20 Vartarg .150 Short

[ASbobcat]

Seems I'm again typing as you are.

Yes any other powders would be especially valuable to me. I have CFE BLK, Lil Gun, 2200, 2520, 1680, H110, if that's possible.

Wow I have to get GRT running. Sounds like it's an invaluable wildcat data source.

You have made my day....thank you.

My experience with 20VT can perhaps modify your list of potential powders. Using pistol/shotgun powders is tempting, because ballistics look impressive on paper, BUT there are serious downsides. These powders (H110 and Li'lGun) have wide swings in pressure with very small changes in charge. They also burn rapidly, dramatically increasing throat wear.

I would suggest H4198, RL-7, AA1680 and AA2200 for most consistent safe results.

 

[ricco1949]

My experience with 20VT can perhaps modify your list of potential powders. Using pistol/shotgun powders is tempting, because ballistics look impressive on paper, BUT there are serious downsides. These powders (H110 and Li'lGun) have wide swings in pressure with very small changes in charge. They also burn rapidly, dramatically increasing throat wear.

I would suggest H4198, RL-7, AA1680 and AA2200 for most consistent safe results.

10-4..I am aware of the temperaments of Lil Gun and H110 in K-Hornet.

I actually favor CFE BLK since I have all my VT experience with it and it has been easy to work with.

However the others may still apply, since .150 Shorty is on the edge of K- Hornet territory.

Thanks for the heads up.

 

[ricco1949]

Here's the lineup. FL VT, .100 Shorty and .150 Shorty

.150 Shorty's gonna be the first entry in the PD Sweepstakes.

Usable capacities of CFE BLK to the neck shoulder junction are as follows:

20.5 FL
18.5 .100 Shorty
17.2 .150 Shorty

 

[ASbobcat]

10-4..I am aware of the temperaments of Lil Gun and H110 in K-Hornet.

I actually favor CFE BLK since I have all my VT experience with it and it has been easy to work with.

However the others may still apply, since .150 Shorty is on the edge of K- Hornet territory.

Thanks for the heads up.

You're very welcome.

As a general rule, I use the slowest powder that will suit my needs.

Charge weight variations are less critical.
Less throat wear. Even though you're using more powder, more of the burn occurs beyond the throat.
Longer case life from lower peak pressure spikes.

 

[SmokinJoe]

Attached is a cartridge comparison , from left: K-Hornet, TCM, My 22 SmokiJoe, 22 Spitfire, 22 Tanuki and 221 FB. I have tried 300MP, AA1680, CFE BLK, Shooters World Black and Shooters World SBR-SOCOM. The SBR-SOCOM has turned out to be the perfect powder for both the Spitfire and SmokinJoe with 40gr bullets. 300MP would be my second best. looks like your cartridge will be very similar to mine other than being 20cal vs 22. Best thing about wildcating a cartridge based on 223 is brass.

 

[ricco1949]

Ran into a problem....

My Giraud trim die is made with my 20 VT reamer. The prototype type Shorty brass I've made won't fit in the die all the way. First thought was the neck is snug because of the thicker necks on Shorty. Nope I'd already reamed it bigger years ago to avoid this scenario.

Got out the 17 Fireball SAAMI drawing and my 20 VT drawing. Ohhhhh.... I overlooked that the 17 Fireball is .005 bigger at the shoulder than the 221 FB and the 20 VT.

My 20 VT reamer ain't gonna be compatible with my 17 FB die converted to 20 VT.

Back to the beginning...order another die to cut off.... 20 VT this time.

 

[20 TAC]

Ran into a problem....

My Giraud trim die is made with my 20 VT reamer. The prototype type Shorty brass I've made won't fit in the die all the way. First thought was the neck is snug because of the thicker necks on Shorty. Nope I'd already reamed it bigger years ago to avoid this scenario.

Got out the 17 Fireball SAAMI drawing and my 20 VT drawing. Ohhhhh.... I overlooked that the 17 Fireball is .005 bigger at the shoulder than the 221 FB and the 20 VT.

My 20 VT reamer ain't gonna be compatible with my 17 FB die converted to 20 VT.

Back to the beginning...order another die to cut off.... 20 VT this time.

I’ve often asked myself about these projects I’ve taken on….is this a Labor of Love or a Love of Labor? . Hang in there lol

 

[ASbobcat]

Ran into a problem....

My Giraud trim die is made with my 20 VT reamer. The prototype type Shorty brass I've made won't fit in the die all the way. First thought was the neck is snug because of the thicker necks on Shorty. Nope I'd already reamed it bigger years ago to avoid this scenario.

Got out the 17 Fireball SAAMI drawing and my 20 VT drawing. Ohhhhh.... I overlooked that the 17 Fireball is .005 bigger at the shoulder than the 221 FB and the 20 VT.

My 20 VT reamer ain't gonna be compatible with my 17 FB die converted to 20 VT.

Back to the beginning...order another die to cut off.... 20 VT this time.

Interesting information. I was unaware of the difference in shoulders. .005 is significant.

 

[ASbobcat]

Attached is a cartridge comparison , from left: K-Hornet, TCM, My 22 SmokiJoe, 22 Spitfire, 22 Tanuki and 221 FB. I have tried 300MP, AA1680, CFE BLK, Shooters World Black and Shooters World SBR-SOCOM. The SBR-SOCOM has turned out to be the perfect powder for both the Spitfire and SmokinJoe with 40gr bullets. 300MP would be my second best. looks like your cartridge will be very similar to mine other than being 20cal vs 22. Best thing about wildcating a cartridge based on 223 is brass.

I agree about the quality of 223 brass, particularly LC NATO.

I love the efficiency of these small cases. My observations from decades of playing around with various cartridges is that there is an "optimum" case capacity for any given bore diameter (powder burned vs velocity). I suggest that the VT is optimum for 20cal, but the smaller variants are probably better suited to .17cal.