Mossberg questions

BfloBill · January 1, 2017, 02:49 PM

Ok. This is a 2 part issue:

First: I bought an old Mossberg shotgun for next to nothing with the intention of making it a project gun. When dry fired the action cannot be cycled without depressing the action release lever. When firing rounds, the action works properly about 60% of the time, but you need to depress the lever to cycle the action the other 40%. If anyone has a solution, I am all ears.

Second: While trying to troubleshoot this issue I looked online for exploded views of the trigger assembly and bolt assembly to see if I could spot what is wrong/missing/broken. In doing so, I noticed that they are both different than anything I can find online. The bottom of the receiver is stamped 500 AT, but the only thing that keeps coming up are the newer 500's. This gun was found in the back of a closet and if I had to guess it is from the 60's or 70's. Does anyone know when Mossberg changed its bolt configuration?

g.willikers · January 1, 2017, 03:20 PM

You might just try replacing the action lock lever with whatever type is available to start.
And replace the springs for it, while you're at it.
The springs might come with a new one, though.
That might cure it.
It's worth a try.

BfloBill · January 1, 2017, 06:25 PM

I can't even think of replacing parts, because I wouldn't know what to order.

Every diagram for the 500 I have found does not look like my trigger assembly. Most notably the part towards the rear of the assembly that looks like an upside down field goal post. I'm starting to think this is a much older model than the parts available at Brownell's.

It just doesn't add up.

FITASC · January 1, 2017, 07:01 PM

Ty posting a few pics here - there are a lot of Mossberg owners

turkeestalker · January 1, 2017, 10:33 PM

This is a link to another thread here from a couple of years ago that may help to describe the components involved and their interaction with one another for proper operation. The trouble being had in the thread is the opposite of what you're experiencing, but it does a good job of explaining how the 500 is designed to work which may help you out. It also has a very good photo of the 'lock' involved which could help you to determine what part and or corresponding spring to order.

https://thefiringline.com/forums/sho...d.php?t=549965

I have an older Western Auto branded Revelation shotgun which should be the same as your older Mossberg 500. I removed the trigger assembly to take a look and the 'lock' is the same as what is pictured in the thread.

When the hammer is in the cocked position, the lock lever is held in an upward position so it is in contact with the bolt, blocking it from any rearward movement and locking it in place. Once the trigger is pulled, the disconnector spring tension should pull the lock downward to clear the bolt and allow it to move rearward.
My guess is that you need a new spring and possibly a lock, but who knows.. a good thorough cleaning and a little file work may do some good.

Here is a link to an exploded view of the trigger assembly.

http://www.mcarbo.com/mossberg-500-/...d-diagram.aspx

I'm thinking you need part number 1 in the diagram, possibly number 2 and likely number 3.

Hope some of this long winded response helps.

turkeestalker · January 1, 2017, 11:27 PM

OH... I forgot to mention that the 'A' simply denotes that it is a 12 gauge, and I may be mistaken but the 'T' stands for target I believe.
I'm guessing that means that yours was born to skillfully bust clay birds far better than a mere 500A!

dreaming · January 2, 2017, 03:58 AM

The "T" might stand for "Tactical".

Does your bolt have a firing pin spring? See this.

BfloBill · January 2, 2017, 04:25 PM

It has a 24 inch Slugster barrel with front and rear sights. It has to be a deer gun. I will look into some of the links mentioned and maybe get some pics up in the next couple of days. Thanks.

BTW-On the exploded view you provided, the Connector (13) does not exist on mine. But on mine the Trigger (64) has a vertical portion attached to the rear which probably has the same function. The rest of the assembly looks the same. Maybe mine is even older than I thought, at least that would explain why I am having trouble finding the info.

ocharry · January 3, 2017, 12:27 PM

try pushing the slide forward to unlock it before you pull it back to open the action

if its working ok when you shoot a shell in it then that forward then back might make it work,,,,,that is the normal thing that happen when the gun goes off and recoil happens,,,,push forward and then back

ocharry

BfloBill · January 3, 2017, 01:01 PM

Pushing forward before pulling back did not work for dry firing or for firing live rounds.

