Halfback w/ a Delrin, No O-ring, ACS bolt?

[Beornwolf]

I recently halfbacked my Victor 4 which I picked up brand new at a flea market for $20. Just a simple little halfback, hacksaw and file. I just measured, and I'm about 3 1/2" into the top tube. It works perfectly with the stock bolt.

I plan at some point on upgrading it with an ACS bolt (The Kingmann one I suppose, the only other one I know of is the ACP Terminus) and with an electronic trigger. ACS bolts and delrin bolts generally have no o-rings, so my questions are:

1. Will it work since I halfbacked the marker body?
2. If so, should I get the "Universal" ACS bolt or the Back Cocking?
3. Is there any way for me to tell how far a delrin bolt has to be in the top tube for the marker to function?

Also, I know this is a little off topic, but can anyone recommend an electric trigger frame that will fit the Victor 4 (Same body as the Victor 1, 2, and 3)? I know the older style frames will work (Sprint, Dragun "The One", etc..) but they're pretty hard to come by these days. Does the 2007 Kingmann E-Trigger or the current Rocking Trigger 2.0 fit the marker?

Here's a picture of my halfback to show how it looks:

[TheDarkShadow]

all of the frames you mentioned will fit, nice half-back job too