Explaining the "Ball Detent?"

[Black Majik]

Hello shotgun guru's.

Can you guys explain to me the ball detent and what model 870's have them. As far as I understand, the wingmasters have them, the express line doesnt. Do the older Wingmaster have the Ball Detent?

Now, I believe its the locking mechanism of the magazine cap on the 870. Is that correct? What does it look like? What other types of of locking mechanisms are there?

A Wingmaster barrel with the ball detent on the barrel. I thought it was a locking mechanism for the magazine tube to clamp the barrel to the tube. What am I not undertsanding here?

How can I check to see if the barrel has a ball detent?

I have a 2002 Wingmaster, I believe it has a ball detent.

I'm going to pick up an old wingmaster tomorrow that I want to turn into a home defense gun. So I would like to buy a 18.5" barrel for it. Does the older Wingmasters also have the ball detent? What kinda of barrel do I need to ensure that they're all compatable?

With or without the ball detent, can I add a magazine tube without any issues?

Please explain all this to me. I'm so confused. I checked the search and it made me more confused.

Thank you.

 

[Matt-man]

A picture is worth a thousand words. See the attached pic for the ball detent. It's in the barrel ring. The detent engages dimples in the magazine cap, and this keeps the cap from rotating. The magazine cap is what holds the barrel on the gun.

The Express guns have a plastic piece inside the magazine tube that engages the magazine cap. They use that instead of the detent to keep the cap from rotating.

The magazine extensions that I have seen (Scattergun, Vang) have assumed the presence of the ball detent, since you can't use the Express-style retention system with a mag extension. If you don't have a detent, your extension will shoot loose. I've seen it happen.

I purchased my 20" RS barrel a year or so ago, and it came with the ball detent. I read recently on this forum that new barrels don't have the detent or the hole it lives in. If the barrel has the hole but no detent (the 26" VR barrel on my Express was like that) the detent and its spring can be had for about $9 from Brownell's.

 

[simmonsguns]

If a barrel does not have a detent and you are going to install an extension,you can use a magazine extension clamp to hold the whole thing together,these also have a sling swivel attached to the bolt that holds the clamp pieces together.

 

[Fred Fuller]

Richard,

It is the _barrel_ which has the ball detent. Specifically the ring which goes around the magazine tube- see the exploded drawing at http://www.urban-armory.com/diagrams/rem870.htm , specifically part numbers 39- 40. The transition has been gradual, Wingmaster and Police guns still use the detent, older Express guns did too. In initial Express guns after the transition to dimples and the plastic mag cap retainer, the holes for the detent and spring were still drilled in the barrel ring but the detent was not installed.

If you're buying new, just get a police gun barrel- it will have the detent. If you are looking at used barrels, check the front of the barrel ring and it will be apparent if the ball detent is in place. If the used Wingmaster you are looking at for a HD gun has a 2 3/4" receiver, you can put a barrel with a 3" chamber on it but the receiver can't handle 3" shells- stick to 2 3/4" only in non-Magnum receivers no matter what barrel is mounted. That's no loss in a HD gun, 2 3/4" shells are plenty for HD. How can you ID magnum receivers? The serial number ends in an M.

With or without a detent you can add an extension, just use a clamp to keep everything in place detent or no.

lpl/nc (not a guru, but maybe someday...)

 

[MrTuffPaws]

The 20ga 870 expresses have the ball detent. I have one.

 

[Black Majik]

Thanks guys for the explanation, I think I understand it now.

Matt, thanks for the picture, that definitely helped.

Lee, I appreciate your replies, they're always been very helpful.

 

[Matt-man]

No problemo. The gentlemen who pointed out that a clamp takes care of the problem are of course correct. The one I saw shoot loose had neither a detent nor a clamp.

 

[c_yeager]

The gentlemen who pointed out that a clamp takes care of the problem are of course correct. The one I saw shoot loose had neither a detent nor a clamp.

This is probably true, but I have to wonder why Remington goes to the trouble of including the detent even on the Express HD with the mag extension. It seems that Remington feels that either the dimples or detent are necessary even on a gun with a factory extension and clamp. Since they cut every corner they possibly can on the Express it makes me think that maybe the detent is a good thing even with the clamp.

 

[Fred Fuller]

c_yeager,

Remington's factory extensions are two-piece units. A dual threaded collar joins the existing mag tube on one end to the mag extension on the other. Even with a clamp on the mag extension tube the collar could still work loose to some degree without the detent.

I think a better explanation is that this is the same setup as a similar model of the 870P uses and it's just easier to use the same barrels as the police guns get rather than running two lines to build different barrels. The 18.5" ImpCyl bead sighted barrel is the cheapest replacement barrel Remington offers last time I looked, they must build a lot of them.

Majik, thanks for the flowers...

lpl/nc

 

[c_yeager]

I think a better explanation is that this is the same setup as a similar model of the 870P uses and it's just easier to use the same barrels as the police guns get rather than running two lines to build different barrels.

They have different barrels anyways. The 870HD is cylinder choke while the 870P is IMP cyl. I bet you are still right though, both barrels probably get processed in the same way (i.e. recieve the same collar(?) which includes the detent. Additionally the inclusion of the detent allows the user to remove the extension and go to a traditional magazine cap without having to worry about how the cap is going to stay put. So i guess it does make sense, and with a one piece extension it probably isnt something to worry about.

 

[Fred Fuller]

Brain damage is a terrible thing. There I was thinking Remington had gone to IC on all their 18-20" barrels if not special ordered Mod or produced with RemChokes. No such, they still list the HD as a CYL bore. So they aren't coming off the same line after all. Shoulda checked, gotta keep a closer eye on this stuff.

Told ya I weren't no guru,

lpl/nc

 

[sm]

IIRC
Speedfeed had the "special wavy washer" that keeps the mag cap tight onto the mag tube if using the "non-detent" bbls. I believe these come with the Speedfeed set ups.

I cannot remember for sure if Choate has these - pretty sure, as I normally reach for Choate stuff.

Don't ask me for part #'s and stuff. I was just standing there, and a guy says "fix it" . So I grabbed from a cigar box of some various parts and "fixed it".


It ran 50 slugs with no problem...and continued to last I heard.

Don't ask me - I just shoot the durn things.