Barrel/Mag Tube off center

dblhelix · November 4, 2009, 12:57 PM

Hi everyone. I recently acquired an older Mossberg 500 ATP8. Everything looks great on the gun, but I did notice one thing that has me scratching my head. The barrel and the mag tube are perfectly in line with each other, however it seems that they are not totally in line with the receiver. Upon closer inspection, the mag tube is a bit uneven where it meets the receiver and thus the tube and barrel come out slanted to the right a little bit.

Is this something that can cause any small or major problems? If so, is there any way to fix it? Thanks in advance for any insight you all can provide.

hogdogs · November 4, 2009, 01:03 PM

It sounds like the mag tube is bent or hole was machined off center. It could possibly affect the lock up lug from fully engaging.

If it were me, I would order a new tube from mossberg if it is bent. to see if it is bent, just unscrew the tube. if it is bent, you will see the outer end going from one extreme to the other.

To loosen the tube, you will want a rubber strap wrench and may need to heat the receiver and tube in the oven to 200-225 or so and cool the tube at threads with a frozen wet rag...
Brent

dblhelix · November 4, 2009, 01:13 PM

Thanks for the quick reply. When I looked at it, the base of the tube is at a very slight angle into the receiver. Therefore I'm thinking the hole might be machined off center.

Since the barrel and mag tube are perfectly in line with each other, would this also mean that the hole for the barrel is off center as well? In either case, what would be the suggestion as to correcting it?

hogdogs · November 4, 2009, 01:18 PM

If the receiver is off center, I ain't sure there is a repair for it. I would inspect both the locking lug and lockup hole in barrel and see if there is any evidence of un even wear. If it appears there is none, I would just learn the POA/POI for that particular gun and run it...
I was just as deadly with an old single shot 12 gauge with an obviously warped barrel as I was with any other gun... Just learned to compensate for it...
Brent

dblhelix · November 4, 2009, 01:28 PM

I looked at everything else and nothing looks to be abnormal with it. It has been shot before (not by me yet) and doesn't look to have had any parts replaced. I'm going to venture a guess that this isn't a major issue with the functionality of the gun.

In either case, I'm going to give it a thorough workout this weekend so if there are any problems I'll find them. Thanks for your help!

dblhelix · November 8, 2009, 10:49 PM

Update:

I put about 50 shells through it this weekend. It's a non-issue with the functionality of the gun. Hooray!

hogdogs · November 8, 2009, 10:50 PM

Glad to hear it and thanks for the update too...
Brent

November 4, 2009, 12:57 PM	#1
dblhelix Member Join Date: November 4, 2009 Posts: 42	Barrel/Mag Tube off center Hi everyone. I recently acquired an older Mossberg 500 ATP8. Everything looks great on the gun, but I did notice one thing that has me scratching my head. The barrel and the mag tube are perfectly in line with each other, however it seems that they are not totally in line with the receiver. Upon closer inspection, the mag tube is a bit uneven where it meets the receiver and thus the tube and barrel come out slanted to the right a little bit. Is this something that can cause any small or major problems? If so, is there any way to fix it? Thanks in advance for any insight you all can provide.

November 4, 2009, 01:03 PM	#2
hogdogs Staff In Memoriam Join Date: October 31, 2007 Location: Western Florida panhandle Posts: 11,069	It sounds like the mag tube is bent or hole was machined off center. It could possibly affect the lock up lug from fully engaging. If it were me, I would order a new tube from mossberg if it is bent. to see if it is bent, just unscrew the tube. if it is bent, you will see the outer end going from one extreme to the other. To loosen the tube, you will want a rubber strap wrench and may need to heat the receiver and tube in the oven to 200-225 or so and cool the tube at threads with a frozen wet rag... Brent

November 4, 2009, 01:13 PM	#3
dblhelix Member Join Date: November 4, 2009 Posts: 42	Thanks for the quick reply. When I looked at it, the base of the tube is at a very slight angle into the receiver. Therefore I'm thinking the hole might be machined off center. Since the barrel and mag tube are perfectly in line with each other, would this also mean that the hole for the barrel is off center as well? In either case, what would be the suggestion as to correcting it?

November 4, 2009, 01:18 PM	#4
hogdogs Staff In Memoriam Join Date: October 31, 2007 Location: Western Florida panhandle Posts: 11,069	If the receiver is off center, I ain't sure there is a repair for it. I would inspect both the locking lug and lockup hole in barrel and see if there is any evidence of un even wear. If it appears there is none, I would just learn the POA/POI for that particular gun and run it... I was just as deadly with an old single shot 12 gauge with an obviously warped barrel as I was with any other gun... Just learned to compensate for it... Brent

November 4, 2009, 01:28 PM	#5
dblhelix Member Join Date: November 4, 2009 Posts: 42	I looked at everything else and nothing looks to be abnormal with it. It has been shot before (not by me yet) and doesn't look to have had any parts replaced. I'm going to venture a guess that this isn't a major issue with the functionality of the gun. In either case, I'm going to give it a thorough workout this weekend so if there are any problems I'll find them. Thanks for your help!

November 8, 2009, 10:49 PM	#6
dblhelix Member Join Date: November 4, 2009 Posts: 42	Update: I put about 50 shells through it this weekend. It's a non-issue with the functionality of the gun. Hooray!

November 8, 2009, 10:50 PM	#7
hogdogs Staff In Memoriam Join Date: October 31, 2007 Location: Western Florida panhandle Posts: 11,069	Glad to hear it and thanks for the update too... Brent