Barrel length recommendations for .20 Practical

[5spd]

I built my 20p ar15 with a 22" heavy bbl, not varmint weight since I carried it field to field.
I am suppressed also, so didn't want a mile long barrel overall.
If you are just going to be off a bench or so and not walking with it a 24" will be a tad better.

 

[Fast14riot]

My 20P AR is built around a 24" BHW in spr profile, .750 gas block. Good medium weight without all the extra mass like my 24" heavy bull match barrel on my prone upper. Doesn't string like a real light profile does when hot either.

The top one is my .20P, I'm pushing 32vmax just at or over 4k with IMR4198.

 

[Hohn]

mac86951 - My .22-250 is an AR10, I put that gas port 17" down the barrel, that's rifle length +5" and am quite happy with it. +4" probably would have been enough but this is very easy on brass. I know Gene designed the system to work with a port pressure of 19,000 psi and that as bore gets smaller relative to case volume that point moves further down the barrel. Quickload would help here but I don't have it.

jepp2 - My AR10 with the 27 and Nightforce scope weighs around 13# and it's a bit heavy for a walk around varminter. My son's 16" AR15 is what inspired me to build the .20 Practical, it's so light and handy and is death on Prairie dogs out to 300. So probably want to keep the barrel lighter on the Practical. My .22-250 barrel is kind of a medium palma taper to the gas block, then goes to .730 to the muzzle. Probably do something lighter for the Practical.

Mark

You sure about that? Port pressure on a 20” rifle is closer to 9000 psi.

 

[Cemetery21]

My 20P AR is a 24" bull barrel BHW polygonal rifled tube. No problem freefloating it. I built a 27" Lilja on a XR-100 at the same time. The AR is about 75 fps slower with the same load so I load them both to shoot 3950 with 32 gr Hornadys. No load workups - everything shot better than 3/4 MOA, so I just loaded for a speed that would be easy on the barrels.

Edit - standard rifle length gas works fine. I always run adjustable gas blocks so I can tune them to just lock back on empty with my load.

 

[redrockranger]

I'm building a .20 Practical on the AR platform. Will use a Schneider P5 rifled barrel as I have one on my .22-250 and love it. Looking for recommendations on length. This rifle will see a lot of Prairie dog use. Finished my .22-250 at 27", that might be a tad long for a .20. Also, if anybody has experience on this cartridge in an AR, would you move the gas port down the barrel any?

Mark

24" length and @ least 11 tw.

 

[searcher]

Go with a 26" heavy barrel with a standard rifle-length gas system and a Wolff light recoil spring. This seems to be the optimum in practical use if you are not carrying it around. If carrying, I'd go with a 24" standard-weight barrel. The longer barrels are nice to keep muzzle rise and flash down, though these Practicals excel with fast burning powder - so the extra length argument for extra velocity is muted.

 

[Mark M.]

Bullberry barrel works in Utah conducted a test optimizing barrel length for the 204 Ruger, I believe they started with a 28" barrel and test firing for velocity, cutting an inch off the length each time, they found that 22" was optimal, anything shorter would result in a loss in velocity, anything longer did not gain velocity, the case capacity of the practical is slightly less but couldn't image the results being any different

 

[MBuechle]

So, it seems an update is in order. Went with a Lilja as Schnieder doesn't make .204 barrels. It's an 11 twist 3 groove, finished at 26". It's 1" to the gas block, .936 benieth and then 7/8 to the muzzle. If I want to lighten it I can always flute it. Cambered with a 4D rental reamer, I think I remember it being PTG but not sure. This is the tightest grouping rifle I have ever owned or shot! It's a little heavier than I had planned at 12# but will definitely allow full view of Prairie dog explosions. I can't wait.


Seat depth sweep, the bottom holes. 32 Vmax over 8208XBR. Easiest load work up I've ever done. The lands are at 1.820 COL, so as you can see, it likes .003 & .017 off. If this is the way all Liljas shoot, I see more in my future.