View Full Version : Bolt problem...

12-10-2006, 12:47 PM
First off I would like to say Hi to everyone on the board. I have been reading for a while but this will be my first post.

My problem is that my bolt seems to be scraping on an inner part of the gun. I don't know if this is normal wear for these plastic bolts or if there is something wrong. I bought the gun used and it was like this when I bought it, but it seems to be getting worse. I can physically feel it scraping when i remove and replace the bolt. Is this normal? Has anyone else had this problem and what have you done t fix it? I have included pics for reference, please refer to the green arrows...

227 these are the scrapes on the bolt, i used green arrows to show where because they are kind of hard to see in the pic.

228 points to the spot where the bolt is getting stuck.

12-10-2006, 01:32 PM
Possibly the bolt sweld up from the previous owner oiling the bolt to much causeing it to swell. IDK thats the only thing i could think of.

12-10-2006, 01:33 PM
First off...welcome to the forum. I had not noticed on my old bolt that I replaced but it has the same marks. Looks like they might be coming off the cocking bar. Just a wild guess,but I bet that's where it's coming from. Might be your velocity is set to high or maybe you may have gotten some oil on the bolt and it swelled? Just a couple of ideas. I do know I had to drop the vel. on mine quite a bit.

Hob Hayward
12-10-2006, 02:06 PM
Try sanding the bolt down. I had scratching issues on my ACS when it was in my imagine, not sure why, but I used 1500 grit sandpaper to smooth it down.

12-10-2006, 02:13 PM
ok, thanks guys. I'll try sanding it to smooth it out. and see how that works. I think I may be using too much oil before and after play so I'll try cutting down a couple drops. Thanks everyone.

Hob Hayward
12-10-2006, 02:36 PM
Don't oil the bolt, its not necessary, and its possible that it caused your bolt to swell. I oiled my ACS and it didn't swell, but kingman is not at all consistent in what they use, so they cold well have used different delrin when they made your than when they made mine.

The Booth Man
12-10-2006, 10:46 PM
I noticed this on mine as well. In fact, the sratches are pretty deep. This may be a wild guess, but it started to scrape on mine after I disassembled the top Snap Bolt assembly and put it back together.

12-11-2006, 09:54 AM
i figured out what the problem was. I measured the bolt with a micrometer and found that it wasnt really swollen. I tried sanding it lightly anyway and that didnt help so then i looked at the body again. I took a needle file and carefully filed the body on the spots where i put the arrows on the picture. That fixed the problem right away and the bolt now slides smoothly. It looks like the bolt pin smacks the body there when you fire the marker and slightly bends it each time, causing it to deform and hangup on the bolt. Im glad i got that fixed, now I'm not as worried about investing in an alamo city bolt. thanks guys!

12-12-2006, 08:20 PM
I looked at my unit and no problems there, but when i firts got my MR2 i had one scrape down the top middle and right side middle, upon closer inspection I found that the screws holding on the feed neck were too lone and protruding into the chamber and scraping the bolt, now that your porblem is fixed you may want to check this out as well


12-28-2006, 12:37 PM
i fixed this problem with my marker easily by just using a nail file from a nail clipper lol took about 5 minutes (3 being, finding the springs that flung out when i took off the cocker) nothing major

01-09-2007, 07:06 PM
I have the same exact problem, but it's not the bolt but the milling of the marker in the upper bolt chamber. When the upper cocking bolt groove was cut the very front part of that groove that is vertical (when you remove the cocking mechanism) isn't round inside the bolt chamber, the semicircle of that forward part of the groove isn't round but the edges sag and rub on the bolt. Just pull your bolt and if you have two sets of grooves parralel to each other on the top portion of the bolt, then you have the same thing i'm talking about here. Only way to remedy it is to grind those edges on the forward side of that milled groove. Just pull the bolt, remove your barrel and look down the upper chamber as if you were aiming the gun, using the light coming in from the front of the marker with the barrel removed, you can easily see that it isn't round and that is what is causing the interference. tricky part is going to be removing those edges and keep any debris from getting into the marker while grinding the edges off. I haven't done mine yet but will be here soon. Not going to upgrade my bolt until I remedy the problem with the bad milling.

01-09-2007, 08:08 PM
what i did was put my barrel squgee in from the barrel side until it was about a half an inch away from that spot to keep debree from getting into other things ;) then simply used a metal nail file, other people say to use a needle file or something forget what it is called but u can pick one up at a local hardware store