Question: Making a New Caliber

[beechbum444]

Question to yall on the forum about making a new caliber....What is the process????? I have the idea in mind so where do I start?? How do I have a reamer made? How do I get specs for it to be made? Who is a good company to have a one off barrel made? These are just a few questions that I can think of......If you have any suggestions or even more comments, please do not hesitate, any direction is appreciated...…….

Thanks for looking

[dbosman]

If you do a web search you'll find several reamer manufacturers. Depending on what you're working on, you may be able to use a couple of off the shelf rental reamers to get close to what you design.
There are any number of barrel makers, all of whom are backed up. ;-)
Before you spend money, though, do a search for the caliber and your parent case.
If you're talking a new rim size diameter, you'll be looking to have a bolt made or opened up.

[nun2kute]

I wish I could help, but I'm in the same boat. Still looking for a 40 cal rifle blank. (AR type) I have been meaning to go talk to the Machinist I had open up the upper for my 458 about it, hoped he might give me some direction. I thought that if I could make a dummy round, Hornady could make the reloading dies. I just haven't pursued that project much yet.

[NyFirefighter357]

Read the "Ladybug" thread.

http://castboolits.gunloads.com/showthread.php?356567-Introducing-The-22-ladybug

Two companion threads also.

http://castboolits.gunloads.com/showthread.php?361688-22-Long-Long-Rifle-CF-from-25ACP-Trials

http://castboolits.gunloads.com/showthread.php?344080-25-Auto-Long-rifle-Wildcat

[dh2]

I would start with Pacific tool and Machine I get wildcat reamers from them, they will make reamers to order.
What are you after there may be a wild cat to fit the bill all ready out there

[beechbum444]

762 x 39 expanded out to 40 caliber in a marlin 336 action....the 400 AR uses 765 carcano brass for the taper to feed from a straight magazine.....and Id rather use 762 as a parent case. It would basically be a 401 wsl I think and hope a 35 rem bolt would work and the guides might work with very little fidgeting...If the 35 rem bolt would not work, Id have to go with a win 94 action with a 357 mag bolt but the COAL would fix the feeding issues (hopefully) ……...Any Thoughts Out There

[adcoch1]

Any reason to stick with a x39 case? You could easily do a 40-30 with a 30-30 case as the parent. The expanding of a x39 case would take some work and a common bolt head size in a levergun may be difficult. A reamer can be had from a few different companies, and barrel blanks can also be found, or possibly just use a 40 or 10mm ar barrel. Once you have the gun built and some cases expanded and fireformed, hornady or p,t&g can make dies. Or you could ream out a 10mm die for neck sizing. Lot's of ideas.

[NoZombies]

If you can't do most of the work yourself, find a gunsmith you like, who likes the idea of the project. PTG makes nice reamers, but I've made most of my own because of cheapness/laziness. For one off jobs a "spoon" or "D" reamer can do fine, and honestly, I usually get at least as good a finish using the "D"-type reamers as I do with commercial or home-made fluted reamers.

[beechbum444]

you are right about the 40-30 round....It just seems that 762x39 brass is everywhere....I first wanted to do a 40-50 SS and then a 445 super mag with shortened 303 brass and use 303 brass for the 40-50ss....trimmed a little.....a 35 rem dia is .460 and oal is 2.5 and the 762 rim diameter is .447 and I think I can get a 2.2-2.3 oal im just curious how much wiggle room there is between ammo manufacture and bolt/ extractor manufacture …...a 357 rim dia is .440 butttt. then Id have to go with a winny action but I would think its easier to go with a smaller bolt head size......just thought a Russian designed round designed to go into an ak retro fitted to go into a pre 1900 designed lever gun would be really cool and it could launch a 250-290 gr lead boolit close to 2000 fps

[crankycalico]

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

[sharps4590]

New caliber or new cartridge?

