Silencer front protrusion attenuation ability and recoil reduction in regards to barrel length

[WildBoarHunter]

Hi,

I have two barrels for my Blaser R8, 308 win 52 cm length and 6,5×55 58 cm length. I am intrigued as to which combination would be quieter and more manageable from the two:

1.) 52 cm barrel (rifle overall lenght 97 cm) and silencer with 14 cm protrusion (overall length of the rifle with silencer 111 cm)
2.) 58 cm barrel (rifle overall lenght 103 cm) with silencer with 11 cm protrusion (overall length of the rifle with silencer 114 cm)

The reason I am asking is that I indend to buy another barrel and am not sure whether to buy the short one or the standard in regards to attenuation, recoil reduction and silencer length.

Thanks for your replys. They are appreciated.

 

[TringSaint]

Not sure if I can be of any help as I have 3 rifles with 3 barrel profiles and lengths ranging from 16” to 22” and each with a different mod attached.

Of the 3, the Steyr in 6.5se with 20” barrel and ASE utra jet z mod is the quietest wrt report, then the 243 with 22” barrel and ASE SL5 mod, and finally the rem 700 in 308 with 16” barrel and dpt mod.

All mods are end of barrel, two are steel and one is aluminium.

But, none stop the crack and depending on where I am shooting has a huge impact of noise attenuation - open field with the rem is quieter than in a wood with the Steyr and so on.

 

[Edinburgh Rifles]

Reviews and Tests – Edinburgh Rifles

Forward protrusion is packaging criteria and has little to do with performance and specifically sound attenuation
little out of date now but the test above is one of the very few independent tests of moderators covering all specifications as well as recoil and sound attenuation

 

[Oldstalker]

In general terms........ The longer the barrel the more powder will burn behind the bullet before it exits the barrel. This leads to higher velocities - usually around 50 fps per 2 inches of barrel length in medium calibres. There should be less muzzle blast also from a longer barrel for a given load.
For a given barrel profile the longer the barrel the heavier and therefore more inertia when it comes to recoil.
Noise reduction is a very complicated equation/calculation; it has much to do with containment of the barrel blast, so the bigger the moderator diameter (size of the cylinder) the greater the noise reduction but complicated by numbers of baffles and how much gas escapes the moderator how quickly.
Remember that there is a cone of noise usually about 15 degrees around the line of exit where there is additional noise compared with a reading taken (at a similar distance) beside the firer. This cone of noise is often audible to the deer especially if there is no wind. AND finally, if you are in a tunnel there is no apparent noise reduction - your ears get the full echo!
I hope that is helpful in general terms, but see @Edinburgh Rifles comment above #3

 

[muddy42]

I'd go for the shorter barrel, always. Stalking with a long barrel is no fun - the rifle slips off your shoulder, which is a distraction and can bang on the car boot or branches with extra noise and resultant fear of loss of accuracy. A shorter barrel coupled with a heavier solid moderator restores the balance, heavier mods are generally more robust and effective at sound reduction. I'm afraid I have little time for the argument about the extra fps per inch of barrel length, which is meaningless in the overall scheme of things.

 

[WildBoarHunter]

I'd go for the shorter barrel, always. Stalking with a long barrel is no fun - the rifle slips off your shoulder, which is a distraction and can bang on the car boot or branches with extra noise and resultant fear of loss of accuracy. A shorter barrel coupled with a heavier solid moderator restores the balance, heavier mods are generally more robust and effective at sound reduction. I'm afraid I have little time for the argument about the extra fps per inch of barrel length, which is meaningless in the overall scheme of things.

In regards to your comments, I was using 30-06 and 308 win calibers for a decade and then went for 6,5×55 as I was looking for something with a little bit less recoil due to health issues but with still enough punch to be able to hunt wild boar and red deer. For years I was pleased by the 6,5 mm, its accuracy - which is by the way better than 308 win at least in my experience, and also its somewhat lower recoil while still giving enough punch you dispatch even large game cleanly.
But comparing 308 and 6,5×55 side by side, I must make a few remarks.
First, the 6,5 mm likes somewhat longer barrels to get the most out of it. But as stated, longer barrel in combination with a silencer does shift the balance of the rifle too much forwards.
Second, The bore diameter is obviously smaller with 6,5 mm caliber so this makes a blaser standard contour 6,5 mm barrel considerably heavier than standard contour 7,62 mm barrel.
Third - so I noticed when using short 308 win barrel that the rifle is lighter, shorter and also the overall balance of the rifle with the silencer on is a lot better and there is almost no noticeable forward weight.

So while both calibers are really excellent and some of the best I ever used I would still say the 308 win is the overall winner and more universal of the two. It tolerates shorter barrels well, punches harder, the bullet is larger diameter which is important especially on driven hunts, and also the rifle is lighter, shorter, handier...

 

[muddy42]

In regards to your comments, I was using 30-06 and 308 win calibers for a decade and then went for 6,5×55 as I was looking for something with a little bit less recoil due to health issues but with still enough punch to be able to hunt wild boar and red deer. For years I was pleased by the 6,5 mm, its accuracy - which is by the way better than 308 win at least in my experience, and also its somewhat lower recoil while still giving enough punch you dispatch even large game cleanly.
But comparing 308 and 6,5×55 side by side, I must make a few remarks.
First, the 6,5 mm likes somewhat longer barrels to get the most out of it. But as stated, longer barrel in combination with a silencer does shift the balance of the rifle too much forwards.
Second, The bore diameter is obviously smaller with 6,5 mm caliber so this makes a blaser standard contour 6,5 mm barrel considerably heavier than standard contour 7,62 mm barrel.
Third - so I noticed when using short 308 win barrel that the rifle is lighter, shorter and also the overall balance of the rifle with the silencer on is a lot better and there is almost no noticeable forward weight.

So while both calibers are really excellent and some of the best I ever used I would still say the 308 win is the overall winner and more universal of the two. It tolerates shorter barrels well, punches harder, the bullet is larger diameter which is important especially on driven hunts, and also the rifle is lighter, shorter, handier...

Interesting analysis. I also liked the 6.5x55 I used for a while. Everything is a compromise of factors and subjective preference. Personally I just don't think its worth having >20 inch barrels in any calibre. The extra velocity is meaningless for normal UK stalking, but if you feel that is important just buy a larger calibre. Reloading opens up so many more dimensions - I download my 308 to reduce recoil. Ive never done this specifically, but I understand you can reload with faster powders to get the best out of a shorter barrel, mitigating the speed loss.

P.S. A few years ago, you could buy reduced recoil ammo for a 308, but maybe covid stopped this.