ocharry · January 4, 2017, 11:04 AM

poop,,,well worth a try,,,

is it dirty inside?? maybe a good cleaning,,,just a thought

ocharry

turkeestalker · January 4, 2017, 05:28 PM

Christmas 2014 I purchased two new Mossberg 500A shotguns for my sons as gifts. I removed the trigger assembly from one of those and also from my Revelation for comparison.
I believe that the 310 was produced for Western Auto by Mossberg between the mid 70s and 80s, not as early as the 60s but I could be full of beans.
Anyway, here is a photo from the rear with them side by side, the Revelation being on the left and the Mossberg on the right.

Though there are some nominal differences in the shape of some the parts, they are still basically the same. The hammers were cocked on both in the photo, therefore not sticking up vertically but laying horizontally.

SHR970 · January 4, 2017, 09:45 PM

You need to look at the interaction of the (3) Action lever lock (which holds the bolt shut) the (2) Action lever lock spring, and (1) Action lock disconnector spring. When you cock the gun the Action lock spring pushes the action lock up behind the bolt holding it shut until one of two things happens.

Option 1 you manually push the bolt release (Action lock) over coming the lock spring manually.

Option 2 fire the gun where the hammer moving forward actuates the lock disconnector spring which over comes the lock spring and pushes the lock down out of the way of the bolt.

Since the bolt won't unlock the Disconnector spring is worn or bent. Have it replaced. While you are at it you might as well replace both springs.

FITASC · January 4, 2017, 09:48 PM

As old as this gun seems to be, it might be wise to replace ALL of the springs inside..................

BfloBill · January 6, 2017, 07:51 PM

Dreaming- Thanks for the video. The main portion of the bolt looks the same as yours, but the center portion that rocks has a different configuration. It appears to operate the same, and mine doesn't have a spring either.

Turkeestalker- Thanks for the effort, but when I try to open the pic it comes up as an invalid attachment. If you want to retry, I still wouldn't mind seeing it.

SHR970- You may have the answer. With my trigger assembly out, when I pull the trigger and ease the hammer forward the Action lever lock does not move. When I look down into the assembly while holding the trigger back and easing the hammer back and forth, I can see the spring, and understand how it should disengage the Action lever lock, but it isn't putting pressure on the spring to disengage the lever. There are several good videos on taking the trigger assembly apart. I am going to do that and make sure it is put together right, and probably end up ordering the new springs to see if that fixes it.

SHR970 · January 6, 2017, 09:35 PM

BfloBill..

Glad to be of service. As FITASC said a Mossy owner will come forward.. I have 3 currently and have trouble shot many more. Hopefully you will resolve your issue shortly. The tang that engages the hammer is your first and primary place to look.

turkeestalker · January 14, 2017, 08:41 AM

Have any luck sorting things out Bill?

BfloBill · January 15, 2017, 11:44 AM

Pretty sure it's the action lever lock spring. Not sure when I will get around to buying one and testing it, but one thing I can guarantee is that if that's not it I will resurrect this thread!

January 1, 2017, 02:49 PM	#1
BfloBill Senior Member Join Date: August 2, 2010 Location: Buffalo, N.Y. Posts: 457	Mossberg questions Ok. This is a 2 part issue: First: I bought an old Mossberg shotgun for next to nothing with the intention of making it a project gun. When dry fired the action cannot be cycled without depressing the action release lever. When firing rounds, the action works properly about 60% of the time, but you need to depress the lever to cycle the action the other 40%. If anyone has a solution, I am all ears. Second: While trying to troubleshoot this issue I looked online for exploded views of the trigger assembly and bolt assembly to see if I could spot what is wrong/missing/broken. In doing so, I noticed that they are both different than anything I can find online. The bottom of the receiver is stamped 500 AT, but the only thing that keeps coming up are the newer 500's. This gun was found in the back of a closet and if I had to guess it is from the 60's or 70's. Does anyone know when Mossberg changed its bolt configuration?

