Can size

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daman
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Can size

#1 Post by daman »

I have a question about moderators...

At present i have two, one each on my .223 and .308

Both have the same screw cut (1/2" UNF)

So, potentially I could fit the .308 mod on the .223? (Obviously the other way around would be risky!)

Obviously the bullet should pass through the larger hole, but will the moderator have much effect? Any figures on how less efficient it would be? Any risk?

Ignore the legal aspects, I'll talk to my FEO before doing anything...

Cheers

-daman
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Blackstuff
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Re: Can size

#2 Post by Blackstuff »

In theory it must be less effective as the bigger the gap around the bullet the more noise is projected forwards, exactly how much less effective is another matter!
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Re: Can size

#3 Post by David TS »

If they are the same make and dimensions, and you put a calibrated noise meter on it, I doubt it would make much difference in db output at all.
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daman
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Re: Can size

#4 Post by daman »

Ok, my reason for asking (if you couldn't guess) is that if the larger calibre can would work on the smaller calibre then I could 1-for-1 the slot for something else....

Does anyone have any hard figures on the physics though? I don't have access to a noise meter, but interested to hear if there is a measurable sound / recoil reduction
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Re: Can size

#5 Post by breacher »

What you gain ( there is a gain ) with increased volume, you will lose with increased exit hole size.

There is a sweet spot to be found with regard to exit hole and volume.

I believe that BR Tuote got it perfect with their reflex t8.

And unless your FAC specifically states that mod x can only be used with rifle y - you can use any mod on any rifle. Your FAC is your authority to possess and use it - what rifle you use it on is up to you unless you have been restricted by an extra condition.

I have used a .308 Ase Utra Compact on my .223 AR and a couple of .308 rifles on different days - worked just fine on the AR - the slight increase in noise was really marginal.
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Sim G
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Re: Can size

#6 Post by Sim G »

What Brian said...
In 1978 I was told by my grand dad that the secret to rifle accuracy is, a quality bullet, fired down a quality barrel..... How has that changed?

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Re: Can size

#7 Post by DL. »

It says the difference between a .308 and .223 bore channel could mean the difference of 2db on Jackson's site.
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Re: Can size

#8 Post by daman »

breacher wrote: And unless your FAC specifically states that mod x can only be used with rifle y - you can use any mod on any rifle. Your FAC is your authority to possess and use it - what rifle you use it on is up to you unless you have been restricted by an extra condition.
I wasn't going to get legal on this thread, but that is why I'll need to speak to my FEO. On my cert I have 2 mods listed as a .308 mod and a .223 mod. Now it doesn't explicitly say 'must be used on a rifle of the same calibre' but I'd imagine if someone wanted to be picky they might argue that my mods are calibre specific.

Thanks on the comments on gain - sounds like sharing the mod could be viable from a physics point of view, just accepting the benefit on the .223 might be a bit less than with the smaller hole.

-daman
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Re: Can size

#9 Post by Ovenpaa »

I typically size the baffle aperture for a .223 at 6,8mm which is actually quite tight and I have come across factory devices at 7,5mm and more for a .223. The exception is a custom device we are building right now for a 5,7mm which is sized at 6,0mm however this is a real exception, of an unusual construction for a very specific application and it is going to be difficult to gauge effectiveness until the trigger is first pulled.
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Re: Can size

#10 Post by breacher »

daman wrote:
breacher wrote: And unless your FAC specifically states that mod x can only be used with rifle y - you can use any mod on any rifle. Your FAC is your authority to possess and use it - what rifle you use it on is up to you unless you have been restricted by an extra condition.
I wasn't going to get legal on this thread, but that is why I'll need to speak to my FEO. On my cert I have 2 mods listed as a .308 mod and a .223 mod. Now it doesn't explicitly say 'must be used on a rifle of the same calibre' but I'd imagine if someone wanted to be picky they might argue that my mods are calibre specific.

Thanks on the comments on gain - sounds like sharing the mod could be viable from a physics point of view, just accepting the benefit on the .223 might be a bit less than with the smaller hole.

-daman
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So, the .223 relates to the calibre of what you possess - not how you use it.
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