Self cast plastic sabots?

[LUTNIT]

I was wondering if anyone has ever tried or heard of others trying to cast their own plastic sabots. I dabble in resin casting for scale miniatures using silicone moulds and both polyester (the smelly, toxic one) and polyurethane (the scentless more or less safe one) resins. Being in Canada I have to special order component sabots through registered importers and they are often months delayed or unavailable. If I could cast my own plastic sabots for use with cast bullets it would reduce my cost per round by 25-30%.

The silicone and resin combined result in about a 1% shrinkage from original to final cast but that can be compensated for by making the master slightly oversized.

As far as I have looked into the important factors are the material is strong enough and either self lubricating or lubed (alox might work?) and that the size follows close tolerances. I would of course take a couple measurements off of each sabot I cast before loading it to make sure it isn't dangerously oversized.

Viable option or exercise in futility?

[HangFireW8]

Depends on your results! I am all for self sufficiency!

I have only one word of advice, too slippery projectiles are bad for consistent powder burn and accuracy.

Good luck!

[jim4065]

What's the compressive strength of a sabot as compared to lead? I'm curious because we shoot oversized lead bullets all the time, and just rely on the "enormous" pressure of the expanding gas to swedge them down. As long as there is no air gap, won't anything that chambers shoot OK? (With the "correct" powder charge, of course.)
It sounds like an interesting way to get specialized projectiles to a higher speed, like maybe a "flechette" coated in thin wax, then 90% entombed in your plastic - with just the nose poking out. Would the plastic (or other medium, such as glue) be released on exit from the muzzle, resulting in a high strength steel penetrator zipping along near 5000 fps? Sweet!

[longbow]

I don't like to be negative about things like this because I experiment a lot myself but I doubt you will get a resin cast sabot that will hold good enough tolerances to be consistent. the other big issue is toughness. If you follow the sabot threads, even outfits like BPI had to make several attempts to get successful materials.

Also, they aren't "cast", they are either injection moulded under high pressure or machined.

Easiest for the home manufacturer would be machined but you would require a lathe of CNC mill to do it.

I have a friend in New Jersey that designed a sabot and had a machine shop turn out his prototypes. Not sure is he intends to mass produce using machining or injection moulding. partly it would depend on material.

Plastics like Delrin, Nylon, some polyurethanes and maybe some others are suitable for the pressure and friction requirements. Some are castable and some are not.


Hmmm, now that I am rambling, a thought comes to mind. Urethanes are castable and some can be very tough and hard. It might even be suitable for what you are thinking though consistent dimensions within thousandths of an inch would likely be difficult to maintain without using pressure casting (injection moulding).

Personally, I think that machining has the best chance for home manufacture.

Now, I have to ask ~ are you shooting rifled gun? Why not go full bore slug and eliminate the sabot or use 'wad slugs" like Lee or Lyman sabot slug?

I load slugs for smoothbore and use full bore slugs or slugs in regular shotcups. In fact so far my favourite projectile is round ball. I loaded up some 0.735" round balls and shot them in a friend's rifled Remington 870 and they shot very well. Of course they are not sabot slugs and will not have the range of most sabot slugs.

Longbow

[jmort]

I will leave it to Ajay aka VDOMemories and Hubel458 to market their sabots. BPI sells their blue sabot. There comes a point where it is better to buy than produce. For me, brass, hulls, wads/sabots are examples of me buying rather than attempting to manufacture.

[LUTNIT]

Now, I have to ask ~ are you shooting rifled gun? Why not go full bore slug and eliminate the sabot or use 'wad slugs" like Lee or Lyman sabot slug?

I load slugs for smoothbore and use full bore slugs or slugs in regular shotcups. In fact so far my favourite projectile is round ball. I loaded up some 0.735" round balls and shot them in a friend's rifled Remington 870 and they shot very well. Of course they are not sabot slugs and will not have the range of most sabot slugs.

You make some very good points about material choice and tolerances. I figured for the few dollars it would cost in silicone to make the mould I could give it a shot and measure some to see. I figured there may be tolerance issues but wasn't sure what they might be. One major issue I have thought of is that delrin and nylon like plastics are somewhat self lubricating and can also be mixed with different chemicals when injected to add further lubricating features. The urethane resin I use comes out fairly hard, not too brittle, but dry as a desert. If I don't get the mix within <5% accurate it doesn't cure properly so adding another chemical before it's cured most likely wont work. I was thinking maybe an exterior similar to Lee's micro band lube grooves which lends itself well to liquid alox tumbling.

