17 tcm/17 9mm

[Waskawood]

I am not sure that I will push the shoulder back. It appears that by going to a 40 degree shoulder the neck will grow to a bit over .200'' which is what I want.
Mikie, I had a very slight ring just above the extractor groove on my first pieces of brass. I have since used my Dremmel with a felt polishing tip and Flitz polish to polish mouth of the die and it seems to have cured that.

[Nor Cal Mikie]

philip:
Looks to me like if the brass is fireform to a 40* shoulder, the neck will get shorter?
Havn't got that far myself so I don't know for sure.

Neck length is somewhere between .175 and .200 before any fireforming is done. Standard 22 TCM case OAL is about 1.025. Necked down to 17 is around 1.033.
Depends on which die you end up using and how it works in the forming process. None of this is cut and dried. You do as many steps as it takes to get you brass the way YOU want it.
My main goal is to get/build the shortest reloadable case I can get my hands on and only for one reason.
I want to hear the BANG and see the bullet produce a hole in the target.
No guesswork. I want to see my hits.
I got close by building my 20 VT "short" but not quite. (20 VT with the shoulder pushed back .200)
Anything past 100 yards would allow the rig to settle down so I had a good target picture. Even with a 15 pound rig, I got movement at 100 yards. Not a lot but just enough. And the 17 TCM is shorter by about another .200.
And, it's not a matter of being recoil shy. I've got a M1A that will take care of that.
Going to a rim fire wasn't an option in my book. I want to build/reload my rounds to get to where I wanted.
The 17 TCM will hold somewhere around 15 grains of powder to the shoulder neck junction. Pushing the shoulder back = less case capacity= less recoil movement.
Why not build something that will take 7 or 8? Or, even less?
The 17 VHA would be a good candidate. Just a matter of finding/building dies.

[philip]

Mikie,

I`m picking up what you`re putting down....

I`m just curious, not criticizing.

I figured that a straight neck down and fire form would be easiest and really close to the .17AH, but with much better brass.....

Good luck with your project, I`m watching all posts about this eagerly anticipating the results.

Phil.

[philip]

I was privileged enough to snag a Wasatch from Drew that is getting a .20-221AI chamber in a 12 twist Pac Nor.

A .17-22TCU AI would make for a nice switch barrel gun for this action.....


Now I wish I still had the N120 that I sold to Allen.....

Phil.

[sgtg]

Hey guys here are a couple shots of my 20 Boomer. I chambered it Friday and shot it this weekend. A 32 grain Z max 12.8 gns. 1680 was 3100 FPS no pressure and very accurate. sgtg out

[Nor Cal Mikie]

Just sent a note to Paul (pbike) to see if he has "just the die body" available so we can go even shorter.

sgtg:
Picture didn't come thru.
Mike.

[Nor Cal Mikie]

Phil:
Never took any thing you asked as critical. If you don't know, you have to ask to find out.
Good thing you can't see inside our heads. Might find a mixed up mess.
And, I STRONGLY believe that building wildcats is an addiction!
I know I'AM hooked.

[bowfisher]

Originally Posted by sgtg

Hey guys here are a couple shots of my 20 Boomer. I chambered it Friday and shot it this weekend. A 32 grain Z max 12.8 gns. 1680 was 3100 FPS no pressure and very accurate. sgtg out

What the barrel lenght on that build, sgtg?