Tuning Vent holes in a shroud

[Corvid_hunter]

I can't remember which air rifle I saw this feature on. The forward part of the shroud had several rows of small vent holes that ended an inch or so from the muzzle. Would these holes act like an air stripper and lessen or remove the 'dirty' air from behind the pellet prior to it exiting the barrel?

 

[harrymoreland]

Huben K1.

 

[MACTEN]

I can't remember which air rifle I saw this feature on. The forward part of the shroud had several rows of small vent holes that ended an inch or so from the muzzle. Would these holes act like an air stripper and lessen or remove the 'dirty' air from behind the pellet prior to it exiting the barrel?

I don't know if it acually helps or hurts, but my .25 K1 has the holes and is extremely quiet. I should put some tape on the holes some time with the DB meter and check.

 

[dizzums]

doubt it would do much to improve stripping but could be wrong .. i got a 'strip T's' aftermarket stripper on the end of an unmodified shrouded barrel and it does make noticeably tighter shots though, i was actually surprised, i bought it on impulse because it looked cool as hell lol ..

 

[Airgunmann]

I have vented my raw shroud in the rear and added baffles to help the air move threw the whole shroud I drilled 5 or six small holes evenly spaced it helped quiet it down a little bit u can feel a small puff of air out the rear of it after shooting 

 

[bigHUN]

Now I got a big sheit on my head for this somewhere last summer but I cannot resist.

The MK2 Impact shroud (early 2020), the Canadian version was a blank shroud end plug (the black piece) and I duplicated the US version (alumin) and also added a SST stripper cone to vent inside and backward in the tube.

Later on - some development from ER show the shroud venting at rear (shooter end) he drilled some 5-6 holes 2mm OD. There is a read about somewhere here @ AGN. PPl were experimenting with number of holes also the drill OD's.

Last year I got a new shroud with integrated harmonic tuner, this one already have the stripper built in from the factory. And, it is working well, look at this picture:

I am not going to convince people for the benefits of the integral or internal air stripper and venting the shroud, there is google there are other resources where they can entertain with the idea.

I am shooting BR in my gunclub only, I don't have any ldc's or suppressors, but I have several airstippers, and I have a proof that these actually work.



Edit:

I am reusing the "old" MK2 shroud with my Leshiy2, and looks pretty good to me

 

[Airgunmann]

Did you vent the rear of your mk2 shroud did it make it quieter? 

 

[Airgunmann]

Was thinking of trying this so it would use the whole shroud because the rear is sealed with a oring and it would help for the air to expand 

 

[blacksmith304]

bigHUN, could you tell me more about that tripod your leshy is on? 

 

[bigHUN]

Did you vent the rear of your mk2 shroud did it make it quieter?

I don't care for sound effects (I shoot in a gunclub) but for sure I want to strip off the air blast = turbulence that gets pushed in front of the pellet/slug before leaves the muzzle. With or w/o airstripper there is a noticeable difference in POI.

You can mark the position on the shroud in the way the portion that is hidden beneath the scope rail. 2-3 mm holes maybe 4-6 of them will give you a noticeable puff when venting.

 

[Airgunmann]

Ok I understand the earmuffs then I know a lot of other guns vent the shroud with good luck with sound reduction and thought I'd ask yeah the air stripper does a nice job you can tell by the color of your rag thanks 

 

[218bee]

Cousin has a Cricket Compact in .22 that has a couple of holes drilled in the rear of the shroud from the last owner. Made the gun louder . Not by much, but noticeable. We electrical-taped over them and problem solved.

 

[Airgunmann]

It does make it louder to the shooter but not out in front of the gun and I believe it depends on the length of the shroud I was going to vent a impact shroud on 700 barrel kit impact crickets are pretty short aren't they I want it to use more of the length of the shroud other wise with the rear oring it is sealed in the back and would only use part of the length

 

[Kinetic45]

Cousin has a Cricket Compact in .22 that has a couple of holes drilled in the rear of the shroud from the last owner. Made the gun louder . Not by much, but noticeable. We electrical-taped over them and problem solved.

Note that the holes can't be very large or the sound does increase. A lot of guys use something around 1 to 2mm.

You'd think "those are too small to do anything" but it does allow the pressure to vent yet keep the sound pressure wave inside (somehow). Use 1/16" and it's too big (again somehow ??!?!?!)

 

[nomojo65]

Probably saw these on a RAW barrel sleeve I have mine partially covered 

with a tuner but they extend another 1/2 in. Under this tuner. The vent holes were on the barrels with no moderated attached. Not really sure what purpose they serve? Maybe a air stripper of sorts? 

 

[Airgunmann]

Ok I've vented the 700 mm barrel on my mk2 found a piece pipe that just fit over the barrel wrapped felt around it and slit it into the shroud I the milled 2 more slots in the air stripper cut the pipe proper length and install the air stripper back into the shroud reinstalled the shroud assembly onto the barrel and put on the koi I downloaded a db reading app tested it before the mod and was getting 70 to 71 db readings after the mod it went was reading between 66 to 68 out of the .25 pushing 34 gr at 905 the smack at the target is definitely louder then the rest of the shot I'm happy with the results and thought it's pretty quiet for being a koi on the end running 60 ish ftlbs don't know how accurate the app is but you can hear the difference from before I was reading a comparison chart and decibel level for a regular conversation is like 65-70 decibels

 

[shambozzie]

This work nicely on @ 30 fpe cricket compact .22 shroud. Top and bottom.