I am getting ready to get the equipment & supplies needed to start casting big bore airgun projectiles. I'll be using 98% lead & 2% tin alloy, to keep it around 5-6 brinell hardness.
I know I'll need the alloy, melting pot, dipper, extra lead pot, casting thermometer, some projectile molds, and perhaps some flux. Also need some type or way of resizing. Anything else required for casting?
I really do need to resize the projectiles to either .308 or .309 diameter, to get the most consistent accuracy/velocity. I do not want to lube these projectiles in the sizing process. Is it feasible to just use a commercial .308/.309 sizer die, make a contour mold to fit projectile base and run them through the sizer dies (lubed)nose first utilizing a drill press for the leaverage? Everything would be perfectly inline, the sizer die would be attached to metal work base. Am I misunderstanding something in the resize process? Do I really need a commercial sizer setup to size these 5-6 brinell projectiles? Cheapest one I found is the lyman 4500 sizer at around $100. Thanks

I'll bite. What sort of lead projectile are you planning on casting for your airgun? What sort of .308 caliber airgun do you have?

I'm curious, and there is a benefit to you for feeding the curiousity beast.

Easiest simplest cheapest resizing would be done in a LEE push through sizer (they come in .308 and .309 I believe). Simplest cheapest "airgun light" style bullet mold that I can think of would be a LEE 311-93-1R which is really an old style 93 grain flat meplat carrying 32-20 bullet which you are going to size down from .311" to your desired .308-.309" in that LEE push through sizing die.

Of course, several folks on the list already have a wide variety of mini-sized .30 caliber bullet molds and have hundreds of them already cast lubed and sized sitting around in a coffee can getting dusty (since they very rarely shoot them).

Once you tell us what sort of airgun you are shooting (curious, yes I am curious - aren't you?) you are likely to get some better advice as what sort of pre-existing cast slugs would do well in it and you may even get an offer of a trial bullet or two from the fellow curious-sort people.

I remember 9mm airguns being available, and 25 caliber airguns and a big Chinese .40 cal round ball airgun, but no .30 caliber airguns seem to come to mind.

Oldfeller

[ 11-18-2003, 04:30: Message edited by: Oldfeller ]

It's a Dennis Quackenbush .308 Exile. There are others like you have mentioned. Such as Shinsung 9mm's, Quackenbush 50's, Sam Yang 909 45's, Gary Barnes guns etc.. I've heard of a few guys buying a 909 45 caliber and putting on a different barrel, such as a .308 or .243, etc..

I believe Mr Quackenbush experimented around with differing twist rates for the Exhile, and settled on one that is a good performer with 130g .308 M1 bullets. I have read posts from a guy who has experimented around with a few types of bullets/molds, and he found the .308 spitzers to be the best performer so far.

I am just a beginner in the casting world. I think I have the right general idea on most of the process. But was wondering about the best and cheapest way to resize. As I don't want to spend over $100 just to resize if I don't have to. It just seems to me that since I will be using 98% lead, 5-6 brinell, that I don't need a lot of pressure to push these throuh a sizer. I am not at all familiar with these Lee push through sizers you mention. What do you use to push them through? I will be using .309 molds mostly. I wasn't sure if I could resize a .311 down to .308 easily, without a lot of pressure.

I'll probably start with a 309 spitzer mold, I think they run $50. And probably a couple of those cheaper Lee molds also. Pistol bullet molds are worth experimenting with. I heard one guy mention that he has tried a 85-95g pistol bullet, but didn't group very well. I would also be experimenting with the idea of drilling out the base a tad. So that air would get in and expand projectile base to make a nice seal. Although this would shift the balance point, it's worth experimenting. I'm very interested in trying out lots of molds and/or projectiles, even if someone else has already tried them. So if anyone has any projectiles that they wish to donate to the cause, that would be great. Although I really prefer a soft brinell, not the typical 15-16 or more cast hardness. The National Bullet Co has 120g 308's for cheap, and they shoot decently. Mr Quackenbush has stated that using cast bullets poses no threat to barrel life. In his words, "won't do a thing to it". But, just the same, I am leary of using anything harder than 8 brinell.
It's pretty neat the way Mr Quackenbush makes these. They are made on old WW2 equipment up in a cottage in the ozarks.

The Lee push-through sizers use a regular reloading press. You can pick up one of the Lee aluminum framed ones very cheap, even new. A better deal might be to find a used (iron/steel) press at a gun show, or a local dealer, if you don't already own one.
It ocurrs to me, that you might be able to sharpen the push-through sizer's ram, and make a ram that would sort of swage a hollow base on your soft projectiles. Might not work, but it might be worth the time to turn a spare ram out of a 5/16" or 3/8" bolt, just to see. You could do that with nothing more than an electric drill & a file. >>>>>>>>Bug

How much is the Sam Yang .45 going for? You could sneak in a 45 caliber minne ball from the muzzle loader world complete with a relatively thin hollow base skirt (a custom mold part could make the skirt as thin as you wanted, of course).

Idle curiousity only, of course. A cheap LEE single station press and a LEE push through sizer die would set you back $45-50 retail, with LEE offering deals on factory rebuilt units on the press all the time on their web page.

Oldfeller

This is a crazy enough project to get me interested. Email me a snail mail address and I'll send you a sampler pack of stuff that just might work with explanations of what I did so you can duplicate what works.

Price is that you post results when you get them.

