The Marauder's valve is quite limited in porting, having only a .3" spot faced flat spot to seal against, with .22"x.24" ports that leaves nearly .03" to seal against.
I've never been too happy with transfer sleeves made from plastics, sure they work but sometimes they don't seal great, sometimes they do, they deform and if/once they do, they're trash, and, .03" wall on plastic is...well some may say a ticking time bomb. I've never blown a transfer port but heck, I am sure it's possible.
The transfer port I am running is made of a series of tubes epoxied together with tight press fits. I drilled my breech end of the marauder to .343" at a depth of around .185", this allows me to seal to the breech instead of the barrel. This also allows me to swap out calibers/barrels very easily with just loosening the two set screws atop the breach while swapping out probes with my custom bolt that allows it. Mike/mackeral gave me the idea which he took from Travis, and it works quite well as the barrel to breach fitment is to tight it doesn't allow blow by, and o-rings aren't even needed there, but could be added optionally.
I will say I struggled for quite some time to get a really good seal with a one piece delrin/nylon sleeve. I even machined not one, but two so well that they snap fit into the .06" deep .3" diameter spot face flat on the valve, literally snapped in, and it would still leak upon assembly at that connection. There is no forgiveness in assembly when you rely on a piece of plastic to crush perfectly every time. I should have tried something soft like teflon but again, upon multiple assemblies you risk deformation that won't reseal and you'll be remaking the seal again. Frustrated I came up with a few designs and went at it.
Here are 3 different designs. Design 1, requires critical dimensions. Design 2 much for forgiving. Design 3, beefier orings, the ones pictured are not the 100% correct size, I tossed em on for the picture, overall close in size though and will work great, just need to order the o-rings or shape the breach one a hair smaller.
From left to right, #1) Old transfer sleeve (Nylon). #2) New/prototype, aluminum/brass sleeves oring in breach and replaceable soft seal for valve side. #3) New prototype sleeve #2, beefed up double o-ring version.
Don't mind the marks, I time my transfer ports as they are blended to match my oval porting on both valve and breach sides. I can also double o-ring the middle design too but I was just having fun with different ideas.
I'd say this style of transfer tube is a must for marauders, mimicking the original design but just beefing it up. If it works, it works, and it simply works. The marauder breach doesn't have screws that seat the transfer sleeve perfectly from front to back and o-rings not only solve that, they extend the life of your transfer sleeve if you tear down a lot like I do to tinker, and even if not who wants to redo something unless its to improve or change it up, such as I did today.
-Matt
I've never been too happy with transfer sleeves made from plastics, sure they work but sometimes they don't seal great, sometimes they do, they deform and if/once they do, they're trash, and, .03" wall on plastic is...well some may say a ticking time bomb. I've never blown a transfer port but heck, I am sure it's possible.
The transfer port I am running is made of a series of tubes epoxied together with tight press fits. I drilled my breech end of the marauder to .343" at a depth of around .185", this allows me to seal to the breech instead of the barrel. This also allows me to swap out calibers/barrels very easily with just loosening the two set screws atop the breach while swapping out probes with my custom bolt that allows it. Mike/mackeral gave me the idea which he took from Travis, and it works quite well as the barrel to breach fitment is to tight it doesn't allow blow by, and o-rings aren't even needed there, but could be added optionally.
I will say I struggled for quite some time to get a really good seal with a one piece delrin/nylon sleeve. I even machined not one, but two so well that they snap fit into the .06" deep .3" diameter spot face flat on the valve, literally snapped in, and it would still leak upon assembly at that connection. There is no forgiveness in assembly when you rely on a piece of plastic to crush perfectly every time. I should have tried something soft like teflon but again, upon multiple assemblies you risk deformation that won't reseal and you'll be remaking the seal again. Frustrated I came up with a few designs and went at it.
Here are 3 different designs. Design 1, requires critical dimensions. Design 2 much for forgiving. Design 3, beefier orings, the ones pictured are not the 100% correct size, I tossed em on for the picture, overall close in size though and will work great, just need to order the o-rings or shape the breach one a hair smaller.
From left to right, #1) Old transfer sleeve (Nylon). #2) New/prototype, aluminum/brass sleeves oring in breach and replaceable soft seal for valve side. #3) New prototype sleeve #2, beefed up double o-ring version.
Don't mind the marks, I time my transfer ports as they are blended to match my oval porting on both valve and breach sides. I can also double o-ring the middle design too but I was just having fun with different ideas.
I'd say this style of transfer tube is a must for marauders, mimicking the original design but just beefing it up. If it works, it works, and it simply works. The marauder breach doesn't have screws that seat the transfer sleeve perfectly from front to back and o-rings not only solve that, they extend the life of your transfer sleeve if you tear down a lot like I do to tinker, and even if not who wants to redo something unless its to improve or change it up, such as I did today.
-Matt
