I've decided to hack up my AR2078

[leftcoast1]

I'm going to try a mod i've read about several times. It should yield 800fps in .22 bulk fill only with a good consistant shot count. I'm sure I will be enlisting the CO2 God for help. The modded probe will probably be the hardest part. I think I'm going to start it on monday. I'll let you all know.

[yel01z06]

let us know how it goes. What mod are you doing to it?

[ribbonstone]

....what ever the out come, you always learn something.  YEP...have learned some negative things as well as positive, but if you learn what doesn't work, can figure out what does.

[leftcoast1]

I'm going to lighten the hammer and open up the valve also alter the bolt probe. After that's done I'm going to get a delrin topped valve. The only downside is once this is done it's bulk fill from here on out. If it yields what it's supposed to it will turn out nice

[TCups]

Jason:

Good luck and let me know how it turns out.  I have ordered myself an AR2078 and enlisted the help of another of the CO2 "gods", Mike Melick, to tune the rifle down and go for a target version strictly for punching paper.  Both should be fun.

[leftcoast1]

Hey T check with Peak I think see had one from Mike Just like you are talking about. If you are getting it from Mike it will be sweet. Let us know.

[PeakChick]

Tommy, I thought I tease you just a bit. Here is my AR2078A that Mike tuned as a paper puncher. Shoots in the low 600s with 8.3 - 8.5 gr pellets. It just makes one little hole in the paper (Grackles too), effortlessly. It is not pellet fussy at all. I have it set up now as a mini-sniper and short to mid range Grackle tool. You will really enjoy shooting your new AR.

[leftcoast1]

Turn out so well. I would say it needs to be done on a mill. I was told it can be done by grinding it but notso for me. I will putting in a call to Archers for a new valve kit and off to mike it will go when I get the money. :0

[mikeiniowa]

I'll bet you tried the grind the sides flat to open the valve up.....aluminium is a bugger to work with,,,,what I have been doing for the dedicated bulk fill is to drill the end of the valve out to !/2 inch and then taper the sides to help the flow, then add a #1692k36 spring from McMaster-Carr, you will need to reduce the end of the valve to fit the end of the spring do it stays put and taper it, you can open the area around the valve head in the brass end and make it larger, taper the opening to fit the ID of the aluminium end so the gas flows smoothly, ow away the washer and pin, or at least set them aside.....should get you in the ball park, depending on the rest of the porting etc......

[leftcoast1]

Yep Mike dead on the money. I forgot what a pain in dairy aire it was to work with aluminum. When I get new my new valve I'll get with you. Maybe I should buy 2. hehe.
Thanks Mike.

[tat2dman]

See the PM I sent ya...

[leftcoast1]

Got it Barry thanks.

[yel01z06]

did u ever get your mod done Jason?

[leftcoast1]

Started it and it turned to crap. I just got some extra parts so I'll start over soon as I finish my G1.