Optimum barrel length for 6.5CM w/can?

jb1023

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Is there an optimum barrel length for a 6.5 CM when running with a can? I have the rifle but I want to get a can for it and am thinking I would like to shorten the barrel some as it is currently 25" w/medium palma contour with another 2.5" for the break. I'm thinking a 31-32" barrel (with can mounted) might be a bit unwieldy. I understand I will be giving up some velocity but I've read were some cartridges have a "preferred or optimum" length. Or should I just leave it alone and deal with the extra length and weight?

If it matters, I load Hornady 147 ELD-M's in front of RS Hunter and RE26.
 

Mark @ Exo

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I've been debating that for the past couple of months. Doing all of the research, reading all of the articles, etc. I mainly debated 18-20" and I settled on 20", which is being built at Mesa Precision right now. My can is a Thunderbeast Ultra 7. My goal for this build was deer-sized game out to 500-600 yard max.

I plan on running 120-130 class bullets for hunting, mostly the 124 Hammers. I will for sure be playing with a bunch of other bullets and weights for ringing steel, and just to satisfy my own curiosity.
 

KurtB

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I've got a medium palma in 6.5x47. I have mine at 22" with a UL7 on it. Feels good to me in a McMillan A5 fiberglass stock. You'll love that Creedmoor suppressed.
 

jb1023

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I've got a medium palma in 6.5x47. I have mine at 22" with a UL7 on it. Feels good to me in a McMillan A5 fiberglass stock. You'll love that Creedmoor suppressed.
I placed an order for a Deadair Sandman-S. I'll update this thread in about 12 mos 🙄 and let you know if I decided to cut down my barrel or leave it at 25"
 

AKironhead

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If you plan on sticking with the 147s I would learn to live with the length. Those will be moving pretty slow from a 20" barrel. I run a 24" with an Ultra 7 and opted to reduce the overall length on the stock end by going with a folding manners.
 

TBuckus

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18 or 20 would be good, but you’ll probably want to go with a lighter bullet than a 147.
i have a 7wsm that would shoot 162’s at 2800due to the short barrel.
switched to 155gr Hammers and got it back up to just under 3k.

my next build for a can will be a 20” 6.5CM
 

Buck Fever

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The bad bush
I can't get a can around here but I have read that they can add some velocity because the gasses kind of have to stay behind the bullet instead of disperse almost as soon as the bullet leaves the muzzle.

I don't think I would hesitate to use 147 grain bullets in a 22" barrel, adding a can might make the velocity comparable to a 24" with a plain muzzle.

I have an Aero M5E1 with a 22" fluted barrel in 6.5 Creedmoor from Wilson Combat. I don't know if I would want to add a 7" suppressor on top of that due to length and balance because I want to be able to shoot it unsupported. If the balance was different or I knew I would always have something to shoot off of, it would probably be the length i would choose.
 

cohunt

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I can't get a can around here but I have read that they can add some velocity because the gasses kind of have to stay behind the bullet instead of disperse almost as soon as the bullet leaves the muzzle.

I don't think I would hesitate to use 147 grain bullets in a 22" barrel, adding a can might make the velocity comparable to a 24" with a plain muzzle.

I have an Aero M5E1 with a 22" fluted barrel in 6.5 Creedmoor from Wilson Combat. I don't know if I would want to add a 7" suppressor on top of that due to length and balance because I want to be able to shoot it unsupported. If the balance was different or I knew I would always have something to shoot off of, it would probably be the length i would choose.
You might gain a bit with a can but its insignificant--- most I've seen with mine in any cartridge is 18fps, some guys say they loose just a bit-- but then you also need to remember the sd/es of your original load and if temp will change your load--- in the end I wouldn't rely on any increase with a can.
 

lancetkenyon

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20" 6.5SS w. TBAC Ultra 9, 156 Berger Elite @ 2976fps (back)
22" 6.5SLR w. TBAC Ultra 7, 130 Berger Hyb @ 2925fps (front)

20200327_200149.jpg

If I had a 6.5CM, I wouldn't go any shorter than 20".
The old barrel on the 6.5SLR was a 28" Bartlein. When I rebuilt it, I went 22" Proof to shed 3#. Also went from a 140 HVLD @ 2920 to a 130 Hyb @ 2925, and could not be happier with the way it drops game. My daughter had killed some great animals with it.
 

jb1023

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20" 6.5SS w. TBAC Ultra 9, 156 Berger Elite @ 2976fps (back)
22" 6.5SLR w. TBAC Ultra 7, 130 Berger Hyb @ 2925fps (front)

View attachment 204130
If I had a 6.5CM, I wouldn't go any shorter than 20".
The old barrel on the 6.5SLR was a 28" Bartlein. When I rebuilt it, I went 22" Proof to shed 3#. Also went from a 140 HVLD @ 2920 to a 130 Hyb @ 2925, and could not be happier with the way it drops game. My daughter had killed some great animals with it.
Lance, you are getting 2976 from a 6.5SS w/20" barrel? Wow. I have a 6.5SS w/24" and get about 3150 but with the 147-M so 4" longer on the barrel and 9gr less on the projectile.

I don't plan on touching the length on the SS when I get the cans, just the CM. The CM is essentially my practice rifle so I don't care as much about velocity. As long as I can get to 7-800yds, without lobbing rainbows, I'm happy. That being my criteria, I think I can probably loose a few inches off the barrel just to make it more manageable. But I will not do anything till the cans are out of jail and I can play with them a bit.
 
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lancetkenyon

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Jun 3, 2013
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Arizona
26" 25SST w. TBAC Ultra 9 on left, 131 Blackjack @ 3233fps
26" 6.5SS (no can attached) 2nd from left, 150 SMK @ 3047fps
20" 6.5SS W. TBAC Ultra 7 middle, 156 Elite @ 2976fps

Makes a big difference in OAL of rifle. For western hunting, not sure how big of a deal the added length is 95% of the time.
20200705_082742.jpg
 
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