Mossberg Technical Support... Semi-Auto

Mossberg Technical Support... Semi-Auto Model Specific Info...

1. Model 50/51 CONEBACK Cocking Knob... Dimensioned Drawing
My newest "accumulation"!!!!

2. Trigger Spring Installation 151 (all models) 50 & 51 conebacks, and 351 (all models)
151K and 151M owners needed
351K trigger problems(I think)

3. Semi-auto Bolt Tune-up. 100 series models and up
151M extraction problems
And the whole thread if you want to read the whole thing!!!
151M extraction problems

4. Disassembling the 100 series semi-auto bolt.
Model 151M help needed

5. Disconnector pin removal for the 151's, the 152's and the 250K models made easy
152 Disconnector Pin Removal Problem Disconnector pin

6. Trigger modifacation to lower trigger pull, on the 151,152 and 250K models. Courtesy of Mossaddict.
Polishing trigger parts for 151K

7. Comparison of the "old" and "new" style FP's with their respective hammers. This is for the 300 series semi-autos and their clones.
Scored a New Haven 250C/Mossberg 350KA

8. Comparison of the 300 and 100 series FP's, hammers and bolts. And a repeat of the "old' and "new" style FP's and hammers for the 300 series semi-autos.
1088 firing pin update

9. Discussion of the functioning of the sear, disconnector, hammer and bolt on Mossberg semi-autos. Relevant to the 100 and 300 series semi-autos only. More than 1 shot with a trigger pull??? READ THIS!!!
Semi-auto sear, bolt, hammer...

10. Model 50 & 51 FLATBACKS. Lots of internal parts pictured, discussed and explained. If you are having problems with a FLATBACK check out this thread. Your answer could be right here!!!
Flatback Fun

11. A discussion of the differences between the FLATBACK and CONEBACK outer mag tubes. Coneback outer mag tubes = easy!!! Flatback outer mag tube = very hard to find, kind of like "frog hair" or "hens teeth"!!!
I added a western field 04m489a (mossy 50) to the...

12. Why you shouldn't use HYPER VELOCITY and maybe even HIGH VELOCITY ammo in a CONEBACK Mossberg of any model. Post # 18 has the picture of the destroyed receiver.
Q about M51 style rifles.

13. A discussion on the differences between a 1 series and a 3 series cocking knob and problems that can be encountered when you "swap parts"!!!
https://www.rimfirecentral.com/forums/showthread.php?t=552949

14. Replacing a FP and a hammer on a 3 series semi-auto. A 351C to be exact, and some things to be careful about!!!
https://www.rimfirecentral.com/forums/showthread.php?t=552056

15. Magazine adjustment for the aftermarket 10 rounders. The first link goes to the actual post that describes the "solution". The second link is the whole thread.
https://www.rimfirecentral.com/forums/showpost.php?p=11568873&postcount=4
https://www.rimfirecentral.com/forums/showthread.php?t=1168273

16. A diagram of how the 2nd design "cartridge cut-off spring" is installed on the upper end of the outer mag tube.
(1) 151 cutoff spring | Rimfire Central Firearm Forum

 

Mossberg Technical Support... Bolt Action

Mossberg Technical Support... Bolt Action Model Specific Info...

1. Drilling and tapping the receiver. This will work for BOLT ACTIONS or SEMI-AUTO"S. Go to post #13 Courtesy of ballistx
Drilling and Tapping M44US

2. Removing extractors from a 142. This thread should focus in on the info you need!!! This should work for any model with the "staked" extractors.
A "staked extractor" removal tutorial!!! | Rimfire Central Firearm Forum

3. Bolt comparison pics of a 146 vs a 142 for identifacation purposes.
140 Series bolts

4. Replacing an ejector on a 46B. A 146 will be the same!!! Page 5, post #68 has the dimensioned drawing.
Mossberg 46B won't eject

5. Fabricating Number 3 sight parts!!! Courtesy of dhuse. Post #6 has the sketches!!!
Need help on #3 sight part.

6. Disassembly and reassembly directions for the 340 and 620/640 series bolts. Posts #10 & 11 have the info!!!
This is rather embarrassing,,,

7. Some good info on model 26 rifles, particularly some good detailed pics of the bolt. Post #34 has the detailed pictures!!!
OK, need some help!!!

