What a typo!!!
Yes they are all IN STOCK READY TO INSTALL OR SHIP!!!
Feable mind at work here.
when dealing with a muzzle brake, there is a protective cone that is directed back from the muzzle brake. If your in this cone, as the shooter is, the muzzle blast is not dramatic. If you are in close proximity to the brake outside this cone, your going to get the full brunt of the blast.
Muzzle blast intensity is determined by several things but when dealing with a brake its mainly caused by muzzle pressure when the bullet is released from the crown and the velocity in which the escaping gases leave the brake itself.
The higher the exit velocity, its my theory that the sharper the crack will be to the shooter and bystanders.
The smaller your ports, the higher your muzzle pressure and escape velocity will be and as such, the sharper the crack you will hear and feel.
Going into this project I wanted to try to do something to decrease this sensation. I am not saying my brakes are quiet but with these final designs, they do seem to be much less intense then some of the standard partition style muzzle brakes we commonly use. How can this be possible you say?
Well, my brakes have ports with alot of surface area, they also have alot of volume in each port compared to more conventional 90 degree ports. It was my theory that if we used larger volume ports more gas volume could be contained in the brake for a longer duration of time.
Now it is true that the higher the muzzle pressure the better the brake will work, so if the gas pressure is dropped by larger exhaust ports, one would think the brake would be less efficent which comparing apples to apples that would be true but that is where the larger surface area and 30 degree back angle on the ports come in to compensate for this lower escape gas velocity that the larger volume ports create.
Make any sense???? Probably as clear as mud.
Basically, I increased the volume of the ports to decrease the escape gas velocity to reduce the intense crack you hear and the intense slap you feel from some muzzle brakes.
Then the larger surface area and 30 degree back rack on the ports compensates for any loss in recoil reduction caused by the slower venting of the muzzle gas pressure.
In shooting all three of these brakes head to head against brakes such as the Holland QD and DE 3 and 4 port brakes, I know this theory to be true.
Again, I am not saying my brakes are any quieter because the back angle on the ports does narrow the protective blast cone that the shooter is in, BUT, I can tell you for a fact, when you shoot a Holland or DE brake, the blast from the brakes is very directed and high velocity. All you have to do is watch one being fired and the escaping muzzle gas comes out of the brake VERY aggressively. The escaping gases also reach out much farther because they are more focused and confined so you get that jetting effect coming off the brake.
When you shoot a PK brake, the escaping gas is dramatically slower coming out of the brake, not nearly so directionally defined. In fact, its common to shoot a PK brake and then look up and see gas and smoke rolling out of the brake for a significant time after the shot has been fired. This tells me that the escaping gas is much lower velocity then the other brakes.
As far as the big 5 port PK, here are some pics, this one is fitted to one of my Allen32 contour barrels with a muzzle diameter of roughly 0.960", not overly small.
Certainly a much larger brake at 4" in length compared to 1.8" length for the small port. Still on the appropriate barrel, they do not look out of place at all and when you shoot them, they look even better!!!