[rockrat]

clymer has made reamers for me before when I came up with ideas for different cartridges (30-357max and 44/284 and 38-72 with 405 win. rim). Manson reamers also does custom work.

nun2kute--- You might be able to send an AR15 barrel to JES and have him bore it to 40 cal.

How about taking a 35 rem case and opening it to 40 cal, as an alternative. Don't think you are going to get a 280-290gr boolit going 2000fps using the X39 case, but I might be wrong. Using the 35 rem case might be an easier proposition.

Check out Green Mountain barrels for your 40 cal. I think they have them

[country gent]

Start out by drawing up what you want. scale it up 5 or 6 to 1 ( 6" on paper = 1" actual size). This shows you idea much better and also body tapers and such stand out more. This drawing will firm up the design and give you something to work from. This drawing will see a lot of use. Next I bore a sizing die in the lathe to the drawing and start forming some cases, not a lot but a few for dummy rounds and to have the forming process down to where it works. Sometimes a slight change in body taper, shoulder angle or shoulder set back makes a big difference in how a case forms. This is the time before the reamer has been ground. I load 3-5 dummy rounds with the desired bullet and Overall length. These are hands on of the new cartridge, and can be used to check magazines dimensions and theory to a point. Now talk to your reamer grinder ( I use Dave Manson normally) and work with him, Send him a copy of the drawing and 2-3 or the dummy rounds. He now has your thoughts and work on hand including samples he can measure. Trust me here his measuring equipment is probably years ahead of yours, and he can measure it in the way that works for him.
He may call with small changes he wants to aid extraction or case life or to ease grinding the reamer. Once the reamer is ground then its build the rifle and final dies. ( Some Air hardening stocks shrink slightly when hardened and tempered allowing the die to be cut with the reamer). On cases that are necked up with little other changes a tapered expander may work to make the test cases, sometimes other dies can be found to make the dummy rounds 1 for body taper, another for shoulder locations angle and one for neck size.

This can be a slow process and a lot of planning between each step is good.

[Chev. William]

You might check what "Lothar Walther" lists in the Bore/Groove Diameters you are looking for.
Chev. William

[cwlongshot]

I wish I could help, but I'm in the same boat. Still looking for a 40 cal rifle blank. (AR type) I have been meaning to go talk to the Machinist I had open up the upper for my 458 about it, hoped he might give me some direction. I thought that if I could make a dummy round, Hornady could make the reloading dies. I just haven't pursued that project much yet.

Have you seen the 400AR? I am also a big 40cal Fan! :bigsmyl2:

https://400ar.wordpress.com/

https://www.bing.com/search?q=400AR&form=IENTNB&mkt=en-us&httpsmsn=1&refig=9741216ac8ef40cbf48e6105ef65baf0&sp=-1&pq=400ar&sc=8-5&qs=n&sk=&cvid=9741216ac8ef40cbf48e6105ef65baf0

CW

[beechbum444]

I've seen the 400 ar I like it but I think that I can get a bigger .41 caliber boolit in a 762x39 case and I don't need the taper for a box magazine and the carcano brass is not so common

[country gent]

Taper isn't just for box magazines. The body tapers also aids in ease of extraction. as the case is pulled out the chamber is getting bigger. A true straight wall case fire formed tight to chamber will drag the full length

[nun2kute]

CW ... that link to wordpress was an awesome read. Gets me closer, but it and you'all also kinda lets me know I need to do a lot more research and learning. "The more I learn, the Less I know". I was thinking along the lines of 10X51 er' 40-06, AR 10 size. Now I don't know.

[john.k]

There is no need for a reamer to cut a near straight taper chamber with little or no shoulder .................it is easily cut with a small boring bar.,and lapped when to size...A reamer will add at least a $100 to the build.....A D reamer is a good idea,but the chamber must be 90% roughed out,or need only a small metal removal.....Reloading dies can also be made with a D reamer.

[357Mag]

Beechbum -

Howdy !

