[nevekd128]

**disclaimer...DO this at your own risk, any damage or injuries cause by this is your problem, not mine.


1. buy springs.
they need to be strong enough to push the bolt past the detents and never be fully extended, ie neutral.
2. on the spring touching the backcap, at the lowest point, fatten the end of the spring so it will fit a little more snugly in the back cap.
3. insert spring or springs into back cap.
5. screw the bolt assembly into to gun body normally.
6. make sure the bolt springs have enough tension to press itself past the detents on its own.
Notes
- if the springs are too stiff, or you have too many inside, the bolt wont be able to move back far enough in the breach to allow balls to load.
-If the springs are too weak they wont move past the detents.
-The gun will operate the same but with lower settings.
-this still operates as a balanced openbolt spoolie
-the dwell and all pressures should be able to be lowered.
My dwell is at 10
lpr 2 turns and hpr...probably really hot. dont have a chrono

to get the best spring, rjones1213 says it must
1. Fit behind the bolt when at rest. I test this by setting the bolt all the way back without a spring, measure the distance from the bolt tip to the top of the can then remeasure with the spring in place and the bolt held back. If the spring takes up too much room the bolt won't return all the way. Some people may get away with a spring that is too long but still allows the bolt to return almost all of the way. This could cause leaks and balls not feeding.
2. Have no slack through the entire firing cycle. The main part where the spring will have slack is at the end of the stroke. Hold the bolt as far forward as you can and shake the bolt kit, if you can hear the spring moving around it is too short.
3. Push past the detents, pretty simple.

If the spring meets all of those standards I would say use it. If you really want to find the best, test consistency and efficiency with each spring.

[OLD_B4LL3R]

I gotta a good laugh at "all you PMR people dont bother me with, uhhh will this work on my PMR?" good lulz

Man - I'd be scared of that spring getting ejected out the back.... My luck - go right through my Lens....... (Maybe a washer big enough to let the bolt tip pass through, but small enough to make sure the spring wont eject? But I do see where you widened it... but will it hold up?

Play a couple weekends with it, and report back.

I give ya mad props for modding and thinking outside the box!

I still dont understand how such a low LPR setting can hold the bolt back with the springs under tension, I will buy a kit tomorrow and look at them, maybe Im thinking they are to tight of a spring and they aren't? I dunno.

Anyway - Great job and thanks for the time putting the tut together!

.

[nevekd128]

take out your dm9 or pm8 and air it up, and try to push the bolt forward with an allen key, there is alot of pressure holding the bolt back lol

[nevekd128]

Originally Posted by OLD_B4LL3R

I gotta a good laugh at "all you PMR people dont bother me with, uhhh will this work on my PMR?" good lulz

Man - I'd be scared of that spring getting ejected out the back.... My luck - go right through my Lens....... (Maybe a washer big enough to let the bolt tip pass through, but small enough to make sure the spring wont eject? But I do see where you widened it... but will it hold up?

Play a couple weekends with it, and report back.

I give ya mad props for modding and thinking outside the box!

I still dont understand how such a low LPR setting can hold the bolt back with the springs under tension, I will buy a kit tomorrow and look at them, maybe Im thinking they are to tight of a spring and they aren't? I dunno.

Anyway - Great job and thanks for the time putting the tut together!

.

i shoot it again today and had no drop off shooting 10bps psp(i always cap 10) and my lpr was out 1.75 turns, but i can lower it more still, but i found i need to crank up my hpr more, so im thinking the hpr will need to come up more since the lpr is lower and the dwell is so low. or i could try putting the dwell to 15 and seeing what happens .... im guessing smooth as glass?/

[rjones1213]

Thanks for the How-To, I plan on doing this very soon

[icweiner]

i dont like the "dont screw your tophat in all the way" part of it. why will the bolt be pushed to far forward? you arent making anything longer. im guessing because the pressure wont hold the bolt all the way back?

[KingJester68]

a compressed spring takes up area...

[rjones1213]

The bolt kit won't fit into the gun unscrewed that far, it is made to fit only with everything completely screwed together so I don't think it stays apart once put into the gun. I am def going to get this working on my DM8 since I used to have a spring modded shocker and it shot amazing. I already love my DM8 and I can't wait to make it smoother.

[dyepb_16]

every time i try this it initially aires up fine and the bolt is back but after i shoot once the bolt sits like halfway into the breech. any idea why or what i can do to counter act this? also i went to home depot and got the same spring kit and i think i am using the same springs as you and tried stacking them and it didnt have nearly the same ammount of forward force as yours and didnt even fully extend like yours does. this is stumping me

[KingJester68]

you need to increase your lpr. The LPR is used to adjust the pressure used to push the bolt back to resting position i.e. out of the breech. He also mentioned having stretched the springs that he used. Did you remembered to do that?

[dyepb_16]

the op lowered his lpr so why would i have to increase mine? plus i tried increasing it all with the same results. i tried a few springs then went back to them and now they work...... sorta. I have stretched them out and did that every other time but they always depress back any idea how to get them to not depress back? and with out the springs everything seals fine but with the springs it has a small leak out of the back cap. also would this work with the top hat mod?

