Question: Making a New Caliber

[Texas by God]

Side tracking:

How would you go about lengthening an existing cartridge? I have always gotten an itch to stretch out a 38 smith and Wesson to the same case length as a 38 special, and run at 38 special +p pressure

Why? They would be identical save for .002" bullet diameter.......

[beechbum444]

great ideas....keep the ideas flowing.....I think that I might start with a savage 110 action and a barrel chambered in 762 x 39.....afterwards ream it out....before I go down the lever action route.....

[Moleman-]

Make up a couple dummy rounds and send them into Manson Reamers. Dave will Make you a chamber reamer and headspace gauges if you need them. If you're handy and have access to shop equipment you can make a reamer, gauges and chamber your own barrel. For me getting all the diameters and lengths, angles correct is harder than fluting so I go with 6 flutes. I'd also suggest getting QuickLoad or some similar reloading program. You have to set it up to use the specs of your case, but I've found it to be pretty accurate with several wildcats I have.

If you end up with a case with no taper you can make your reamer with .002" to .003" extra clearance at the base. The case will fireform up to the chamber and will extract easier now that the case is tapered. If you can't make or modify an existing die set, most of the die companies will make you a set.

[Good Cheer]

beechbum,
My way of doing it was to design the cartridge and have a rifle smith I had experience and confidence with handle the project.
That way the rifle, the reloading dies and the chamber reamer were all part of the deal.

Another path forward can be to have chamber and/or bore (reboring) alterations done and then send fire formed brass and dummy cartridges sent to have dies fabbed.

Or another by example that I'd like to do...
Shorten 375H&H dies to use reformed 7.62x54R brass.

There's lotsa ways to have fun!

[nekshot]

I am getting cheaper the older I get! I use 5 to 6 pieces of masking tape in place of headspace gauges. I know thats not the correct way but it works for me.

[Texas by God]

I have a 22-06 cartridge somewhere around here.
And a .370 Savage.
And a 6mm/6.5 Rem Mag.
And a 7.5 x 57mm.
Some day maybe....

Sent from my SAMSUNG-SM-G930A using Tapatalk

[beechbum444]

Taper....is .005 to....008 taper from base to case mouth not enough??? 9mm 40 401 wsl have zero to .001 taper from base to case mouth

[country gent]

Texas By God, I have key fob I made its a 50 bmg necked down to 22 cal. I did this on a whim. Had a roller made out of a pope cutter for a job set the case up in the lathe at low rpm and started rolling adding pressure to get to 22 cal.

[crankycalico]

Why? They would be identical save for .002" bullet diameter.......

in theory if the 38 sw got stretched out to 38 special length, and used 38+p pressure, consider the velocity you could get with the 200 grain bullets.

[Screwbolts]

IMHO " caliber" normally refers to bore diameter. What new Bore/caliber diameter are you thinking of using?

Sorry if I missed it in the above posts.

Ken

[dragon813gt]

IMHO " caliber" normally refers to bore diameter. What new Bore/caliber diameter are you thinking of using?

Sorry if I missed it in the above posts.

Ken

I wish you luck fighting that battle. People constantly use the term caliber when they mean to say cartridge.

[beechbum444]

bullet diameter would be .410 stuffed into an expanded 762x 39 case , neck diameter .434 and base diameter .443, OAL , still working on it....270-350 grain lead boolit……...1300-1400 fps 400gr would be great,.....not sure where boolit weight gets too much to decrease goal fps......

[cas]

7.62x39 brass is everywhere... but is good 7.62x39 brass everywhere?

Taper does make extraction easier, but it also makes bolt thrust worse. When you're dealing with "weaker" action types, that's a bigger concern than extraction.

You'd be better blowing it out a little, making it look like a bigger .35 Rem.

[Screwbolts]

Wasn't a battle, just a question, and not interested in a battle.

Ken

[Shawlerbrook]

Like your idea, but I think I would start with a 35 Rem. or 30 30 to eliminate any bolt face modification.

[beechbum444]

good point , I have been back and forth on the bolt face issue, If I put this in an AR platform, all I have to worry about (in theory) is a barrel and chamber reamer ……..BUT I want it in a lever gun. The 357 bolt made for he win 94 action is sooooo close in size .440 verses the 35 rem in the 336 action....I keep coming back to the 35 rem and 3030 as a parent case but I'm trying so hard to go down the road less traveled

[blackbahart]

you are possibly trying to duplicate the 401 Winchester if you use the 7.62x39 to 40 cal ?

[John Taylor]

I am getting cheaper the older I get! I use 5 to 6 pieces of masking tape in place of headspace gauges. I know thats not the correct way but it works for me.

One piece is about .004" thick, use factory unfired ammo for checking.. If a gun closes on one piece it is a bit loose, two pieces it needs work. I have had Winchester 94s come in that were still being used that close on six layers, about .025" headspace. On a 30-30 the brass will not always stretch but the primer will back out. Wisner's use to make thicker locking lugs to take up the space.

[John Taylor]

A while back I decided to make a new caliber rifle. Got a box of 28 gauge brass and checked to see how big a bullet it would take. Real reverse engineering. The bullet would be .590" diameter so I made a barrel with that size groove diameter. A 28 gauge shotgun reamer was used which gave a nice taper throat. The barrel was mounted on an old single shot break open. I still need to do some work as the old gun did not have a forearm. Next will be to make a bullet mold, the 58 cal Mini mold is to small. This will be about the same as shooting a 58 cal muzzle loader with around 100 grains of powder. I may need to find someone younger to take the first shot.

[Jniedbalski]

The 28 gauge sounds like a cool project . How did you grove the barrel? Your selph or send it out