Pump action Omen...

[DavidBoren]

Found a mechanical frame that fits the Omen. For those who may be curious, it's an Arrow Precision Inferno frame.

The sear lines up perfectly. It would work as a mechanical semi-auto with just the frame switch, but why stop there?

The low pressure chamber is threaded for Autococker barrel threads. I am going to get a plug made to adapt an Autococker pump kit in place of the LPC.

New holes will have to be drilled in the frame to line up with the holes in the Omen body, but that is easily managed.

This is a work in progress, and sadly not very high on my priority list right meow. Thought I would share what I got, thusfar:

[Cyberpyr8]

That's really cool. Thanks for the update.

[grendal50]

AirSoldier used to have LPC plugs with a 1/8"npt hole in the front for a gauge. I think I have 2 kicking around, 1 is on an Omen 1.5, the other was for my own pump Omen project that has been on the back burner for years. I was using a PMI Piranha frame cut flat on the top, the back hole lined up pretty well and only the front need redrilling.

[DavidBoren]

I have the rear frame screw from the Inferno in the Omen right meow. Mainly to hold the frame in place so I don't lose any of it, but the thing also happens to operate with just the rear screw holes lined up and secured.

I happened across a new (in box) Inferno Terminator edition that came with an aluminum APP/Pro Line(?) 45 grip instead of the A5/Maverick/Tracer style grip (that was on my OTHER Inferno).

Anyways, it's nice having an all-aluminum frame solution for this beast if I ever choose to send it to ano. Until then, it already matches pretty well.

[Jonnydread]

Well now I’m paying attention

[DavidBoren]

It only needs a front frame hole drilled and a back block 3D printed, I just don't have the tools for any of that.

[grendal50]

That's an idea I hadn't thought of, and an option I didn't have at the time. I do have a 3D printer..... I'll get back to you, my modeling skills suck, but this looks simple.

[grendal50]

Quick render, gonna print out one in white Petg(it's what I have on rn), no hole yet for pump arm.

[DavidBoren]

Thank you very much for including one of these.

From lining this up, I think that the added feature to be drilled and tapped for the pump rod could be both thicker and deeper.

From front to back, extend the extrusion to be flush with the back of the top tube portion (the taller, left portion in this picture).

And also bulk the extrusion out to the left of the market, so it is not flush along the side... that nice clean edge in the front of this picture... needs to be fattened towards us.

This will both provide more "meat" to tap into, and offer a little flexibility in the location.

[DavidBoren]

Looking at this last night, it appears that the spacing, center-to-center, of the pump handle guide rod and the pump rod used on Autococker pump kits should work on the Omen (with little to no modification necessary). This is encouraging. And the pump rod of a full-length pump kit appears to be adequate, as well. It's honestly too long, but that is the preferred direction to be off, and the easiest to fix.

Edit: Tonight I took out the bolt forward spring, replaced the mainspring with an SLPS mainspring, and replaced the valve spring with another SLPS spring. I also installed the 3D printed back block.

It worked 100% just dry firing it over and over... without air. It's 11pm, in an apartment, AND I literally have no air (other than 12g cartridges, but I won't do that to a plastic valve stem).

Looks like it's time to actually buy a pump kit. I will be inquiring about a custom 1/8npt pump handle guide rod soon...

[DavidBoren]

Evil Omen 2.0:
CP 0.685 barrel,
*random pump handle for reference*
LPC plug with 1/8npt port (will use for pump guide),
SLPS valve spring,
SLPS mainspring,
removed bolt forward spring,
Evil Omen 1.0 vertical ASA,
Arrow Precision Inferno grip frame,
Evil Scion bottomline regulator,
*13ci tank for reference *
3D printed back block.

Plus or minus what it will look like when I get the EZ pump kit. I know, it needs more purple...

[DavidBoren]

I brought the trigger frames with me to work, so I could maybe get that hole drilled. The Omem frame screws are ~4.2" center to center, which places the front frame screw hole directly in front of the Inferno frame's safety... I should be able to still make the safety work, but drilling a hole here is going to be inconvenient, at best. The placement really could not be worse, with a vertical face at the centerline of where the new hole has to be drilled... you can see the sweep marks from my calipers in the provided picture.

I hate to do it, but I might cut the trigger guard off so I can approach from the other direction... mill the trigger guard off nice and smooth, so I have a flat face to drill into. Really don't want to have to do that, but I am not sure what my other options are... I don't have the ability or tools to helicoil the Omen body to match the existing front frame screw hole in the Inferno frame, so modifying the Inferno frame to match the Omen body is my best [and only] route to take.

Ideas?

[DavidBoren]

Since the trigger frame is aluminum, do you think I could bolt a strip of steel across the top using the existing frame screw holes... then drill through the steel strip?

Would the steel plate stabilize the bit enough to drill relatively straight through the aluminum underneath... even with that weird edge right at the centerline?

[DavidBoren]

Okay, this is what I have going on, so far...

I took out the sear and put a scrap piece of 1018 bolted across the top of the Inferno frame, using the existing screw holes.

I have a pilot hole drilled where the front frame screw hole of the Omen frame would be.

The face directly below the pilot hole is actually slanted, not vertical... either way, the bit is going to want to deflect. The steel guide plate may actually end up acting as a fulcrum to snap the bit if the tip deflects too much before biting into the aluminum... not that snapping a bit is the end of the world, but it is something I would at least try avoid.

Would using a mill style cutting bit with the square tip be better than a drill bit? Can you drill straight down with those? At least far enough to give me a start for a real drill bit?

[DavidBoren]

It came out a little off-center, but I can probably correct that when I open the bore up to its final dimensions... right meow, it is a 5/32" hole, and it needs to be 3/16"... I didn't have a 3/16" bit sitting around the drill press, and I already got harped on for using company equipment/time for my own dumb $#!+... so, this is as far as I got today.

[Cdn_Cuda]

Glad to see this being revived! I have an Omen with a gutted frame I have trying to make mech. Project stalled, but looking forward to see how you do!

[DavidBoren]

Aww, much better... a little dollar store xacto knife file and like three bowls later: