[SalemPB]

so i had just fixed all the the leaks in my gun and had set my lpr to the lowest it could be, i gassed up my gun and began slowly turning up the lpr as i fired, once i got to say 2 or 3 turns it randomly fired really loud and blew out an o ring in the bolt, the oring was undamaged but it had been taken off of its socket, i replaced it and it happened again, does anyone know what the problem might be? maybe i need to be even more careful and slow when im adjusting the lpr but i really dont think that is it. Any feedback would be great! thanks! (p.s i have yet to open up the gun and take out the lpr and change o rings)

[510waffles]

sounds like the oring is incorrect size

[TheGuy]

Which oring on the bolt?

Try turning your HPR to zero then back it out to where the gun is shooting 280-290fps.

[510waffles]

He could be shooting at 500 FPS with LPR at highest pressure and an oring isnt suppose to fly out so check the oring size in the manual

[SalemPB]

okay thanks, but u guys dont think it has anything to do with the lpr itself? and it was the o ring that fits inside the bolt, i have a rubber oring i think i need an eurathane one or w.e its called, is this true?

[510waffles]

SalemPB, on 28 July 2012 - 11:31 PM, said:

okay thanks, but u guys dont think it has anything to do with the lpr itself? and it was the o ring that fits inside the bolt, i have a rubber oring i think i need an eurathane one or w.e its called, is this true?

urethane ones arent going to seal properly. even if the LPR overpressurizes, orings should not fly out. Best you can do is probably buy an oring kit. Worry about the bolt shooting out an oring, then worry about the LPR if you cant get it to shoot.


5 turns out from all the way in on the LPR is about 75 PSI so thats a good place to start


I forgot to ask, but is the gun ever shooting when it blasts the oring out?

This post has been edited by 510waffles: 28 July 2012 - 11:54 PM

[SalemPB]

no it was doing its low lpr pops everytime i pulled the trigger then randomly when i turned it up one time i fired and it burst the o ring in the bolt, and its one of hte orings thats on the inside of the bolt, i was dry firing it the whole time and i was not able to get it go be able to succesfully dry fire it

[510waffles]

the lpr pops?

[SalemPB]

510waffles, on 29 July 2012 - 12:07 AM, said:

the lpr pops?

no as i was turning up my lpr an o ring popped out of place (it was a loud shot) and then it wouldnt do anything because the oring was out of place.

[510waffles]

from the back of the gun? or the breech?


take out the bolt engine and make sure all the orings on it are nice and snug

This post has been edited by 510waffles: 29 July 2012 - 12:09 AM

[SalemPB]

510waffles, on 29 July 2012 - 12:09 AM, said:

from the back of the gun? or the breech?


take out the bolt engine and make sure all the orings on it are nice and snug

yeah just did and theyre all on theyre pretty good, when i pinch them together a few come up slightly, is that a sign of wear and tear?

[Pakistani]

turn both of your regulators IN all the way(clockwise) until they stop turning.
turn out the HPR screw for ~3 turns. then slowly turn out on the LPR.

shooting out an oring means the HPR is up too high.

[Steel546]

SalemPB, on 29 July 2012 - 12:30 AM, said:

yeah just did and they're all on they're pretty good, when i pinch them together a few come up slightly, is that a sign of wear and tear?

That doesn't sound like an LPR problem. Are you sure you're using the LPR and not the HPR? It's okay if you pinch them and they come up a bit, that's normal. And I bet it's the top hat o-ring, it's surprisingly common on DMs in my experience. I'd go along with what the other guys are saying here.

• Put all o-rings back into place, lube bolt.
• Turn in LPR and HPR all the way.
• Back LPR out 3 to 3.5 turns. Turn gun on, eyes off.
• Slowly back out HPR, pull trigger intermittently and keep doing both until gun starts shooting normally.
• Chrono next chance you get.

In this picture below, is it number 7?

Pakistani, on 29 July 2012 - 12:54 AM, said:

turn both of your regulators IN all the way(clockwise) until they stop turning.
turn out the HPR screw for ~3 turns. then slowly turn out on the LPR.

shooting out an oring means the HPR is up too high.

