Marauder transfer port is not symmetrical, was possibly not air tight.

[SpeedyBB]

So I learned my transfer port is not symmetrical because I accidentally shot it off the tube when the gun was apart, more on how that happened down below if you're interested. Anyway, I had never pulled the transfer port off of the tube before, never fell off either, I once gave it a wiggle and it felt like it was in there tight, so I just assumed it was a snug fit and left it alone. Me shooting it off was the first time it had been off, and I noticed that it has a really hard time fitting into the tube on one side (the way it was from the factory), but the other way it fits right in. There were even marks on the transfer port left by the tube where it was forced in from the factory. The transfer port opening on the breech end is just slightly larger than the tube, so the large end that doesn't fit well into the tube does fit fine into the breech. So now I have flipped it around the other way. I'm not sure if it was ever completely air tight all along now, seems like it probably wouldn't have been full engaging the rubber o-ring tightly enough since it wasn't slotting into the tube the way it was meant to. I need to let the blue loctite cure, but I fired 4 shots through the chronograph after I got it back together and there is a 25-30 fps gain. Sometimes when tuning and shooting through the chronograph a lot there were shots that were way off the curve, usually too low, I figured it was just the chronograph, now I'm thinking it was the transfer port. Now that it should be properly engaging the o-rings on both sides I'll update you guys later to see if this could be a potential problem from the factory to check for if someone has erratic velocities. Now, I did just add more graphite to the hammer and tube, whether that would really add that much velocity is yet to be determined, it didn't seem like all of the previous graphite I added was depleted though, and always cocked really smooth. 

How I shot the thing off the tube. I have had the gun apart numerous times now, and I had it apart again to add some blue loctite to the stroke adjustment screw because it was moving like a quarter turn in just 20 shots, really annoying I couldn't take it anymore. I figured since I was in there I might as well add more graphite powder to the hammer, and my method of distributing it evenly around the tube without dumping it down the trigger group requires me to remove the trigger group. When I was putting it back together I guess I somehow managed to get the hammer to engage the sear. I was tightening hammer screw and two trigger group screws down and *bang*, scared the daylights of of me. Thankfully it the transfer port wasn't pointing towards my face or one of my ears, but I heard the transfer port go *tink* *tink* *tink* on the other side of the room. Got a flashlight and started searching. I managed to find the transfer port under my desk, and even managed to find the o-ring not far from where the transfer port was. I was surprised how lucky I got because it took all but 60 seconds to find both of them. No damage to the trigger group or sear as far as I can tell, it feels just like it always has.

[USAFANG6799]

Interesting find.
Another example of things happen for a reason?

[SpeedyBB]

Interesting find.
Another example of things happen for a reason?

Yea, I guess so.
Fingers crossed it'll just be a better shooter than it already was.

[triggertreat]

Lol, Don't feel like you're the Lone Ranger on shooting TP and O-rings across the room.  You did get really lucky on the find as well.  I have spent much, much longer on the hunt.


If you want to know for sure that your TP and breech O-rings are sealing good, use the degas tool while holding your finger over the shroud/muzzle opening with the shroud tight to the breech.  Just open the valve slightly and get the air going a small amount and then cover the muzzle once comfortable with a small air flow going.  You should get back pressure against your finger and shouldn't here any leaks from the TP or breech seal.

[SpeedyBB]

Lol, Don't feel like you're the Lone Ranger on shooting TP and O-rings across the room.  You did get really lucky on the find as well.  I have spent much, much longer on the hunt.


If you want to know for sure that your TP and breech O-rings are sealing good, use the degas tool while holding your finger over the shroud/muzzle opening with the shroud tight to the breech.  Just open the valve slightly and get the air going a small amount and then cover the muzzle once comfortable with a small air flow going.  You should get back pressure against your finger and shouldn't here any leaks from the TP or breech seal.

You do that in a similar way? I don't even remember how I could have managed it, but it obviously happened.

As for checking for a leak, I'd do that if I had a degas tool, maybe I should get one then. I have the transfer port turned the other way now though. That said, velocities did seem more consistent and pressure went down just a little bit slower despite it being a cool day and the gun shooting 25-30 fps faster, exactly 100 psi every 5 shots, how convenient. The 25-30 fps gain remained on the first string but that calmed just a little bit but still remains a bit higher than before, I guess a fresh coating of graphite powder was responsible for much of that. It might sound slightly different than before but can't say for sure. It starts hammer bouncing about 100-150 psi later than it was, so I have gained at least an extra 5 shots. There may been an accuracy improvement, but it doesn't seem like it was much if anything. I think there was a leak but it was a small leak.
It's something to watch out for. If you have a marauder check to see if your transfer port seats into the tube properly.

[triggertreat]

Lol, Don't feel like you're the Lone Ranger on shooting TP and O-rings across the room.  You did get really lucky on the find as well.  I have spent much, much longer on the hunt.


If you want to know for sure that your TP and breech O-rings are sealing good, use the degas tool while holding your finger over the shroud/muzzle opening with the shroud tight to the breech.  Just open the valve slightly and get the air going a small amount and then cover the muzzle once comfortable with a small air flow going.  You should get back pressure against your finger and shouldn't here any leaks from the TP or breech seal.

You do that in a similar way? I don't even remember how I could have managed it, but it obviously happened.

As for checking for a leak, I'd do that if I had a degas tool, maybe I should get one then. I have the transfer port turned the other way now though. That said, velocities did seem more consistent and pressure went down just a little bit slower despite it being a cool day and the gun shooting 25-30 fps faster, exactly 100 psi every 5 shots, how convenient. The 25-30 fps gain remained on the first string but that calmed just a little bit but still remains a bit higher than before, I guess a fresh coating of graphite powder was responsible for much of that. It might sound slightly different than before but can't say for sure. It starts hammer bouncing about 100-150 psi later than it was, so I have gained at least an extra 5 shots. There may been an accuracy improvement, but it doesn't seem like it was much if anything. I think there was a leak but it was a small leak.
It's something to watch out for. If you have a marauder check to see if your transfer port seats into the tube properly.

No, not by accidently firing the trigger, but usually degassing too fast while forgetting about the bottom O-ring.  Or, manually firing the valve with a rod and hammer when working on it.


Yes, my two Marauders are sealed tight when testing as described.  The .22 has a stock TP.  It is just slightly off center with the valve's exit port, which is common, but it does seal tight regardless.

[Tucobenedicto]

I don't own a maurader,i have a Prod,but the TP is similar.
I think the TP must free float  a bit or can be the seal on the "snug fit" side can't be compressed enough to seal properly,so yes,can be a potential
issue.

[bear air]

I have an armada that I'm having problems getting a cothran transfer port to seal properly. I have been using the Hill HFTP and I think the way it works is a little forgiving with things like this.