OK, this came up in another thread, so I am posting instructions here.

I just got a Remington 870 Express HD. I like everything about the gun except that the forend extends too far back, such that it would hit a 6-shell SideSaddle. Spare ammo is everything in a fighting shotgun, and I don't see compromising with a shorty 4-shell SideSaddle as a good alternative. Neither did I want to dump more $$$ into a replacement forend.

Its Dremel Time.

The modified forend works great, and looks just like it came from the factory this way:







Actually, this was an incredibly straight forward modification. Here is what I did:

1) Check the shotgun is empty (duh). Check again.

2) Pump the action all the way to the rearmost open position.

3) Offer up the SideSaddle to the receiver, and mark the forend (e.g. with a Sharpie marker) with a "cut here" line to show the excess material to be removed. You want to err a little on the tight side, as you will be removing about another 1/8" of additional material to clean up the cut.

4) Remove the forend per the field strip instructions in the manual. Set the rest of the shotgun to one side, far away enough that it will not get dirty - you are going to make a mess in the next few steps.

5) Cut carefully along the "cut here" lines, starting at the edge of the forend, using a Dremel and a cutting tool like this:



Actually, mine did not cut deep enough, so I had to follow up with a regular Dremel cutting wheel, but this made a bit more mess as it melts the plastic rather than cutting it. Hand tools can also be used if you like doing things the hard way.

6) Clean off all the plastic swarf, then offer up the forend the the receiver, this time with the SideSaddle properly installed and with shells placed in the SideSaddle. Make a note of any fine adjustments required to get good clearance.

7) Now you are going to clean up the cut edges:
    a) Use a round file to radius the corner between the horizontal and vertical cuts.
    b) Use a box cutter blade, held perfectly perpendicular to the cuts, to scrape the flat areas lengthwise. You want to scrape, not cut, so as to smooth and level the surface.
    c) Use a flat file to clean up any uneven areas. Radius the edges.
    d) Scrape again with the blade to get a nice radiused edge along the length of the cuts.
    e) Offer the forend up one last time to confirm everything looks as you would like.
    f) Finish up with some fine emery cloth (works better wet).

8) After all the cutting and filing, the plastic will have formed a lot of fine burrs and fibres, which cause it to have a lighter "dry" appearance. To get the cut edge to properly match the original factory finish, use a butane lighter to gently heat the cut edge. Be careful not to set fire to the plastic... you are just looking to reflow the cut surface to create a finish that matches the original surface.

Thats it ! Post here if you have any questions, or if my clumsy description needs clarification.

very nice and you didnt make anyone beg

I did the same thing about a year ago. After I bought an after market forend I realized that I liked factory one better. The only thing i did diffrent was remove the extra length of the forend all the way around. I would post pics but the camera is dosent work rite now.
Great post by the way

Very nice write-up and great results!

I modified the PD Expresses we have, and the express forearm on my Wingmaster to accept a sidesaddle, and to fit in the patrol car racks.

I simply cut the "tail" off with a scroll saw, and dremeled the edges smooth. Loos factory, and works freat. Took about 3 minutes for the entire mod, including taking off and putting back on the foreend.

Quoted: I did the same thing about a year ago. After I bought an after market forend I realized that I liked factory one better. The only thing i did diffrent was remove the extra length of the forend all the way around. I would post pics but the camera is dosent work rite now. Great post by the way

Quoted: I modified the PD Expresses we have, and the express forearm on my Wingmaster to accept a sidesaddle, and to fit in the patrol car racks. I simply cut the "tail" off with a scroll saw, and dremeled the edges smooth. Loos factory, and works freat. Took about 3 minutes for the entire mod, including taking off and putting back on the foreend.

Thanks for the feedback. I thought about cutting the whole "tail" too, but I kinda like the look of the original, and the square cut-out looks maybe a little more distinctive. Either approach would work great, I'm sure. The melting/reflow really inproves the final finish too.

Very nice - you should be working at Remington.

Saw guy do something like that on his 870... took it to a shotgun class.

Under rapid fire / stress, caught the meat of his palm between the back end of the foreend and the receiver.

The hand lost...

Might recommend taking it all off, and putting a decent gap in there so that palm and receiver cant get pinched. YMMMV, just wanted to share the info

Nice work taging for future refrance.. this goes along with my plan for my 870

Looks good!  I shortened mine using a hack saw and smoothed out the cut with a fine file and some sand paper. I cut mine all the way around too. The method isn't as important as the result though, the main point being that it is easy to mod an Express forend for use with a side saddle.

Now I have a Surefire forend on it so it sits in a drawer.