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Have been bullet casting and reloading for 40+ years and have run into a ballistic puzzle I've never seen before. I'm currently casting a Lyman "Devastator" hollowpoint, in .45 ACP which is advertised as a 180 grainer but actually casts out at around 200 grains using wheelweights and 1% tin added.

It shoots and feeds very well, but it's velocities are hugely below what they should be for a 200 grain bullet. In a 5" Govt. Model, they run 103 fps less than a 200 grain cast lead semi-wadcutter with the identical load. In a 4" Springfield Champ, they run about 182 fps less than in the Govt. Model (Accurate #5, and Win-231).

I've carefully retested with a variety of powders, miked the bullet base to ensure it's actually sizing to .452, compared bearing surface to other shapes, etc...with no clue as to why this particular 200 grainer seems to need book max leads to barely make major, while my other 200 grain shapes are running 100 fps faster with identical loads.

Anybody run into something like this before? Any chance the huge hollowpoint design is aerodynamically slowing the bullet down that much in just the 9 feet or so out to the chronograph? Any input would be appreciated...I'm stumped.
 

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I would think the HP would be seated less deep than the SWC bullets, leading to reduced pressure/velocity for the HP load.

Does the bullet cast well? I've been looking at this mould for quite some time, thinking it may be something that I have to have.
 

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Discussion Starter #3
Walking Point - Yes, the HP is seated slightly less deep than the semi-wadcutter but the difference is so slight, I'm still skeptical that it would cause such large velocity differences. I'm using a relatively short OAL on the HP of 1.230 since it feeds so well at that length, but I'll try incrementally reducing it a bit and see if it boosts velocities significantly.

So far as the bullet itself...very accurate, and the large hollowpoint expanded impressively in a 55 gal barrel of water, at a muzzle velocity of approx. 825 fps. Given that most hollowpoint designs I've tried over the years are not the easiest or fastest to cast, this one is one of the more difficult to cast consistantly.

I get best results at temps of at least 800 degrees, bottom pour furnace, with the outlet spigot in direct contact with the sprue plate. That extra pressure produces an increased number of "finned" rejects, but almost eliminates the primary problem which is incompletely filled out bullets. Once you get all the temps working and your rythem worked out, it smooths out some.

If somebody was commercially making this bullet, I'd probably buy them instead of casting them. At the moment, making your own is the only way.
 

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CPT Jack:

1. Check your molds. Make sure that there is not a small piece of alloy or a burr that is preventing the mold from closing.

2. Check your crimp diameter. Your crimp should be about .470. If it is above that, crimp at .470. If you are at .470 now, acjust to .468 and check your velocities again.

3. What powder are you using for this cartridge? If you want increased velocity without too much more pressure, try Unique or Herco. Power Pistol will DEFINITELY give you the results you are looking for, but I have only used it in jacketed bullets--and then with a max load about 2 to 2 1/2 grains below the listed max. When they say Power Pistol, they mean it!

4. For 200 grain bullets, I have used 5.0 of HP38 with good results. Clays also works well for me, as does Herco for ball or jacketed rounds. Herco gives a softer recoil, too.
 

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1.230 is not that short of a OAL. Most of my HP's are usually 1.200 to 1.225 depending on profile and manufacturer. Tracy
 

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Is it possible the bullet's hollow point is big enough to that the bullet collapses in on itself some and as a result goes down the barrel easier than a more "solid" bullet design? This would be my guess anyway.
 

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I’ve noticed the same differential between this bullet and my others of comparable weight. I find it to be bullet depth, reducing the pressure. I gave up on this one as I can never get it to consistently turn out. I tried every trick I know with a success rate of less than ten percent. I posted on a thread related to this mold, a while back. I may dust it off and give it another try…….
 

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Three thoughts on trying to get the mold to cast better. Try a flow one inch from the sprue plate with the bottom pour pot instead of pressure pouring. and open up the sprue plate hole to a larger size. Finally a good graphite coat inside the mold cavity could help on the fill out.
 

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Thanks for the info. I've tried different alloys and casting temperatures as well as various distances from the spout and flow rates. I'll give the graphite a try. My belief was that the pin temperature couldn't be maintained and caused solidification prior to fill out.
 

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Maj Tom said:
Thanks for the info. I've tried different alloys and casting temperatures as well as various distances from the spout and flow rates. I'll give the graphite a try. My belief was that the pin temperature couldn't be maintained and caused solidification prior to fill out.
Hollowpoint bullets can be a real pain to cast. Often you can't get the nose to fill out completely, no matter what you try. What alloy are you using, and are you casting with a ladle or bottom pour? ==Bob
 

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Opening the sprue plate hole to a larger size will give increased venting around the lead stream. Place the block and pin on a hot plate and heat the entire assembly to 165.degrees before casting.return the pin to the hot plate while you are releasing the bullet from the mold to keep it warm. you may want to vary that warm up temp to fine tune the process. Good Luck.
 

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What alloy are you using, and are you casting with a ladle or bottom pour?

I’ve used a myriad of alloys. Base metal is wheel weights and have added tin and line – man metal (vary hard, high antimony) to various percentages. Right now I’m dropping wheel weights. I’m doing bottom pour.

I’ll give the hot plate a try. I dropped over a hundred yesterday and had 8 with a fully formed nose. I kept all that were + or – 1 grain. Give a stout push on the sizer and a relatively uniform nose can be had. I’m dropping 225 Rn at the same time so the time isn’t wasted. Thanks for the info….
 

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Re: What alloy are you using, and are you casting with a ladle or bottom pour?

Maj Tom said:
I’ve used a myriad of alloys. Base metal is wheel weights and have added tin and line – man metal (vary hard, high antimony) to various percentages. Right now I’m dropping wheel weights. I’m doing bottom pour.

You can also dip the hollowpoint pin in the molten alloy for a couple of seconds before inserting it in the mould. That'll keep it warm enough. I now exclusively ladle cast, using a Lyman ladle, modified for left-hand use. I've never had stellar results with bottom pour. The ladle is slower, but my reject rate is so low that I feel it's worth the extra time. ==Bob
 

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I ladle poured for years and have just switched to bottom pour. Once I figured it out and remeber to stir the pot consistancy is about the same as ladle, at least for me. Also a 'south paw', therefore I use an RCBS furnace. I'll try the afore mentioned suggestions either today or tomorrow.
 

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Heating the pin...

Dropped alot of good hollow point today. I heated the pin with a torch after each bullet drop. Provided good fill out on the tip. Thanks for the information! Now looking forward to working up a good load for them. BTW with wheel weights they drop at 192 grains.
 

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TA DA!!! Laws of thermodynamics solve yet another problem. Dont applaud, just throw money.
 

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Thermodynamics

Great, I’m in a discussion of applied physics/dynamics in another thread and now engaged in a thermo discussion here. I guess I need to dust off the old engineering degree……Things were much simpler when all I had to worry about was trigger control, which I haven’t mastered yet or I’d shoot perfect 10x’s every shot!

Thanks for the help!
 
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