I am taking manufacturing so know about injection moulding but can't afford one for my garage :(

Yes this is intended for a rifled barrel. I use Lee 1oz slugs in WAA12 wads for smoothbores and can get about the same accuracy as factory rifled slugs. I have tried them in the rifled barrel for my 870 and they are all over the map. I've tried nitro cards under the slugs, tape around the slug to make it larger, and other little things but nothing seems to make them work in my 870. I have looked into the Lyman sabot slug mould but may be getting a Savage 220 rifled bolt gun soon and the reviews for the 20ga version from Lyman are pretty poor.

Only after posting this did I see the other recent thread about Accurate Molds full bore slugs. That may be the way to go as it is open to both 20 and 12 gauge. The 900gr 12ga mould does have my attention :twisted: Would those full bore slugs work well with pan lubing or do they not need lube? I've never looked into full bore slugs in a rifled barrel before.

[longbow]

Don't neglect the 0.735" round ball. They shoot well for me from smoothbore and did really well (2" groups at 50 yards) from the borrowed rifled 870.

Those loads were a plain round ball sitting on a hard wad column over a gas seal. Worked great. that ball is also 580 grs. +/- depending on alloy so not a light weights. Not 900 grs. either but heavier than most slugs.

I just got a Lee Drive key mould and will hopefully be shooting some this weekend. Again in smoothbore. I have some as cast and some modified as attached wad slugs Brenneke style. I also have some round ball loads to shoot too ~ these are 0.662" RB's and 0.678" RB's in shotcups and some modified with "tails".

You can buy 0.735" RB's from Track of the Wolf. Not sure if they can ship to Canada though. I seem to be able to get some stuff from the States but I know much is restricted now though with an FFL they should be able to ship.

if you can't get them from the US I could send you a few if you want to try them.

The other side of the coin here is that if you are looking at getting a new mould, you will not regret buying from Accurate Molds! Tom is great to deal with and his moulds are terrific. I only have one for my .44 and a friend bought one for his .45 auto. Both beautiful and cast perfectly and to spec.

Longbow

[john hayslip]

Never done it but from what I read you can melt most plastic jugs and mold the result. Lindsay Publications in Illinois has/had a book, inexpensive, on doing it but he has announced his coming retirement and will be closing shortly. I saw recently an add for a machine that you use of a drill press to do the molding. Can't find it right now.

[LUTNIT]

You can buy 0.735" RB's from Track of the Wolf. Not sure if they can ship to Canada though. I seem to be able to get some stuff from the States but I know much is restricted now though with an FFL they should be able to ship.

I just ordered some fibre wads from Track of the Wolf since they are one of the few that ship to Canada. Shipping isn't cheap but their prices are so good it works out to about the same as paying a broker to have them import anyway. I say "to have them imported" but really it's "to have them legally exported from the US".

The problem with ordering from the US isn't Canadian importation or dealers needing to be an FFL but ITAR. It is illegal to export most ammunition related items out of the US (brass, projectiles, powder, primers, shot, etc.) without jumping through a lot of hoops but for some reason it doesn't seem to cover unprimed shotgun hulls (unless they're brass) or wads. Most US retailers wont export wads or unprimed hulls either though because they aren't sure or don't want to risk it. From what I can tell from the reading I've done, in order for the export to happen a licensed Canadian reseller and the US exporter have to fill out a lot of paperwork and pay some tax stamps. It's a huge bother and can take months from the time the order is placed to when you get it. That is why Canadian reloaders have to buy components from within Canada and can't order from the US. Thankfully there isn't too much of a markup for the Canadian market. Tools are unrestricted (except automated annealers and reloading presses) so that isn't an issue ordering from the US.

I'm not sure if round balls could be exported as simple lead or would require all the rigmarole of exporting jacketed bullets.

The Lee 1oz key drive slugs work great in all my smoothbores. I was just over at Accurate Molds and got a shipping estimate, expecting something horrible for shipping to Canada. USD$5 shipping to Canada!? Well I found my new favourite mould maker :D So in 3ish weeks I'll have a 900gr .720" slug mould. So much for the sabots :( If this 12ga works out I'll be ordering a 450gr 20ga and maybe the 700gr 12ga once I can confirm when I'm getting the Savage 220.

[I'll Make Mine]

I think you could cast resin accurately enough for sabots (yes, that's counter to some of the above). It would require a rigid mold with pretty tight registration, and you'd have to have a quantity of molds or one large one with a bunch of cavities to account for mixing a large enough batch of resin to get the catalyst consistent from batch to batch. The weakness of resin sabots is most likely to be in getting them to shed immediately at the muzzle; with injection molded sabots, the usual method is to cut crossed slots, accurately centered and at a perfect right angle, through the sides down to the base, and mold in a little "cup" around the outside of the bullet cavity to catch air and assist the centrifugal force. The cuts would have to be done after casting, I think -- they don't want to have a gap or kerf, which would be unavoidable if cast in, just a discontinuity in the material (cut with a razor blade or similar, in a jig). Oh, and sabots (on our kind of scale, as opposed to a tank gun) work MUCH better in a rifled barrel than a smoothbore...

