Making an 870 2 3/4 in 3" - Possible?

eltorro

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Is it possible to make an 870 Remington digest 3" shells? The shotgun is a Wingmaster 2 3/4... one of the early series.
I have the 3" barrel already. Is there anything else?
 
I believe you only have to remove the 2 3/4in. ejector and replace it with a 3 in. ejector. The ejector is riveted to the frame and after it is replaced your frame may need to be reblued. You can actually load and fire a 3in shell from a 3 in barrel installed in a 2 3/4in frame but it all goes to hell when you try to eject the empty, the case has to be all crunched to get it out or the barrel has to be removed. I believe WILSON was refurbishing old police 870 and making them 3 in., without enlarging the ejection port. The larger ejection port is on the 3 1/2 in. guns
 
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I am thinking about doing the same thing with my Grizzly-MAG. I might cannibalize my other Grizzly 870 for the 12.5" barrel (chambered in 3") and the ejector assembly if necessary. I might do some more research first though.
 
I think that the ejection port on the receiver is longer on 3 inch frame.
Try ejecting a spent 3" shell it might not fit.
 
I think that the ejection port on the receiver is longer on 3 inch frame.

Try ejecting a spent 3" shell it might not fit.


Ports are the same in both the 2 3/4" and 3 " receivers.

as said above the only difference is the ejector - the bump that hits the shell rim is further back ( from the front) by 1/4 inch so the shell travels back further before being bumped- that way the mouth of the shell clears the front of the port after the rim is bumped. you have to rivet the new ejector in place.



Remington stopped offering the 2 3/4 ejector years ago.
 
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The new ejectors work with both 2-3/4" and 3" shells. I have converted my 870 that way and it works great. You will have to use new rivets which will show but they usually can be masked fairly well by careful use of good touch-up blue.
 
So after swapping a 3" barrel onto my Grizzly-Mag, I tried cycling a mag full of 3" shells through the gun (without firing, just racking them and ejecting them). I got mixed results. They fit in the mag fine, they eject fine (I tried ejecting some spent rounds too) but I got mixed results with the feeding. The rounds seemed a bit too long, they would get jammed up some of the time. Sometimes they would feed without any problems though. I'm gonna have to play with it some more and see what happens...
 
OH really!?!

so the 2 3/4" stamped barrels are actually 3"???


3" fit the mag but I think the feed ramp is very close to the tip of the shells and the angled follower can't keep the the shells tip up, so you get more jams.
 
OH really!?!

so the 2 3/4" stamped barrels are actually 3"???


3" fit the mag but I think the feed ramp is very close to the tip of the shells and the angled follower can't keep the the shells tip up, so you get more jams.
Yes, if we stamped them 3" people would try to use 3", so they are only stamped 2 3/4".
 
So after swapping a 3" barrel onto my Grizzly-Mag, I tried cycling a mag full of 3" shells through the gun (without firing, just racking them and ejecting them). I got mixed results. They fit in the mag fine, they eject fine (I tried ejecting some spent rounds too) but I got mixed results with the feeding. The rounds seemed a bit too long, they would get jammed up some of the time. Sometimes they would feed without any problems though. I'm gonna have to play with it some more and see what happens...

The magazine itself should not be a problem, because it is just a hollow tube, the worst that could happen in the mag is that you hold one less round when it is loaded with 3 inch shells.

The problem probably has to do with timing in the feed cycle.

FEED CYCLE: When a shell is fired and the slide moved rearward, the fired case is pulled rearward by the bolt. Near the end of the rearward movement the rim of the fired shell strikes the ejector shoulder, causing the shell to pivot and eject through the port. The bolt continues to move rearward and the left action bar cams the shell latch which releases another shell from the magazine. The fresh shell comes to rest on the carrier and is cammed into position directly in front of the bolt, ready to be pushed and locked into the chamber by the forward motion of the slide/bolt.

PROBLEM: The most likely cause of the jam is that the fresh shell is too long to fit onto the carrier and is hanging up when the carrier attempts to lift it into the firing line in front of the bolt. Another possibility is that the carrier is attempting to lift the fresh shell into position before the shell being ejected has cleared.

FIX: Correcting these problem/s could involve modifying or repostioning any or all of the following components: receiver, carrier, action bars, ejector shoulder, carrier shoulder.

RECOMMENDATION: The easiest way to fix this would be to buy a 3 inch grizzly. The gunsmithing fees associated with troubleshooting and modifying your shotgun could end up costing several times more than your griz is worth, and would give it a resale value of $0.00. If it was designed to work reliably with 2-3/4 inch shells, don't mess it up.
 
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UHG you missed one critical thing


So after swapping a 3" barrel onto my Grizzly-Mag
as in MAG fed, box MAG that is. So what you described is not the problem, Since there is no carrier. What it is from what I can see in mine, is the top of the mag is far bellow the center line of the chamber due to the fact that a 12 guage is so larger it looks like the shells catch on a lip from the feed ramp to the barrel, I am thinking about die grinding the edge of the chamber at the bottom to stop the sells from catching there.
 
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Jethunter:
Thanks for taking the time to write that post, your advice is appreciated, however as Darkshadow pointed out the shotgun in question is a fed from a detachable box magazine, not a normal tube mag. There's nothing wrong with the shotgun as it is, I'm just trying to see if I can get it to cycle the 3" shells instead of the 2 3/4" shells it was intended for.

Darkshadow:
Let us know how it goes, that would be awesome if you could get it to work.
 
I'll do it tomorrow with some better light for pics.


Have to buy some 3" shells to see, I only have 2 3/4" since there is lots of them available 3" is not that important to me (well maybe in a pinch) but for better feeding.
 
UHG you missed one critical thing



as in MAG fed, box MAG that is. So what you described is not the problem, Since there is no carrier. What it is from what I can see in mine, is the top of the mag is far bellow the center line of the chamber due to the fact that a 12 guage is so larger it looks like the shells catch on a lip from the feed ramp to the barrel, I am thinking about die grinding the edge of the chamber at the bottom to stop the sells from catching there.

oops.... i may be dyslexic, but at least i can spell good
 
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