Can you post some pictures of your mag tube wear?
- Thread starter Stoop14
- Start date
Guy you’re a mind reader! I was just wondering this same thing. I have about 250 rounds through it so far and under the piston sleeve the bluing is gone on pretty much one side. I will post pictures tomorrow. How about yours?
Anybody else know what is considered to be in factory tolerance?
Anybody else know what is considered to be in factory tolerance?
I hope this works.
My tube is showing signs of what I would consider normal wear. The main scoring marks (bare metal) came from the first outing, after roughly 75 plus rounds. I came home and performed a good cleaning, upon the next outing produced a reduced layer of bluing. Its not so much that the bluing has worn off but that it seems to be wearing down
One thing I have noticed is that a lot of folks say the piston should come out of the piston sleeve freely. While it will come out it catches at the very end of the sleeve. When the gun is assembled the piston will not come out of the piston sleeve unless forced and then it will have to be forced back in.
Not sure how many other experience this type of performance.
My tube is showing signs of what I would consider normal wear. The main scoring marks (bare metal) came from the first outing, after roughly 75 plus rounds. I came home and performed a good cleaning, upon the next outing produced a reduced layer of bluing. Its not so much that the bluing has worn off but that it seems to be wearing down
One thing I have noticed is that a lot of folks say the piston should come out of the piston sleeve freely. While it will come out it catches at the very end of the sleeve. When the gun is assembled the piston will not come out of the piston sleeve unless forced and then it will have to be forced back in.
Not sure how many other experience this type of performance.
I wonder if they make a Teflon ring that's thin enough to be inserted in-between to keep it from wearing out? kind of like shaving a teflon board with a block plane kind of thin....
I don't have a 930 but I have the same problem on my newly refinished Ithaca, so ....I'll get out my block plane....
I don't have a 930 but I have the same problem on my newly refinished Ithaca, so ....I'll get out my block plane....
I also noticed if i put the gun together then pulled the gas piston out of the spring sleeve with the security barrel on it was a very hard pull it out and even harder to push back in like there was some resistance, then i tired the same thing with the field barrel and it slid in and out in and out like silk. So i'm thinking my excessive wear is due to the barrel is warped or something. I only put maybe 125 rounds through this gun if that.
Stoop,
You brought up a good point, I know the new 930's have a thicker walled barrel, I can't help but wonder if this is the reason that the piston is sticking.
I really doubt both of us have warpped barrels, thats why it makes sense that the piston works on the field but no on the security.
I would like to see other peoples wear who have higher round counts to really look at long term wear.
You brought up a good point, I know the new 930's have a thicker walled barrel, I can't help but wonder if this is the reason that the piston is sticking.
I really doubt both of us have warpped barrels, thats why it makes sense that the piston works on the field but no on the security.
I would like to see other peoples wear who have higher round counts to really look at long term wear.
I would also like to see higher round count wear like 500+ I just put another 100 rounds through it today, some more blueing is gone lol. I wouldn't think it should scrape away blueing. I had 2 failures. One the bolt shut after the last shot, it didn't hold open. The other the bolt and the lifter got jammed up. I'm really not impressed so far with this gun.
I have mixed feelings. I wish it was more of a eat anything 100% of the time, but I realize that the reality of a $600 semi-auto being 100% with everything all the time, maybe a bit much to ask. Honestly, I think that if all I shot weas High Brass, then it would be 100%.
Also, I think the bluing wear is normal. I have seen so many older pump shotguns that show the same kind of wear. I wonder if anyone is not experiencing any wear on the mag tube.
Also, I think the bluing wear is normal. I have seen so many older pump shotguns that show the same kind of wear. I wonder if anyone is not experiencing any wear on the mag tube.
gman079
.22LR
It is perplexing to see that kind of mag tube wear. I wish I had a high speed video camera to see what the 930 is doing in full recoil. Other than the numerous sliding of the piston on the mag tube, I have a feeling the barrel is flexing causing the mag tube to flex which in turn causes the piston to rub extremely hard against the tube. Of course this is just theoretics without the use of high speed video to back it up!! This just reminded me of what could be happening to 930 mag tube when I watched an ak-47 in high speed video how it the barrel was flexing in battery.
http://www.youtube.com/watch?v=TwH4kwl06-g
http://www.youtube.com/watch?v=xeeeFxA_9nA
shotgun barrel in recoil
http://www.youtube.com/watch?v=6pZD99lTfQk
http://www.youtube.com/watch?v=TwH4kwl06-g
http://www.youtube.com/watch?v=xeeeFxA_9nA
shotgun barrel in recoil
http://www.youtube.com/watch?v=6pZD99lTfQk
I am seeing some on my tube and I suspect it is due to 2 things going on:
1) Scoring when taking the barrel on and off due to misalignment of the forward gas seal clamped in behind the big gas spring (red/blue) in the gas block. I know I put a few good marks on mine putting it on and off when there was resistance (especially when it looks like a line stretching down from the threads). I found that by moving the seal slightly with an insert (I machine one from aluminum stock diameter = 0.993”) I could reach a position where the barrel just drops on with little resistance – no marks.
