Remington 870 Magnum parts

[navyboy]

Hi All,
I have a few questions for people with alot more experience than me:

1. I have 3 870s magnum and non magnum bought used, outside of the barrel do any of the parts in the magnums come from the factory with magnum only parts and if so how can you identify them.

2. on barrels marked 3", are those automatically magnums or does the barrel have to say magnum.

3. how can I ensure/measure whether the receiver is setup to eject only 2 3/4, 3" or 3 1/2 shells. one is only marked Remington 870 express

some are missing parts and i want to make sure I put the right parts in.

thanks in advance.

Navyboy

[doom720]

Hi All,
I have a few questions for people with alot more experience than me:

1. I have 3 870s magnum and non magnum bought used, outside of the barrel do any of the parts in the magnums come from the factory with magnum only parts and if so how can you identify them.

2. on barrels marked 3", are those automatically magnums or does the barrel have to say magnum.

3. how can I ensure/measure whether the receiver is setup to eject only 2 3/4, 3" or 3 1/2 shells. one is only marked Remington 870 express

some are missing parts and i want to make sure I put the right parts in.

thanks in advance.

Navyboy

Someone fact check me on this but this is my understanding:
1. https://www.gunpartscorp.com/gun-manufa ... st-rem-870
Any specific part, read through all the options. Where applicable, you will see in the descriptions "2-3/4 in only // 2-3/4 in and 3 in // 3-1/2 in // etc)
Specific parts to be careful with would be mainly ejectors. Older style lifters without the flex-tab may be 2-3/4" only but I'm not sure off the top of my head.

2. "Magnum" in this application is typically 3", "Super Magnum" is 3.5". The terminology is irrelevant, just be concerned with length markings on the barrel. If it says 3" regardless of magnum markings or not, it will shoot any 3" (or 2-3/4") ammo. Remember that the chamber is inside the barrel. If you put the barrel on the wrong receiver, you will immediately have problems with ejecting and/or feeding.

3. 3-1/2" is easy - if the receiver doesn't say "Super Magnum" on it, it's not set up for 3-1/2. 2-3/4 vs 3" is the trickier question, but afaik as long as the barrel says 3" you should be able to run 3" on any receiver. 'M' in the serial number indicates that it is designed for 3" on 870s that are not clearly marked magnum, and I believe all express variants from the past 15-20 years are 3" guns by default.

Biggest rule of thumb, don't attempt to shoot anything bigger than what's on the BARREL because that's when you start running into situations where things can fail catastrophically.

Any other "oopsie" situation with parts typically presents itself as FTE or misfeeds.

[JeffCooper]

Totally agree here. Never stuff a cartridge in to a bbl that isn't STAMPED. Example is my police magnum says right the bbl 2-3/4 OR 3". IMHO, trying to stuff a super mag in to a 3" bbl could ruin your day. OR worse. I'd like to think that that you would never get to battery with a shell that is too long.

[bigblue]

The only difference in 2 3/4 and 3 inch receivers is the ejector a 2 3/4 ejector can be shortened to work with 3 inch hulls . I have done this several times .