6.8 western velocity?

[glockky]

I’m looking to pick up a 6.8 western but am torn between the 20” and 24” barrel length.

Does anyone have any velocity data on 6.8 western with 20” barrel?

I tend to find a 24” barrel too long for hunting. I’d much prefer a 22” which browning doesn’t offer in the XBolt speed.

 

[Dr T]

You could always get the 24" and have a competent gunsmith cut it back to 22" and give it a target crown.

 

[glockky]

You could always get the 24" and have a competent gunsmith cut it back to 22" and give it a target crown.

Hate to do that to a new rifle with a bronze cerakote finish

 

[jmr40]

I tend to err on the side of shorter rather than longer. While I have no direct experience with that cartridge, I've found the velocity loss with shorter barrels is usually a lot less than most folks think. Even from the same length barrels 25-50 fps velocity difference is common and over 100 fps isn't unheard of.

It is quite possible that rifle "A" with a 20" barrel will match the velocity from rifle "B" with a 24" barrel. But on the other hand, it is also quite possible that the 24" barrel could be 200 fps faster. The only way to know for sure is to start with a longer barrel, and test to find the velocity. Then measure velocity as it is cut shorter. I've never ran across anyone who lost more than 35 fps when they cut a barrel 1" shorter. Most will vary from 10 fps to 25 fps for every inch the barrel is shortened.

My "guess" is about 100 fps difference at the muzzle. You'd have to be shooting a LOOONG way for that 100 fps to matter. The determining factor for me would be muzzle blast and how the rifle looked and balanced. I'm like you, 22" seems like the ideal compromise. But for the way I use a rifle I'd choose 20" over 24".

 

[JimKirk]

The 6.8 Western is nothing but a "Creedmoor ed" .270 Winchester Short Magnum .... the cartridge is gonna favor a longer barrel ... if you are interested in a shorter barrel rifle stick to the regular .270 cartridge ...

My opinion ... it probably won't match everyone else...

 

[BreechFace]

Like @jmr40 I tend to err on the shorter size these days, as I'm running suppressed 95% of the time and feel the added velocity is not necessary for my needs. But it sure is much nicer to run a suppressed rifle that is 22"-26" long depending on rifle and suppressor.

 

[Chuck R.]

I'd go ahead and "guess-timate" 30FPS for each inch, the subtract the 120FPS as a worse case.

Then enter the guess=estimated MV into a ballistic calculator to get an idea of what the expected effect will be. I'm "guess-timating" you'll lose about 30yds in effectiveness IF you go with something like MPBR or some energy level.

Then, compare that to your average shot distance on game.

Every time I run the above drill I end up rationalizing a shorter tube, so it works for me.

 

[dranrab]

The 6.8 Western is nothing but a "Creedmoor ed" .270 Winchester Short Magnum .... the cartridge is gonna favor a longer barrel ... if you are interested in a shorter barrel rifle stick to the regular .270 cartridge ...

My opinion ... it probably won't match everyone else...

You are right on the money. When you look at load data, all of the suggested powders are slow burning "magnum" powders that will need a longer barrel to get up to speed.

 

[Gtscotty]

I'd go ahead and "guess-timate" 30FPS for each inch, the subtract the 120FPS as a worse case.

Then enter the guess=estimated MV into a ballistic calculator to get an idea of what the expected effect will be. I'm "guess-timating" you'll lose about 30yds in effectiveness IF you go with something like MPBR or some energy level.

Then, compare that to your average shot distance on game.

Every time I run the above drill I end up rationalizing a shorter tube, so it works for me.

This^

Most folks who haven't tried it for themselves overestimate how much velocity a shorter tube loses, and WAY overestimate how much that velocity loss will matter. I'd concur with 120 fps at those lengths, maybe less (velocity loss per inch does tend to increase as you get to shorter barrels). The accounts I've read from folks who have chopped WSMs suggest that they do pretty well compared to standard cartridges in terms of retained velocity, I'd expect the 6.8 to be similar. The blast will likely be noticeably worse if you're not using a can though.

My next purchase is likely to be a 20" 7mm PRC shouldered Tikka prefit barrel and a .300 WSM Tikka donor rifle (which in turn will probably get chopped and threaded to 18") to go with it. If you can't find what you're looking for, something like that could be an option too.

 

[BreechFace]

Velocity loss can be curbed as well if one is a handloader. Much of the factory specs on ammunition is loaded with powder that will take advantage of 24" barrels as that is typically the barrel length chosen for testing. Finding slightly faster burning powders one can mitigate some of the velocity loss from a shorter tube.

 

[Goosey]

I'd go ahead and "guess-timate" 30FPS for each inch, the subtract the 120FPS as a worse case.

Agreed, about 120 fps.

 

[WisBorn]

I see Christensen Arms offer the Mesa FFT in 6.8 western with a 20" barrel.

 

[mshootnit]

edit:
I am interested to hear what bullet weight you are planning to shoot, and if a suppressor is to be used.

 

[Peakbagger46]

Barrel length is a bad thing to be shorting yourself (ha ha) on with a cartridge like that. If you want to go short, I’d personally not do so with a big case using slow burning powder.

On a personal note, I hunt all terrain including oak brush and aspen thickets with a long action 24”. I’ve noticed weight/balance matters a great deal more than length when hoofing it all day.

 

[Slamfire]

The 6.8 Western is nothing but a "Creedmoor ed" .270 Winchester Short Magnum .... the cartridge is gonna favor a longer barrel ... if you are interested in a shorter barrel rifle stick to the regular .270 cartridge ...

My opinion ... it probably won't match everyone else...

I agree. Why go with a short magnum and then cut the barrel down?

A 30 caliber bullet in a 20 inch tube will go faster than a .277".