Bigger Transfer port for marauder

[ackuric]

Quick and easy way to allow for bigger TP porting on the marauder, or if you want a slightly meatier TP / sealing surface.. As you can see in pic 1 there is about .290" of space available on the flat spot, I measured the barrel's flat spot at around the same, slightly smaller, @ .285



Yet the stock tp hole from barrel to air tube is only around .265" allowing only around .26-.265" of space which is not a whole lot of area to work with if you want to port over .21" IMO...and the stock TP itself is .262"ish. .

What I did was drill the receiver and the air tube both to 9/32" - .2813" and then reduced some .3125" delrin rod down to .28" and made a transfer port which I currently have ported at .22" that has plenty of meat left. Lots of more port configurations you can do with a .28" tp over a .26-.265" IMO.

This is a cheap/easy way to increase potential tp size WITHOUT requiring a new flat spot on the barrel/valve to seal on, and can be done with hand tools by the average guy. If you feel safe / skilled enough to create new flat spots without requiring o-rings than you can certainly even go bigger!





This is just a test build I am doing myself to see how far I can take the stock marauder valves porting without blowing it up using a .04" valve stem, but that aside (which I don't recommend) this mod is truly applicable to those with both heavily modified stock valves that want more meat on their sealing surface, or aftermarket valves that can take ports much greater than the stock valve can without moving the seat forward.

I feel with a gen ll bolt probe, you can safely port the barrel (.25 cal) up to around .208 sideways x .22 length wise without having pellet loading issues..at least I have.

-Matt