Marauder Air Stripper modified*

[CitySniper]

I stole this picture and idea from Motorhead on the Marauder forums...(think he is over here too?) But Basically the holes on the stock air stripper have been enlarged from the factory 1/8... to.. 3/16 to make it more efficient...
BEFORE:

AFTER:


I did this modification today on my .22 marauder already depinged..and shooting 35 fpe...I can say it really works! Just a touch quieter , especially can tell the difference in the lower psi. range where the gun normally got louder...sounds more consistently even, very pleasant to shoot.

here is a link to the thread: http://marauderairrifle.com/forum/viewtopic.php?f=24&t=5475

[Motorhead]

Yup ... solid mod to make that does indeed quiet report further 

[Finchlake]

How is the air stripper attached to the barrel ? Is it a friction fit? Can it be tapped off of the barrel ? I want to remove it to put my shroud extension on the breach end of the barrel.

[CitySniper]

How is the air stripper attached to the barrel ? Is it a friction fit? Can it be tapped off of the barrel ? I want to remove it to put my shroud extension on the breach end of the barrel.

It is press Fit on....I used a Cresent wrench behind it to tap it off..(comes off easily) then  Did my drilling/sanding and reinstalled.

[Motorhead]

How is the air stripper attached to the barrel ? Is it a friction fit? Can it be tapped off of the barrel ? I want to remove it to put my shroud extension on the breach end of the barrel.

It is press Fit on....I used a Cresent wrench behind it to tap it off..(comes off easily) then  Did my drilling/sanding and reinstalled.

Or a pin punch / nail threw the holes and twist it off.

[Finchlake]

Thanks

[CitySniper]

Okay so you know I had to run the gun across the chrony to see if I lost power.... and guess what? I gained about 10-16 FPS on average throughout my shot string! 

Old Shot String, Before Air Stripper Mod, 2,900 psi. Fill, using 21.30 Grain 5.53mm Baracuda Pellets
1   813.00   847.30   849.70   821.90
2   817.70   846.60   850.00   818.80
3   818.60   848.20   844.60   815.10
4   819.80   848.90   839.80   810.50
5   838.50   853.00   837.70   
6   823.10   849.80   837.30   
7   828.80   861.80   839.40   
8   828.40   844.40   826.60   
9   834.70   854.90   830.70   
10   838.70   852.00   824.00   Max Fpe 35.136

New Shot String, after Air Stripper Mod, Same Pellets and Tune 3,000psi. Fill
1   815.90   864.80   862.70   826.60
2   824.80   872.60   862.50   825.20
3   811.50   862.80   855.70   817.00
4   827.70   872.50   855.80   813.10
5   839.60   868.70   851.80   800.90
6   845.40   869.10   846.70   
7   850.30   871.30   841.60   
8   854.50   871.40   838.70   
9   859.30   873.50   838.50   
10   858.90   874.70   824.30   Max Fpe 36.195

[CitySniper]

Yep!   Verified twice, with three different pellets. My guess is the air is more stable near the muzzle now allowing a bit more speed without more noise. Same thing happens on Powder burners when they use a suppressor their muzzle velocity goes up. 

Like Motorheads' picture I made sure to also angle the hole like a tear drop to allow as much air back into the shroud as possible. Once the shape is there..  use sand paper, or a dremel to smooth and debur just like you would do on cylinder heads on a car to get better airflow.. 

[Dead nuts dog]

Awesome!!! Thanks for posting. I'll be doing that the first day with the Mrod

[Motorhead]

Did not take any pictures ...    ( Will take some ASAP and share )
But taken the IMPROVED air stripper even further by enlarging the bore exit hole to 5/16" and inserting a short section of K&S 5/16" O.D x .029" wall brass tubing ( I.D. @ .254" ) with end facing muzzle sharpened into a cone.  A TRUE AIR STRIPPER NOW.
This further splits the air leaving muzzle making the factory stripper even more effective.
* Guns report even LESS !

