429 Ultra Express

[junkman1967]

Dave Manson has my master round and is making a chamber reamer for it. As soon as I get that in hand I will have some progress to report.

[junkman1967]

Still Waiting on the reamer. Should be here in the next 2 weeks.

[r3dn3ck]

So what's the ballistics? I use a .45Cinderblock which is a .460 rowland case cut to .888 and stuffed with a compressed load of Longshot and a 200gn JHP @2000fps+. ONLY safe in a rifle. I've been contemplating doing something similar with my spare Cinderblock gun and running it up to 2" case length and using a stout load of BL-C2 and .452" slugs and see if I can't get the next 500-750fps generated.

[junkman1967]

Still waiting on the reamer. I hope it gets here soon :)

[mattri]

Interesting project, will be watching this thread. Is your username on the guild the same?

[junkman1967]

Yes same username

[junkman1967]

Got the reamer yesterday. Now all I need is some time to work on the project. Im thinking about building a single shot version like a handi rifle to do some testing with prior to transitioning to the bolt gun. I will have some progress to report soon (I hope )

[junkman1967]

Getting back to this. Going to turn and thread the barrel this week.

[pighunter284]

any further.....

[junkman1967]

Waiting on a barrel nut. Updates soon.

[BobT]

I had wondered about building something very similar to this on a 240 Weatherby case at one time. It would be belted and could run on a standard 308/30-06 sized bolt face and probably even magazines. Only real issue I think would be availability of brass, or at least cost.

Not to hijack Boots but I heard you could run /06 cases into a .240 Weatherby sizer and form a belt on them. Just a thought. Sorry Junkman, back to you !
Bob

[junkman1967]

My round runs on a standard 308 bolt and fits in the magazine of my 308 Axis. I thought about the belted cases, but I already have the custom reamer, so it kinda kills that idea for me. Hope to have some more progress soon, in the meantime feel free to hijack away :)

Joe

[goinssr]

Not much to headspace on with this cartridge. The 444 marlin has the rim to headspace on, this round only has the case mouth and that is not much. I would opt for the .444.
Good luck with it in any event.
Best regards,
Grit
I was wondering also what this cartridge was head spaced on. That case mouth isn't much so it appears that POSITIVE head space may be a bit difficult to achieve. Provided that you can get positive head space with this round and are successful in developing it I would suggest that you look hard at the Hornady 265 grain .429 bullet rather than the 240 grain. The 240 grain bullet is designed to perform at .44 magnum pistol velocities and will not hold together well at the speeds that you propose whereas the Hornady 265 grain bullet was developed specifically for the .444 Marlin which is more along the lines of this cartridge and should do very well.

[junkman1967]

Thanks for the info, I will look into those projectiles. I think it will head space off the case mouth just fine, but we shall see. Early indications are good so far.