.20 Practical project back on

[nmkid]

Well, my grandson has decided that he doesn't want the .223 REM 700 I bought him. He says he thinks he would have more fun with the 10-22 as he only likes to shoot at tin cans and such. Tomorrow I get the factory barrel taken off the .223 and then it's off to the gunsmith. I have many questions on the .20 Practical, (but I'm reading). I'm set on shooting the 40 gr bullets with it. What barrel length should I consider to wring the most velocity out of the gun? I plan on carrying this gun from the house, to my truck and then to my portable shooting bench for PD's. So weight will not be of any consideration. Also, what twist.

 

[SheepDog]

I would want a 24 inch heavy/cylinder barrel. I think that will get close to the maximum velocity and still be rigid enough to quench barrel harmonic effects. The more I read about this cartridge the more I want one but I already have two calibers and three guns that use the 223 cartridge. Two in 223/556 and a 7mm TCU. I don't want another cartridge to keep separate.

 

[LitLBoy]

28" Heavy taper or straight 1.250" 10 or 11T
LitLBoy Oh and try 8208 powder!

 

[JLT]

If weight isn't a consideration, I'd go with a straight 1.25 as LitLBoy mentions, although I don't think 28" gets you much v. a 26". Doesn't take long to burn 28 gr. (or less) of relatively fast burning powder. If you're going to be shooting the 40 gr. VMax, don't get anything slower than an 11 twist. 1:10 wouldn't hurt.

I also give a +1 to 8208 XBR for the 39/40 gr. bullets. If you decide to give the 32s a whirl, grab a pound of H4198 - I've had excellent results with this combination.

Your going to like the .20 P. Lots of fun watching the show in the scope.

 

[ab_bentley]

I'd usually tout 8208, but Benchmark kicked 8208s butt in the last barrel I had. In accuracy and velocity. 40s were leaving the barrel at 3875fps without a hitch. A few groundhogs over 700yds died with that combo.

 

[Phil]

I may have to produce an AR version in the future...............

 

[5spd]

Ive built 4 20P rigs for p-dogs/coyote.
I used BHW bbls, 22-24" heavy sporter bbls, 1/11" twist, (I carry mine walking pdog town to town on ranches)
The 1st was on a heavy varmint bbl which I felt was not needed for what I used it for, thus the rest were all HS weights.
Since I usually have a barrel wrap on and keep it wet I felt I didn't need to have a varmint profile.
The best powders in my Savage & Ar15 builds are 10x, h4198, BM, blc2.
I only run hornady or nosler 32g bullets.
If I was to build just a bench 20P Id go with 26" heavy varmint bbl.
IMO I don't feel longer will produce anything better in terms of velocity or accuracy.

 

[sundance]

I use a 12 twist 24 inch Shilen on my 204 and it liked IMR 4895 with the 40 grain Vmax.Doesn't go through my Harrels measure worth a hoot . I tried a few other powders but not a lot. I wound up with the 32 gr Vmax with 8208 powder at 4200 fps .Faster and flatter than the 40 gr and the prairie dogs really fly apart . I just ordered a Krieger 1 in 12 twist 26 inch to build a Tac 20 and shoot 32 gr vmax and 35 gr Bergers. They recommended 1 in 11 twist if I was going with the 40 grainers.

 

[BforByron]

Ive built 4 20P rigs for p-dogs/coyote.
I used BHW bbls, 22-24" heavy sporter bbls, 1/11" twist, (I carry mine walking pdog town to town on ranches)
The 1st was on a heavy varmint bbl which I felt was not needed for what I used it for, thus the rest were all HS weights.
Since I usually have a barrel wrap on and keep it wet I felt I didn't need to have a varmint profile.
The best powders in my Savage & Ar15 builds are 10x, h4198, BM, blc2.
I only run hornady or nosler 32g bullets.
If I was to build just a bench 20P Id go with 26" heavy varmint bbl.
IMO I don't feel longer will produce anything better in terms of velocity or accuracy.

What was the weight of the AR's in the longer barrels? What would you recommend for a walking coyote AR?

 

[5spd]

What was the weight of the AR's in the longer barrels? What would you recommend for a walking coyote AR?

I went with the 22" bbl on the AR15 build with the standard profile barrel, rifle length gas.
Total with suppressor, scope, bipod, sling, 10 round mag was about 11lbs, but carried nicely.
I ended up selling the 24" bbls and went to 22" on the 20P bolt gun builds for walking rigs, still fast and very accurate.
If I was going to build another AR15 in 20P I would do it with a lightweight barrel at 22" to drop it another pound & as just a coyote rig it would not need to be a heavy barrel. I would also put on a simple collapsing stock for more weight savings instead of the A2 stock.
I don't use AR15s for p-dogs.

 

[hogpatrol]

I have a 26" heavy varmint in 11 twist and it shoots the 32s at 3950 with VV 133. Also an 24" AR with a 10 twist. I would NOT go with anything slower than an 11. Make sure you go with minimum freebore. Mine (a PT&G) has zero freebore and the bearing surface of the 32s and 40s from the end of the neck to the ogive in a loaded round is less than .060.

 

[Fast14riot]

I have a 24" 10 twist AR and it handle 39/40 just fine. I load BL-C(2).

 

[Fast14riot]

One thing with the 40's and in regards to your thread in the reloading section about using mixed headstamp brass, many of the chambers are a zero freebore, if you're running hotter loads in mixed brass in or near the lands, you may see bigger pressure differences than running magazine length in an AR. Just test and watch for pressure.

I run a middle of the road charge in mine, pushing 39's around 3600 and have the same zero at 100 and 200 meters. Less than an inch high at 150.

 

[pacificman]

Well, my grandson has decided that he doesn't want the .223 REM 700 I bought him. He says he thinks he would have more fun with the 10-22 as he only likes to shoot at tin cans and such. Tomorrow I get the factory barrel taken off the .223 and then it's off to the gunsmith. I have many questions on the .20 Practical, (but I'm reading). I'm set on shooting the 40 gr bullets with it. What barrel length should I consider to wring the most velocity out of the gun? I plan on carrying this gun from the house, to my truck and then to my portable shooting bench for PD's. So weight will not be of any consideration. Also, what twist.

I have a 28 inch heavy pac-nor barrel with 1/11 twist that is producing 3855 fps. with 40 grain v-max.
My 20 practical with criterion barrel is 26 inch 1/11 twist producing 3650 fps. They are both very accurate.
I'm using the same powder but the pac-nor was able to handle more powder without pressure signs.
I would go with at least 26 inch barrel. The extra 2 inches on any barrel would probably only get you 100fps more (maybe).
My pac-nor is a three groove while the criterion is 6 groove ....I don't know if that gives one more speed or not....every barrel
will be different. You will love the 20 practical.