January 1, 2017, 03:20 PM	#2
g.willikers Senior Member Join Date: September 28, 2008 Posts: 10,442	You might just try replacing the action lock lever with whatever type is available to start. And replace the springs for it, while you're at it. The springs might come with a new one, though. That might cure it. It's worth a try. __________________ Walt Kelly, alias Pogo, sez: “Don't take life so serious, son, it ain't nohow permanent.”

January 1, 2017, 07:01 PM	#4
FITASC Senior Member Join Date: December 6, 2014 Posts: 6,446	Ty posting a few pics here - there are a lot of Mossberg owners __________________ "I believe that people have a right to decide their own destinies; people own themselves. I also believe that, in a democracy, government exists because (and only so long as) individual citizens give it a 'temporary license to exist'—in exchange for a promise that it will behave itself. In a democracy, you own the government—it doesn't own you."- Frank Zappa

January 1, 2017, 10:33 PM	#5
turkeestalker Senior Member Join Date: February 2, 2015 Location: Cottleville, Missouri Posts: 1,115	This is a link to another thread here from a couple of years ago that may help to describe the components involved and their interaction with one another for proper operation. The trouble being had in the thread is the opposite of what you're experiencing, but it does a good job of explaining how the 500 is designed to work which may help you out. It also has a very good photo of the 'lock' involved which could help you to determine what part and or corresponding spring to order. https://thefiringline.com/forums/sho...d.php?t=549965 I have an older Western Auto branded Revelation shotgun which should be the same as your older Mossberg 500. I removed the trigger assembly to take a look and the 'lock' is the same as what is pictured in the thread. When the hammer is in the cocked position, the lock lever is held in an upward position so it is in contact with the bolt, blocking it from any rearward movement and locking it in place. Once the trigger is pulled, the disconnector spring tension should pull the lock downward to clear the bolt and allow it to move rearward. My guess is that you need a new spring and possibly a lock, but who knows.. a good thorough cleaning and a little file work may do some good. Here is a link to an exploded view of the trigger assembly. http://www.mcarbo.com/mossberg-500-/...d-diagram.aspx I'm thinking you need part number 1 in the diagram, possibly number 2 and likely number 3. Hope some of this long winded response helps. __________________ Vegetarian... primitive word for lousy hunter!

January 1, 2017, 11:27 PM	#6
turkeestalker Senior Member Join Date: February 2, 2015 Location: Cottleville, Missouri Posts: 1,115	OH... I forgot to mention that the 'A' simply denotes that it is a 12 gauge, and I may be mistaken but the 'T' stands for target I believe. I'm guessing that means that yours was born to skillfully bust clay birds far better than a mere 500A! __________________ Vegetarian... primitive word for lousy hunter!

January 1, 2017, 06:25 PM	#3
BfloBill Senior Member Join Date: August 2, 2010 Location: Buffalo, N.Y. Posts: 457	I can't even think of replacing parts, because I wouldn't know what to order. Every diagram for the 500 I have found does not look like my trigger assembly. Most notably the part towards the rear of the assembly that looks like an upside down field goal post. I'm starting to think this is a much older model than the parts available at Brownell's. It just doesn't add up.

January 2, 2017, 03:58 AM	#7
dreaming Senior Member Join Date: October 19, 2016 Posts: 186	The "T" might stand for "Tactical". Does your bolt have a firing pin spring? See this. Last edited by dreaming; January 2, 2017 at 04:05 AM.

January 2, 2017, 04:25 PM	#8
BfloBill Senior Member Join Date: August 2, 2010 Location: Buffalo, N.Y. Posts: 457	It has a 24 inch Slugster barrel with front and rear sights. It has to be a deer gun. I will look into some of the links mentioned and maybe get some pics up in the next couple of days. Thanks. BTW-On the exploded view you provided, the Connector (13) does not exist on mine. But on mine the Trigger (64) has a vertical portion attached to the rear which probably has the same function. The rest of the assembly looks the same. Maybe mine is even older than I thought, at least that would explain why I am having trouble finding the info. Last edited by BfloBill; January 2, 2017 at 04:36 PM.

