Unusual RT Pro Issue. . .Now confirmed as micromag 2k9 problem!

[nak81783]

Nice work! Just make sure you don't repeat the AGD Superbolt issue where the sleeves wore out, cracked, and came flying out the barrel. I think this was because they used delrin, but just keep an eye on it.

[sniper42]

And we have a winner. A longer bolt solved the problem. My first bolt I made from scratch was supposed to be a level 10 replacement but some dimension must be off because all it does is chuff. For the next one I decided to pick up a level 7 bolt from baccipaintball.com for a couple bucks. I turned the outside down and made a sleeve to extend the bolt by .150" and glued it on. I also put a screw in the front so the ball has something to seat against. I will glue some foam to this later.

So far the results are promising. I was able to get up to 300fps before my velocity screw bottomed out. Before the new bolt, at about 240fps, I was getting enough blowback up the stack to launch a ball approximately 1.5 feet up. With the new bolt at 270fps I still have a bit of blowback but it is much less. It will only launch the next ball maybe 6 inches. So a sleeve that is maybe a tad longer might be in order.

With my new bolt the face of the bolt is even with the back edge of the feedhole. Here is a crappy cell phone picture of the new bolt:
i-9wtNb2d-L.jpg

So at some point I think I will have to get my hands on a spare level 10 bolt to make a sleeve for.

Now before testing my new bolt, I had a small hiccup where I apparently shot the ball bearing out of one of my detents.

[sniper42]

Well I seem to have gotten some dimension wrong because all my new bolt does is chuff. I will have to make another go at it and next time I will just make a level 7 bolt for simplicity's sake.

[Blahslug]

Any additional data you can provide would be great. However, could you please also fill in the data points requested earlier in this thread? Distances, does your marker shoot balls out the feed tube stack when there's no hopper on it, etc. I'm 95% confident we have it figured out, and I'm eagerly awaiting results from sniper42's longer bolt.

I will have to put the body back on a gun, and get some air. I will post up when I get some results.

[nak81783]

If someone has a good cad model I can FARO arm my body that is having the same issue. If not I will just model up a body off of the AGD autocad file. I just ran across this issue, and I was going to post about it, but you beat me to it.

My body only gets to the 240-250 range. Its sad, since I love the body.

Any additional data you can provide would be great. However, could you please also fill in the data points requested earlier in this thread? Distances, does your marker shoot balls out the feed tube stack when there's no hopper on it, etc. I'm 95% confident we have it figured out, and I'm eagerly awaiting results from sniper42's longer bolt.

[Blahslug]

mm2k9

If someone has a good cad model I can FARO arm my body that is having the same issue. If not I will just model up a body off of the AGD autocad file. I just ran across this issue, and I was going to post about it, but you beat me to it.

My body only gets to the 240-250 range. Its sad, since I love the body.

[sniper42]

Most certainly not. I've been working on making a new longer bolt for mine. I'm about halfway done and I will post pics once its done. I will also get those measurements.

[nak81783]

Any update on this? I hope we're not giving up.

[nak81783]

Measure away!

On a ULE or other stock body, we're looking for the following:
A to B. From center of rear field strip screw hole to bolt spring seat (If we've all been measuring the same thing, this will have a wide range. It isn't critical.).
A to D. From center of rear field strip screw hole to aft edge of feed tube.

ULE Schematic.JPG
Locations in schematic are approximate.

[OPBN]

Is my schematic going to suffice to get measurements from everyone?


-Mr. Snippy (I hope this isn't an omen for things to come after the bun in the oven is born)

Should be for me. Do we need to specify what to measure in a standard body to confirm we are comparing apples to apples in the case the both my working body and Snipers non-working body come up with the same measurements?

When I got a twofer the second pregnancy its what I went in and got.....

[nak81783]

Is my schematic going to suffice to get measurements from everyone?


-Mr. Snippy (I hope this isn't an omen for things to come after the bun in the oven is born)

[nak81783]

I would still like to see a side pic of Snipers marker. What if as someone else mentioned, bottom milling is just off? He says the "body hole" is longer, exactly what does this mean? I still say we need a pic/diagram fo the body and bullets or whatever showing exactly what needs to be measured to make sure we are all comparing apples to apples.

Bottom milling being "just off" is a bad thing. This would mean trigger frame screws, sear slot, and sear axle holes all need to move. Not the easiest fix in my opinion.

"Body hole" is the "A to B" measurement in the schematic I uploaded. At least, that's what I took it to mean.

[nak81783]

This is the best I can do with the time I have available.

1. 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.

MM2K9 Schematic.JPG
Locations in schematic are approximate.

2. 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.

[OPBN]

I would still like to see a side pic of Snipers marker. What if as someone else mentioned, bottom milling is just off? He says the "body hole" is longer, exactly what does this mean? I still say we need a pic/diagram fo the body and bullets or whatever showing exactly what needs to be measured to make sure we are all comparing apples to apples.

[nak81783]

image.jpg

We've known the primary issue since working bodies are around 3.5" from rear field strip screw center to aft edge of feed tube and sniper42's is 3.65".

What the issue is now, is how to fix it. Dukie went in depth about something I had only touched on before - the breech bein machined wrong. With the latest measurements you and sniper42 provided, I do not think its the breech. I believe one of the three options I posted before (when you thought I was heavily caffeinated) will work, but it depends where stock exists to do machining. This is why I still want the measurements, in their entirety, from the other thread from working and non-working bodies alike.

I still think a custom bolt might be the best option (does not affect external cosmetics), but I'm hoping someone else can figure out an easier way.