You want them lubed or unlubed? Most of the stuff I have on hand is already lubed and a bit harder than you specified, but if that thing of yours will shoot jacketed bullets, it'll sure shoot my alloy (6 parts WW to 1 part lino). You really need them that soft, I don't mind the casting, but it'll slow things down some.

[ 11-19-2003, 02:09: Message edited by: Leftoverdj ]

Bug, the base swaging Bolt/ram idea is worth a try, nice thinking!

Oldfeller, the Sam Yang 909's are going for right around $500. They are actually a .454, for use with .44 blackpowder bullets, .45 auto, & .45 long colt, etc.. One guy, who has been shooting his 909 since the late 90's, found that most of them shoot good with the 145-155g collar button design from the western bullet co. These collar buttons were designed for the 45/70 gov. military cartridge, bullet diameter is .457-.458 at the two narrow driving bands. Without any lube they look like a big 'ole airgun pellet to:-) There are probably other designs that would shoot just as good if not better, just a matter of testing, etc... That minne ball you mentioned sounds interesting. Any place on the internet to see pictures of these minne balls? I don't personally own a 909, but it's still interesting.

Leftoverdj, Thank you very much for the act of kindness. I'll send you out an email. I don't shoot jacketed projectiles out of it. Only for use with cast projectiles, hard cast max. Nothing over 16-20 brinell, although I personally don't want use anything over 8-10 brinell. Do you happen to know the brinell hardenss of your special alloy? Pure lead with a touch of tin to make them fill out good is perfect.

If I remember correctly Mr Quackenbush makes his barrels out of the same type of metal that .22 barrels are made out of. As bullet hardness goes up the fps will go down, and if it has a hollow base it would need to be soft enough for the air presure to expand it and make a good seal. The harder the alloy used the thinner you would want to base skirt to be. To a beginner, it seems logical that the harder the alloy used and the more outward pressure (pressure inside base expanding outward)it exerts on the barrel the more friction (lower fps) and greater barrel wear will occur. Correct?

I am also interested in finding sources/people who have the equipment and are willing to cast me some nice consistent 308's out of softer alloy. I am willing and expecting to pay for this service.

[ 11-19-2003, 06:53: Message edited by: airgunhaven ]

I'm pretty aure that friction is not a problem. Firearms barrels are worn more by the powder gases than a lead projectile and there are records of .22s still giving reasonable accuracy after 200,000 shots.

I'm also pretty sure that air pressure is not going to sxpand skirts much unless they are mighty thin skirts. My feeling is that a very slightly oversized projectile is swaged by the act of firing to fit the tightest part of the bore and that a film of lube is a partial seal that can comp for a few ten thousandths.

What kind of velocities are we talking about here? I'm assuming around 8-900 fps? And what will be the max range it will be shot at?

I will try and get info on exactly what the barrel is made out of. Same as .22's if I remember correctly. But I had better double check, as my memory sometimes plays tricks on me, lol. I'm not sure if .22 barrels are heat treated, but I am pretty sure the one on my .308 Exile isn't. If it is indeed .22 quality then wear issue would no longer concern me. Except in that the rifling is very shallow, guessing .003 maybe. Generally airgun barrels have very shallow rifling, compared to firearm barrels. (And airgun barrels are usually made out of soft steel, no heat treatment.) Maybe since it's so shallow the rifling would wear quicker than a .22's would, and degrade accuracy. I am not very experienced in these matters, so better to be safe than sorry I think.

Hollow bases/skirts would need to be thick enough so that the bigbore pressure doesn't rip the base apart, but thin enough to form a good seal. Experimentation needed. The skirts on regular .22 airgun pellets (11-20 ft lbs, 14g @600-800fps) are generally very thin. I own a Shinsung Career airgun in .22 caliber, and the pellets made especially for it have much thicker skirts than a regular pellet. The Career can generate up to 60-70 ft lbs at muzzle, 30g @1000fps. The Exile .308 can generate around 200 ft lbs at muzzle, 120g @850-900fps. Pressurized air can be very powerful. Usually, to my knowledge, all the other .308 & .50 caliber airgun shooters use regular cast bullets or round balls, no hollow base/skirt. And they seem to shoot just fine! So I would consider experimenting with hollow bases to be an enhancement experiment, just to see and learn. Ideally I think the hollow base would be fairly shallow (not to deep) and would be slightly oversize, so that the barrel resizes it, just the base/skirt.

Exhile's generally shoot 120-130g @800-850 fps. I've heard of a few that have been tweaked a bit and they are getting around 900-950fps with the same 120-130g. Of course lighter projectiles will give more fps, and heavier ones less.

Max range it will be shot at it yet to be determined. Depends on how well it groups at various distances. I'd like to be able to go out to 200-250 yards max. I usually shoot at 100 yards or less. I need to get a hold on a BC # for a .308 projectile going under 1000fps so I can plug that into a ballistics program and see how much of a drop it will have in the long haul.

I have a mould that drops fairly pointed 130 grain plain base .309 bullets intended for the M-1 Carbine. That sounds like your best bet. Worth trying are the Hornady hollow base wadcutters and their semi wadcutter intended for .32 pistols. Those are 90 grains and come at .314, but will readily size down to .309. The sizing is best done in two steps for minimal deformation. The fourth possibility is 0 buckshot sized to .309. The result is crude looking but has been quite accurate to 35 yards in 30 caliber rifles.

Loads giving the ballistics you describe have been commonly used by folks seeking low noise for backyard shooting and/or small game hunting. I've made up such bullets and loads myself off and on for years. You can get good results, but past 60 yards your range estimation abilities come into play.