8. Extractor replacement on a 42A. Only shows the installation, nothing about removing the original extractor.
42A extractor replacement!!!

9. Model 46 FP and ejector repair. A bit of welding and fitting was required to solve the problem!!!
Model 46 bolt won't come out

10. Bolt shims for correcting headspace and where to get them. Courtesy of gunsisme and edlmann!!!
Mossberg Technicial Support!!!!

11. More bolt shims!!! They were used for a 640 so they will most likely work for any 3 series bolt also. May work for others also!!! Courtesy of Bradical.
Speeding up Lock-time in the 640 Style Actions

12. A bunch of pictures of Mossberg bolts, from different models. Oldest at the beginning of the thread, newest at the end of the thread. This is a work in progress, so you might not find a picture of the bolt you are looking for... yet!!!
Mossberg Bolt ID thread.

13. Repairing a safety lever... no welding required, just hand tools!!! Courtesy of bone.
Repairing a Pin type Safety lever with out welding

14. Bolt action trigger mods!!! BE CAREFUL. Courtesy of Dollar Bill.
341 restore/repair/refinish

15. More trigger mods, again... BE CAREFUL. Posts 2 & 5. Courtesy of Mossaddict, & Metaleer.
https://www.rimfirecentral.com/forums/showthread.php?t=403931

16. Magazine adjustment for the aftermarket 10 rounders. The first link goes to the actual post that describes the "solution". The second link is the whole thread.
https://www.rimfirecentral.com/forums/showpost.php?p=11568873&postcount=4
https://www.rimfirecentral.com/forums/showthread.php?t=1168273

17. Some great pictures of a 44 bolt and trigger mechanism laid out.
https://www.rimfirecentral.com/forums/showpost.php?p=11826049&postcount=14
https://www.rimfirecentral.com/forums/showthread.php?p=11831925&posted=1#post11831925

18. How to SAFELY remove and reinstall the extractors that are retained by "stake marks".
A "staked extractor" removal tutorial!!! | Rimfire Central Firearm Forum

19. Dimensioned pictures of a model 26 bolt. If you think you are interested in making your own bolt for this model!!!
26B/C bolt fabrication, but... | Rimfire Central Firearm Forum

 

Mossberg Technical Support...

Mossberg Technical Support... Generic info, ie not model specific.

1. Ball bearings to repair the S-100 and S-130 peep sights. Courtesy of DKSAC2 and foxfirerodandgun
Fixing Rear Peep Sight Detents

2. Magazine ID info... R498, R632, 1220, 2384 and 3235 Magazines
R498, R632, 1220 & 2384 Magazine tutorial!!!

3. Magazine info regarding the correct mags for a particular model rifle. From my "Component Parts List"s. Posts 4 & 6
mossberg mag ??

4. R-119 Magazine disassembly and reassembly.
https://www.rimfirecentral.com/forums/showthread.php?t=499145

5. Pin Punches... how to make custom ones!!!
I did it again!!!!

6. Tuning the "Clip Fed" Magazine. Works for both semi-auto's and bolt actions, Courtesy of Mossbergman
Mossberg 152 K
This picture should help also!!!

7. Havlin scope mount modification Herzo's original modification to a Havlins scope mount. Courtesy of Herzo.
https://www.rimfirecentral.com/forums/showthread.php?t=340535

8. 46M scope mount modification Good info and pics added by LRJ. Courtesy of Herzo and LRJ.
https://www.rimfirecentral.com/forums/showthread.php?t=461778

9. Adding a Rosewood fore end tip to a stock. Added this just for fun!!!
https://www.rimfirecentral.com/forums/showthread.php?t=192615

10. Some good info on the S-101/S-106 front sight. The individual parts are disassembled and laid out and an order of reassembly is given. Post #5 has the pictures!!!
https://www.rimfirecentral.com/forums/showthread.php?t=547708