January 3, 2017, 12:27 PM	#9
ocharry Senior Member Join Date: October 20, 2006 Posts: 687	try pushing the slide forward to unlock it before you pull it back to open the action if its working ok when you shoot a shell in it then that forward then back might make it work,,,,,that is the normal thing that happen when the gun goes off and recoil happens,,,,push forward and then back ocharry __________________ The felon does not fear the police, and he fears neither judge nor jury. Therefore what he must be taught to fear is his victim." - Lt. Col. Jeff Cooper, USMC

January 3, 2017, 01:01 PM	#10
BfloBill Senior Member Join Date: August 2, 2010 Location: Buffalo, N.Y. Posts: 457	Pushing forward before pulling back did not work for dry firing or for firing live rounds.

January 4, 2017, 11:04 AM	#11
ocharry Senior Member Join Date: October 20, 2006 Posts: 687	poop,,,well worth a try,,, is it dirty inside?? maybe a good cleaning,,,just a thought ocharry __________________ The felon does not fear the police, and he fears neither judge nor jury. Therefore what he must be taught to fear is his victim." - Lt. Col. Jeff Cooper, USMC

January 4, 2017, 09:45 PM	#13
SHR970 Senior Member Join Date: January 24, 2011 Posts: 1,427	You need to look at the interaction of the (3) Action lever lock (which holds the bolt shut) the (2) Action lever lock spring, and (1) Action lock disconnector spring. When you cock the gun the Action lock spring pushes the action lock up behind the bolt holding it shut until one of two things happens. Option 1 you manually push the bolt release (Action lock) over coming the lock spring manually. Option 2 fire the gun where the hammer moving forward actuates the lock disconnector spring which over comes the lock spring and pushes the lock down out of the way of the bolt. Since the bolt won't unlock the Disconnector spring is worn or bent. Have it replaced. While you are at it you might as well replace both springs.

January 4, 2017, 09:48 PM	#14
FITASC Senior Member Join Date: December 6, 2014 Posts: 6,446	As old as this gun seems to be, it might be wise to replace ALL of the springs inside.................. __________________ "I believe that people have a right to decide their own destinies; people own themselves. I also believe that, in a democracy, government exists because (and only so long as) individual citizens give it a 'temporary license to exist'—in exchange for a promise that it will behave itself. In a democracy, you own the government—it doesn't own you."- Frank Zappa

January 6, 2017, 07:51 PM	#15
BfloBill Senior Member Join Date: August 2, 2010 Location: Buffalo, N.Y. Posts: 457	Dreaming- Thanks for the video. The main portion of the bolt looks the same as yours, but the center portion that rocks has a different configuration. It appears to operate the same, and mine doesn't have a spring either. Turkeestalker- Thanks for the effort, but when I try to open the pic it comes up as an invalid attachment. If you want to retry, I still wouldn't mind seeing it. SHR970- You may have the answer. With my trigger assembly out, when I pull the trigger and ease the hammer forward the Action lever lock does not move. When I look down into the assembly while holding the trigger back and easing the hammer back and forth, I can see the spring, and understand how it should disengage the Action lever lock, but it isn't putting pressure on the spring to disengage the lever. There are several good videos on taking the trigger assembly apart. I am going to do that and make sure it is put together right, and probably end up ordering the new springs to see if that fixes it.

January 6, 2017, 09:35 PM	#16
SHR970 Senior Member Join Date: January 24, 2011 Posts: 1,427	BfloBill.. Glad to be of service. As FITASC said a Mossy owner will come forward.. I have 3 currently and have trouble shot many more. Hopefully you will resolve your issue shortly. The tang that engages the hammer is your first and primary place to look.

January 14, 2017, 08:41 AM	#17
turkeestalker Senior Member Join Date: February 2, 2015 Location: Cottleville, Missouri Posts: 1,115	Have any luck sorting things out Bill? __________________ Vegetarian... primitive word for lousy hunter!

January 15, 2017, 11:44 AM	#18
BfloBill Senior Member Join Date: August 2, 2010 Location: Buffalo, N.Y. Posts: 457	Pretty sure it's the action lever lock spring. Not sure when I will get around to buying one and testing it, but one thing I can guarantee is that if that's not it I will resurrect this thread!