8hole mod

[Alienation]

I have heard alot of this "8 hole mod" for faster recharge, and I was just wondering if anyone had done it themselves and had pics on how to do it, or even a step by step guide on how to do it?

[Sumthinwicked]

drill press and a vise LOL

[snoopay700]

Unless yoru mag gets shootdown, don't do it.

[Alienation]

I get really horrible shoot down and I checked the spring pack in behind the adjuster and it seems to be well oiled and not compressed and I changed the asa and it doesn't have any air restrictions that I can see of.

[Sumthinwicked]

you could buy the back half of the valve with the 8 hole mod and see if you like it diamond labs and ans both had them as aftermarket parts like 27 bux

[Alienation]

Well is there any other reason it could have shoot down?
I checked everything and its all in good working order. I also have a lvl 10 coming and want to make sure that it's fixed before I put that in

[Sumthinwicked]

the tank reg itself should be set to 800 psi or higher if your at anything lower than that youll have shootdown besides that i cant think of much fyi the lvl10 will use more gas up just a warning

[Alienation]

What would be the best thing to do to try and avoid shootdown when I get the lvl 10?

[Sumthinwicked]

high pressure tank 850 psi output from the tank reg will do wonders

[Spider-TW]

Which on/off do you have? The length of the on/off pin versus how tight you make the rear frame screw and the tolerances in your rail can make a difference in the recharge rate.

I just now thought about it, but you should be able to put a ULT or L10 shim under the new style top on the classic on/off. (:confused:, maybe it needs to be a larger diameter).

The limit of the sear travel when the on/off is open is when it hits the bolt spring or the underside of the body. If you had a spring that was pooched out (that's a technical term) it could restrict the on/off opening differently from one time to the next if the spring rotates while firing.

I know for sure that with an RT on/off in a classic and pins that are too long, the shootdown can be one shot in 10 seconds up to mild shootdown at 10 bps.

[Alienation]

How do I tell which on off I have? I'm not that experienced with mags quite yet :p

[Spider-TW]

How do I tell which on off I have? I'm not that experienced with mags quite yet :p
Do you know where the on/off is?
Are you the original owner of this mag?
How long has it had this shootdown?
What kind of markings are on the valve and reg?

A round stainless on/off bottom has a stainless classic pin (mostly straight sides with a smooth notch) in it.

A square brass bottom is an RT on/off, or possibly a ULT (they fit) if someone has been tinkering with it.

Shootdown is all about air supply. Like the others said, it starts with your bottle reg. Everything between the bottle reg and the on/off has to supply the air for the paint you are throwing, so you are looking for obstructions in lines and valves or sticky regs.

The purpose of the 8-hole mod was to make sure gas could go from the reg to the valve body without having to go half way around the face of the regulator (causing shootdown). All automag "Classic" valves are lined up and shouldn't get any benefit from a mod. Many older "A.I.R." valves are lined up also. You can mark each side (the valve and the reg) on the outside with a marker and screw them together to see if they are lined up. After doing this a few times, I realized that my marks were not as good as the holes were aligned on my "Classic" valve. :rolleyes:

[Alienation]

I know where the on/off is (I think), and I'm not the original owner. The mag has had shootdown since I first aired it up after buying it, I will post some pics of my on/off and see if you can identify it.
It has a classic A.I.R valve and the holes don't line up, how do I fix that? All the writing lines up and everything but the holes are on opposite sides of the valve.

Here is a pic of my on/off (or what I think is my on/off)
http://img.photobucket.com/albums/v239/hacman01/IMG_1631.jpg

[Coralis]

Thats the original style on/off top ( the brass piece) you might want to purchase a new style one that looks like this http://store.airgundesignsusa.com/index.cfm?fuseaction=catalog.prodInfo&productID=25&categoryID=18
http://store.airgundesignsusa.com/images/product/large/lg_25.jpg

[Alienation]

Would that be what is creating the shootdown, or is it ok just to keep that piece for now?

[Spider-TW]

Would that be what is creating the shootdown, or is it ok just to keep that piece for now?
You have a bone stock 68 automag of elderly measure. ;) What serial number is it? It may have a bronze spring in the power tube instead of a "spacer" as well.

That replacement should help, but if one hole is at 12 o'clock and the other is at 6 o'clock, you will see a big improvement with one of two mods:

As Sumthinwicked said, an aftermarket reg with 8 holes in it is pretty cheap. They come up on ebay fairly often also.

The other thing that has been done is to drill the opposing hole in the reg body yourself. It doesn't need 8 holes, it just needs to be aligned. If you have access to a drill press, you take the seals off and the piston out and copy the existing hole at the right location. If you search the tech forum for '8 hole mod' you'll find a little more about this. Particularly, you can accept posts by athomas as accurate. With this mod you get to keep your laser etching intact, which I like. Match the hole depth and remove the burrs from the inside of the reg.

All your regulated gas has to go around the face of the reg to get to the valve body. A hole in the right location lets it jump right over.

[Alienation]

Where can I find the serial number? I looked all over and can only find 1 number and it's on the reg "CF12039" not sure if that is the one or not.
I also do not have access to a drill press, but I do have a vice and a hand drill, probably not a good idea though I'm guessing.

[Spider-TW]

Where can I find the serial number? I looked all over and can only find 1 number and it's on the reg "CF12039" not sure if that is the one or not.
I also do not have access to a drill press, but I do have a vice and a hand drill, probably not a good idea though I'm guessing.
That's the serial number. It should etched in two places right next to each other.

If your alternative is to never use your reg again, I would be tempted to try it by hand. However, for a little more than the price of shipping, Luke at www.lukescustoms.com can drill it for you, if you can mark it and/or describe it accurately. He is here on AO, and it will be straight. ;)

[Alienation]

I wouldn't trust myself on drilling out the reg, cause I want to keep it as classic as possible.
Thanks for all the help too.

[Coralis]

Just do a search on ebay for ans phase 2 they made a back half for mags that is the equivalent of and 8 hole mod and they are usually pretty cheap
http://i20.ebayimg.com/06/i/08/6d/77/5a_1_b.JPG


Shootdown can be caused by other things as well like if your pin valve on your air bottle is pushed in too far or not far enough it can starve the mag for air . Try doing a search for shootdown that should give you some more troubleshooting help