Load development for custom moulded boolits

[Brick85]

I'm looking to buy a custom mould or two in the relatively near future, mainly one of the .40 cal hollow point ones MiHec is offering. Question is, once I get the mould and cast some boolits, what do I do with them?

I know that the Lyman manual for cast bullets has a lot of loads for various casts, but .40 S&W is too new to be in there. And besides, this isn't a Lyman mould. How do folks figure out and work up loads for these custom moulds?

Being pretty new to both casting and reloading, I don't want to screw around too much, but I picked up a box of 155 grain LRN .402 bullets cheap, and had to figure out a load (I had some HS-7 powder available and decided to use that). After looking at the data for .45 LRN from Laser Cast and comparing that to the .45 FMJ data in my Speer manual, I decided to just load the powder at 80% of what the Speer manual said for FMJ .40 S&W with the LRN .402 bullets. It worked pretty well except for the COAL, which I have to work on a bit (and the loads seemed kind of hot toward the end).

Is this a great way to lose fingers, or am I on the right track to work up loads for custom moulded boolits?

[Bret4207]

Cast usually works at much lower pressures than jacketed. Just find a boolit of similar weight, cast or jacketed, or heavier weight and start with starting loads or even a bit less if you go with a heavier boolit. IOW- if your boolit is a 40 cal 183 gr ( actual weight) for instance and the only data you can find is for 170 jacketed, use a starting load or a bit less and work up.

Remember that even if data is in the Lyman, RCBS or Lee books it doesn't mean your boolit weighs what theirs did. As an example Lyman uses #2 alloy. Their 429421 might show a weight of 240 gr. Mine made of straight WW might weight 256 gr. If I use a softer alloy they might weight 263 gr. Someone else might make then of an extremely hard alloy and they may weight only 230 gr. In this example it's a 30gr+ spread and you start with the lower loads and work up. You just have to think a bit and use the classic handloading methods of yesteryear, when we didn't have access to 8 bazillion books, magazines and the internet to work with.

[archmaker]

Concur with what Bret4207 says.

One of the joys I have from reloading my own is to know that the boolit that I made with the load I developed shoots as tights as the gun will allow.

With that in mind, learn to experiment with your powder selection and weight.

When I start to develop a load my first question is what is this going to be used for? Hunting, Target, Competetion or Plinking?

Based upon my answer, I will then look to see what powder is going to provide me with the max velocity I need (I usually have a few pounds of different powders for each cartridge). Regardless of which one I am aiming for, I then find the starting load and work up from there, if I can't find one to match the boolit I am using I will look above and below the weight of boolit that I do have, and see what the most conservative starting load is. From their I will usually divide, based upon the max, the increase in powder toward max into 5 or 6 loads, steeping up from the starting load. For instance if the starting load is 5.5 of X powder and the max appears to be 6.8, I will make up loads of 5.5, 5.8, 6.1, 6.4, 6.7.

I will pay strict attention as I am shooting to the cases to make sure their is no evidence of excessive pressure, and that the round is comfortable to shoot. I will also see which ones provide me the best accuracy.

After that if 5.8 and 6.1 shot the best for instance, I may go back to the reloading bench and load some 5.7, 5.9, 6.0, 6.2 and see how they shoot.

just .02 cents

[mooman76]

Why do you think the 40 is too new for the load manual. It's in the Lyman 47 & 48. I don't have the 49 yet. Yes they only have Lyman moulds listed. You pick data that is the closest to yours and go from there. You can use data for a heavier bullet and use it for a lighter one not visa versa. Just work up your load as always. Lee also has limited data for lead bullets and I concer with what the others have stated.

[Brick85]

Why do you think the 40 is too new for the load manual. It's in the Lyman 47 & 48. I don't have the 49 yet. Yes they only have Lyman moulds listed. You pick data that is the closest to yours and go from there. You can use data for a heavier bullet and use it for a lighter one not visa versa. Just work up your load as always. Lee also has limited data for lead bullets and I concer with what the others have stated.

They have it in the cast bullet book? I meant loads for cast bullets in .40, not jacketed or factory bullets (the Speer manual has loads for .40 and 10mm). This is all hearsay to me; I haven't managed to lay hands on the book yet.

[mooman76]

Yes they have cast data for the 40 in the regular lyman load manuals. If you don't have one and you are shooting cast you need to get one. Most of the others don't cover cast bullets too much cause they want you to buy their bullets. I use the lyman for manual more than any other because of those reasons. I didn't check the cast bullet book but that book is a little out of date. Still good book but not as up to date as we would like.

[Bret4207]

The last Lyman Cast Bulley book is from the late 70's/early 80's. I don't believe the 40S+W or even the 10mm were in there. The Pistol and Revolver book has info though IIRC.

[Wayne Smith]

Let me elaborate slightly on Bret's first sentence. With any load a cast bullet will operate at lower pressures than a condom load. Lead offers less friction/resistance as it slips through the barrel. This simple fact states that your primary problem with lead boolits will not be pressure in the case but, ala Larry Gibson's many posts, pressure on the boolet. Your pressure issue will be leading, not blowing up the gun.

