Definite manufacturing issue with 2k9 mag

[Henchman]

Trying to get to the bottom of my 2k9 issue of not being able to get it up to a proper velocity, I decided to make a quick measurement.
And they're is definitely a manufacturing prolblem.
I measured inside the body from whe the valve ring in a regular mag body is, to whe the field screw goes. It was about 2 3/4 inches.
With the 2k9 it's 3 inches.
Thats a huge difference with the small tolerances Automags work under.

Can anyone here with a 2k9 and a standard mag, checkmy measurements.
If those with proper functioning 2k9's report different numbers then I can only surmise that some of these we not milled correctly.

[OPBN]

Measured a ULE and MiniMag body, both came in at about 2 7/8" to the front of the FS hole. Measured my MM2K9 without the insert and came in around 2 15/16, With the insert it is closer to 2 3/4, but probably because there is a lip on the insert keeping the tape measure from going in the extra 1/16 of an inch. I chrono fine. 285/290 all day long.

[Henchman]

Measured a ULE and MiniMag body, both came in at about 2 7/8" to the front of the FS hole. Measured my MM2K9 without the insert and came in around 2 15/16, With the insert it is closer to 2 3/4, but probably because there is a lip on the insert keeping the tape measure from going in the extra 1/16 of an inch. I chrono fine. 285/290 all day long.
Mine is 3" with the insert.

[OPBN]

Just so we are on the same page, I am using a tape measure that just fits inside of the body. I am sliding it in until it hits something. In this case it's the lip from the insert.

[Henchman]

Rechecked my measurements,also using a tape measure.
I am measuring from where the spring will hit the insert on the 2k9, and the metal insert on the ule body.

The ULE ring to the FS is 3 1/2 "
The 2k9 ring to the FS is 3"

[Henchman]

OPBN, when you look into the breach, what do you estimate the thickness of aluminum from the insert to where the removable breach is? Mine is about a 1/4" of aluminum.

[OPBN]

Rechecked my measurements,also using a tape measure.
I am measuring from where the spring will hit the insert on the 2k9, and the metal insert on the ule body.

The ULE ring to the FS is 3 1/2 "
The 2k9 ring to the FS is 3"
Ive measured 3 seperate bodies and all of them are 2 7/8 to the front of the FS hole. If you are getting 3 1/2" something is wrong. The spring sits on the inside of the insert, my tape measure will not fit inside the insert, so I am measuring from the lip. Before you were saying the MM2k9 was longer, now you are saying its shorter?

[Henchman]

Ive measured 3 seperate bodies and all of them are 2 7/8 to the front of the FS hole. If you are getting 3 1/2" something is wrong. The spring sits on the inside of the insert, my tape measure will not fit inside the insert, so I am measuring from the lip. Before you were saying the MM2k9 was longer, now you are saying its shorter?
Im sure my tape measure is a little off.
The big issue is the discrepency between the two different bodies, using the same tape measure.

Coudl you look down teh feedneck, and see rough how thick teh aluminum is where teh insert sits against. I have a sneaky suspicion that some offense bodies were not milled down far enough inside. Causing some of them to not work properly, because there is too much pressure because the bolt can not slide in far enough.

[zondo]

With ring:
http://i411.photobucket.com/albums/pp198/robzondo/dbccb4c1.jpg

Without ring:
http://i411.photobucket.com/albums/pp198/robzondo/14692ef5.jpg

I have yet to be able to get mine over 260 fps.

*EDIT*
Here is a ULE body on a Noxious rail:
http://i411.photobucket.com/albums/pp198/robzondo/57c7f955.jpg

I have no issues adjusting upwards of 300 fps with this.

Anyone have a good set of calipers to measure the ID of the MM2k9 and compare with another body?

*EDIT2*
Found my calipers and measured 6 times apiece. only measured right at the entrance of the body, not inside.

ULE= 1.0080, 1.0000, 1.0035, 1.0070, 1.0090, 1.0055 for an avg of 1.0055

MM2K9= 1.0020, 1.0030, .9990, .9945, .9990, 1.0000 for an avg of .9996

Curious if anyone found any difference with theirs. Incidentally, the OD on the widest portion of my L10 bolts are .9770.

[RT Lover]

the ptp mag seems to have some real issues with the 2k9 i thought ptp was fixing them? best thing is probably have xmagteror cut u a new body

[Henchman]

the ptp mag seems to have some real issues with the 2k9 i thought ptp was fixing them? best thing is probably have xmagteror cut u a new body
I think using a lathe to correct it, would most certainly be easier, and cheaper.

