7.5", 10.5", 16", or 20" Barrel effectiveness

[1911rocks]

It stands to to my limited reason that as the barrel length increases the effectiveness of the can increases (perhaps I'm wrong). Is this universally true? How about Bolt vs. Semi-Auto? My thought is that a 24+ bbl on a Bolt Action rifle will provide the best suppression.

[c5_nc]

Most people that have AR-15 5.56 SBRs end up settling on 11.5-12.5", there is more decreasing return velocity increases after this. A suppressor on this length still makes for a long OVA. A 8-9" 300blk build is much better suited, subsonic loads generally have complete powder burn off in 9".

[c5_nc]

Most people that have AR-15 5.56 SBRs end up settling on 11.5-12.5", there is more decreasing return velocity increases after this. A suppressor on this length still makes for a long OVA. A 8-9" 300blk build is much better suited, subsonic loads generally have complete powder burn off in 9".

[Capt. Link.]

It stands to to my limited reason that as the barrel length increases the effectiveness of the can increases (perhaps I'm wrong). Is this universally true? How about Bolt vs. Semi-Auto? My thought is that a 24+ bbl on a Bolt Action rifle will provide the best suppression.

Its up to the baffle design if higher or lower pressure gases respond better.Many people have noticed that brand A on a pistol is more quiet than brand A on a rifle using the same ammo.Every suppressor has a velocity sweet spot.In general you are correct as barrel length lowers the gas pressure and overall SPL.

[1911rocks]

I will say that the 7.5" barrel MUST have the Baffles hardened! At least the Blast Baffles and perhaps the next 3. If not they may make it through 10-20rds. I haven't tried my can on a 20+" bbl. yet.

[Historian]

It stands to to my limited reason that as the barrel length increases the effectiveness of the can increases (perhaps I'm wrong). Is this universally true? How about Bolt vs. Semi-Auto? My thought is that a 24+ bbl on a Bolt Action rifle will provide the best suppression.

Its up to the baffle design if higher or lower pressure gases respond better.Many people have noticed that brand A on a pistol is more quiet than brand A on a rifle using the same ammo.Every suppressor has a velocity sweet spot.In general you are correct as barrel length lowers the gas pressure and overall SPL.

Thank you again for your treat of cool mountain stream thinking and presentation on an issue.

A good example is the choices of pool cues during a game, be it 9-ball or three cushion
billiards on a 5' x 10' table. [ Where did those pockets go? Do you need BATF approval
to insert pockets that have disappeared? ]

[Capt. Link.]

[ Where did those pockets go? Do you need BATF approval
to insert pockets that have disappeared? ]

I'm waiting for the next round.I have the popcorn all ready!

I will say that the 7.5" barrel MUST have the Baffles hardened! At least the Blast Baffles and perhaps the next 3. If not they may make it through 10-20rds. I haven't tried my can on a 20+" bbl. yet.

I'm taking for granted that you are speaking of the 5.56. The 20" tube should run much cooler and possibly more quiet.I honestly feel that less than 18" degrades the ballistics to the point that a heaver caliber should be used.At 7.5 inches the flash burn is possibly more dangerous than the bullets.humor

[Capt. Link.]

How much trouble have you had running a 7.5 barrel. Do you have pictures of the build.
I do agree about using a blast baffle and having it treated for wear.I wonder if some tool steels could self harden when shot...A2,W1,O1.It would save some amp-bucks.

[1911rocks]

Capt Link: Well, I just threw out (2) Perforated Cone Baffles that were blown apart. Not only were they blown apart, but they went form Concave to Convex.LOL. I went with a Hardened Carbon Steel and that solved the problem.

[curtistactical]

Depending on the design it will be different but here are the approx. numbers for my quick attach 5.56 suppressors using 5.56 55gr ammo. 10.5"=137db., 16"=132db., 20"=129db., I have noticed past a certain point on barrel length less of difference is seen. The longer the barrel the more the powder will be burnt up and the less gas you will have to suppress. The lengths will vary depending on caliber and load. A 5.56mm is about 90% burnt up with a 20" barrel while 338 lapua is only about 55% burnt up in 20".