Can the sear be removed from the system? I think so.

[XM15]

Lightening the bolt is a good idea. I think you gain alot of things from that. Less recoil/kick lighter spring and lower pressure to operatate. I would flute it like a firearm barrel with 6 or 8 flutes. I would even tree pan the flange on the valve side to shave even more weight. I would think a bolt like that would be at least 30% or more lighter.

[hill160881]

Very good Idea, like taking notches out of the area where the sear grabs?

Something like this? I can always take more off but I already took off 4.5mm on the diameter and cut notches.

It is really light. My scale wont turn on, dam. It makes a noticeable difference in recoil when dry firing.

[hill160881]

The next step is to de-volumeize the shot chamber. Here is the sketch of the insert I want to have Luke make. but I need to figure out a starting point on the % reduction.

[snoopay700]

Little late in on this discussion, but do you know what surprises me most about this: That no one thought of it earlier... Think about it, PumpMag. The sear's ONLY function in a pumpmag is to hold the bolt back to overcome the wave-spring... The logical next step should have been, well, the sear has no real purpose then in other configurations... Well, apart from preventing the degassing fart when the air pressure is too low.

Wow... sometimes innovations is just so simple, it is missed altogether.

Nicely done Hill.

Actually a few have had this idea throughout the years, myself being one of them, warbeak being another to come to mind, though i'm sure there were many more. The main problem was always time and money, but i'm assuming he found a deal or had the parts on hand.

Hill, i think you'd be better off making it so that it matches the ID of the inlet to the dump chamber, and make it the entire length of the dump chamber. Then you should also make it so it gradually opens up to the ID of the power tube. I think you'll see the greatest increase in efficiency this way.

EDIT: this is what i mean hill, the grey is the insert

[hill160881]

Thanks much.

Actually i am into the Ego mags, and have been making the frames for people. So I had all the parts minus the different noid. That was less than $50. If you have a Star framed Ego mag then all you need so far is the noid. But i dont recommend you do this unless you have a passion for making a efficient mag that doesent eat it self. You may go crazy and never achieve it, or both.

[XM15]

I wasn't actually thinking of notches in the bolt like that. I was thinking of something more like this.




Its a old foamie bolt before the lvl 7. The stock lvl 7's I have weigh 2 oz this one with the foamie and lightening milling weighs in at 1.6 oz a 20% weight difference. If you want to try it out your welcome to it. The sear edge of the bolt is kind of worn but I think it will work.

[hill160881]

Cant do that with a L 10 because they are so thin. At least that is what the cads drawings show. Good Idea for a Level 7 bolt to take the weight out.

[Newt]

If you can find a vendor who will do real type III hard anodizing, a 7075 aluminum bolt may be a viable option these days.

[Frizzle Fry]

This is the real danger. If something looses pressure it will go full auto until you turn off the air.

I'm picturing every scared renter ever when their Tippmann runs low on c02, can't completely recock, and goes full auto. Or anyone who's ever used a Proto SLG (which does the same thing when the tank runs dry) or (god forbid) Proto SLG users who've experience a sear snap. I can't find an SLG animation, but trust me it looks familiar...

[hill160881]

3+ cases and no run away yet. :) (Knocking on wood right now.)

[hill160881]

Ok today was the first real day of play and the only problem i am having is an occasional drop in LPR pressure because the AKA reg is just not up to this task. This causes a hot shot and it brakes the ball in the barrel. So I am putting the pebble on it next week.

In the mean time I thought I would show off the great accuracy that this new firing order produces. At 20 yards it is ball on ball. Keep in mind that I am standing and in simi mode so I have to pull the trigger every time at high rates of fire. Also THIS IS DXS FIELD PAINT. So not the greatest.

At 20 yards and 280 fps I will hit you in the head almost every time, even while ripping . It is so accurate that it is scary, All the way out to where they hit the ground. One reason is no more recoil. Devilman got a side by side comparison between my pinstriped baby and the reverse mag, so he can confirm my statements as will this video. That poor mask.

Notice how silent it is at 20 yards away.

http://www.youtube.com/watch?v=lr9WFby2t74

[Pneumagger]

Thats pretty sick.