11. Production numbers of the Spiegel Mossbergs and scopes. Courtesy of Gunhugger!!!
https://www.rimfirecentral.com/forums/showpost.php?p=2004554&postcount=2

12. Disassembly and reassembly for a Mossberg M4 Scope Re-Assembly. Courtesy of Gunhugger!!!
https://www.rimfirecentral.com/forums/showthread.php?t=201801

13. A link on how to repair cloudy lenses in a scope. Courtesy of Sarge756!!! Go to post#5 for the link!!!
https://www.rimfirecentral.com/forums/showthread.php?t=1053746 And here it is directly... just in case. http://jimshomeplanet.com/lensglue.html

14. A link to an after market custom scope block maker!!! All you Spiegel fans... PAY ATTENTION!!!
https://www.rimfirecentral.com/forums/showpost.php?p=5252557&postcount=10
And here is the link by itself!!! http://www.steveearleproducts.com/scopeblocks.html

15. S-102 sight help. Courtesy of foxfirerodandgun and Mossbergman!!!
https://www.rimfirecentral.com/forums/showthread.php?t=549081&highlight=S102+assembly

16. Replacements for old hardened, cracked rubber scope eye cups... AND an idea to help prevent rust on you rifles, courtesy of ray883!!!

Sorry, but need to clarify something. The generic 19mm rubber eyepiece is harder to find on Google. Go to eBay and search for Nikon DK-19 rubber eyecup. You will find them for $4 with shipping included.

and here is the link on the rust prevention trick!!! https://www.rimfirecentral.com/forums/showpost.php?p=5451246&postcount=37

17. Custom trigger guard fabrication. The example shown is on a 26B, but the idea ought to work on any Mossberg with the plastic trigger guards!!!
https://www.rimfirecentral.com/forums/showpost.php?p=4594766&postcount=44 Post #57 also has a picture of a hand fabricated trigger guard. https://www.rimfirecentral.com/forums/showpost.php?p=4607011&postcount=57

18. Electrolysis cleaning, for anyone with a heavily fouled bore this might be interesting!!!
https://www.rimfirecentral.com/forums/showthread.php?t=917674

19. Magazine adjustment for the aftermarket 10 rounders. The first link goes to the actual post that describes the "solution". The second link is the whole thread.
https://www.rimfirecentral.com/forums/showpost.php?p=11568873&postcount=4
https://www.rimfirecentral.com/forums/showthread.php?t=1168273

20. R-118/119 Release Lever Spring fabrication!!! The thread title is "Mossberg 44 US Magazine use/disassembly?" but this is really about making a "Release Lever Spring" for the R-119/119 magazine. The 2nd link goes to post #23 where the process is described. Plus other good mag info.
https://www.rimfirecentral.com/forums/showthread.php?t=1166911
https://www.rimfirecentral.com/forums/showpost.php?p=11868181&postcount=23

21. Mossberg #4 adjustable peep sight internal construction!!! Courtesy of Sav22!!!
Mossberg #4 adjustable aperture sight | Page 2 | Rimfire Central Firearm Forum

22. Mossberg #3 sight info, courtesy of Bone!!!
Mossberg No. 3 variations | Rimfire Central Firearm Forum

23. Mossberg S-104 or No. 4 peep sight info courtesy of Bone!!!
Mossberg No. 4 S104 Difference's | Rimfire Central Firearm Forum

24. S-101 and S-106 dimensioned drawings. In case you need to make a spring or a screw for these 2 front sights!!!
S-106 / S-101 Sight spring dimensioned drawing... | Rimfire Central Firearm Forum

 

great idea sir :bthumb:

 

Hello tfrank. As soon as I get moderator status, it will be a sticky and if you accept........the thread administrator. Regards, Rick.

 

That sounds fantastic!!!



That sounds fantastic!!! I accept!!! God Bless, Frank.

 

Fantastic, we really need a section people can go to to learn about the common and less common fixes.
A gunsmithing or rifle improvement section would be great:bthumb:
If there is any way I can help, please let me know, I'd really like to see this get off of the ground. Thanks for volenteering to do this, I know it's a big undertaking. There is so much knowledge that people on this section of the board have about Mossbergs, a place to share it would be great.