[RT Lover]

true if you can! Hope it works out man! maybe u can fix others also?

[OPBN]

My measurements on my AGD bodies are off. I realized from looking through the sear slot that they are not going fully forward due to my tape measure being too wide. Regardless, my measurements look the same as Zondos on my PTP and I can chrono fine.... Wonder why the difference?


*Edit - I found a thinner tape measure, and my ULE measures around 3 1/16 to the front of the hole with the ring and clip in. My MM2K9 measurements are still 2 7/8 with the insert and 3" without. Still looks very similiar to what Zondo is showing.

I tried measuring my ID and came up with measurements ranging from .9895 to .9760. The only part I can get a good measurement on is the side to side and it comes in at around .9880.

Also, I measured the L10 bolt that I am using and mine comes in at .9810.

Henchman, maybe someone else can get you the inner breach thickness. Honestly I am terrible at guestimating and hate disassembling this thing. The only way to get a good measurement is to take it totally apart and actually measure it.

Frizzle Fry mentioned that his steel washers had to be pressed in while mine and it seems others just dropped in. However, he has not mentioned any issue with velocity and neither have I.

[Henchman]

I am sending it to ptp, and they are going to check it out.
I'll let everyone know the outcome.

Mark

[zondo]

I am sending it to ptp, and they are going to check it out.
I'll let everyone know the outcome.

Mark

Meaning Tracy or Russel?

[Henchman]

Meaning Tracy or Russel?
Forrest.

[zondo]

Forrest.

Touche... :p

[DoubleDutch]

Henchman, do you have a final resolution or fix on your velocity issues? I have the same problem, I am still unable to get my MM 2K9 up above 250 fps. Same valve (ReTro with L10) shoots above 300 in an ULE body.

I measured without the stainless steel washer, as shown above, and from the lip to the FS screw is 3.1 inches.

[Henchman]

Henchman, do you have a final resolution or fix on your velocity issues? I have the same problem, I am still unable to get my MM 2K9 up above 250 fps. Same valve (ReTro with L10) shoots above 300 in an ULE body.

I measured without the stainless steel washer, as shown above, and from the lip to the FS screw is 3.1 inches.
Still waiting to hear back from ptp

[Atension]

I have a specs issue also. The body I have has rear diameter that is too small to fit a classic valve. An x-valve fits but only just and causes sever bolt stick issues that I dont get using my ULE body. Also contacted PTP and awaiting response.

[zondo]

Heard from Forest yet?

[Henchman]

Heard from Forest yet?
Yes. He's been working on it, but has been swamped with other work as well. But should be getting to the bottom of it in the next week or so.

[WUNDERWAFFEN]

Keep on them. They have been "swamped" for years now.

They do have extra bodies that Tracy is trying to sell you could ask them to replace the defective body.

Oh & while you have Forest's ear, ask him about the shirts.

[Drix]

Oh & while you have Forest's ear, ask him about the shirts.

I feel like some people around here bought T-shirts so they could get a free gun or something.

[knownothingmags]

when i had any issues, which of course were minor compared to what you guys are dealing with, someone was always there more then happy to help.

[zondo]

Any update on this? I'm thinking Forrest had to have some free time by now...

[splashkitsrock420]

wow....im scared to use mine......i havent even set it up......much less sent it off......ill keep an eye on this one......:)

what sucks they did a good job on the look and feel of this gun but with so many issues makes ya wanna say "come on man!!!"

[Konigballer]

Yeah, I'm glad I stayed out of this when they brought it out. I thought, 'thats neat', but I've never been a big Micromag fan. I still don't know how a reputable company that made mag parts/acessories for YEARS could screw this up so bad.

[BigEvil]

(Dont look too closely at the deten't positions either)


:spit_take :cry:

[knownothingmags]

mine rips awsome,
no problems on my end.

yes detents are funky.

ill read through this thread fully and see maybe i am having the same problems but dont know it.

who knows.

[OPBN]

No issues here. Love my MM2K9.

[zondo]

What length on/off pins is everyone using?

Did anyone have to adjust the clevis length?

[zondo]

(Dont look too closely at the deten't positions either)


:spit_take :cry:

I am going to be pissed at myself if this is the case...

[nak81783]

Could anyone with a MM2K9 body please do the following:

1. State whether you can or cannot achieve 300fps in the MM2K9 setup using a valve that is verified to work in another setup.

2. Measure the following:
A to B. From center of rear field strip screw hole to bolt spring seat (without washer).
A to C. From center of rear field strip screw hole to aft edge of breech piece.
A to D. From center of rear field strip screw hole to aft edge of feed tube.