Try adding an LP volume chamber. That may halp with the occasional hot shot issue.

So to sum up... you're getting more efficiency, smoother shooting, better accuracy and the only changes are:
1) reverse sear cativation
2) Decreased dump chamber volume
3) correct spring selection and lightened lvl 1o bolt.

[hill160881]

Thats pretty sick.

Try adding an LP volume chamber. That may halp with the occasional hot shot issue.

So to sum up... you're getting more efficiency, smoother shooting, better accuracy and the only changes are:
1) reverse sear cativation
2) Decreased dump chamber volume
3) correct spring selection and lightened lvl 1o bolt.

I have not yet reduced the chamber size but yes. The efficiency is about where a Level 7 clasic mag is right now. That is with a L10. I hope to use a plugged L10 bolt with the reduced shot chamber. My goal is to get it from 1280 to 1500 rounds per 68/45.

It is a fickle beast though. To much or to little pressure on either reg can cause it to not work properly. The input pressure will change things as well, because that is what controls how much pressure is needed by the LPR.

The gold bolt spring is the one I am using again.

[Pneumagger]

I was thinking...

A classic valve with the reg capped and the top of the on off chamber bypassed to the input should behave EXACTLY like your reverse mag valve. You would probably have to pt an RT on/off in the classic valve though.

The pressure feedback regulator on the xvalve (the reason it recharges so quickly) is irrelevent when you use the on/off to control bolt movement. No reason to take apart a $$ xvalve to play with the dump chamber when you can get the same result from a classic.

using a nice large braided line, or fat hardline, or capping the reg to make a sort of volumizer might give you quicker flow to the bolt.

Something else to think about... do you think a heavier bolt helps get your velocity up? A heavier bolt has more inertia to get moving allowing the dump chamber to build more pressure before the bolt stem can clear the powertube. Then maybe you can use the small bolt springs again.

Finally, why not just set the lpr pressure above and beyond what's needed, or give the ram more leverage. As long as you have a QEV, I think you'd be fine. Are using a ULT or RT on/off?

I love following this project.

[hill160881]

I dont think a clasic valve would work due to the flow rate. Also I rely on the RT effect to get it to function without shoot down(theory). Taking the pwoer tube off an x valve takes seconds now that I know how, so the de-volumeizing inserts will take less time to install than a Level 10 carier. The x-valve I have been using can be easily done by hand without destroying the oring.

The heavier bolt and heavier spring does not help wit turning up the velocity. I went back to a lighter spring and bolt and the speed went up not down. I did not foresee that outcome but it kinda makes sense with how the level 10 bolt works with a slower build up of pressure as opposed to a intense release of air. Less air is lost through the small port in the stem of the bolt prior to venting(theory).

A larger line is not needed, I would think in this design due to the flow rates at a input pressure of 800+ psi. I cant cap the reg on the back because the X valve is not as easy to cap due to its reliance on the high input pressure for its response time on the on off assembly, as the input to the valve and the top of the on off assembly are connected internally. Hince the input pressure affecting the rt speed. This may work with a clasic valve like you stated above but may suffer from shoot down if the shot chamber could not stay at the 300+psi during sustained fire. The on off in a clasic mag just wont flow much air without alot of pressure behind it and you cant plug the top of it because that is what makes it move down, the pressure from above the little teflon o-ring in the top pushes it down.
If it were pluged it would need a spring. Even if a rt on off were used it would still need the pressure from the top to push it down.

The higher the LPR pressure the harder it is to get a consistent crono, it is a very fine ballance between input pressure and lpr pressure, depending on how fast (fps) you want to shoot and how efficient you want it. If I set the LPR to high I cant get it to crono over 250, if I set it to low it will end up with hot shots and not be very accurate, or it could just runn away. Basically I turn the LPR down 1/4 turn or as far as I need to get it to hit 290. I then when cronoed at 290 I adjust the lpr up to get it to 275 ish. The LPR pressure has more to do with the true dwell than the board. Higher pressure shorter dwell, lower pressure longer dwell.

This is what the testing suggest anyway. It may all change when I de-volumize the shot chamber.