid rod, turned down to .357.

You can make Hot Glue rounds too. I made a mold out of a .357.

205296

Drill the primer hole bigger, and skip the powder.

[sawinredneck]

Not to stir the pot, this video will do that plenty! But I believe this is the video the op is referring to. I have several disagreements with this video!
https://m.youtube.com/watch?v=XqSLJwA9DrM

[PBaholic]

OMG!

Lead is not "Poisonous". Like every element in nature, too much of it can cause issues.

You can drown with too much water too!

[myg30]

Not to stir the pot, this video will do that plenty! But I believe this is the video the op is referring to. I have several disagreements with this video!
https://m.youtube.com/watch?v=XqSLJwA9DrM

I really,really,REALLY wish I didn't watch this fool and give him another viewer on his list. Just the fact that he has TOYS all around behind him in view sends an important message out about him.
My feelings WILL GET ME BANNED, so I'm just going to let this go AND his video on Pres.Trump and the NFL.
I have a fix for the NFL but post it in another section.
I've not tried the wax nor plastic boolits yet. I might be able to get my SIL to print me some on his machine at work. Looking into this.

Mike

[sutherpride59]

I'm not very knowledgeable when it comes to plastics or engineering but I would assume that if it were easier to make plastic boolits and resulted in comparable performance then the entire gun industry would have moved to it long ago. I'm putting this one in the section with low flow toilets.

[Harry O]

Many years ago, an outfit was selling a light polymer-bullet loaded to very high velocity. They offered .38 Special first. It was loaded to normal .38 Special pressures with a fast powder (like Bullseye). The bullet looked standard sized, but it weighed less than 100gr (probably quite a bit less). And, it got rifle velocities from a 2" barrel revolver. I don't remember the exact velocity, but from memory, it was between 2,500 and 3,000fps. They showed shooting at a quarter of a beef (before and after) and it really chewed a hole in it. However, it had a few reported failures to stop in cold climates in the wintertime or against leather clad bikers. It died a quick death. It was really limited to shooting at someone with nothing heavier than a T-shirt on.