Efficiency of a .30 cal moderator in a 270 Win

[Border]

Barrel length is also a factor. A longer vs a shorter barrel will "silence" better with the same moderator assuming same cartridge/load.

 

[Edinburgh Rifles]

Unfortunately the range of bores are .22, 6.5, .30 cal and the .270 falls between them
However the 6.5mm rated mod has a bore in excess of 7.5mm which is more than enough for a .270 with a decent thread on the muzzle and does transform the sound attenuation

It’s the same with many makes
Those with oversized bore and much larger chambers will get away with it a little more

 

[Mike_E]

Unfortunately the range of bores are .22, 6.5, .30 cal and the .270 falls between them
However the 6.5mm rated mod has a bore in excess of 7.5mm which is more than enough for a .270 with a decent thread on the muzzle and does transform the sound attenuation

It’s the same with many makes
Those with oversized bore and much larger chambers will get away with it a little more

I guess buying the 6.5mm mod and putting an 8mm drill through the last few baffles would not be too hard either? Odd that F&D do not do a "7mm" mod as its reasonably popular.

by "decent thread" would you think all factory threads would be good enough?

Cheers
Mike

 

[Sonicdmb73]

I guess buying the 6.5mm mod and putting an 8mm drill through the last few baffles would not be too hard either? Odd that F&D do not do a "7mm" mod as its reasonably popular.

by "decent thread" would you think all factory threads would be good enough?

Cheers
Mike

Are “Factory” threads actually Factory done?
I believe more than one Gunsmith has had to put right muzzle threads. The other thing is what tolerance they are cut to. There’s more than one standard that might have been used.

 

[Namman]

Are “Factory” threads actually Factory done?
I believe more than one Gunsmith has had to put right muzzle threads. The other thing is what tolerance they are cut to. There’s more than one standard that might have been used.

Barrel length is also a factor. A longer vs a shorter barrel will "silence" better with the same moderator assuming same cartridge/load.

How is everyone measuring the sound reduction between calibre specific and generic mods? There are so many variables at play here including barrel length, bore volume and case capacity, type of load/powder, that this is a purely subjective discussion.
I have only ever used .30 cal mods on all my rifles up to .30 cal with no detectable differences between mine and my friends' rifles with calibre specific mods.

 

[Sonicdmb73]

How is everyone measuring the sound reduction between calibre specific and generic mods? There are so many variables at play here including barrel length, bore volume and case capacity, type of load/powder, that this is a purely subjective discussion.
I have only ever used .30 cal mods on all my rifles up to .30 cal with no detectable differences between mine and my friends' rifles with calibre specific mods.

In my case it was the MK1 ear as my dB meter doesn’t have any facility to record peak on such a short duration.
That aside both my friend and I noted a distinct difference in volume between the two.
The ground between my target and firing point is relatively flat it then slopes up behind for some distance. Reflected sound will be from the old pit.
If you want to read more about the theories of sound reduction in moderators. Silencertalk.com has some quite in depth information.
I used it in designing my moderator.

With regard to the point of how true are muzzle threads. I used a taper reamer to form a cone shape to the holes through so they got incrementally largely the further away from the muzzle. A slight potential increase in noise over a definite increase in safety.

 

[Namman]

In my case it was the MK1 ear as my dB meter doesn’t have any facility to record peak on such a short duration.
That aside both my friend and I noted a distinct difference in volume between the two.
The ground between my target and firing point is relatively flat it then slopes up behind for some distance. Reflected sound will be from the old pit.
If you want to read more about the theories of sound reduction in moderators. Silencertalk.com has some quite in depth information.
I used it in designing my moderator.

With regard to the point of how true are muzzle threads. I used a taper reamer to form a cone shape to the holes through so they got incrementally largely the further away from the muzzle. A slight potential increase in noise over a definite increase in safety.

I'm afraid my Mk 1 ear has been damaged by more than 40 years of shooting, mostly without these hideous mods!!

 

[Sonicdmb73]

I'm afraid my Mk 1 ear has been damaged by more than 40 years of shooting, mostly without these hideous mods!!

Eh can you speak up a bit.
But seriously I wish I had listened when I was a teenager with a shotgun and later with rifles.
Mind you years of DJing and construction work hasn’t helped.
I will take the moderator hideous or not, to save what hearing I have left

 

[Farmer_J]

Using our .243’s My Atec hertz 119 rated 6.5mm is definitely quieter than my brothers Stalon. I believe the Stalon is rated in two separate groups .204-.243 & .243-30/06. Quite a difference in bore sizes.

 

[Edinburgh Rifles]

I guess buying the 6.5mm mod and putting an 8mm drill through the last few baffles would not be too hard either? Odd that F&D do not do a "7mm" mod as its reasonably popular.

by "decent thread" would you think all factory threads would be good enough?

Cheers
Mike

Thats exactly what I have done on mine!
Except mine is a .308........ (yes thats correct...8mm bore, 7.85mm bullet - 7.62mm is the land diameter, 0.075mm radial clearance. works a charm!)

I would think they are...
but sadly am proved wrong occasionally...

 

[Mike_E]

Thats exactly what I have done on mine!
Except mine is a .308........ (yes thats correct...8mm bore, 7.85mm bullet - 7.62mm is the land diameter, 0.075mm radial clearance. works a charm!)

I would think they are...
but sadly am proved wrong occasionally...

i'm picking up a 270 soon... will be in touch for a F&D.

thanks
mike