Old 20ga to HD build.

General discussion about Remington 870 shotgun.
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Old 20ga to HD build.

Post by BKinzey » Fri May 22, 2020 6:13 pm

I had an old Wingmaster 20ga I decided to change for HD use. I’d read several stories how 20ga is a good HD choice if you have recoil concerns. The first 20ga 870s were built on the 12ga frame. You can load 12ga shells in the mag and they will cycle into the receiver but of course they won’t chamber. The switch to a “LW” (lightweight) frame came around 1977. I’m not confident of the exact year.

My advice? Buy a police trade-in. Yeah, in 12ga. Faster and probably cheaper, with more options to be had. Buy low recoil shells if needed. Trade-ins usually function fine after a good cleaning if a little cosmetically beat up and they usually come with most of what you want on a HD gun.

I did all my shopping online during COVID-19, the local gun shops were closed and I was keeping my travels to a minimum anyway.

The new barrels are designated light weight or commonly "LW". Unfortunately the used ads don't often state that. there is a date stamp of manufacture on the barrel but it is 2 letters and you need a chart to figure it out. I found the chart but still couldn't figure out the date codes. Maybe you will have better luck. I have 2 barrels, one marked "CJ" and the other "PC".

I did most of my looking on Gunbroker. In a month of searching Gunbroker I only saw one barrel I could confirm would fit. I let it be relisted twice in hopes the price would drop. It didn't, and I bid the minimum and won that one.

Many sellers don't really know what they have, other than a 20ga barrel. An easy test is to pass a quarter through the barrel ring. If it can pass, it will fit. I had one guy insist his barrel wasn't a LW, but a quarter wouldn't fit. I didn't buy that barrel.

With shipping my barrel came in at $200. The barrel I bought is a modified choke and the barrel I has was a full choke so I cut down the full choke. Cutting the barrel and having the front sight drilled and mounted (looks professional) was another $100. A 3 round mag extension was $50 (get one for a 12ga). $350 is well into the price on a 12ga Police trade-in.

I wanted ghost ring sights. The rear sight is no problem, but the front sights I wanted were made to fit a 12, so a sight mount that looks like poop or more machining costs. I'm leaving them stock.

Ammo is hard to find if you are looking for 20ga buckshot, most of it is 3" shells. Another problem for me, being in California, is that due to background checks needed for ammo, there are heavy restrictions on buying ammo online, so it's best for me to source locally.

I thought it was a good idea to mod an old shotgun I had for HD. Now, after the additional costs, fewer choices for sights and ammo, I don't think it was worth it for me and my old 870 and can’t recommend it unless one wants a "project".

Some thoughts, observations, blathering.

With 20ga shells in a 12ga extended magazine I’m wondering if that will affect cycling?

I’m more for function, but I did notice a 20ga barrel looks a little odd over a 12ga magazine. I did cut the barrel to 20” so it would look better over a +3 round magazine.

The Choate mag extension came with a clamp. I don’t have it as tight as I wanted as I think it started to push the barrel and magazine apart. I’m sure this is due to the different circumferences of the two. Blue Locktite has been added. I bought the blued version and the color matches but closer inspection the Choate has rougher machining.

Since I also have a 12ga 870 I tried swapping barrels. The 20ga barrel fit on the 12, but the 12ga barrel didn’t fit on the 20ga gun. Not sure why, didn’t look into it. Didn’t try running 20ga shells through the 12 either.

The pistol grip stock is an Adaptive Tactical EX Performance. Came with a large forend that I didn’t like so I’m not using it and I’m on the fence about the pistol grip. I got it for the adjustable stock. After purchase I read here on the Rem870 Forum recommendations for a different brand.
870 20ga HD.jpg
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Re: Old 20ga to HD build.

Post by Vitaly » Fri May 22, 2020 7:40 pm

Thanks for sharing info and photo. It was really interesting to read!
http://www.Rem870.com - Blog about the Remington 870 Shotgun

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