As a reference, here another version I did to a Crosman shrouded NP springer.
* You can see the brass tube looking threw the vent holes.



Ideally you want bore tube to be @ mid hole as viewed from the side so air thats split away from bore can readily flow out the vent holes into shroud.

here an Air Arms stripper further elaborating on the concept of splitting the air to maximize shroud filling.
 

[Rescue35]

That is called "Free bore boost". Very interesting phenomenon.

[pyroboy33]

Okay so you know I had to run the gun across the chrony to see if I lost power.... and guess what? I gained about 10-16 FPS on average throughout my shot string! 

Old Shot String, Before Air Stripper Mod, 2,900 psi. Fill, using 21.30 Grain 5.53mm Baracuda Pellets
1   813.00   847.30   849.70   821.90
2   817.70   846.60   850.00   818.80
3   818.60   848.20   844.60   815.10
4   819.80   848.90   839.80   810.50
5   838.50   853.00   837.70   
6   823.10   849.80   837.30   
7   828.80   861.80   839.40   
8   828.40   844.40   826.60   
9   834.70   854.90   830.70   
10   838.70   852.00   824.00   Max Fpe 35.136

New Shot String, after Air Stripper Mod, Same Pellets and Tune 3,000psi. Fill
1   815.90   864.80   862.70   826.60
2   824.80   872.60   862.50   825.20
3   811.50   862.80   855.70   817.00
4   827.70   872.50   855.80   813.10
5   839.60   868.70   851.80   800.90
6   845.40   869.10   846.70   
7   850.30   871.30   841.60   
8   854.50   871.40   838.70   
9   859.30   873.50   838.50   
10   858.90   874.70   824.30   Max Fpe 36.195

Hey C.S. just curious that is a really sweet shot string, have you done any custom work to your m-rod?

[CitySniper]

Thanx Pyro...Nope all the internal parts are stock. But the gun has been completely taken apart cleaned /lubed and put back together..Oh yeah only part not factory is the breech O-ring...I got an upgraded one from Mac-1. The settings are basically maxed out and I am using the heaviest most accurate pellets the gun likes.

P.S. from what I am hearing on the Marauder Forum... This Air Stripper modification is suppose to be more noticeable on the already louder .25 Marauder. Probably benefits more from it because it uses more air to shoot those heavy pellets.

[Rescue35]

The barrel is larger on the .25 and there is less room in the shroud to disipate the pressure wave.

[pyroboy33]

Thanx Pyro...Nope all the internal parts are stock. But the gun has been completely taken apart cleaned /lubed and put back together..Oh yeah only part not factory is the breech O-ring...I got an upgraded one from Mac-1. The settings are basically maxed out and I am using the heaviest most accurate pellets the gun likes.

P.S. from what I am hearing on the Marauder Forum... This Air Stripper modification is suppose to be more noticeable on the already louder .25 Marauder. Probably benefits more from it because it uses more air to shoot those heavy pellets.

Nice  , I read your first post again and noticed that you mentioned your M-rod has a depinger installed, which partly explains that sexy shot string  .

[CitySniper]

Yeah, The depinger does quiet the PING and is just some Vinyl tubing rolled up stuffed half way down the airtube and if anything that is costing me 1-2 shots by taking up airspace. I have had my .22 Marauder like 3 years now and it keeps getting  better, which keeps me away from buying the .25 caliber.

But I still want one..I honestly do not need the extra power though

[Dead nuts dog]

Hi

[rkr]

3mm thick felt is the material that some commercial LDCs use. You need something in there to hold it in place though, hair curlers are used in Weihrauch unit. Then again, if you go that route you could just use washers for baffles and free up some volume inside the shroud.

[CitySniper]

Dead Nuts...to answer your question real quick and without getting this thread locked. I will say Yes, and I suggest you do a search on the forum marauderairrifle.com for Mr. clean magic eraser

[Dead nuts dog]

Thanks and not trying to get the thread locked!!