20 cal ruminations

[TAJ45]

Thank you. Am in touch w Ray. A font of information.

 

[L.Sherm]

Ray H knows more about the 20JI than anyone I know. It's a 222 case shorten .160" and blown-out to a 40 degree shoulder. On about one grain more powder than the 20VT it will produce at least 200 fps faster. Mine runs 3960 fps with the 32 gr V-Max. It will run over 4K if ya want!

Sounds like Rays javelina is right on par with my 20SCC. I run a 34 nightmares at almost 3900fps in a 24" barrel. It's about a grain more than the vartargs also.

 

[TravisC]

In a 20-250? That is a monster difference in pwdr wgt.
Or are you referencing your Valk?

This is in my Valkyrie. Sure there are other options, but I had so many components I figured I'd use them up.

 

[Scooby-93]

I'm running 25.8 grains of benchmark and hitting 3865fps average today.

Looks like it’s a very efficient case, maybe even more than the 20br looking at that velocity? What length barrel?

 

[TravisC]

Looks like it’s a very efficient case, maybe even more than the 20br looking at that velocity? What length barrel?

I'm running a 24" barrel.

 

[20 TAC]

Realize this is an older thread, but wanted to share a pic of my case forming steps originating off the 223 case to make what I called a “20 Falcon”. In fairness, it is so close to the 20JI that, had I known the JI existed, I probably wouldn’t have gone through the case design/dies/forming learning opportunities and just ran the JI. Case capacity squarely between the 20VT and 20-222. Labor of love but probably my most accurate chambering.

 

[20 TAC]

L-R 20VT, 20 Falcon, 20-222, 20 TAC, 204

 

[moorepower]

I like the KISS principal. I wanted one that was Practical shooting from a single shot, Practical from a magazine fed bolt action and Practical from an AR. I really wanted a .20H but never got around to it.

 

[TAJ45]

Going back through the posts.....a great read w all the input. Still have not landed on any one case.
I had most recently been ruminating on the 222 w shoulder pushed back abt .060 and 30°.

 

[urbanrifleman]

Only a few more weeks until the 20 Sploder reamer arrives. (20-223a)

 

[TAJ45]

So tell me young feller, how long the neck, what dia and what angle? No turn I'm thinking?

 

[SmokinJoe]

One more option maybe, this one is in 22 cal but if you have a reamer made it is a simple reduction in neck size : I developed my own small capacity varmint cartridge with 223 boltface. Never been particularly happy with the rifles available for small capacity cases (Cooper, Anschutz, CZ, etc) for one reason or another, but have some really nice Dakota Predator/Varminter rifles with the 223 BF so decided to make up a cartridge that would work in them with the performance of the Hornets, Bees, Spitfires. I made the neck long a la 222 so it would be easier to load. Performance came out pretty close to what I wanted with 18 grs of powder pushing a .224 40gr bullet at about 3350fps and good accuracy. Attached are some pics of the forming procecess, comparative cartridges and the reamer print FYI.

 

[20 TAC]

One more option maybe, this one is in 22 cal but if you have a reamer made it is a simple reduction in neck size : I developed my own small capacity varmint cartridge with 223 boltface. Never been particularly happy with the rifles available for small capacity cases (Cooper, Anschutz, CZ, etc) for one reason or another, but have some really nice Dakota Predator/Varminter rifles with the 223 BF so decided to make up a cartridge that would work in them with the performance of the Hornets, Bees, Spitfires. I made the neck long a la 222 so it would be easier to load. Performance came out pretty close to what I wanted with 18 grs of powder pushing a .224 40gr bullet at about 3350fps and good accuracy. Attached are some pics of the forming procecess, comparative cartridges and the reamer print FYI.

Interesting project and love the long neck! That cartridge would be an excellent high volume colony Varmint shooter. Easy on barrels I bet.
I found my project to have little or no practicality but the whole exercise from start to end was a gratifying project. Just started another such project with a friend. Due to a busy child and other interests (fishing), limited shooting for me would suggest that another specialty case is the last thing I need. Gotta love the challenge.

 

[SmokinJoe]

It was a fun learning experience and accomplished my goals, so guess it was worth the effort/expense.