[~Ranger~]

I have been getting some issues since I installed the MB03 upgrade kits, piston. I rack the bolt and sometimes the sear just doesnt seem to catch the piston. My sears look fine, but I was thinking maybe its the piston.
Here is a pic of the kit. The piston if you look close to where the sear catches, the ring directly in front of that spot looks a little too close and I feel that its stopping the sear from moving up close enough to the piston catch. If this pic isnt good enough, I can take mine out but ughhh.. I am actually tired of taking it apart by now,lol.. :doh:

If that part of the piston can be shaved more in the rear I figure the sear will set into place better. Does this make sence?

Other that this, the piston does what it should. So far I like it and I feel more safe and cozy inside knowing the piston isnt plastic anymore,lol..

 

[woogie]

If you put the stock piston back in the rifle do you still get the slam firing?

It could be that the piston is a little bit out of spec.

 

[~Ranger~]

Yeah the stock piston still slamfires. I noticed that the stock piston next to this one was nearly exact except that part I was talking about on stock piston is shaped different and is more at an angle and the metal piston is straight up and down. I havent used a micrometer cause the batteries are dead. But side to side and head to head and rear to rear they seem perfect match except this one spot.

 

[woogie]

Can you get a picture of the "problem spot"

 

[MiloXC3]

the stock piston next to this one was nearly exact except that part I was talking about on stock piston is shaped different and is more at an angle and the metal piston is straight up and down.

You could have a 90 degree piston with a 45 degree trigger.
(Sorry, I can't see the picture, I'm on my phone)

 

[Masterjuggler98]

The part of the piston that centers it inside the cylinder you mean, right? Take your gun apart one more time and this time take the trigger out too. See how well the sears mesh with the piston and if it has little to no room to mode around then file down the guide rind to give the sear more room. It could be that because the guide ring is at a perfect 90 degree angle like you were talking about it might not leave enough room for the sear to move freely. That's my theory anyway.

 

[~Ranger~]

 

[~Ranger~]

Here is a pic of my piston sear. Looks ok to me.

 

[Masterjuggler98]

Piston looks like an exact clone except for the holes on the plastic body, and it being made of metal. Did the plastic one catch or were you having the same problem with it too? This "piston not catching" problem, is it the same as slam firing or are you just not getting the sear to move in the first place? Maybe you just need to clean and lube the trig-mech? Those black smears on the paper towel means you need to clean it because it still has the factory lube on it.

 

[zero]

It's definitely not the 45/90 degree piston/trigger sear problem.

Zero

 

[~Ranger~]

It does look pretty much exact doesnt it,lol.. just that guide ring is off a little. The plastic one would catch but then slamfire when sliding the bolt forward. After turning the piston so many times it just stopped working "slamfired when bolt pushed forwards". This new piston hasnt slamfired, it works perfect 90% of the time and once in a while it just wont catch or I have to jerk it hard, for it to catch. "Thats what she said,hahahaha"

 

[Masterjuggler98]

@Zero- I have no idea what you are talking about. The piston and trigger are both 45 degrees.

@Ranger- could it be that the sear is sticking sometimes? Try taking the trigger apart and clean/lube it. also check to see if the sear is wobbling around in the trigger housing. If it isn't then it might be you have the screws too tight on the trigger box and it's putting pressure on the sides of the sear, causing sticking, although I doubt that's the reason.

 

[~Ranger~]

The sear was recently installed since I got the new piston. It moves nicely like it should. The spring is nice and stiff like it should and its all functioning like I believe it should,lol..

 

[Masterjuggler98]

Try dry firing it or plinking a bit but this time fire 20 rounds and every time you cock it make sure to slam the bolt back instead of just pulling hard. Just to see how it works. I have a theory that it might not be pulling back far enough, and that you might need to take off .1mm or something small like that off of the end of whatever stops the bolt from going too far back.

 

[~Ranger~]

I actually just put it back together. I wrapped the piston catch lip "whatever the heck its called,lol.." with e tape.. Lots and lots!! So I can make sure to not have a chance to nick it. I got out the metal file and went to town on theat guide ring. I made it more like the plastic ones shape and put it back together. I did about 10 dry fires and it felt pretty nice. I wanna use a dremel but we know what happens when using a grinding/sanding wheel on aluminum,lol.. I need to locate where I put my other dremel bits, cause I can only find them disks.

I have thought about rigging up a way to insert something into the spring hole on the piston and use a drill to hold whatever I can use to fit the piston. Spin that sucker full speed and use the file to kinda mill the shape better.

I will be out back soon testing it for accuracy so I will also get in some more tests on the new shape of the piston. I will take a pic by tomorrow to show my work, just incase this fixes it and helps someone else.

I kinda wanna wait incase I have to do more, before I take pics.

 

[Masterjuggler98]

Maybe get a cork or some rubber stopper and attatch it to a drill bit. Then you have your own poor man's piston lathe LOL. I used a similar method when I put the nozzle to the piston head in the drill chuck and used a flathead screwdriver on my leatherman to taper/polish it. But anyway, if it's working better so far then I have absolutely no idea whathe problem was and why that fixed it. Whatever works.

 

[~Ranger~]

Thats not a bad idea really. I may try that. And the problem I still think my piston had was the guide ring was in the way of letting the piston sear open up and catch the piston. Since that part got filed down I think it feels and sounds better when I rack the bolt. I will of course keep ya'll informed.

 

[Masterjuggler98]

Ranger, I don't want to say I told ya so but... I told ya so. For future reference, if you have to research a product just to find out who it was made by, and even then be skeptical of it, chances are it's not going to be good. As long as you got the piston to work in the end.

 

[~Ranger~]

I wish I could have had more money to play with. My reasoning for that piston and kit was just for the fast delivery, low cost and it was available now. I think this piston is ok for what it is. Just a replacement to make it work, later on I can figure out what quality parts I can get but I only had $57 to work with and that was $40. I couldnt find anything in the price range I had except from sites way out of the way so time was a serious factor. I had to have my rifle working for the game at Riverbottom. And I was very happy that day cause my rifle kicked ass! Took a few minutes to fine tune the rifle at the game but 20 minutes later I was getting kills left and right! Wow I had a blast,lol.. And if this piston is fixed by the file, I would gladly buy one for my kids Bar10 actually. I also like the metal to metal "Click" I hear when I rack the bolt. It sounds pretty nice and more realistic I think.