Now, if you've got slugs lined up and don't need sabots, then never mind...

[TRG3]

Have you considered a plastic ball or cone to place in the cavity of a forster style slug? While I've never cut open a Federal TruBall shell, I understand that the foster-style slug has a plastic insert in the cavity of the slug in order to maintain its shape on firing. The TruBall slug is very accurate in my 12 gauge H&R USH. The Lee Key Drive slug would be a great candidate for this effort.

[LUTNIT]

Thanks everyone for the advice and comments so far.

@I'll Make Mine
I had figured I would have to make some accurate cuts to each sabot to get them to strip properly. I was going to try both discarding sabots and mechanically attached sabots that stay with the bullet for the duration. Was thinking of some where I actually cast the resin with the bullet in the mould so it locks into the lube grooves.

@TRG3
Wouldn't the bar across the cavity prevent something from fitting in properly to expand it evenly? I suppose Lyman slugs would work better perhaps?

[I'll Make Mine]

@I'll Make Mine
I had figured I would have to make some accurate cuts to each sabot to get them to strip properly. I was going to try both discarding sabots and mechanically attached sabots that stay with the bullet for the duration. Was thinking of some where I actually cast the resin with the bullet in the mould so it locks into the lube grooves.

I don't see any advantage to a sabot that doesn't discard -- it's just a method of firing a lighter bullet, but you get the worst qualities of both a light bullet (poor ballistic coefficient, accuracy effects of large velocity loss) and a heavier bullet (heavy core and light belt mean the bullet will stabilize like a long, small diameter slug rather than a short fat one, meaning faster twist needed -- which brings up the likelihood of slipping the sabot on the core from rifling torque, equivalent to a soft bullet skidding in the rifling). A round ball or collar button is likely to work better, IMO, than a non-discarding sabot.

[TRG3]

Thanks everyone for the advice and comments so far.



@TRG3
Wouldn't the bar across the cavity prevent something from fitting in properly to expand it evenly? I suppose Lyman slugs would work better perhaps?

As SNL's Rosana Rosana Dana would say, "Never mind!!" You're right about that bar on the Lee Key Drive. A senior moment must have crept in! Perhaps hot melt glue would serve better for that slug. The Lyman 525 would definitely be a better candidate for a plastic cone. Regardless, a 20 gauge .125 hard card for either slug to rest on in the bottom of a Federal S3 wad improved accuracy for me using a 12 gauge H&R USH. (Actually, the .690 roundball shot even better, eliminating the need for any added hot glue, plastic cone, etc.)

[jabilli]

Recently I've been looking for methods of making .223 projectiles that perform maybe somewhat close to the jacketed stuff you can buy at the store. I'm doing this for two reasons: 1. Cost 2. Availability.

You'll see some chatter in the forums about powder coating bullets: Someone made some in .223 the other day and I'm hoping he'll get out and shoot them very soon...Also I'm hoping he has a chrony.

You'll see folks talking about casting Zinc bullets- This has my strongest interest. Seeing that I don't have a job right now, I'm not able to pump funds into new equipment for testing...However I will soon be able to procure materials needed for further testing (I need to get a pot I can melt Zinc in/get one of those hotplate burners, I'm thinking a 1100W atta do it...25$ and I'm good to go)

You may find interest in paper patching- a topic I was reading on just before finding your post(maybe 1/2 hour ago)... People are able to obtain fairly respectable performance figures out of CB's using this method. Even more interestingly (to me) I've found that people have been doing this with Teflon Tape with very good results. After reading that people have been doing this to paper patch boolits, I wondered if people have tried covering the boolit in its entirety with Teflon (I know it's been done commercially...and IIRC they are no-no's to own...something about armor piercing.) While wondering this I figured it would probably work best if the Teflon were melted to make a sort of teflon-shell (teflon tape can unravel, I was trying to think of a way to get it to not)... I looked and it seems Teflon has a melting temp of about 620*F... Note fumes breathed in can be harmful... So in the next few days I'm going to run down and grab a roll or two of Teflon tape and play around with it (About 1$ a roll IIRC)

Shortly after looking into Teflon Tape and maybe melting a shell around it- I wondered if polyester resin- Like the stuff surfboards are made with, could be of any service in terms of making a bullet jacket. This is where I came across this thread.

Interesting idea- Making a sintered type bullet using powdered lead mixed into polyester resin? I'd think this could work fine as long as the operator keeps the fluid at a temperature where it flows somewhat freely. The task, then, would be to come up with a method of hardening the resin in the mold? ... One way to do it might be to dunk the mold, along with the resin inside of it, in a batch of catalyst... I assume the operator would have to dunk the mold in some water, or, somehow rid the mold of catalyst before beginning to pour resin in it again...