I formed some sample cases of a new .411" cal wildcat based off .35 Remington, which was the brainchild of a Michigan deer shooter.

While .35 Rem ( Remington brand brass ) has a nominal ID of .400" from the shoulder/body juncture down to .125" the case web....
he wanted to use .405Win left over bullets, and also go w/ a 1.800" case max oal, for legality.

I used a small assortment of ( LEE ) expander mandrels, to mildly expand the cut-off .35 Rem cases to .41" cal ID.

The shooter had hoped to run a .405Win reamer in "short", to cut the chamber for the .35Rem-based wildcat brass.
Math showed that this would not be tenable, and the project thereafter was idled.

It does appear that use of the .405 Win reamer run-in short could be a viable approach, were one able to instead use
7 X 64 Brenneke as the parent case ( IMHO ).

I believe an AR format was being considered, and of course.... case' major diameters are always a central question.

I shot a .224" cal wildcat based on .35 Remington in a single shot bolt action rifle. I used the stock .308 bolt face,
and it had an M-16 style extractor installed. I never had any problems w/ case/cartridge feed or extraction.

For barrels, you might check w/ MMC, PAC-NOR, Criterion....... there's a variety out there I should think.


With regards,
357Mag

[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

[beechbum444]

Yes much like 401 wsl but with a heavier 41 cal booolit with less velocity

[NoZombies]

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.

The same as a 38 special using +P pressures with a 200 grain bullet.

I'm all about doing things because you can, but this one seems like an awful lot of work to duplicate something that's both cheap and easy, with no discernible benefit. What am I missing?

[John Taylor]

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

About 20 years back I built a rifling machine. It has a sine bar that can be moved to change the rate of twist. So far the fastest twist I have done is 1 in 8.5", from there I can go all the way to strait. Smallest caliber I have done is 7MM and the largest is 72 caliber. It takes a different cutter box for each caliber. I can do 2,3,4,5,6 or 8 groove. So far I have done 4,5,6 and 8. I did a Wh hex bore several years ago but have not built a rifle around it.itworth

[blackbahart]

that's starting to sound like a 41 Rem Mag ,think marlin made some levers .Or 414 max/super mag ?

[Chev. William]

About 20 years back I built a rifling machine. It has a sine bar that can be moved to change the rate of twist. So far the fastest twist I have done is 1 in 8.5", from there I can go all the way to strait. Smallest caliber I have done is 7MM and the largest is 72 caliber. It takes a different cutter box for each caliber. I can do 2,3,4,5,6 or 8 groove. So far I have done 4,5,6 and 8. I did a Wh hex bore several years ago but have not built a rifle around it.itworth

John,
Do you still have that custom rifling machine setup?
Would you consider rifling a Blank in .25ACP with 8 grooves/lands and 1 turn in 8 inch twist?
Would you start out with a used .22LR barrel and bore/ream/lap it first to the correct starting bore diameter?
These Questions intrigue me greatly.

Chev. William

[John Taylor]

John,
Do you still have that custom rifling machine setup?
Would you consider rifling a Blank in .25ACP with 8 grooves/lands and 1 turn in 8 inch twist?
Would you start out with a used .22LR barrel and bore/ream/lap it first to the correct starting bore diameter?
These Questions intrigue me greatly.

Chev. William

So far the smallest caliber I have done is 7MM. Each caliber has to have it's own reamer to get to the proper size and it's own cutter box. When I first started reboring barrels I told myself I would never do anything under 32 caliber because of the difficulty making the cutter box and cutter. The 7MM was done for a customer that I made many barrels for and he could not come up with a 4 groove barrel in that caliber to replace an early Winchester. I have done many calibers up to .72 but I have not done many recently. I can get liners for the 25 ACP and you already have a source for barrels.

[Chev. William]

Yes I do but not much in the way of Choices: either 1:14" TJ liners or 1:9.8" LW barrels are all I have found to date.

Chev. William