Barrel Length VS Twist

[Butch Syme]

I will be building a new bench rifle in the near future but I keep hitting a snag at barrel length. I have preformed searches and but I cant seem to find the answer I am looking for.
I have noticed the ppc guys tend to use a shorter barrel (21" to 24") compared to the br guys who are straching their barrels to 30" or longer. I understand the desire for velocity leading to the extended barrel length.
I want to chamber the 6BR but I would prefer a 22" tube. Do any of you guys forsee any issues other than the loss of velocity at extended distances?

 

[Yellow11]

Look at the maths, by typing a few specifications into Quickload, and then base you choice on the information available!

 

[SS427]

I believe the PPC guys go short in order to make weight and they don't need the extra velocity at 100 and 200 yards.

If you plan to shoot 600-1000 yards then the extra velocity could be very important to you. If you plan to shoot 300 or less, I don't think you give up anything with the shorter barrel other than a little velocity. Short fat barrels in theory are more accurate than long fat barrels, and much more so than long skinny barrels. In theory at least.

 

[golfer2b2000]

I have a 6 Dasher that I purposly had shortened down to 20" from 26". It has a 1-8 twist. I figured this way. It seems like most people are "velosity hungary"...I bought mine basically for varmint hunting. It has done very well at 200 yards, and as soon as the weather starts getting better I plan to go out to 300 yards. I cant see how velosity will have much of an effect lets say out to 400 yards. If you know your bullet drop. I may be wrong, and will check more on this. But I bet my dasher with the shorter barrel will shoot the same wether it be 26" long, or 20" long. Around here the longest range I have is 400 yards. I am anxious to see what it will do there

 

[Butch Syme]

I would be very interested to see your results. I know the velocity increases at longer ranges is beneficial for cheating wind and staying super sonic but I dont need any of that up to 400 yards shooting at varmits and still have mobility while in the field. Plus have a very accurate and good looking rig sitting on the bench.
I built a 6mmAI with a 30 inch tube for shooting 1000 yards but it was a pain swinging it around in the PD towns.

 

[golfer2b2000]

That is basically why I did it.That is for mobility. In my section of Pennsylvania we usually dont get any shots over 600 yards, and 1000 is basically unheard of. So why should I lug around a rifle capable of shooting 1000 yards. I had a 6mmBR I just sold that I had the barrel cut down to 20", but it was also a 1-14 twist. I took many chucks at the 300 yard range without a problem. It was a lot easier to carry, and was a lot less muzzle-heavy. I will be getting a 6mmBR back from Manners stock next week. It has a Lawton action on it and the barrel length is 26". I was thinking about also cutting it down but have decided to leave it alone, and buy a new lightweight barrel and have it cut with the same reamer that the other barrel is. I will make it also 20", and probably a 1-14 twist. I am hoping to keep the weight down around 7 pounds. Then if I want to shoot informal benchrest, all i have to do is switch the barrels. If anything, it will be fun tinkering with it...

 

[25AI260]

golfer"""""
i just pic-up a used 6mbr 14twx20" on rem.action a couple months ago... haven't much testing time, weather hasn't been nice to me...
wondering what bullet weight an powder you'all are using in 14tw 20"
i have shot it to 300 an looks promising an will have a chance [ i hope] to shoot some paper out to 500... waiting for at least 60* weather

 

[Steve Blair]

Shortening a Dasher barrel from 26" to 20" should only reduce velocity by <200 fps. The only thing I do in short barrels, like my 22" .223 40XBR, is use slightly faster powders to reduce muzzle blast. If two barrels are the same profile and one is 20", the other 26", the shorter is likely more accurate. There are obviously many factors present but the shorter barrel has a lower inertial mass and should produce a smaller dispersion. When shooting at long range (600+) velocity variation and environmental factors become more significant than simple dispersion.

 

[golfer2b2000]

I just sold the rifle to a gentleman out in Arkansas. Basically because I have 4 varmint rigs. I was using 34 grains of varget, and a 65 grain vmax bullet. This was getting to be a pretty hot load. But it shot really well. I was able to use up to and including 70 grain bullets. I was shooting an old Barnes bullet called a VLC. This little blue colored bullet was devastating on woodchucks. It was a 58 grain bullet. I made several kills with it that never exited the critter. I mean it looked like I never hit it. But a quick opening of the chest cavity proved that the bullet turned the inside to jello. I was a bit reluctant to cut the barrel down for ease of carrying, but never did I ever regret it...

 

[RJinTexas]

Say Gene, I believe those 22" to 20" 14tw barrels are just about the right length for a building a good long range XP100 pistol. I'll stick with my way too heavy long 26" to 30" barrels on my rifles. But then again I don't have to tote them around. Anyway that's why they make 360 degree rotating top portable shooting benches for. "LOL"

Buy the way if happen to come across any more of those heavily weighted McM MBR stocks now ya know where you can sell them.

Regards
RJ

 

[25AI260]

Thanks Golf"""""". i'e actually tried varget...

RJ""""" i mite actually get out this week .... hope'n !
if its nice enough i may set the chrony up too..

 

[AckleymanII]

Another consideration is that when you go with at least a Max Heavy Varmint contour, then you have 6" of straight shank on the back end, so that you could get more than one chamber on that barrel.