20 Vartarg Barrel Length

[Shimmer]

I was thinking about getting or building a 20 Vartarg and was wondering what the optimal barrel length is for this cartridge. I was thinking around 22". Will there be much of an increase in velocity to go up to 26" and what about going shorter, will there be a drop in velocity?

 

[brfun]

This probably isnt the answer you are looking for. All I can tell you is mine at 24 inches the 32grain class of bullets shoot best at about 3650fps and the 40grain class around 3500fps. It will shoot a little faster but not accurately.
This was disused in a tread a while back if you do a search you might find it. I am just going off memory but I think it was a guy Kevin I think that has some good input having shot a number of 20s.
Brian

 

[rider_hunter]

I have heard from two people that tested there velocity with the barrels long and started cutting them down an inch at a time till they lost velocity one said it was at 20" that he started to loose it the other said 21"

 

[flatlander]

I don't have a problem believing the 20"-21" bbl length results of such an experiment. Using a case with such small capacity and using fast burning powders, it's only logical to expect very little gain in velocity by going past 22" bbl length. That's the length I'm probably going to use if & when I build myself another 20VT - I left a Bartlein 5R blank at 26" on the first one I built, and always felt it was ridiculous to have a bbl that long for such a small case.

 

[varmintshooter]

I have 3 20 vt, 2 are 24" and 1 is a 20" all are 12 twist and will shoot 32, 39 and 40 gr bullets. I shoot the 20" the most with a suppressor and did lose a little velocity but not much. IIRC 39's are just shy of 3500 and 32"s are 3700 or so. I have killed pdogs and ghogs at over 500 yds with the 20" barreled gun. BTW I use H4198 with all bullets.

 

[Ledd Slinger]

22 inches. It's not meant to be a really fast 20 cal so I would build the rifle to be more compact and easier to weild. Can go shorter, but if you're gonna shoot it a lot, it's nice to have a little extra length to set the chamber back later on and still maintain good velocities.

 

[steve123]

In an improved version, with 32 vmax, 17.7 grains of H4198, gave 3740 fps in a 25" 12 twist and 3675 fps in the 21" 11 twist. Those are light loads in my chambering.

 

[Rallyant]

In an improved version, with 32 vmax, 17.7 grains of H4198, gave 3740 fps in a 25" 12 twist and 3675 fps in the 21" 11 twist. Those are light loads in my chambering.

any noticeable volume difference between the 21" and 25"?

 

[dedogs]

any noticeable volume difference between the 21" and 25"?

11 year old thread. dedogs