Switch those. High LPR isn't dangerous, high HPR is.

[SalemPB]

okay thanks for all the help it sounds like my problem before was that i was only turning up the lpr instead of both at the same time, either way it was really strange. but thanks and next time i get a chance ill go and set them back and then slowly turn em up at the same time

Steel546, on 29 July 2012 - 01:05 AM, said:

SalemPB, on 29 July 2012 - 12:30 AM, said:

yeah just did and they're all on they're pretty good, when i pinch them together a few come up slightly, is that a sign of wear and tear?

That doesn't sound like an LPR problem. Are you sure you're using the LPR and not the HPR? It's okay if you pinch them and they come up a bit, that's normal. And I bet it's the top hat o-ring, it's surprisingly common on DMs in my experience. I'd go along with what the other guys are saying here.

• Put all o-rings back into place, lube bolt.
• Turn in LPR and HPR all the way.
• Back LPR out 3 to 3.5 turns. Turn gun on, eyes off.
• Slowly back out HPR, pull trigger intermittently and keep doing both until gun starts shooting normally.
• Chrono next chance you get.

In this picture below, is it number 7?

Pakistani, on 29 July 2012 - 12:54 AM, said:

turn both of your regulators IN all the way(clockwise) until they stop turning.
turn out the HPR screw for ~3 turns. then slowly turn out on the LPR.

shooting out an oring means the HPR is up too high.

Switch those. High LPR isn't dangerous, high HPR is.

Yes !! It was number 7! i was slowly turning up the lpr and randomly one shot was like BLAM and blew the oring out of place

[cybermaniac15]

That oring only pops out if the hpr is too high.

[Steel546]

SalemPB, on 29 July 2012 - 01:20 AM, said:

Yes !! It was number 7! i was slowly turning up the lpr and randomly one shot was like BLAM and blew the oring out of place

Damn, do I know my DMs or what. I'd still do what I suggested above.

[SalemPB]

thanks for the help everyone! truly appreciated!

[Pakistani]

Steel546, on 29 July 2012 - 01:05 AM, said:

Switch those. High LPR isn't dangerous, high HPR is.

no, thats wrong. high HPR might blow an oring off the bolt, but high LPR will kill your noid and consequently your gun.
in fact, i've demonstrated this at the field before by turning my dm6's HPR up all the way before. shot the ball out at 420fps and blew an oring. nothing was effected afterwards.
the LPR is what you have to worry about.

the method i posted has been used in all of my dms since 2005(dm4-present) and its the most bulletproof way to set up a DM.

This post has been edited by Pakistani: 29 July 2012 - 02:24 AM

[alex5947]

Did you, or someone else recently maintain the hpr or the lpr? If so you might have a shim missing in either the lpr or hpr, which I believe can make the gun over pressurize. Also replace all the origs in the hpr, lpr. And check the reg seat for damage if the dm7 has one.

Also, to tune your dm.

1. Turn all your regs in so the gun is not pressurized.
2. Slowly begin turning the hpr until you hear air flow through the passages, then stop. You should not have to turn a lot. You only do this so the lpr can cycle.
3. Begin turning the lpr until the bolt fully cycles back and forth without any hiccups, and you are getting a good response from the bolt from the time you pulled the trigger.
4. Then you can start adjusting your hpr to your desired velocity

[Steel546]

Pakistani, on 29 July 2012 - 02:24 AM, said:

no, thats wrong. high HPR might blow an oring off the bolt, but high LPR will kill your noid and consequently your gun.
in fact, i've demonstrated this at the field before by turning my dm6's HPR up all the way before. shot the ball out at 420fps and blew an oring. nothing was effected afterwards.
the LPR is what you have to worry about.

the method i posted has been used in all of my dms since 2005(dm4-present) and its the most bulletproof way to set up a DM.

Alright, I recant my statement. Of course you don't want too high of an LPR, but the method I posted I've used on my DM's (as well as every other DM I've worked on) and it works every time. That's why the ~3 turns works just fine for the LPR because you don't even need to worry about it, it's like the stock setting. Why do you think the Rails didn't even have them?