Jump to content
UKV - The Place for Precision Rifle Enthusiasts
Sign in to follow this  
onehole

Pressure within moderators

Recommended Posts

Just out of pure interest does anyone know what pressures are generated within moderators?  I know it will vary from cal to cal but cant help noticing some mods are built quite lightly and some like a tank,,,,,anyone? ,O

Share this post


Link to post
Share on other sites

I think, the pressure at the muzzle equates to 20 - 30,000 psi depending on cartridge (I recall reading this from Vaughns Rifle Accuracy the Facts book)

 

So it would, seem that pressures within then mod would be similar, though I have no hard mathematical evidence to back up my hunch.

 

Perhaps a mathmatition or stress engineer amongst our group could add to the discussion....?

Share this post


Link to post
Share on other sites

Boyles law (?) as the volume increases the pressure decreases ... so it'll depend on the volume. I imagine that if you worked out the volume of the gas produced by the powder and the amount of force needed to push the bullet out the neck, up the barrel and the increase in volume, you'd end up with a horribly complicated sum. Powder deflagrates (what a great word) so I imagine that the pressure isn't constant either, which wont help. I'll go for/guess about a 1/60th of the breech pressure.

 

Share this post


Link to post
Share on other sites

I guess this makes it difficult to proof them for more than one calibre  as pressure curves could be sharper on a smaller calibre than say a .308W which many mods seem to be proofed for .

Share this post


Link to post
Share on other sites

Happened to look at this last night. According to Quickload my 308 load in a 20" barrel has a residual 8 kpsi while a 7 SAUM was about 12 kpsi in a 25".

Not quite sure how that relates to what the mod experiences...

Share this post


Link to post
Share on other sites

Thanks for replies,,,,,guess its pretty high initially but reduces so quickly that even a lightly built mod can cope well enough..........O

Share this post


Link to post
Share on other sites

 

 

I think it depends on calibre size/charge , and barrel length , the designer for 3D TI suppressors from ODL in NZ , said that the blast/pressure from a short barrel AR15 , say 10 inches was the same as a large magnum rifle in  338LM .

Me I want strong suppressors , that can easily cope/handle the calibre its used on .

 

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  

×

Important Information

By using this site, you agree to our Terms of Use and Privacy Policy