Re: Integrally suppressed FN .308 Patrol Bolt Rifle
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KYS,
The best way to think of rifle caliber integrals is to consider them dedicated sub-sonic rifles. Otherwise there is little reason to use an integral design as integral barrels can provide four distinct advantageous.
First is the obvious one, make the barrel an active component of suppression. Its role? an active portal to divert gas prior to the blast component. Subsonic projectile flight is the goal.
Second, and less well understood is any effort within the design to capture the barrel by the external envelope, thereby improving the harmonics of the barrel.
The third is the rare requirement to provide the operator with a barrel thats profile belies the fact that the barrel is suppressed. At best, those barrel look like bull barrels. We include here any requirement to use integrals to reduce OAL.
And lastly the fourth, the term is applied to suppressor delivered to states within the U.S. that disallow threaded barrels. These are commonly called the AWB States. As a result a blast can is permanently attached to a standard barrel. Whereas these are commonly refered to as "integrals", they would be better refered to as a "dedicated" suppressor.
And that takes us to your question. The term integral as opposed to "dedicated" means confusion where some hosts design suppressors that must be attached to a specific host barrel profile. Like...The Covert. The Covert is essentially a swing stock AWS (suppressed) which uses subsonic ammuntion, in other words the barrel does not tap gas. 300m range. That barrel can, as you suggest, be replaced independant of the dedicated "blast" can.
The result of true integral gas tapping...
As a direct result of the #1, the barrel life is much shorter in a rifle caliber integral for a whole host of reasons. Many simply approach the problem by turning down the barrel to a pencil this profile and start tapping until the selected cartridge/load results is subsonic. There is much more to it than that, tap design and placement is the game. High heat, capture and dispersement early by taping of a host of caustic gases and then laying them on top of a captured barrel has real consequences. A integral can be a tour de force of tuning and when it is on a bolt gun, the quietest of all suppressed weapons, providing 3 out of 5. Round count is managed to a minimum in rifle calibers, whereas in a .22 it isn't required. In either, accuracy can be vastly improved as #2 comes into play.
I doubt ns505 hs come to realize that he is better served in almost all regards with a blast can.
P.S. Best integral .22 rifles use a single gas port...one.