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590A1 Bayonet

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Dave_1

.22LR
Will the standard 20" length 590A1 (51663) accept a bayonet (M9)? Does it come ready for the bayonet or is anything extra required to do this?

Thanks
 
Dave_1 said:
Will the standard 20" length 590A1 (51663) accept a bayonet (M9)? Does it come ready for the bayonet or is anything extra required to do this?

Thanks
Click to expand...


Yes, the standard 590A1 comes with the bayonet mounting bracket.
http://www.mossberg.com/product/shotguns-pump-action-mossberg-590a1-special-purpose-590a1/51663

If you talk to Ontario, you will find that all of their bayonets - the M9, M10, OKC3S, etc., have identically the same distance between the guard center and the latch center, which is 5.00" exact. So if you encounter difficulty in mounting a bayonet from Ontario, the tolerance error is probably with the gun (+/- 1/16 inch). As you can see, that can be as much as 1/8" total error. That happened on my 590SP, so I had to make a minor adjustment on my gun. (I added a shim to the magazine cap).
I ended up choosing the OKC3S as it is longer (8") and meaner -- scary sharp.
 
john beery said:
Yes, the standard 590A1 comes with the bayonet mounting bracket.
http://www.mossberg.com/product/shotguns-pump-action-mossberg-590a1-special-purpose-590a1/51663
Click to expand...
http://www.mossberg.com/product/shotguns-pump-action-mossberg-590a1-special-purpose-590a1/51663

Also commonly referred to as a bayonet lug. All 590A1 models have a bayonet lug, but only some of the 590SP's come with one.

Dave_1 said:
Will the standard 20" length 590A1 (51663) accept a bayonet (M9)? Does it come ready for the bayonet or is anything extra required to do this?

Thanks
Click to expand...

john beery said:
If you talk to Ontario, you will find that all of their bayonets - the M9, M10, OKC3S, etc., have identically the same distance between the guard center and the latch center, which is 5.00" exact. So if you encounter difficulty in mounting a bayonet from Ontario, the tolerance error is probably with the gun (+/- 1/16 inch). As you can see, that can be as much as 1/8" total error. That happened on my 590SP, so I had to make a minor adjustment on my gun. (I added a shim to the magazine cap).
I ended up choosing the OKC3S as it is longer (8") and meaner -- scary sharp.
Click to expand...

I'd be willing to bet that the 590 is pretty well within tolerances. The difference you see is most likely due to the barrel not being mounted fully, or the magazine cap not screwed in all the way. I'm not saying there aren't variances within the build specs... but 1/8" is a lot when we're talking about functioning machines. If someone's bayonet isn't mounting, I'd look at the bayonet first... then check if the barrel and cap are fully tightened... and only then would I suspect build quality/tolerance as the culprit.

That said... I've never heard anyone having an issue with mounting an M7... if you're sticking with the Ontario M9, some might be a little loose, but otherwise should fit. I have no experience with the M10, but have heard that the OKC3S handle sometimes gets in the way of the magazine cap and may need altering.
 
I own the exact same model...and the Ontario Knife Company M9 bayonet fits perfectly...!!





 
Dave

As you can see, some people (not all) have a tolerance issue -- and it always is on the side of the bayonet being too long. As both Mossberg and Ontario recommend the M9 bayonet for the 590a1 (or 590 SP) shotguns, logic says that you should have the best chance of success with the M9 right out of the box.

But having said that, please review my earlier post as the Ontario technical department was adamant about the dimensions I posted. And interestingly, my OKC3S was too long for my 590 by 1/8". And yet it has the exact dimension of 5.00" between the centerlines of the guard and the latch that Ontario specifies. Before I purchased the Ontario blade, I tried a S&W version and it was too long, so I returned it. With two bayonets from two different companies being too long, I concluded that the tolerance error is probably with my 590.

If we can get enough people here to participate -- we can do our own tolerance range check. I just measured from the front end of the magazine cap back to the rear edge of the bayonet latching tabs (that protrude out on both sides of the bayonet lug) and got exactly 4.90".
 
blacksmith said:
While I don't think that is perfect, it is certainly better than the USMC bayonet. I think the easy answer is that bayonets may-or-may-not fit both the rifle and the shotgun.
Click to expand...

I agree (as I did when viewing your first post) that the M9 fits perfect. Or close to it. As long as the front edge of the magazine cap is at least flush with the front edge of the bayonet guard, then it is good enough.

So that is why I am asking everyone to do a simple measurement and report back -- to see if there really is a tolerance issue with the M590. Measure from the front end of the magazine cap back to the rear edge of the bayonet latching tabs (that protrude out on both sides of the bayonet lug).
 
blacksmith said:
15601587821_a41a6e0e50_b.jpg
Click to expand...

My OKC3S looks exactly like yours on my 590. It just barely starts to cover the magazine cap.

Here is what it looks like after I modified

016_zpse3ef1d4a.jpg
 
Smart Pig said:
Dave

As you can see, some people (not all) have a tolerance issue -- and it always is on the side of the bayonet being too long. As both Mossberg and Ontario recommend the M9 bayonet for the 590a1 (or 590 SP) shotguns, logic says that you should have the best chance of success with the M9 right out of the box.

But having said that, please review my earlier post as the Ontario technical department was adamant about the dimensions I posted. And interestingly, my OKC3S was too long for my 590 by 1/8". And yet it has the exact dimension of 5.00" between the centerlines of the guard and the latch that Ontario specifies. Before I purchased the Ontario blade, I tried a S&W version and it was too long, so I returned it. With two bayonets from two different companies being too long, I concluded that the tolerance error is probably with my 590.

If we can get enough people here to participate -- we can do our own tolerance range check. I just measured from the front end of the magazine cap back to the rear edge of the bayonet latching tabs (that protrude out on both sides of the bayonet lug) and got exactly 4.90".
Click to expand...

I'm not sure I understand the measurement you're looking for by here's mine.
de09b5a4dfa5721901cce22f697841f3.jpg



Sent from my iPhone using Tapatalk
 
Thanks for the measurement and having the photo with it.
It shows 4 7/8" to the back edge of the bayonet latching tab. That is basically the same measurement I have on mine. If you were to try to attach an OKC3S bayonet, it would not sit over the magazine cap. What is unknown is whether an M9 or M7 bayonet would fit? (According to Ontario, there is no difference between bayonet versions as far as mounting dimensions go.) This also supports Blacksmith's assumption that there is definitely a difference between the mounting distances between his rifle and his shotgun, which should not be.

Before any conclusions can be made, we need more people to take the same measurement and also to provide pictures of their 590 with a bayonet -- hopefully an M9 or M7.
 
I just found an article that was posted on this forum a long time ago. It pretty much resolves the question as to where the difference is. We can cease taking measurements on the 590. There is definitely a big difference between the OKC3S bayonet and the M9. Somewhere between 1/8 to 1/4 inch. The tech at Ontario fed me bad poop. Look at the pictures in this link and it is self explanatory.

http://www.guns.com/review/2012/12/04/shotugns-and-bayonets-from-okc/
 
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