Silent Hunter silencers

[Kayback]

I thought the velocity increase was from reduced drag thanks to the suppressor and the muzzle blast exiting the barrel.

[treeman]

u thought wrong

[JouDoring]

The tests showed with a 338 round about a 100 fps increase, and with the 243 a 150fps average increase.

That quite a bit.

Once i have my one fitted i'll do some teste with and without. Maybe see if i can find a decibell app.

[Arnold]

The tests showed with a 338 round about a 100 fps increase, and with the 243 a 150fps average increase.

That quite a bit.

Once i have my one fitted i'll do some teste with and without. Maybe see if i can find a decibell app.

They probably put the chronograph to close to the muzzle and some of the gasses influenced the reading because a 100 and 150 fps velocity increase is crazy!

The difference that could be measured is most probably within the accuracy of the chronograph

[Bonedoc]

I haven't experienced this amount of increased velocity using a silencer. I have a Silent Hunter on my .308, maybe 20 fps difference.

[Messor]

http://www.gunsite.co.za/forums/show...kload+silencer

[JouDoring]

Thanks

That is very interresting. Going to also do some tests.
My theory on the increase is: without the silencer, the air pushed out in front of the bullet desperses immediatly and the bullet experiences drag the second it leaves the barrel.
With the silencer on, the air in front of the bullet does not desperse as rapidly and for the lenth of the silencer the bullet then is traveling in air that is also moving forward, decreasing the drag. By the same theory the expanding gas behind the bullet that does not disperce immediatly may still have some forward effect along the lenth of the silencer.

Theory?

[Messor]

My theory on the increase is: without the silencer, the air pushed out in front of the bullet desperses immediatly and the bullet experiences drag the second it leaves the barrel.
With the silencer on, the air in front of the bullet does not desperse as rapidly and for the lenth of the silencer the bullet then is traveling in air that is also moving forward, decreasing the drag. By the same theory the expanding gas behind the bullet that does not disperce immediatly may still have some forward effect along the lenth of the silencer.

Theory?

You are still at the beginner phase of your thesis Mr Doring :)

For your next challenge, consider the correlation between the gas exit and the muzzle crown. It is widely accepted that an uneven muzzle crown causes the gasses to expand unevenly and thus destabilize the bullet to some degree, that is why the crown of a barrel is so important in the first place.

BUT, with a silencer attached the gasses can only expand into the first chamber, not outwards, and as such cannot expand to the same degree as without the silencer fitted.

It is widely accepted that the expanding gasses behind the bullet moves faster than the bullet, I mean they are the force pushing the bullet, and at muzzle crown they explode in a pattern similar to crown symmetry, giving an accurate or non accurate launch at bullet exit.

If you trap this expanding gas(faster than a bullet), would they not accelerate the bullet even more?

Questions that arrives, would the specific chamber dimensions of the silencer cause accuracy or non accuracy when regarding the expanding gasses theory?
Why, if the gasses moves faster than the bullet, don't you read anywhere that people just say it's the expanding gasses in the silencer than pushes the bullet faster than normal?

[JouDoring]

"If you trap this expanding gas(faster than a bullet), would they not accelerate the bullet even more?"
This is where my thinking is. It would not only push the bullet, but rather move along with the bullet, in essence the bullet will be flying with the wind.
All those super fast gas and air must have an effect on the bullet. If the silencer is nice and evenly built, concentric and all the effect will be an accurate one.

I'm going to call my friend that works with cannon shell and mortar design.

[Glockster]

Freebore boost. The phenomenon known as "freebore boost" occurs in particular suppressor designs and sometimes requires a particular loading of ammunition. It is caused by a primary expansion chamber ahead of the barrel's muzzle which acts as a barrel extension as a bullet passes through it. Propellant gases continue to expand inside the chamber and push the bullet through the baffle stack at a slightly increased velocity. The suppressor can actually increase bullet velocity up to about 40 feet per second (12.1 m/s) depending on the design.