Author Topic: Drilling Mrod barrel ports for less report ? (Read 7323 times))

Gertrude · « **on:** October 17, 2012, 02:52:35 PM »

I know I've run across a few posts where people have mentioned drilling the ports at the muzzle end of marauder barrels to make them even quieter.
I have tried searching for it and can't seem to find it/them.

Can someone here be so kind as to explain this to me ? pro's/con's ?
Maybe possibly provide a link to a thread where this has been previously discussed ?
Pics and descriptions are always welcomed.

thanks,
Ron

Rescue35 · « **Reply #1 on:** October 17, 2012, 04:52:14 PM »

I actually used a dremel to grind out and elongate 3 of the holes to allow better flow into the rear part of the shroud. You have to be carefull to leave enough material around the circumference to not weaken and break the cheap piece of plastic.

Norm_m · « **Reply #2 on:** October 17, 2012, 04:53:04 PM »

Hello Ron
Have not heard of drilling a hole at the muzzle end of the shroud but have heard about doing it at the rear end of the shroud. If the air stripper and baffles are doing their job, sending the air towards the rear of the shroud a small relief hole will help discharge that air permitting more air to enter the rear of the shroud making the baffles and air stripper to be more efficient. Wrapping some Mr Clean Magic Eraser around the barrel behind the air stripper also helps to reduce noise.

I've done it to all my shrouded barrels and I always feel a small puff of air coming from the exhaust hole after the shot is fired. IMO that does suggest that the air stripper is doing its job reducing the air coming out of the muzzle end helping to reduce noise.

I hope other members will chime in with their ideas & suggestions.

Norm

Rescue35 · « **Reply #3 on:** October 17, 2012, 04:56:07 PM »

I had the impression he was referring to the holes in the air stripper.

Thanks for the new idea Norm.

Norm_m · « **Reply #4 on:** October 17, 2012, 04:58:27 PM »

LOL
I was just going to reply that I reread his post and decided he was talking about the airstripper. And yes making those hole larger will help but you do need to relief that air somewhere.

Motorhead · « **Reply #5 on:** October 17, 2012, 05:12:44 PM »

Yup ... AIR STRIPPER gets altered.
Place a nail etc ... across the holes, twist stripper off end of barrel.
Carefully drill the 6 holes out to 3/16"
With a dremel back chamfer the edge of each hole to help direct flow out each hole into shroud space.
Press back onto barrel and go shoot.

MUCH less lead dust out muzzle

This is another style of end cap stripper, view gives you the hole and back chamfer mods required to do as you ask.

Gertrude · « **Reply #6 on:** October 17, 2012, 06:39:05 PM »

Thanks guys,
yes it is the air stripper I was thinking of.
I have not yet removed the shroud to see it, but I have looked at the diagrams on the parts list.
I will do this mod tonight.

Norm,... I noticed the Brittany in your avatar. I love Brittany's.
My first, "Princess", was an amazing dog, and a very dear friend. She passed many years ago and we still miss her.
My current, "Brandy", is also a fantastic companion, and incredibly smart. She NEVER stops hunting. (even if it is just for Flies or Lizards in the back yard, lol. If she is not hunting,... she is sleeping.

Ribbonstone · « **Reply #7 on:** October 17, 2012, 10:51:58 PM »

The addiction to quiet.

Nothing really does as much for quiet as the following:

1. Adjusting the rifle to use an efficent amount of air per shot.
2. Often, getting that last 2 or 3 foot poounds oust a whole lot in terms of noise and air use.
3. VOLUME is a big help in a shroud. Extentions can be a big help.

Gertrude · « **Reply #8 on:** October 18, 2012, 12:30:55 AM »

Gun has been tuned by Mac-1 and I have already added the shroud extension.
Air Stripper is now drilled and chamfered.
I guess that's about all I can do to get it as quiet as possible.

Does anyone have any pics of their Magic Eraser installs ? I haven't tried doing that yet.
Thanks again all, Great forum and members here. Learning a lot, and having some fun at it too,
What could be better than that ?

rkr · « **Reply #9 on:** October 18, 2012, 04:12:06 AM »

Some felt stuffed to the rear of the shroud also helps as it dampens the shockwave when it reaches the rear end of the shroud.

Rescue35 · « **Reply #10 on:** October 18, 2012, 10:39:19 AM »

John

I agree, I did not have to open up mine on the .25 version when I went to .30 caliber. The main job of the plastic dohicky is to center the muzzle in the shroud and inline with the baffles. It really is a cheap but poor design for pressure wave abatement.

I'll see about making one to your specs next time I have my .22 apart unless you can send me some measurements. It's not much more work to make two at the same time. I was thinking aluminum would be more durable than plastic anyway. What caliber are you wanting .177?

Powder burner · « **Reply #11 on:** October 18, 2012, 11:48:02 AM »

can we expect a report? no pun intended.

Rescue35 · « **Reply #12 on:** October 18, 2012, 11:55:12 AM »

Quote from: Powder burner on October 18, 2012, 11:48:02 AM

can we expect a report? no pun intended.

I still laughed.

