I received my Banish 22 Suppressor and have been loving it. I have been shooting it on my Sig P322 and FN 502. Works great! Does what it is supposed to do.

I decided to try it on my H&K 416D .22 rifle. I had to buy the adapter and attached the can and it fit great. I ran about 5 rounds through it from the 20 round mag and it was working great. Then the next round was really loud like a normal .22 crack. The next 5 or six were all loud, then the next few were like the first 5, suppressed noise. Then loud rounds again. This went on through the whole mag?

All the ammo was the same between the pistols and the rifle. All 40g JHP rounds from CCI. All round from the same box.

Any ideas what would cause some rounds to be quiet/suppressed and the others much louder?

Never experienced this with either pistol. Just the H&K 416D.

Let me know your thoughts.

Thanks!

Perhaps all the rounds were staying subsonic out of the shorter barrels, but some are going super out of the longer one.

KSGM is on the case for the best explanation. But it matters a bit what "loud rounds" really means. And what "much louder" means.
When I shoot my .22 suppressors supersonic rounds are louder. That you can tell. But I would never call them loud or much louder. different for sure. But definitely not loud as relates to gun fire.
Me I'd take off the suppresor and shoot a few rounds and see if how they sound and then put it back on and see how those sound. If its not quieter by a lot (even if the supersonic ones are louder) then further investigation is needed.