Automag w/ AIR Valve/L10 @ 250fps

Hi, I'm trying to get my mag working to get back into playing. It's been in the closet for almost 10 years and air'd up fine, but I'm having trouble getting the marker to fire at lower velocities for indoor play. To start off I disassembled the valved and oiled everything up well, following that I was having trouble with it firing quite hot for the first shot, ~30 fps above the following shots if the marker sat for any amount of time (10 seconds) so I replaced the regulator seat and that seems to have solved this problem.

I had the #1 carrier installed w/ two shims and the longest spring and the marker was firing around 300fps, so I switched to the #2 carrier which seemed to slide better on the bolt with out any leaking, and switched to the shortest spring. This seemed fine, but the bolt seems to be hitting paint fairly hard, and if I put my finger in the breach (not tongue!) it hits quite hard but still vents the air and resets. I can get the gun to fire around 240fps, but it jumps around from 230 to 265, I'm wondering if this is typical?

So I'm curious what I can do to make the bolt softer on paint, I'm wondering if I try cutting a spring to try and get it to keep firing around 250.

I'm also looking get more consistency in the speed if possible. The marker seems incredibly sensitive to turning the velocity adjuster, I can turn it a fair amount and the velocity doesn't change much, then it seems to get to a magic point where the velocity drops substantially in less than 1/8th of a turn.

Thanks for any help.

If you can go to a larger carrier size and still have no leaks, try the next larger size as well. You may not have the largest carrier size yet. Make sure you remove all of the shims when testing the carriers.

The shorter spring will hit harder. Find out the lowest velocity that the gun starts to fire using the spring you want to use. The optimum velocity value for your setup is about 20fps above that lowest value that will allow the valve to cycle. If the velocity is way low, then use a longer bolt spring and do it again. If the long spring gives you a starting velocity that is too high, then start cutting coils off one at a time and test the new velocity numbers until you arrive at a range that works for you. Make sure you put the cut side against the bolt.

The velocity fluctuations can be caused by a carrier that is not a perfect match. The inconsistency in the friction can cause the fluctuations at lower velocities when the friction change is a larger percentage of the differential force compared to a higher velocity setting where the friction change doesn't have as much affect.

Thanks athomas, that all makes sense. I went to the larger carrier thinking that the varying friction may have caused the fluctuations since it seemed a very tight fit when sliding by hand. I'm missing the 2.5 carrier but will try #3. I'll follow your suggestion regarding the spring troubleshooting and lowest firing velocities. I'll hopefully be heading to Moncton tomorrow after work to fill my tanks!

The #3 carrier is quite large and a full size increase is quite a big jump when you are approaching the correct size carrier. Not many orings need a carrier that big. I suspect the 2.5 is the one you may need if the 2.0 is still too tight. If the 3.0 is too large, try a new oring and go through the sizing procedure again. You may find an oring that only requires up to a 1.5 or 2.0 carrier size, which you probably have in your kit. Most orings fall into this range.