DM8 Trial and Error. Important details I learned about LPR tuning.

okitoki · 01-27-2010, 08:26 PM

Dang... And I just sold my 7 so I won't be able to test that out

but sounds like a few people are having good results.

Good call :thumbsup:

Ginger Kid · 01-27-2010, 09:58 PM

I trul appreciate you posting this. Was wondering why i needed to raise my lpr pressure recently.

Rip Machine · 01-27-2010, 10:25 PM

Thank you. We need to get as many Matrices out there shooting to their full potential.

paintballer777 · 01-27-2010, 11:34 PM

Good post mine was torn as well

jward15 · 01-29-2010, 08:23 AM

really sweet read.i was having fsdo for a couple months now but my dm8 still shot good after that.i was considering selling bc i just couldnt fix the problem.i would have never thought it was that oring on the brass retainer.replaced it yesterday and now i cant wait to use my gun again with no fsdo.thanks alot.

Rip Machine · 01-29-2010, 03:00 PM

Glad to hear it bud. Although I don't have my DM8 anymore, I will have another DM in the future, i'm sure. But I was wanting to see if using a 010/90 urethane o-ring (should appear solid white) in place of the buna 010, which I believe is normally a durometer or 70, someone please correct me if i'm wrong, would potentially be more durable, and perform better. I may try this on one of my teammates guns in the future.

eyeownyu · 01-29-2010, 09:39 PM

im pretty sure all stock orings are durometer 70. so ya changing to a 90 would help.

rnauman821 · 01-29-2010, 11:12 PM

The next time I order rings I might just get a bag of 90's just to see.

**Lurker27** · 01-29-2010, 11:14 PM

Great thread

nevekd128 · 01-30-2010, 01:27 AM

hmmm i wonder, does the same thing happen or could happen to the brass fitting in the hyper 2/3?

im away from my marker(away in college) but i cant remember if those shread too.
but i remember that the book says 3-3.5 turns out on the hyper 2 is about 280 FPS, but whenever i would chrono when i check before i clean my reg, the hpr is usually in the 4.25-4.75 range.

So maybe its a combination of both, ill try new 10's in my hyper two and LPR, this should be in the proto forum too

nevekd128 · 01-30-2010, 01:29 AM

i actually would perfer to tune my gun to this thread, just set dwell to twenty, then fiddle with the lpr until the velocity isnt erratic.
sounds good enough to me

dane/dawg · 01-30-2010, 07:16 PM

..just checked my #10 oring on my dm8 and sure enough it was shredded..this should be in the ultimate sticky..

rnauman821 · 01-30-2010, 07:33 PM

I checked both my protos the other day and they have the same issue...

Im really really tempted to order some 10/90 orings pretty soon and see if its a fix.

eyeownyu · 01-30-2010, 10:42 PM

i just did this to a friends dm8. same results. i had to run it at 6 turns before just to get it cycling without leaks.

now with the mod its running fine at 3, i can prolly take it down even more.

ZerOxShadows · 01-31-2010, 01:41 PM

Great info. I would also like to see what some of the Dye reps say about this.

I was told by my Dye Tech to put my finger down the feedneck into the breach, apply some pressure on the bolt face, fire it, and adjust the LPR so that the bolt doesn't shoot too hard nor too soft. It's kinda hard to explain where the sweet spot is but this allows me to fine tune my LPR without having to go to zero.

ZerOxShadows · 01-31-2010, 02:14 PM

Reading through my manual again it says to reset the LPR, the user should screw in until "slight resistance is felt". Dye could argue that it never intended the user to go to zero, fore-knowing that this will likely cause the seat retainer o-ring to shred.

nevekd128 · 01-31-2010, 02:16 PM

Quote:

Originally Posted by ZerOxShadows

Great info. I would also like to see what some of the Dye reps say about this.

I was told by my Dye Tech to put my finger down the feedneck into the breach, apply some pressure on the bolt face, fire it, and adjust the LPR so that the bolt doesn't shoot too hard nor too soft. It's kinda hard to explain where the sweet spot is but this allows me to fine tune my LPR without having to go to zero.

hmmm that sounds like a good way to loose a finger tip

eyeownyu · 01-31-2010, 04:32 PM

Quote:

Originally Posted by nevekd128

hmmm that sounds like a good way to loose a finger tip

no...i do this all the time, and you can tell how smooth your gun is by this method, i just dont think its very accurate. you could still be getting inconsistency over the chrono and such.

nevekd128 · 01-31-2010, 04:59 PM

.... i still dont really believe it but whatever

eyeownyu · 01-31-2010, 05:07 PM

lol do it with your gun, it wont hurt as long as you put pressure against the bolt with your finger. if you let your finger in the breech all loose, then it will hurt.

ZerOxShadows · 01-31-2010, 06:28 PM

Quote:

Originally Posted by nevekd128

hmmm that sounds like a good way to loose a finger tip

It's a bolt not a meat slicer.