"20 Practical" cartridge?

Just read an article (sorry I can't link to it right now) about a .20 caliber cartridge made by necking .223 brass, intended for AR platforms. All well and good if you like the idea...
Claimed ballistics were 40gr. bullet at 3900+fps. Again, that's fine if it's what you want but some years ago I followed several gunwriters' exploits with small-bore, mach 4 cartridges and it seemed like barrel life wasn't much due to the nature of the fouling under those conditions. Has anyone been able to solve that problem or was it just a matter of using better cleaning products?

If I was going to assemble a sub-caliber AR, it would be the 20 practical. I dont hear of any problems you mentioned regarding the 204 ruger.
So, I cant see where the 20 practical would be an issue. It falls just under the 204 in case capacity and performance.

A good read

http://www.accurateshooter.com/cartr...des/20caliber/

Thanks!

To get 40gr 20 calibers up to 4k your going to need BR capacities. I have two 20 tacticals and a 204 Ruger even with 26" barrels 3750fps is about the top end for 40s.

Quote:

---

Originally Posted by BK7saum

A good read

http://www.accurateshooter.com/cartr...des/20caliber/

---

thats a great one. so is todd kindler's book, the terrific twenties.


i luv the 20 vartarg so much, that i've gotten rid of all varmint rifles. (223 and ai, 22-250 and ai, 17 rem)

dk17hmr, I'm really interested in the 20 Practical. What platform are yours built on?

Bolt action and a 14" contender barrel. They are 20 Tacticals though.

I've been thinking in terms of an AR in 20 Practical, didn't even think of a Contender. How much does the 14" lose?

I have never chronographed the 14" vs the 25" 20 tacticals. I need to do that some day.