Anyway, something fun my brain cooked up.

[Bullshop]

You didnt mention swaging.

[longbow]

LUTNIT:

Check out BPI or Bilozir Fine Guns (Canadian BPI distributor): http://www.bilozir.net/

I have ordered from him before and am currently checking out what he can get as I have to restock. I bought several thousand nitro card wads, fiber wads, hard card wads, regular shotcups, powder, primers, hulls,. the works, from him a few years ago.

I would have figured that in Ottawa you would have some pretty good selection unlike where I am in Southeastern B.C.

Also, a bit of follow up. I commented on 0.678" RB's. I finally got my mould, cast, loaded and shot. The 0.678" balls gave predictable groups of about 4" at 50 yards first time out but I only saved 5 for the 100 yard target. I put 4 out of 5 into a group of 7" wide x 4" high. Not sure what happened to the 5th, it went AWOL. Nonetheless, I will be loading up again today and hopefully will be shooting today or tomorrow at 100 yards to see how consistent they are. If I can keep RB's in groups of around 8" at 100 yards I will be a happy camper!

If not, well, then I have more experimenting to do!

Good luck!

Longbow

[jason f]

Why did you order your full bore slug at. 720. Seems a little small for the 12 gauge. I have the 700 grain full bore slug from accurate and mine is 733 diameter. I also have a 20 gauge full bore that cast a 628 diameter slug. Both shoot great out of my h&r ultra slug guns.

[LUTNIT]

@jabilli
Burning teflon can release poison gas. I really wouldn't want to try melting teflon to cast around stuff.
As for lead powder mixed with polyester resin I never thought of that. It may have to be patched or lubed really well since I think the resin may burn with the friction of a rifled barrel. I did have the idea of making resin slugs similar to wax slugs with birdshot mixed in but haven't gotten around to testing it yet. I also want to try wax and hot glue slugs in a rifled barrel to see how well they work.

Dunking one part of the resin in the catalyst to cure it wont work as it needs to be really well mixed. Taking your idea I was thinking more of mixing a resin with a working time of at least 10-15min fully, filling the mould 1/3 or so full, and pouring in lead shot which will sink to the bottom. Figure out the exact ratio to get the mould totally filled.

Another problem I thought of was gas cutting of the resin. Since it's weaker than even pure lead you could have issues with the gas damaging the resin bullet (or sabot as per my original idea). I suppose in a rifle a gas check could be applied and in a shotgun a gas seal wad could be used to alleviate this.

Regardless I now have a bunch of new idea to try out just for curiosity's sake.

@longbow
I considered ordering from BPI through Bilozir but I was more looking for as simple as possible and to need as few products on hand as possible. Full bore slugs allows for most any fibre wads to be used without having to have sabots, special wads or shot cups, or anything else around. If I cast my own sabots I wouldn't have to worry about supply of components as I can make them myself. I have ordered a .690 round ball mould to try out with shotcups, cloth patches, and possibly paper patches that I am hoping will be far more flexible than the 900gr full bore slugs I am casting now. As fun as 900gr slugs are there isn't much flexibility with only 3" hulls.

As for shopping in Ottawa there are only 2 retailers for reloading supplies; LeBarons and Bowmac (through the pro shop at one of the ranges). LeBarons only sells very generic reloading stuff since they don't want to keep a lot of low demand inventory around. Bowmac carries MEC, Rem, Win, and Fed tools and components but they seem to think anyone who reloads for shotguns other than target load is nuts and wont cater to them. When I asked if they knew of anyone locally who reloaded cast buckshot or slugs the answer was "no" followed by a "why would you want to? It doesn't work." They carry Lee slug and buckshot moulds in their warehouse but you need to request them to the store and they give you funny looks when you pick them up.

@jason f
Whoops, typo. The one I ordered was .730". Just cast my first ones today and they come out at an average of .7315". Fit in a Federal high brass hull is quite snug.

[longbow]

And I thought I had it hard here in the sticks! I would have figured there would be enough waterfowl shooters around Ottawa to support several big shops and lots of supplies. I also would have figured there would be some slug and buckshot shooters around.

However, even if I had better access to reloading components, I am inclined to stick with slugs in the 1 oz. to 1 3/8 oz range simply because it is easier to reload and more slug recipes for that weight range than when you get over 600 grs.

I have more or less settled on wad slugs mainly due to ease of loading and so far I have gotten generally better accuracy using wad slugs than full bore. I have to think it is partly due to the jump[ through the forcing cone with the cushion leg helping keep everything aligned.

Longbow