88123

3. Place two balls in the feed tube (positioned vertically) without a hopper. Shoot the bottom one, and report what the top ball does (flies out of feed tube, feeds properly, jostles a bit, etc.). Try to quantify if possible. For example, it flew 2 feet out of the feed tube.

4. With a ball chambered, does the centerline of the ball line up with the centerline of the bolt and the centerline of the barrel?

Hypothesis 1: Bolt geometry is too far back relative to breech. Bolt releases power pulse too far back, losing much of the pressure up the feed tube.

Hypothesis 2: Air blast isn't centered on ball. It is concentrated above or below it.

The previous posts simply measure compression of the spring, which can be remedied by using a shorter or longer spring, using a thicker steel shim, or boring out some of the material at the bottom of the hole (depending on if your measured distance is shorter or longer than AGD spec).

Your data is greatly appreciated. Thank you.

Edit: Here's a link to the other relevant thread. Takes a while for us to figure out it's the body.
http://www.automags.org/forums/showthread.php?265053-Unusual-RT-Pro-Issue


-Nathan

[Henchman]

Will do. Need to pick a proper caliper this week.

[Henchman]

Well, the issue is exactly what I suspected all along. I even told the people at PTP when I sent my 2k9 back to them,mand they said the measurements were correct.
They had it over a year. I just got it back. They said it was fixed, and that it was an issue with some o-rings etc.

Not.

When I tried to get it over 170bps bps, it started leaking air again.
I order a caliper.

Well, the measurement is a whole half centimeter or a liittle over 3/16 of an inch short of what it should be.
From the center of the retaining screw to the edge of the breach, it measures 7 1/2 cm. vs 8 cm for a proper working Tac one.
So, the spring is already extremely compressed and too much force is needed to compress the bolt when firing the gun.

[sniper42]

So the feedhole is too far back? See at least on mine, the hole for the valve is actually bored deeper than a standard mag, even with the steel insert installed. What is the depth from your quick strip screw to the front of the steel insert?

[Henchman]

That's the measurement I'm talking about.
The breach wasnt drilled out deep enough.
The screw holes in the right place.

[sniper42]

Interesting. My body is drilled .150" longer than a standard mag yet has similar problems. Yours should be a somewhat easy fix though. You would just need to have the hole bored a little bit deeper, assuming all other dimensions are ok.

[Frizzle Fry]

I'm seeing similar variances with my Minimag, ULE and Xmag bodies.

I'll check more markers but they seem to have as much .185" variance in either direction with these stock AGD bodies.

[nak81783]

So, the spring is already extremely compressed and too much force is needed to compress the bolt when firing the gun.
Respectfully, if this were the only issue, and it may be the issue on your particular body, you could simply cut down a spring to get it working. Frizzle Fry's response bolsters this, and could simply be the reason we all have slightly different Level 10 spring setups. Apparently, this is not a dimension AGD felt the need to hold a tight tolerance on. From our ability to adjust dump chamber pressure to the selection of springs we have, as well as the ability to trim springs to suit, I would agree this dimension is not critical.

However, there are certainly other issues with other bodies, as sniper42's also does not work, and the measurement you are talking about is longer on his body, not shorter.

I feel the only way to get to the bottom of this is to get the data I requested from working and non-working (for whatever reason) bodies alike. If you feel there is another measurement that can contribute, by all means, add it to the list.

I am certainly not the know-all, end-all, but I do feel it's time to let the data drive us. Let's get all the hypotheses out there, and collect whatever data may be necessary from as many members as are willing to contribute to prove or disprove each and every hypothesis.

Relevant thread: http://www.automags.org/forums/showthread.php?265053-Unusual-RT-Pro-Issue

[OPBN]

For measurements it may help if someone took a picture of a MM2K9 and used paint or something to highlight exactly what we are measuring. I can post up a closer pic of mine if needed or if someone has an unmounted body would probably be easier and that we are all measuring the same things.

I will say when I carefully lay my MM2K9 on top of my Tac body for comparison, the détents, FS holes, and feednecks seem to line up pretty spot on actually.

[sniper42]

I'm planning on whipping up a print in solidworks once I have some time to sit down and sketch it.

[OPBN]

I'm planning on whipping up a print in solidworks once I have some time to sit down and sketch it.

Ok. Mine was going to be pretty primitive. One thing I would like to do is figuring out how to compare bodies visually. I had thought about putting the bodies on a grid backgroud to show where things fall.

[nak81783]

Henchman: Please reply to this post: http://www.automags.org/forums/showthread.php?265053-Unusual-RT-Pro-Issue&p=2836273#post2836273