Novice caster in need of hollow point boolit casting tips and tricks

[diyahbeetuz]

This week I ventured into the world of HP boolit casting, and oh boy was I given a rude awakening. The learning curve with HP casting is quite steeper than with solids, and for the last few evenings I spent late nights figuring out what the optimal mold and alloy temperature, alloy composition, and cadence is in order to produce decent casts. Can't stress enough the importance of pin temperature, and it seemed that the only way to keep it consistent is to get a good cast rhythm going (baby shark FTW lol) . I managed to get a few hundred made, but it seemed that it was harder to produce good casts with the pentagon pins compared to the round ones. As of now I think I have a good idea of what to watch out for and how to get in the "zone" for HP casting, but I am open to suggestions and tips/tricks from the experts here. I'm wanting to be more educated and informed, thank you in advance!

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MP 357-125 HP PB, 95Pb/5 AC alloy

[Land Owner]

Those look real good. Nothing to scoff at there. So, 9mm then (heavy for 380 ACP and light for 38 Spc.)? Maybe explain what you found to work and what didn't? How did you keep the pins hot (as well as the rest of the mold and spru plate), which is key to prevent malformed HP's. I'm going to learn something - what is "5 AC" in your alloy?

[bangerjim]

I cast HP rounds (all shapes of pins) almost with my eyes closed. No different than standard molds. I use exclusive 5 cavity brass MIHEC molds for all my HP's. Smooth easy effort-less casting. The slugs just drop out of the mold cavities like rain.

What you pictured look just fine. Why do you feel there is a problem?

banger

[sigep1764]

Think he means Air Cooled.

[rintinglen]

Hot and fast-- that's the mantra I preach for hollowpoint boolit casting. It is imperative to keep the mold and pin temperature up if you want good boolits. Don't fiddle around when casting looking at the pretty boolits, but just keep filling, cutting sprues and dumping. Cadence is everything. To paraphrase the Gambler, "there'll be time enough for counting, when the casting's done."

I found that polishing the penta-point pins to remove burrs was very helpful in increasing production. Before polishing, a boolit would often hang up and the mold and the other pins would cool while I messed around dislodging the recalcitrant boolit, resulting in poor fill out and wrinkles on the next pour. Nowadays, though, I mostly cast with the large round pins. It was my experience in timed trials involving a pair of MP H&G 68 molds, one conventional, one HP, that I can cast about 10 hollow points for every twelve conventional boolits using round pins.

The only brands I will use are the RG molds by NOE and the superb Cramer style MP offerings. The single cavity Lyman molds aren't worth the trouble or expense to fool with. After the first ammo drought, I began buying HP molds for everything I load for, at least every pistol cartridge. I have HP molds ranging from 73 grain 32 ACP boolits up to 230 grain 45 ACP, with stops at 380 84 grain, 9mm 128 grain, 38/357 140, 150 and 158 grain and a couple of 44 boolits.

[mattw]

The modern HP moulds have different challenges compared to the old single cavity HP moulds. I cast with both and get good results with both. With any HP mould, that pin has to be hot otherwise the noses are ugly and in the old SC HP moulds the pin just will not come out.

Those look great, me thinks you have it figured out. Heat is your friend and sometimes a little extra tin is needed depending upon the mould.

[cwlongshot]

100% with Rit & Matt above!!


KEEP THE PINS HOT

Also. Pencil lead "drawn" on pins sometimes helps allot!

CW

[fredj338]

SOunds like you already figured it out. I cast a bit hotter with HP mold & keep a good pace going.

[diyahbeetuz]

What you pictured look just fine. Why do you feel there is a problem?

banger

No problem at all sir, just wanting to solicit advice from others that probably know more than I do in order to make my life easier and make casting go smoother and faster. :smile:

[bangerjim]

No problem at all sir, just wanting to solicit advice from others that probably know more than I do in order to make my life easier and make casting go smoother and faster. :smile:

Load 'em and shoot 'em! They look fine to go. I never try for picture-perfect glistening boolits or shiny-as-new brass. They all shot the same (as long as you don't have grime on the brass!). I clean spent brass with a bath in 200F citric acid (found in the canning department of most grocery stores) and water, rinse, and dry in the sun. I PC all my rounds so any dullness or frosting I really do not care about. I am not holding a photogenic technicolor fashion show here. And after all..........they all go splat on the other end!!!!

Here's to great success in your new casting venture!

bangerjim :guntootsmiley:

[Targa]

Yep, those casts look great to me. I am probably going to dive into hollow point molds for the first time as well for .357

[diyahbeetuz]

Those look real good. Nothing to scoff at there. So, 9mm then (heavy for 380 ACP and light for 38 Spc.)? Maybe explain what you found to work and what didn't? How did you keep the pins hot (as well as the rest of the mold and spru plate), which is key to prevent malformed HP's. I'm going to learn something - what is "5 AC" in your alloy?

Thank you for the positive remarks. Yes it's for 9mm, but I do have plans to do different calibers in the near future. So far, the hardest part of casting HP for me is keeping the pin temps hot enough and maintaining it. Since the mold is brass, I preheated that using a hot plate to a little over 400 F. Then I took a propane torch, made the pins stick out away from the mold cavity, then heat them up to around 600 F (contact-less laser thermometer was a big help for these steps). Alloy temp was bouncing around between 650 and 750 F, I'm using a cheap Lee Production Pot and I'm casting outdoors and where I live it's getting pretty chilly now. I'll probably upgrade to a PID-controlled casting pot at some point, but we all know that casting and reloading is an expensive hobby, right? I have to stop starting at the noses of the bullets if they are formed correctly, otherwise I will lose my tempo and heat on the mold/pins. Also, the alloy mix was 95% lead and 5% Pewter AC Casting Alloy (92% tin, 7% antimony, 1% copper). I wanted to keep it relatively soft for better expansion, but if I'm being honest I'm not particularly worried about the expansion performance at this point. I just want to experiment on accuracy and versatility, if anything.

[Gamsek]

Bullets look just fine, and you are on a good way.

What improved my casting results with HP/HB brass moulds (I have many from MP, including MP 359-125) is:

Do’s:
Hot plate - let it sit on a hot plate for at least 20minutes so it soak temperature including pins
Hot alloy, go to 780F, don’t be afraid.
When you cut the sprue, tap tap on a handle hinge bolt just to open halves a bit, then flip the mould tap tap till slide out, tap tap.
Shafts must move freely- did you read tips & tricks on MP web page? Some nice tips.

Don’t: avoid dipping mould in alloy to warm
It, don’t use propane torch and don’t smoke it.

For end: more you will use it, better results you will get. Some brass moulds start to “work” after third casting. Then it’s poetry.

I must say for beginner (in brass HP) you got nice results !
https://uploads.tapatalk-cdn.com/20201010/d590d8ab1435679be6ea6aba9c8c398a.jpg

[fatnhappy]

I have a number of single cavity Lyman HP moulds and never thought they were any more difficult to cast with than my other moulds.

Then I got a brass mihec Cramer style mould.
My first casting session was a dismal failure. I conducted a self evaluation and came to 3 conclusions. I need to reduce my hand movements to increase my casting pace. I needed to lubricate my pins with graphite. I needed to increase my melt temp or increase my tin content or both.

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