The Form 4 finally came back on my Mini 4, and I was able to make some observations this weekend on a 10.5”, 12.5”, and 16” barrel.
On all three barrel lengths, the ‘blast’ was reduced to nearly zero. Huge improvement and much more pleasant to shoot.
With all three barrel lengths, the suppressor reduced the noise from “really loud” to “loud but not unpleasant without hearing protection”. There was a small difference in perceived noise with the different barrel lengths, but not much to my unscientific ear.
Standing off to the side, there seemed to be a lot more noise coming from the supersonic crack down range than from the position of the shooter. I doubt a larger suppressor would make much of a difference in the experience, being as the majority of the noise already seemed to be coming from bullet flight.
The suppressor did not hide position at all. Someone standing a couple hundred yards away near the main road (over hilly terrain) found it very obvious what direction the shooting was taking place. It just sounded like a .22 instead of a 5.56.
Before the sun went down, I was very pleased with my decision. There was no more blast and the noise reduction was enough for bullet flight noise to predominate. On top of that, all three guns remained well balanced and easy to handle with the Mini 4, there was no excess pressure or debris back in the shooter’s face at all, and all three shot extremely flat. This may be related to the fact that a lot of earlier effort went into tuning the gas ports and buffer systems.
Then the sun went down, and I was surprised by the fact that my ‘suppressor’ flashed a heck of a lot more than I was expecting. I used WC844 pull down powder, which I have observed gives off similar flash to most commercial defensive ammo (and a lot less than cheap plinking ammo). On the 16” gun, the first shot let off a small but significant spout of flame. Subsequent shots flashed about as much as an A2. The 10.5” flashed a whole lot. Not as bad as a classic brake or open muzzle, but not far from it. It was enough to momentarily red-out my vision, even with a light on target. The 12.5” was somewhere in the middle. Not enough to red-out my vision, but still a substantial and distracting plume.
Originally, my plan was to put the Mini 4 on the 10.5” SBR for home defense. My hope was to have something that was as short as reasonably possible that eliminated concussion and environmental disturbances indoors, and was still a lot quieter than an unsuppressed carbine. All of our eyes are different, but for me this combination simply does not work. The amount of flash coming off the combination creates too much of a liability to my night vision to be worth the benefit in the low light environments where home defense scenarios are most likely to occur. If I absolutely had to use the 10.5”, I would rather just use a flash hider and good electronic hearing protection. I think the 12.5"/mini combination would be usable, but still suspect that at a similar overall length and weight a 10.5"/M4 2000 combination would have been better.
Overall, this is how I would summarize my opinion:
If you want a suppressor to act as a brake without causing environmental disturbances (such as in 3-gun) the Mini-4 is a great choice.
If you want a suppressor to shoot at the range with only light hearing protection, or to decrease noise pollution without altering weight and balance too much, then the Mini-4 is a solid choice. I don’t think the experience would be much (if any) different with a larger can, because there is already enough suppression for the supersonic ‘crack’ to overshadow the ‘boom’ from the muzzle.
If you want a suppressed gun to use for home defense or any other defensive scenario where low light may be a factor go for a M4-2000 or similar.
In my situation, I grossly underestimated the amount of flash that would come off of the Mini 4 and wish I had just gone with the M4-2000 in the first place. Considering the proposed regulatory changes to trusts and the fact that my local chief LEO wouldn’t sign if I could not put the new suppressor on my trust, it would be very risky to try to order another suppressor right now. When you add in the near certainty that I will not be at my current job (and quite possibly in a different state) 18-24 months from now when the next Form 3/4 combination comes through, I am pretty much stuck with this for the foreseeable future.