My Best, John K

 

All help is welcome!!!

Anyone is welcome to contribute, and ALL are encouraged to contribute.
God Bless, Frank.

You already have my answer to that!!! I don't have all the info by any means. For this to be successful will require the forum members to contribute. For my part I will go back through my posts and put up links to info that I believe is good to have handy in an easily referenced small area, rather than spread out through the whole forum and spanning years of posts.
All I plan on doing is posting links to the info that is already here!!! I have no intention of trying to reinvent the wheel, so to speak.
So if anyone finds info in a post anywhere on RFC that might be relevant to us here, please by all means PM me a link to what you found and I can add a link to it!!!
God Bless, Frank.

 

+1:AR15firin

 

We need a semi sticky caledd "Franks Fixes" complete with all his info and pics:t ~~JMJ~~

 

Thanks, Jim but...

We need a semi sticky called "Franks Fixes" complete with all his info and pics:t ~~JMJ~~

Thanks Jim, but no we don't. Besides I know of a few instances where I was... how shall I say... not quite on the mark!! What I can contribute will fit quite nicely in the semi-auto post!!! But I appreciate the vote of confidence!!!
God Bless, Frank.

 

Frank, you are THE best at explaining in simple terms. It's like you were a teacher in a prior life.
Pete

 

Well, duh!!!!



Well, duh!!! Maybe that is because I am a teacher in THIS life!!! My "kids" aka my students have given me, and continue to give me plenty of practice in giving what I hope are clear and hard to misunderstand directions. "Right-tighty, lefty-loosey" is one of my favorites!!! In fact I use that one myself on a regular basis!!!

Or are you messing with me on the teacher part???
God Bless, Frank.

 

This is going to be fun :bthumb:

 

Mossberg technical support is in business

No other sight on RimfireCentral has this. This is going to be fun. You can all thank tfrank for a dream come true. Regards, Rick.

 

This is from two years ago! Where the heck,was I

Great deal!!!:bthumb:

Thanks Frank:bthumb::t:bthumb:

 

EXCELLENT! Long time comming. Thanks Frank and Rick.:bthumb:

 

tfrank - While this is from Havlin's website, https://www.havlinsales.com/, it may be helpful to include this in the sticky. Just a thought.

James

1. Models 26B, 26C $18*
2. Models 42A, 42B, 42C, 42M (all variants), 43, 43B, 44US (all variants) $18 (will not fit older Model 42 pre-master action or "long-bolt" rifles).
3. Models 45A, 45B, 46A, 46B or 46M (all variants) $18 (will not fit older 45 or 46 pre-master action or "long-bolt" rifles). *not always in stock
4. Models 140, 142, 144 (all variants) $18
5. Models 146B, 146B(a) $18 * not always in stock
6. Models 320, 340, 342, 346 (variants that take new style pin) $18
7. Models 50, 51, 51M (all variants) $18 *not always in stock
8. Models 151K, 151M (all variants) 152, 152K, 250K $18
9. Models 250C, 350K, 350KA, 351K, 351KA, 352, 352K, 352KA, 352KB $18
10. Models 250CA, 250CB, 251, 350KB, 351KB, 351KC, 352KC, 353, 377, 380 $18
11. Model 400, 400A, 402, 402A "Palomino" $18
12. Models 620, 640, 740 "Chuckster" (variants that take new style pin) $18

 

That info...

That info is already in the sticky with the green arrow!!!
God Bless, Frank.

 

Hello, new to the forum here. Great info. My problem is I have a Mossberg 46B-B that fails to fire. I check the rims of the .22 and they are not dented. I had replaced the firing pin previously as it had broken. The rifle appears to function properly feeding and ejecting just not firing. Any help would be appreciated.

 

???????

Did it fire before the FP broke??? Do you have the correct FP??? Did you clean out the channel the FP rides in??

 

Sounds like it was...

...left cocked in a closet for 20 years.