2) If the gas seal is not aligned well I expect it will create scoring marks on a portion of the tube (in a short range maybe 1/4 “ wide max) each time you fire and the seal moves forward compressing the big gas spring to let off the gas load through the two vent holes. I suspect if it is aligned better the scoring would be less.
1) Scoring when taking the barrel on and off due to misalignment of the forward gas seal clamped in behind the big gas spring (red/blue) in the gas block. I know I put a few good marks on mine putting it on and off when there was resistance (especially when it looks like a line stretching down from the threads). I found that by moving the seal slightly with an insert (I machine one from aluminum stock diameter = 0.993”) I could reach a position where the barrel just drops on with little resistance – no marks.
2) If the gas seal is not aligned well I expect it will create scoring marks on a portion of the tube (in a short range maybe 1/4 “ wide max) each time you fire and the seal moves forward compressing the big gas spring to let off the gas load through the two vent holes. I suspect if it is aligned better the scoring would be less.
I still can't help but wonder what Factory tolerance is. If I called and said hey at what point is this not right and needs to be fixed, what would they say?
Also, some have had full scoring all the way through the bluing, and lots of it. I only have the few ring marks. What I notice most is that the bluing seems to be wearing down. I am wondering if and when I will wear through the bluing all together.
Also, some have had full scoring all the way through the bluing, and lots of it. I only have the few ring marks. What I notice most is that the bluing seems to be wearing down. I am wondering if and when I will wear through the bluing all together.
raven01750
.270 WIN
Guys Relax. The piston is catching on the bottom/edge of the Gas Cylinder because as the gun is fired, the piston moves back approximately 3/4 of the way which results in the two parts wearing in together and is perfectly normal since it doesn't slide in and out 100%. There's bound to be a lip on the barrels Gas Cylinder at the edge on a well used gun.
The blueing coming off is due to high temp gasses and abrasives (Carbon is the hardest substance on earth next to water after all) from the powder along with those substances being scaped along the Magazine Tube while the piston is being thrown back with enough force to push the bolt back hard enough to overcome the tension of the return spring to eject an old round and push in a new one. All happening in about 1/10th of a second. Once again normal.
Deep scratching of the Magazine Tube is NOT normal and would be caused by the alignment ring inside the barrels gas piston cylinder not being centered. But that's easily fixed too.
Come on guys. Have fun. Not everyones weapon is going to be the same due to springs and mating surfaces. Manufacturers design and build every part with a tolerence of + or - and usually check by parts sampling to ensure that the parts they are producing are in conformence of their design expectations. As long as the parts meet that tolerence, they let it go.
Lastly, many of our shotguns fire more rounds in a weekend with tremendous force than most weapons fire in their entire lives. They DO depend on the manufacturers of the ammo to produce high quality ammunition to use but have no real control of that portion of the gun. A shell can have a couple of grains more powder or less than the shell next to it in the box. Or it could actually be bad and out of tolerence but wasn't caught. That wouldn't be Mossbergs fault now would it?
Regardless. Use quality ammo. Understand completely how your gun operates and keep it clean and in good running order and you will have years of fun and even a sense of security. FWIW. It's just my opinion and we know what they are worth.
Paul
The blueing coming off is due to high temp gasses and abrasives (Carbon is the hardest substance on earth next to water after all) from the powder along with those substances being scaped along the Magazine Tube while the piston is being thrown back with enough force to push the bolt back hard enough to overcome the tension of the return spring to eject an old round and push in a new one. All happening in about 1/10th of a second. Once again normal.
Deep scratching of the Magazine Tube is NOT normal and would be caused by the alignment ring inside the barrels gas piston cylinder not being centered. But that's easily fixed too.
Come on guys. Have fun. Not everyones weapon is going to be the same due to springs and mating surfaces. Manufacturers design and build every part with a tolerence of + or - and usually check by parts sampling to ensure that the parts they are producing are in conformence of their design expectations. As long as the parts meet that tolerence, they let it go.
Lastly, many of our shotguns fire more rounds in a weekend with tremendous force than most weapons fire in their entire lives. They DO depend on the manufacturers of the ammo to produce high quality ammunition to use but have no real control of that portion of the gun. A shell can have a couple of grains more powder or less than the shell next to it in the box. Or it could actually be bad and out of tolerence but wasn't caught. That wouldn't be Mossbergs fault now would it?
Regardless. Use quality ammo. Understand completely how your gun operates and keep it clean and in good running order and you will have years of fun and even a sense of security. FWIW. It's just my opinion and we know what they are worth.
Paul
SoCal Choppas
.270 WIN
Picture taken today: 6/12/2012
My 2nd SPX has actually less abnormal wear and tear then my first SPX..you can go back to my old posts to see the wear on the first SPX. This wear is on the bottom side of the mag tube.
Round count is as listed below
raven01750
.270 WIN
That's caused by the alignment ring inside the barrels gas cylinder. Try to do a different alignment or just buff up the inside edge to reduce the sharp edge that's cutting into the magazine tube. Good luck. Have a great day.
Paul
Paul