Monotype for 300 BO

[Green Frog]

As per the title, I have a goodly quantity of Monotype, still in large-sized individual letters. Can anyone suggest a mould design for which I can use this material, preferably as is, to cast bullets for general use in the 300 Blackout at supersonic velocities? A suggested range of charges for this bullet with Accurate #9 would be helpful as well if it could be had. I'm using an AR-15 platform with 16" stainless barrel and adjustable carbine-length gas system. I'm not interested in hyper-velocity loadings, but would like good reliability with the possibility of shooting the occasional coyote, etc.

TIA ~ Froggie

[dilly]

That's some expensive shooting. Have you considered trading a portion of the monotype off for a larger quantity of range scrap?

Your call.

Also what's your AR's twist? Very important with blackout.

[runfiverun]

holy hardness batman you'll probably break most of them trying to get them loaded.

I use 9.5grs of AA#9 in my 300 bo pushing a 165 gr boolit to about 14-1500 fps.
I dunno if it would run your AR or not, if you have a pistol length gas tube thingy it might.
but either of my 7 twist bolt guns shoot it just fine.

[lightman]

Thats way too hard, and a waste of good alloy. Trade for or buy some soft lead to mix with your mono.

[Green Frog]

OK, since I had only seen jacketed stuff touted strongly for supersonic loadings of 300 BO, I thought I would need something super hard for cast bullets. I've got lead, WW, and some other assorted Pb alloys I can work with, but I was going to just make sure I was hard enough. BTW, I also got about 50+ pounds of what I was told were "linotype plus" ingots which I understand were antimony-rich alloy to "sweeten up" linotype that had been remelted many times and had some of its antimony "burned out." Is this the correct story on this stuff?

Back to my original question then... can I just pick a 125-130 grain bullet of the proper diameter (and nose shape) and cast some up using some of the monotype mixed with pure lead at a rate of X parts monotype to Y parts lead and be good to go?

Froggie

[dilly]

OK, since I had only seen jacketed stuff touted strongly for supersonic loadings of 300 BO, I thought I would need something super hard for cast bullets. I've got lead, WW, and some other assorted Pb alloys I can work with, but I was going to just make sure I was hard enough. BTW, I also got about 50+ pounds of what I was told were "linotype plus" ingots which I understand were antimony-rich alloy to "sweeten up" linotype that had been remelted many times and had some of its antimony "burned out." Is this the correct story on this stuff?

Back to my original question then... can I just pick a 125-130 grain bullet of the proper diameter (and nose shape) and cast some up using some of the monotype mixed with pure lead at a rate of X parts monotype to Y parts lead and be good to go?

Froggie

Yep, that's basically how it works. You'll probably have better luck with a gas check bullet design.

What I was saying about the twist is that if your rifle barrel has a fast twist, you'll do better with a very heavy bullet. If your rifle has a slow twist, you'll do better with a lighter bullet. Because some loadings are supersonic and some loadings are subsonic, 300 blackout bullets can be as low as 110 grains and as high as 247 grains. That's a big range!

Let me go browse NOE's website and see if I can find a mold in stock that might work for you. I know I say some of the "crayola of death" design on there recently, but I don't know how well that bullet has been reviewed.

[dilly]

http://noebulletmolds.com/NV/product_info.php?cPath=30&products_id=774&osCsid=9lptn5a7ll0ituj8hhb1vahbs6

Here's a 129 gr gas checked bullet. I can't say I'm recommending it as I have no experience with it and that nose is kind of funky, but there it is. Maybe you can learn a little more about it elsewhere. There are a lot more options if you go a little bit higher in weight.


I'd be tempted to go with this one and maybe size it down a bit.

http://noebulletmolds.com/NV/product_info.php?cPath=31&products_id=71&osCsid=9lptn5a7ll0ituj8hhb1vahbs6

[lightman]

Dilly has you covered pretty well. Your bullet weight needs to match your barrel twist and to a degree, your velocity. As to alloy, I would start at about 25% type and 75% soft lead and check and adjust from there.

One of my first lead scores when I first started casting was a bunch of type metal. Not knowing any better I used it straight up. The bullets were purdy, but were hard to size, hard to get out of the mold and brittle. They did not shoot all that well either!

[petroid]

Get the lee 312-155 or 312-160 or noe 311414. Get gas checks. Cast 50/50 coww/pb or 50/50 mono/pb.

[cainttype]

I recently had CB member BNE do XRF analysis on several samples of alloys (He has a thread with details in the S&S subforum). The monotype alloy tested 53.3% Pb, 27.2% Sb, 17.4%Sn, and 2.1% Cu... Even a 50/50 mix with pure would be exceptionally hard.
I'd consider having BNE analyze a sample so the exact composition can be known. It not only allows you to mix alloys accurately, but you will be able to reproduce exact alloys in the future with that info in hand.

[Green Frog]

Thanks for all the input, guys. I had hoped to use a hard enough alloy to eliminate the need for gas checks, but from what I seem to be gleaning here, having the whole bullet harder opens a NEW can of worms. I have access to plenty of tin and old COWWs, but since I am shooting BP in North-South Skirmishes (and a .58 Zouave Minie ball takes a lot!!) my limiting resource tends to be pure, soft lead. Not to flog a dead horse, but how about a 3/4 or 2/3 alloy of monotype with the rest dead soft lead? Would that be soft enough to bump up as it is fired, but hard enough to eliminate the need for GCs?? I'm kinda grasping at straws, I know, but I'm trying to conserve lead and eliminate the extra work and expense of using the checks. Thanks again for all the interest and suggestions.

Froggie

[Dale53]

Green Frog;
As you'll remember from Schuetzen Shooting, a Plain Base bullet can shoot extremely well up to about 1400 fps. If you will be content with that velocity, then an equivalent mix of 20/1 (I would suggest a bit harder) should do just fine. If you want or need more velocity, then gas checks are your friend.

You'll probably get more consistent results with a plain base alloy at least as hard as WW's + 2% tin. Even a bit harder wouldn't be amiss.

Using gas check bullets, then an equivalent to Lyman #2 would be called for to gain maximum accurate velicity.

If you are planning to hunt with this, then a flat nosed bullet would be called for...

Just a thought or two,
Dale53

[dilly]

Also, if you are interested in staying plain based there are many heavier bullets. I thought you wanted light bullets because you specified supersonic. This will increase your likelihood of reliably cycling the action without breaking the 1400 fps pain based limit.

Traditional supersonic velocities are well above the threshold for gas checks.

I would look for something over 200 grains.

[lightload]

You won't be able to size monotype because of its hardness.

[Fishman]

Get the lee 312-155 or 312-160 or noe 311414. Get gas checks. Cast 50/50 coww/pb or 50/50 mono/pb.

Listen to Petroid.