[FCMEDIC]

If the purpose of drilling out the holes larger in the asa is to allow more air flow so the marker guns at a lower operating pressure why couldn't you drill out the whole opening instead of just making the opening larger. Here are some edited pics for explanation. The black area is to be drilled out.
[IMG][/IMG]
[IMG][/IMG]

[Opteron-O3]

Because if you drill the asa that youre talking about. You will have leaking problems on the asa side that goes in the spyder. The hole nearest to the valve and valve spring. Now with that said it doesn't mean its not possible to do so and have no leaks. You just have to find a way to seal it without making it permanent. Teflon tape works to a point because the air will still try to exit, but it will work.

[ferret15]

too much, dude. On the smaller hole, you have to drill it smaller and keep it high. Otherwise the VA will always give you trouble with leaking. The big hole you should leave the middle section to help act as a stopper for your reg, and you need to be extra careful not to damage those threads when grinding.

[Omitica]

This mod is possible but you need tools and patience.

If you decide to drill out that portion of the ASA, note this first.

The hole's diameter is 10mm.
If you drill out the entire diameter, then you will run into two major problems.
1) You'll have a hole that needs plugging. The threaded hole that connects the body of the gun to the ASA goes in about 7mm.
2) Your valve-pin spring will no longer exert force on your cup seal.

I recommend only drilling a 8mm hole so that you have plenty of room for the valve spring to sit comfortably.

As for that pesky leaking from the hole... Use a vice and a hacksaw to cut a 'set screw like' piece, about 2mm in length. Apply threadlock and screw it in with some tweezers from the inside of the hole you just drilled. If you go from the bottom of the ASA, you'll get threadlock all over the place and it's not fun. Then, put your ASA back into place, and screw it back in with a shorter machine bolt, and be sure to apply non-permenant threadlock, or teflon tape to insure a good seal.

--

The bottom of the ASA, which has that little nipple protruding out should not be drilled out completely. If you notice, the low pressure chamber is seated inside the body of the ASA. You can only drill out a small crescent-moon like shape without breaking the seal. You can drill, or mill it on the side of the nipple that's closest to the valve of the gun.

[rethalis]

I did this mod, and have a spyder running about 290psi. I'm swapping the parts over to a newer style body when it comes in. When I take it all apart I'll throw up pics of my modded front block.

[SparkyGT]

a buddy had one overdrilled, with the threads leaking, ran a aluminum tube through it, cut to fit, loctited in. could jb weld also, the screw hits the pipe and put a small dent in it from looking inside. but the threads dont leak. shoulda took pics i guess.

[nenkitsune]

The best way to drill it, is to try and get the hole to be at an angle from the bottom to the body. Bigger isn't better. It's all about flow and velocity. Big ports flow a TON but lack velocity, and in some cases, will hurt low pressure setups more than help.