Shorter barrel for switch barrel rifle

[FamilyMan]

I have a SA Defiance Deviant on order and plan to have my 26" 6.5CM barrel that is currently on 700 fitted to the new deviant. So I've been thinking, since this has an intergal lug I can easily make it a switch barrel rifle since all I would have to do is swap the barrels right? I also have a TBAC30P-1 going thought the system for this rifle and was thinking of getting anther 6.5 barrel cut short like 20" to run the suppressor on. So I guess my question is am I going to lose a lot by cutting it down to 20"? I will be using this out to 1000 since the range I frequently use has 1000 yard set up but most of the time it will 300-600. I know I will lose some velocity but I can always run my 26" if I need to get more and this way I don't have to have a huge 35" barrel when I run the TBAC. I had planned on sticking with the Creedmoor since I already have all the dies and brass and components. Unless you guys think there is another similar caliber in BC,velocity,recoil that would run better out of the 20" barrel. I am just looking for some ideas since I don't want to drop $700 on a barrel and have the same thing with significantly less performance. A side note is I've always wanted a 7mm-08 but I always find something else to go with.

One last question, if running a shorter barrel does having a faster twist doing anything to help/hurt it or is it totally in related?

Thanks,
Brett

 

[JB02]

Brett, I doubt that the short barrel with faster twist will matter that much. I've read an article of a guy testing out a Surgeon Rifles built 300 NM with a 20" 1/8 twist. You'll sacrifice some velocity, but that may be needed if the suppressor means your barrel will be 35". That long of a barrel wouldn't bother me though.

https://www.accuracy1stdg.com/content/docs/Binder7.pdf

 

[ZLBubba]

On my switchbarrel rig (Gradous built gun with a Surgeon 591 repeater), I run a 22" barrel on my 260REM and a 16.5" barrel for my 308. Best of both worlds if you ask me. I usually leave my 308 barrel on since I shoot the suppressed 308 more often than I shoot the 260.

 

[FamilyMan]

Thanks for the input. would the velocity loss be significant enough to keep it from be accurate consistently out to 1000? Or would just need to dial a little more elevation?

 

[ZLBubba]

I use the two different barrels for starkly different purposes. My 16.5" 308 barrel is my woods gun/truck gun sub-800 yard rig. It's fun as hell and handy to boot at 8.5lbs. My 22" 260 barrel is for hunting when I'm looking at a bit longer ranges and when I want to stretch the gun out to 1k and beyond. My 260 is still making hits at 1200 so I why would I have my 308 serve a similar role? For me, it's like having two different guns completely, and I couldn't be happier about the array of options I have with the rig. I tend to think you get more bang for your buck when a switchbarrel serves a variety of purposes instead of variations on the same role. But hey, to each his own.

 

[LongArm]

ZLBubba, what kindo of speed are you getting out of your 22" barreled 260?

 

[Bo Ployhar]

I cut my last 6.5x47 down from 24 to 20 and lost 80 to 100 fps. lost another 100 going to 16, that was using varget. It worked really good at 20, 16 didn't seem a predicable, not getting enough powder burn possibly.

 

[LongArm]

Not a 6.5X47 but for ref only,

I have a Obermeyer tight bore 260. At 25" it was running 2880 with 44.1gr of h4350. I cut it down to 22" (from the bolt face) and it has ran from 2830 with 43.5gr to 2861 with 44.3gr. The best was 44.1gr. I am also going to try 43.2gr to see if it will group and still be over 2800fps.

This was with remington brass,federal primers and 139 lapua scenars and H4350 powder.