mod an 870 to accept 3.5" w barrel change?

[sopan123]

i noticed that after buying a 3-1/2 in chambered barrel for my 870, the firearm still would not cycle a 3.5" shell as the carrier hits the receiver before the shell can tilt up, jamming the action. what are your thoughts on machining the receiver back a bit to allow the carrier to drop farther? it seems like it would only need about 1/8th" relief to succeed. also i haven't looked to see if there are other limitations to the carrier drop...

[gWebber]

i noticed that after buying a 3-1/2 in chambered barrel for my 870, the firearm still would not cycle a 3.5" shell as the carrier hits the receiver before the shell can tilt up, jamming the action. what are your thoughts on machining the receiver back a bit to allow the carrier to drop farther? it seems like it would only need about 1/8th" relief to succeed. also i haven't looked to see if there are other limitations to the carrier drop...

As I understand the design of 870s the design of the ejector and the ejector spring also come into play. An example would be a receiver with a “V” at the end of the serial number meaning it can take 2 3/4” shells BUT NOT 3” shells.
Where as an “M” would be Magnum” and can handle 3” shells.

Your 3.5” barrel is “Super Magnum” and I’m sure the ejector and ejector spring along with I’m not sure what else would need to be changed.

Then (I don’t know about this either) there’s the whole can a modified receiver handle “super Magnum “ shells safely.

UPDATE:
I researched this some and as far as I can tell the differences between all the normal 870s and the “Super Magnum” 3.5” 870s are sufficiently different that attempting to modify any other 870 into a “Super Magnum” would not work, wouldn’t be safe over time and would cost more than just buying a Super Magnum which will just beat your shoulder into painful mush.

[Dreadi]

The ejection port would also have to be machined. Or find a receiver with an A at the end of the serial number.

[gWebber]

The ejection port would also have to be machined. Or find a receiver with an A at the end of the serial number.

Yes that would need doing too. Everything I could find in relation to attempting to do this in the end said it doesn’t work.