[OLD_B4LL3R]

Originally Posted by dyepb_16

every time i try this it initially aires up fine and the bolt is back but after i shoot once the bolt sits like halfway into the breech. any idea why or what i can do to counter act this? also i went to home depot and got the same spring kit and i think i am using the same springs as you and tried stacking them and it didnt have nearly the same ammount of forward force as yours and didnt even fully extend like yours does. this is stumping me

Yeah, this is what I was talking about. If your bolt system orings aren't broken in, and smooth as a baby's butt, you may have a little more friction than nevekd128, so the LPR pressure is what holds the bolt back into the breech and it may need to be raised to do so.
That's why I was stumped, saying his standard LPR 1.5 to 2 is holding the bolt back. I think my orings may not be broke in yet, cause Im a solid 2.5 to 3 on both my DM9 and PM8, any less and I get mad drop off and skipped shots, from bolt not resetting quick enough.
Another thing to remember is that everyone's dm and pm pressure can be slightly different, that's why there are not 1 setting that works 100% on all the same, just guides on how to "tune" to the best yours will shoot.

I still want to toy with this, but nevekd128 - another question.
Does the spring ride on the tail of the bolt? If so, does it scratch it at all? My concern is the top hat internal rear oring, riding on the tail if it's scratched.
Im off work today, and am going to pick a kit up. I've got a stock bolt I can tinker with, as I have both my DM and PM with Bwing Bolts.

Thanks nevekd128.

.

[ccluff2]

the spring really needs to be conical so you dont scratch your back caps inner bore.

[dyepb_16]

but does anyone have any idea why it would leak out the back of the bolt when the springs are in but seal fine with out them?

[FullMetalJester]

the bolt sail is too far forward for the inner oring to seal in the backcap......

[dyepb_16]

ohhhhhhhh ok that makes sense

[nevekd128]

Originally Posted by OLD_B4LL3R

Yeah, this is what I was talking about. If your bolt system orings aren't broken in, and smooth as a baby's butt, you may have a little more friction than nevekd128, so the LPR pressure is what holds the bolt back into the breech and it may need to be raised to do so.
That's why I was stumped, saying his standard LPR 1.5 to 2 is holding the bolt back. I think my orings may not be broke in yet, cause Im a solid 2.5 to 3 on both my DM9 and PM8, any less and I get mad drop off and skipped shots, from bolt not resetting quick enough.
Another thing to remember is that everyone's dm and pm pressure can be slightly different, that's why there are not 1 setting that works 100% on all the same, just guides on how to "tune" to the best yours will shoot.

I still want to toy with this, but nevekd128 - another question.
Does the spring ride on the tail of the bolt? If so, does it scratch it at all? My concern is the top hat internal rear oring, riding on the tail if it's scratched.
Im off work today, and am going to pick a kit up. I've got a stock bolt I can tinker with, as I have both my DM and PM with Bwing Bolts.

Thanks nevekd128.

.

good point, cause where i am, im shooting it when its about 100 degrees outside and thin layers of monkey poo. i shot it last night and i just set my lpr to 2 turns so i wont have drop off, but it was lower with no drop off i could see at psp10, but i just bumped it up a little just because.

[nevekd128]

and with the backcap gettins scratched...
ive looked in mine and see no scratching as of now, but i do believe it could occur. just make sure the burs on the ends of the springs aren't sticking too far out and it sould be fine. Also try adding some lube with a qtip down there so there is less friction the spring can catch on.

i really forgot to think about that, but ill check mine and see hoe the bore looks

[rjones1213]

I got the spring kit and it seems like you could use 1 spring, there is a cone spring that is big enough to fit into the back cap. I am going to start trimming the spring and see if it can fit when compressed and extended.

edit: with my DM8 backcap, I can not get the 2 springs the OP used to work. they end up just collapsing and overlapping. Hopefully I can find a wider spring to work with.

[rjones1213]

Well here is my spring mod for a DM8. I couldn't get the 2 springs to work so I modified one of the cone springs from the kit to fit.
Here is the spring by itself. Don't mind the funny shape, I did stretch the bottom and pulled it to make it longer with less coils.

Here is my spring next to the 2 springs the OP used.

Here is my spring next to the original spring


My spring is just long enough so there is no room with the bolt fully extended yet fits with the bolt all the way back. I'm not exactly sure how many coils I cut off but I can count if anybody wants an exact number. Since a lot of DMs has different length and size backcaps I would suggest simply cutting your own spring to length.
One thing I did learn is that if the spring is taking up too much room, stretch the spring out and cut more off. This leaves less metal to take up room but leaves enough pressure.

I still need to test this spring in my gun, my DM is not together right now since i've been working on it but I might put it together to test this out.

PS: my bolt kit is completely screwed together with this spring

[icweiner]

you test it?

edit: saw your edit lmao. ill try this next week, i would today but my gun works perfect atm so im not touching it before i play today :p