 

Barrel Change 142A

Looking for info on changing out a barrel on a 142A. Do I need a set of Go/No Go Gauges to check the headspace? If the Headspace is off how do i recify the problem? Thanks

 

A set of...

Looking for info on changing out a barrel on a 142A. Do I need a set of Go/No Go Gauges to check the headspace? If the Headspace is off how do i recify the problem? Thanks

A set of go/no go gauges would certainly be nice but shouldn't be necessary. I use a specially ground set of feeler gauges!!! On your 142A the headspace is typically controlled by the depth of the rim recess in the bolt face. There are also shims that can be installed in the bolt which will move the front part of the bolt closer the barrel. The bolt will have to be disassembled to install those shims. The last thing that you might do is set the barrel back but then you have to deal with what I consider to be somewhat serious modifications. Below is what your barrel will look like if you remove it from the receiver. This picture was done for another post quite a while ago, but fits here perfectly with what I am trying to illustrate. You will notice a dimple drilled in the underside of the barrel, the hold-down stud threads through the receiver and then moves up into that dimple to positively lock the barrel in place. This is in addition to the two sections of straight knurling that produce a mild to really tight press fit, depending on how manufacturing tolerances stack up. I think???

Below is the barrel from a 140K that I relined to 17 Mach2. This barrel was set back and you can see SOME what I felt I had to do to prevent that locating dimple from pulling the barrel back to its original position. The smaller hole to the right of the hold-down stud hole is for a set screw that bears against a bevel, that at this point was not yet filed into the bottom of the barrel. The purpose of the set screw and the filed bevel is to pull the barrel tight against the receiver, then the hold-down stud was tightened. So the barrel is retained 3 ways... by the knurls, the set screw and the hold-down stud. So now I think you see why I consider setting the barrel back as the least appealing method of eliminating excessive headspace. Unless of course it is coupled with a new chamber... say a MATCH chamber!!!

Hope this answered your questions!!!
God Bless, Frank.

 

Thanks!

Thanks for taking the time to give me that information Frank, that will be very useful! I guess the only other question I might have is if I do need Shims, where would I find them? Thanks

 

You will...

Thanks for taking the time to give me that information Frank, that will be very useful! I guess the only other question I might have is if I do need Shims, where would I find them? Thanks

You will have to do a search on this forum to find that out. It has been talked about and discussed a number of times so the info is here. All you have to do is find it!!!
God Bless, Frank.

 

No. 4 Windage adjustment

What is the thread spec (tpi) for the No. 4 Windage (and Elevation) screws? The thread diam. appears to be No. 8 and tpi does not measure as -40, -42 or -44.

Guess I could just buy parts I need, but where's the fun in that.

Thanks,

JOHNC

 

What is the thread spec (tpi) for the No. 4 Windage (and Elevation) screws? The thread diam. appears to be No. 8 and tpi does not measure as -40, -42 or -44.

Guess I could just buy parts I need, but where's the fun in that.

Thanks,

JOHNC

The elevation and windage are both 8-50 tpi. But I use a 8-48 tap and die to rebuild mine and they work just fine. Also the thread for the aperture is 8-40

 

Headspace shims for Mossberg Numrich part #is
270850

 

8-50 tpi

Bone:

Thanks for the info, that's what I was thinking based on the distance between the elevation marks. Tremendous sticky!

JOHNC

 

So I am having some issues getting my new 42m-b to feed from the magazine. I resolved the other issues that the rifle had but this one has me scratching my head. Any help would be much appreciated. Basically as you push the bolt forward the face pushes the cartridge toward the chamber and the bullet gets into the chamber nicely, the rim of the cartridge comes free from the feed lips of the magazine and then progress comes to a screeching halt. The shell just Jams. It seems to take a bit of force to push a shell into the extractors, and there isn't a means that I can see for the magazine to do it. It's almost as if it's the wrong magazine for the gun. Here are some pics that show the jammed cartridge.

 

Cisco, be careful there working with live ammo! Just a little bump or force in the wrong spot can set off that 22LR cartridge! Get yourself some snap caps to work on it with.

 

I know it. I have been very careful... I'll pick up some snap caps tomorrow though.