Max velocities for plain-based boolits?

[homefront]

I'm considering a new mold for my .38-55 Marlin CB, possibly the Saeco 225gr. I've been warned (on another forum) not to expect good things from a plain-based boolit, cast from wheel weights, at velocities over 1,400fps.
The Saeco is a tapered design; .3845 at the rear driving band, tapering to .378 at the front, and meant to be loaded un-sized. Is 1,600-1,800fps asking too much from such a boolit?

[Scrounger]

My own opinion and anyone is welcome to disagree, I won't even contest it. I THINK that velocity is not the relevant factor in how fast we can shoot plain based bullets IF they are hard enough. I think chamber pressure is more relevant. In a case the size of the .38-55, I would hope it would be possible to use a slow enough powder to generate 1800 FPS without exceeding, say, 35,000 PSI. OK, start shooting.

[ktw]

In a straight walled case the size of a 38-55 there is often some room left over for cream-of- wheat or LDPE wads.

If you can't get to your desired velocity with the just the plain based bullet, you should be able to with the COW/LDPE.

-ktw

[Doc Highwall]

I thought it was a good article on pressures and boolit hardness in the LEE 2nd edition reloading manual and what velocity you could get.

[homefront]

Thanks for the input, and the reference (which I'll read tonight).
I've never used fillers, and recall hearing warnings concerning their use and possible barrel damage. What are the rules concerning filler use?

[ktw]

What are the rules concerning filler use?

I have been using COW in the 38-55 with some of the midrange powders (4227-3031 range, something where the powder alone already fills 60-80% of the case capacity) to increase load density. It performs some of the same functions as a gas check. It will increase pressure. With some powders it has given more uniform velocities. It often cleans up the burn in an otherwise "dirty" load. I have only been using it in straight-walled cases.

- Don't simply add filler to an existing load. Work up.
- Don't add a lot of COW over a small amount of fast burning pistol powder.
- Don't leave any air space between an over-powder wad or filler and the base of the bullet.

There have been a number of threads. Try a forum search on "COW" and the user "Molly".
This was one: http://castboolits.gunloads.com/showthread.php?t=34143

-ktw

[Boerrancher]

My own opinion and anyone is welcome to disagree, I won't even contest it. I THINK that velocity is not the relevant factor in how fast we can shoot plain based bullets IF they are hard enough. I think chamber pressure is more relevant. In a case the size of the .38-55, I would hope it would be possible to use a slow enough powder to generate 1800 FPS without exceeding, say, 35,000 PSI. OK, start shooting.

Scrounger,

I think your thoughts are correct. My father had a friend that had a rifle years ago, that had an old Remington roller in a 38-55. It had a progressive type of rifling. The farther down the bore the faster the twist. I don't remember what the final rotation was, but I know he use to shoot cast boolits with some incredible powder charges. I wish I would have been old enough to have fully understood what he and dad were talking about and old enough to remember the load data. I don't even know where he had the barrel made, but I do remember it would shoot hard and fast for an old gun and really good groups.

Best wishes from the Boer Ranch,

Joe

[JeffinNZ]

This is a 300gr PB with a heavy card wad at 100m/110y out of my .38-303 doing just shy of 1700fps. BHN is only about 8 from memory too.

http://img.photobucket.com/albums/v505/JeffinNZ/Shooting%20stuff/38303group.jpg

[homefront]

Jeff,

Very cool!

What powder were you using?

[missionary5155]

Good morning
I agree with presure as being one of the Major culprits. If the proper lubbed Boolit fits the chamber at ignition then presure is all there is. I shoot my proper fitted 44-40 SRC with near pure lead with 10 grains Unique (8 is my plinking load) and there is NO leading. Granted it is not 1800fps but it is range scrape+ pure lead pipe mix. And the range scrap is mine.
Lube, Mix, boolit style (Louvern+++) and barrel condition all have their part too.
Google " Gain twist Rifling"... I think they are still cutting.
Mike God Bless you.

[Bret4207]

It can be done if the boolit fits and if you can work the load up. I might not be easy to hit 1800 fps, but it can be done.

[JeffinNZ]

Jeff,

Very cool!

What powder were you using?

37gr of W748 so a slowish burn for the straight case.