I'll make a .177 for John and a .22 for mine. I'll let you folks know if my calibrated ear detects any differences. I might actually set up some sort of experiment...if I find the time.

Powder burner · « **Reply #13 on:** October 18, 2012, 12:15:32 PM »

Quote from: Rescue35 on October 18, 2012, 11:55:12 AM

Quote from: Powder burner on October 18, 2012, 11:48:02 AM
can we expect a report? no pun intended.

I still laughed.

I'll make a .177 for John and a .22 for mine. I'll let you folks know if my calibrated ear detects any differences. I might actually set up some sort of experiment...if I find the time.

cool deal, dude. thanx.

Gertrude · « **Reply #14 on:** October 18, 2012, 01:13:00 PM »

I wouldn't mind tossing in a few bucks for that.
Imd most likely like 2 of them for. 22's
can easily do some measuring for you,... (27 years in aricraft production and repairs).

Motorhead · « **Reply #15 on:** October 18, 2012, 02:32:36 PM »

The OEM M-rod stripper which is the SAME on .177 & .22 barrels can be FURTHER MODIFIED on the .177 cal barrel by installing a short stub of K&S 3/16" I.D. brass tube within the outlet hole of the factory stripper.
having it go a short way inward towards barrel makes it a more effective stripper without having to machine up something special.
* Photo I posted above you can see this mod also done *

Rescue35 · « **Reply #16 on:** October 18, 2012, 03:27:24 PM »

Quote from: Motorhead on October 18, 2012, 02:32:36 PM

The OEM M-rod stripper which is the SAME on .177 & .22 barrels can be FURTHER MODIFIED on the .177 cal barrel by installing a short stub of K&S 3/16" I.D. brass tube within the outlet hole of the factory stripper.
having it go a short way inward towards barrel makes it a more effective stripper without having to machine up something special.
* Photo I posted above you can see this mod also done *

Is that picture a factory Mrod product? I haven't had my .22 apart in a while but the .25s is plastic with 6 holes. So cheesy I was concerned with snaping it during removal.

These are pretty simple devices. One extrnal step to center the shroud and one internal step to locate on barrel. My main concern is how concentric the bore is to the OD of the average Crosman barrel.

I'll pull the shroud off the .22 when I get home Friday and start measuring and make a plan of attack.

Motorhead · « **Reply #17 on:** October 18, 2012, 03:36:32 PM »

Quote from: Rescue35 on October 18, 2012, 03:27:24 PM

Quote from: Motorhead on October 18, 2012, 02:32:36 PM
The OEM M-rod stripper which is the SAME on .177 & .22 barrels can be FURTHER MODIFIED on the .177 cal barrel by installing a short stub of K&S 3/16" I.D. brass tube within the outlet hole of the factory stripper.
having it go a short way inward towards barrel makes it a more effective stripper without having to machine up something special.
* Photo I posted above you can see this mod also done *

Is that picture a factory Mrod product? I haven't had my .22 apart in a while but the .25s is plastic with 6 holes. So cheesy I was concerned with snaping it during removal.

These are pretty simple devices. One extrnal step to center the shroud and one internal step to locate on barrel. My main concern is how concentric the bore is to the OD of the average Crosman barrel.

I'll pull the shroud off the .22 when I get home Friday and start measuring and make a plan of attack.

Picture is a screw on cap / stripper off of a Titan.
The OEM M-rod one is much smaller, made of Derin and just a press on unit with an o-ring on O.D. for shroud sealing.
Basic function tho is the same.
Once you see the M-rods unit it will make perfect sense .....

Motorhead · « **Reply #18 on:** October 19, 2012, 07:13:47 PM »

Building a MULTI segmented stripper as shown to a length equal to OEM stripper + 1 baffle would be a GREAT idea having remaining baffles all assemble into the same length factory shroud.

As for the brass tube idea, on the factory stripper hole is .250" and you can get heavy wall 1/4 x 3/16 brass or just use the thin wall stuff and slip a few sizes into one another with a drop of CA glue.
Tubes end headed back towards muzzle need only go mid to rear of vent holes, so yes # 3/8 OAL there about. CA glue again will hold it into stripper end hole.

Anyways getting off subject of HEADER TITLE of drill ports for less report, think we covered that

Bill G · « **Reply #19 on:** October 19, 2012, 11:25:22 PM »

Man! I was wanting to be the cool guy here.

Last week I made a stripper from some delrin I had. Haven't taken any pics yet. Anyway, it is a bit longer but has 4 slots milled into it that are larger at the rear than the front (long tear drop shape). At the exit end there is a cone that is pressed into it. The cone has a .281"(K) through hole. The area of the 4 openings, facing the rear of the shroud, is nearly large enough to pass one of thode .25cal. pellets through. LOTS of air can get through. I haven't had time to install it and I'll likely have to shorten a baffle to accomodate the additional length.

BTW, I don't know haw to add pics, anybody got a link or directions?

Bill

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Drilling Mrod barrel ports for less report ?

Author Topic: Drilling Mrod barrel ports for less report ? (Read 7323 times))