Canadian Airgun Forum

Hi everyone,

This is not an official review. I was doing some testing with M11 and found something interesting and wanted to share.

Barrel harmonics are making a big difference in POI and accuracy (somewhat) on this particular gun. I was shooting JSB 15.39 grains domed pellets. Out of every 15-20 shots, one will fly off 1" apart from the rest of the group randomly. Initially I thought it was just me. But then I was able to repeat the cycle a couple of times.

I decided to put a second barrel band on the gun about 5.25" from the front side of the air tube(from gauge). I was surprised by the two immediate effects of this -

1. My groups went 2" above from where they were before putting the barrel band. We are talking about only 20 yards away.

2. Group sizing was pretty much the same(some improvement). However, no more fliers. I shot 50 more pellets down range just to make sure and there were actually no more fliers at all.

This tells you how the barrel harmonics actually impact the accuracy and POI of a particular gun and ammo.

I am inclined to do another round of testing with something like a barrel de-resonator. Will post the results back when I get a hold of one of these things.

Take care.

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Raman V.
CEO
CanadaShootingSupply.ca

What is the barrel diameter on the m11? I have sourced carbon 3k tube that is a perfect slip on fit with cr600w's my end plan I will back to 1 barrel band but only at the end of the co2 tube. (with a custom stock). Should be an interesting experiment.

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I machine, I build , I shoot
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Interesting that's for sure!
The barrel is wider than the CR600W, maybe Raman has the measurements handy, or I can get them tomorrow.
This second barrel band is something worth exploring. The slugs I was shooting, other than the 36.2gr were doing a similar thing..
Glad to hear you got 50 shots with no fliers!

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Website: https://airgunarcheryfun.ca/

Wes Raman; Thanks for the info. I wonder what would happen if you added a second band..especially on the 25 cal brian

I'll test it out as well. Today is a rainy day but hopefully tomorrow morning.
Regards,
Wes

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Website: https://airgunarcheryfun.ca/

I do not have a open 0.25 to test it out. So lets see if Wes can post back his findings.

Will check Barrel O/D shortly.

Interestingly, I came across a YouTube video showing how Stormrider rifle benefited from adding a second barrel band in exactly the same way as I found out on M11. As you know, CR600W, PR900, LR700, Diana Trailscout, Seneca Dragonfly etc are all exactly same design(except for power source) so I expect them to benefit from this configuration in the same way.

https://www.youtube.com/watch?v=NX8pl9iB0iU

I heard that the gentleman who recorded the video, passed away recently. May his soul Rest in Peace.

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Raman V.
CEO
CanadaShootingSupply.ca

A 2nd barrel band was the first mod I did to my cr600w definitely helps poi shifts and scope sighting in as minimizes barrel droop.

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I machine, I build , I shoot
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Walther ;;Where did you get the second barrel band

We have them - http://www.canadashootingsupply.ca/dian ... -band.html

Wes might have a few as well.

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Raman V.
CEO
CanadaShootingSupply.ca

Got it from Wes but Raman has them too. I also make custom bolt handles and muzzle brakes for them:)

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FYI - The M11 Barrel O/D measures around 14.96mm on Digital caliper.

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Raman V.
CEO
CanadaShootingSupply.ca

I found 15 mm ID carbon tube that might fit nicely. .04mm is pretty small. 1.5 thousands of a inch if my math is right.

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Sent via Flux Capacitor uF

There is some interesting information in US patent 5,423,145.
Adding a weight in a specific location will work best for only one bullet (or pallet) size and the same fairing conditions. Switching to other size (and/or to other pressure) can have less pronounced effect, and under certain condition can make things even worse. Stretching the barrel can be more effective, especially with thin barrels, as in airguns. Plain wrapping in carbon fibre tube will not do that, you need to thread the muzzle and put the outer tube under compression by a nut, thus creating tension in the barrel. I did this at one time for a 22LR firearm using a thin wall, close fit steel tube and threading the tip of the barrel to M14x1 (standard muzzle-brake size). In some ways steel can better as it conducts heat better than carbon fibre tube and thin alloy tube is not that heavy. As well it matches the coefficient of thermal expansion of the barrel.

I got bogged down with orders this week (a good thing, not complaining!) but I am very much hoping to get out this weekend and do some testing. I'll try the second barrel band on my 25 cal and will post results.
Thanks,
Wes

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Website: https://airgunarcheryfun.ca/