6x10mm Auto

propeine · #1 04-05-2018, 05:32 PM

Hello all,
I am new to the site but working on something that seems to be up the alley of a few folks here.

Something struck me over the weekend and I managed to find enough stuff around to try it out. What if you made the 22 TCM on steroids by starting with a 10mm case and necking it down to 6mm. With a 55gr bullet and the larger bore for greater expansion ratio, you should be able to drive a 55gr just as fast as the 35/40 out of the TCM.

So off to quickload. Quick calcs show ~2000 fps out of an 8in barrel with AA7, Power Pistol, and Blue Dot. 16in barrel gives another 300-400 fps. This is based on 1911 mag length (1.260), a .640 long 6mm varmint bullet and around .2 neck.

I give you the 6x10mm Auto (although I would probably build a bolt pistol). I've got some other projects for other people that I need to pursue first but this was like 20 mins of messing around in the reloading room. To be fair this is a 90gr 257 Cal bullet because I didn't have any 6mm stuff yet.

These
varmageddon

Or the dogtowns depending on length are the best candidate unless there is a shorter cast bullet.

This would be pretty great as well

http://noebulletmolds.com/NV/product...oducts_id=2308

For the theoretical calculation stuff...this is the intended size

I'm planning a "bushing" die of sorts. My plan is to use the reamer below for the "body" and then the bushings will be normal drill sizes except for the last one at .268. I went with 30° shoulders for a secondary reason too. A 0.375 center drill will give me the perfect lead in to my bushings every time. I just have to machine out the backside of the body die until the opening is the same so I can drop in the bushings. No idea if this is how Redding makes them but it is how I'm doing it.

This is the resizing reamer blank. Only difficult part is the .003 body taper. It's based on the numbers above which fits a 55gr Varmageddon at exactly 1.38" OAL with the base of the bullet at the neck/taper junction. 1.38 is the length of a Tokarev which fit in 1911 mags although at reduced capacity. Nothing says I can't use Tok mags either I suppose.

I need a collet block to finish it so it will be a few days unless I can find one locally.

squirrel_slayer · #2 04-05-2018, 07:34 PM

cool project. I'm about to try my hand at a homemade D-reamer with another project.

Keep an eye out at shooterproshop.com they often have the 55gr Nosler "shots" (same as dogtown/nightmare) for cheap. just a few weeks ago they had 1000 6mm 55gr shots for $60! was a overrun price.

on a sidenote how do you get to that screen in quickload? I've never seen it before.

propeine · #3 04-05-2018, 07:53 PM

Quote:

Originally Posted by squirrel_slayer

cool project. I'm about to try my hand at a homemade D-reamer with another project.

Keep an eye out at shooterproshop.com they often have the 55gr Nosler "shots" (same as dogtown/nightmare) for cheap. just a few weeks ago they had 1000 6mm 55gr shots for $60! was a overrun price.

on a sidenote how do you get to that screen in quickload? I've never seen it before.

Someone on another forum asked me the same thing...this is a copy/paste

Go to data add change save, change data records in active file.
Draw up something similar to what you're interested in.
I knew the base was 0.425 and the bullet end was .422 so I just made the shoulder of my theoretical cartridge 0.422. I knew I wanted 30° for feeding from a magazine and kinda just took a guess at around 0.2" neck.

Then you need to know brass weight, I just started with the weight of the 10mm brass I had since any trimming will make it lighter and lower the pressure anyways. Quickload is just using the weight as an estimate for brass thickness as far as I can tell.

Open the capacity calculator in this menu. Enter all your theoretical data hit calculate and Bob's your uncle.
6mm TCM is even easier since you're really just expanding the neck. Only 1 number to change. Capacity shouldn't change much at all.
Just make sure you change the name in the top bar before you click save when you're making a new cartridge.

Of course I can physically measure the case capacity of mine since I made one that is pretty close too.

Like any software package though, you have to know if your output is in the same ballpark as what it should be. The 22 TCM has published velocity data and reloading data along with reasonably similar case capacity. I make the assumption that 6mm should get slightly better velocity for the same bullet weight due to bore area. Until that first primer strike though I wouldn't really KNOW. Just a guesstimate of performance envelope.

rickiesrevenge · #4 04-05-2018, 08:43 PM

Neat project. Should be similar performance to the 6mm Horny Toad a member did a while back. It was a shortened 6mm TCU. I realize they aren't the same case but they should have similar capacity.

How do you set up the compound for the taper in the case body?

Aaron

squirrel_slayer · #5 04-05-2018, 11:07 PM

Brilliant! thanks Propeine!

propeine · #6 04-06-2018, 02:20 AM

I think I give up a few grains of capcity but gain the shorter case height for efficienc? I didn't see published velocities for the HT either if you happen to know them?

As for dialing the taper, dial indicator, run the compound the length of the body, indicator needs to move .0015. On a longer cartridge you can use 2 indictors spaced appropriately for the same purposes.