Cast HP load data?

[Maximumbob54]

I'm having a red alert all stop moment in my hand loading. I have a mold that casts a 255gr SWCHP. I have been using Unique at a mild but not max load. I was thinking of loading some cleaner burning near max loads. It occurred to me from another thread that I may be very wrong with my loading. Or at least I am wrong with my choice of load data.

Is it the seating depth of the same bullet when cast solid? As in this mold should cast a 265gr solid so I use that data as working up to max?

OR

Is it just the weight of the bullet as cast period that you grab your load data? As in just find load data for a 255gr SWC and that will work just fine.

Right now I have my nose in the Lyman Cast Bullet Handbook. I'm looking at using either Unique or maybe 2400. A max load of Unique would be 255gr/12.1 or 2400 would be 255gr/22.2, while a max load of Unique would be 265/11.7 or a max load of 2400 would be 265/19.8.

So my worry is that if I'm supposed to be using the solid bullet data for the same bullet profile but with the lighter weight due to the HP cavity then that's a pretty big jump in volume of powder I would be using. That's what leads to "Chinese ammo in my 629" type threads (kaboom).

Sadly, I am only now grasping this possible large error on my part from rereading another thread where I asked for load data on a 140gr bullet: http://smith-wessonforum.com/reloading/257470-trying-find-140-lswchp-load-data.html


Before I forget, the mold in use right now is a MP Molds 432256. Great mold by the way.

Edit: I would of course leave out pertinent data. Yes, this is a .44 magnum bullet mold. They drop as a SWCHP at roughly 255gr with some minor variation that always is the case with cast bullets.

 

[Rule3]

What caliber?

It depends on the profile and length of the bullet.

They might weigh the same but how is that weight proportioned. Most HP bullets have a flatter nose so the weight is more to the base of the bullet.

If your HP is the same length as a non HP (don't see how it can be) then I would use the same OAL. If it shorter then a slightly longer OAL would seem logical.

But I could be wrong

 

[2hawk]

The seating depth should be the same with that mold, since the HP is made by pins that don't change the length of the bullet. The crimp groove isn't going to change. I would feel comfortable using the solid and HP data interchangeably unless I was at the very top end. IIRC, the difference between the HP and solid is usually about 10-15gr in bullet weight, so backing down a little for the solids would be prudent, at least until you can work up to a load.

 

[358156hp]

So do your hollowpoint bullets weight 255 gr, or do the solids? I'm assuming (that word again) that you're working with a 44 magnum, by the charge weights, and the mould designation. The hollowpoint bullets will weigh less than the solids will, and with the powders you have listed should be okay. Do not attempt to change the seating depth, use the crimp groove already in the bullet. It appears that this particular mould is a Keith design clone, and there's plenty of loading data available for it. The hollowpoint version of this bullet should weigh about 238 to 245 grains, depending on alloy. The softer your alloy, the heavier the bullet. I did not check your loading data, but in a nutshell, the hollowpoint bullet, with your current powders, should be okay with the solid bullet data with the powders you've listed. The hollowpoint bullet will be lighter, and will likely have a higher muzzle velocity than the heavier solids do.

 

[Maximumbob54]

What caliber?

It depends on the profile and length of the bullet.

They might weigh the same but how is that weight proportioned. Most HP bullets have a flatter nose so the weight is more to the base of the bullet.

If your HP is the same length as a non HP (don't see how it can be) then I would use the same OAL. If it shorter then a slightly longer OAL would seem logical.

But I could be wrong

It's a .432" sized to .430" mold. Without the pins for making HP's it drops them at 265gr but with the pins it drops a 255gr HP. So they are the same length with the HP pins displacing roughly ten grains of lead.

The seating depth should be the same with that mold, since the HP is made by pins that don't change the length of the bullet. The crimp groove isn't going to change. I would feel comfortable using the solid and HP data interchangeably unless I was at the very top end. IIRC, the difference between the HP and solid is usually about 10-15gr in bullet weight, so backing down a little for the solids would be prudent, at least until you can work up to a load.

I was wanting to work up to the top end and thus my sudden halt because of my confusion.

So do your hollowpoint bullets weight 255 gr, or do the solids? I'm assuming (that word again) that you're working with a 44 magnum, by the charge weights, and the mould designation. The hollowpoint bullets will weigh less than the solids will, and with the powders you have listed should be okay. Do not attempt to change the seating depth, use the crimp groove already in the bullet. It appears that this particular mould is a Keith design clone, and there's plenty of loading data available for it. The hollowpoint version of this bullet should weigh about 238 to 245 grains, depending on alloy. The softer your alloy, the heavier the bullet. I did not check your loading data, but in a nutshell, the hollowpoint bullet, with your current powders, should be okay with the solid bullet data with the powders you've listed. The hollowpoint bullet will be lighter, and will likely have a higher muzzle velocity than the heavier solids do.

255gr SWCHP bullets. I won't change the seating depth. I always just use the crimp groove. I do use a softer alloy as I want to work the load up with an alloy that would hopefully work to expand the HP. But I want to work the load before attempting to see if they do expand. I can always start over if I need to change the alloy to something softer again. There won't be much load data change for that.





I think to play it safe I'm going to use 265gr bullet data and work my way up. I'm not a big believer in using primers as a warning for pressure warning signs as it's my belief once you see the primer flattening out you have already gone too far. I'm going to stick with that heavier bullet data and use 2400 so I will just work up to 19gr at first. Maybe see how clean the powder burns as my indicator of the pressure. Dirty should mean lower and once I get it burning clean then it should be just right.

 

[Rule3]

It's a .432" sized to .430" mold. Without the pins for making HP's it drops them at 265gr but with the pins it drops a 255gr HP. So they are the same length with the HP pins displacing roughly ten grains of lead.

Well why didn't you just say so?

In that case I would not worry about it. Use the cannelure and the data for the heavier bullet will be fine and dandy.

 

[venomballistics]

done lots of this sort of loading.
work with the solid version first to get a baseline on the primers the HP variant is almost a direct swap where the primers can tell you if it made any room on the peddle. Your 10G difference I suspect will translate to .1 grain of powder tops as this displacement is rather slight in contrast to some of mine where a pin might displace as much as 45 grains for experimental flying trashcans

 

[Forrest r]

Why not just use the reloading data for the H&G #503 bullet? That's what the mp432256 mold was designed after.

 

[fredj338]

You should be working the load up anyway. Just use midrange data for a 250grLSWC & work it up. The bullets seat a bit deeper & are a bit longer, but wt is close enough. Just don't plug them into max data.

 

[Maximumbob54]

done lots of this sort of loading.
work with the solid version first to get a baseline on the primers the HP variant is almost a direct swap where the primers can tell you if it made any room on the peddle. Your 10G difference I suspect will translate to .1 grain of powder tops as this displacement is rather slight in contrast to some of mine where a pin might displace as much as 45 grains for experimental flying trashcans

I just started using the 265gr solid's loading data. I have a few small batches loaded up for testing.

Why not just use the reloading data for the H&G #503 bullet? That's what the mp432256 mold was designed after.

What book has that specific data?

You should be working the load up anyway. Just use midrange data for a 250grLSWC & work it up. The bullets seat a bit deeper & are a bit longer, but wt is close enough. Just don't plug them into max data.

I'm starting with 265gr solid data. Using 2400 batch A is 19.1gr, B is 19.3, and C is 19.5 for starters. The max load listed is 19.8 grains.