This is not to say that it is impossible to blow up the gun with a lead load! Following the data in the loading manuals for a similar weight condom bullet, though, will not be dangerous to your gun.

[Bret4207]

Thanks Wayne. I must have slept through Effective Communication 101. Oh wait, I didn't go to college.....:mrgreen:

[arcticbreeze]

I have The Lyman Cast Bullet Handbook, 3rd edition, 11th printing. I purchased this book about 10 months ago and it does not list 40S&W or 10MM. I think you guys are talking about the "Reloading Handbook" not the "Cast Bullet Handbook".

[Brick85]

Let me elaborate slightly on Bret's first sentence. With any load a cast bullet will operate at lower pressures than a condom load. Lead offers less friction/resistance as it slips through the barrel. This simple fact states that your primary problem with lead boolits will not be pressure in the case but, ala Larry Gibson's many posts, pressure on the boolet. Your pressure issue will be leading, not blowing up the gun.

This is not to say that it is impossible to blow up the gun with a lead load! Following the data in the loading manuals for a similar weight condom bullet, though, will not be dangerous to your gun.

Took me a second to figure out what you meant by "condom load". Guess my mind is in the wrong place tonight. Thanks for the clarification--I wasn't sure whether the "operating at lower pressures" part meant that I need to load to lower pressures or what. Thanks for the clarification (and the original explanation, too). That makes life a lot easier. One question, however. The last time I tried using cast bullets in my .40 S&W, I had an issue with the length, and loaded them short. They seemed kind of hot toward the end. Doesn't cartridge length have something to do with the pressure, at least initially? If I load a bullet way into the brass rather than further out, it'll be at a higher pressure at first, right? By that token, a cast bullet might be shorter than a jacketed--or longer, depending. Isn't the COAL kind of important?

[dakotashooter2]

Another manual that contains some cast bullet loads is the Lee Manual.

[Brick85]

Oh, I wanted to mention that the Speer manual also does have a few loads for cast bullets, too--for RCBS moulds, of course.

[Wayne Smith]

Doesn't cartridge length have something to do with the pressure, at least initially? If I load a bullet way into the brass rather than further out, it'll be at a higher pressure at first, right? By that token, a cast bullet might be shorter than a jacketed--or longer, depending. Isn't the COAL kind of important?

Yes, very good point. Any time you change the room the power has to expand before it hits the base of the boolit you change the pressure of the load. Minimize this area (lessen the OAL or use a longer boolit) you increase the pressure and the powder needs to be reduced. Increase this area (shorter boolit) and you decrease the pressure.

This is not "higher pressure at first" but higher pressure, plain and simple. This is one way to blow up a gun.

[mike44]

Cast usually works at much lower pressures than jacketed. Just find a boolit of similar weight, cast or jacketed, or heavier weight and start with starting loads or even a bit less if you go with a heavier boolit. IOW- if your boolit is a 40 cal 183 gr ( actual weight) for instance and the only data you can find is for 170 jacketed, use a starting load or a bit less and work up.

Remember that even if data is in the Lyman, RCBS or Lee books it doesn't mean your boolit weighs what theirs did. As an example Lyman uses #2 alloy. Their 429421 might show a weight of 240 gr. Mine made of straight WW might weight 256 gr. If I use a softer alloy they might weight 263 gr. Someone else might make then of an extremely hard alloy and they may weight only 230 gr. In this example it's a 30gr+ spread and you start with the lower loads and work up. You just have to think a bit and use the classic handloading methods of yesteryear, when we didn't have access to 8 bazillion books, magazines and the internet to work with.
This is digging up a old thread but does this method work regardless of cartridge size? I have a encore with a 300 whisper barrel and I would like to shoot cast bullets. theres very little cast info that I can find for this cartridge. Any thoughts?

[Wayne Smith]

Don't see why not. You are shooting a large boolit at below the speed of sound. Sounds like a perfect place for a boolit rather than a bullet. Personally I'd start with a similar weight boolit and use the same load or slightly lower. Remember, you will be working with lower pressure, not higher. In the 300 whisper you are starting with low pressure loads, so why not use the same load?

PS Bret, there was a time when I thought the only thing I did was go to college!

[mike44]

I'm a little surprised that there's not more interest in cast loads in the 300 , I kinda think its a natural, even more so with cost and availability of 30 cal jacketed bullets. I have a lee 170 gr mold on order and was looking for some wisdom. thanks for the advise.

[NSP64]

I think the lack of intrest in cast in a 300 whisper has more to do with availability of barrels. Plus the 300 used 200-250gr bullets. cast molds for that weight are hard to come by. I usually find data for a jacketed load, then reduce it and work up. Lead loads go faster then their jacketed loads for the same powder weight.

[mike44]

64 your probably right, I was thinking from the tc owners point of view. most people with a suppressed ar or bolt rifle wouldn't bother with cast boolits.