This is a new-to-me-it-followed-me-home Remington 870 Competition. They were made in the early 1980s and this one is barrel dated March 1982. It has decent walnut, cut checkering, and a 30 inch full choke. That might be the only barrel/choke configuration they came in (?). The forearm is longer than a normal 870 and there was a lot of modification to the barrel and magazine tube to make this 1100-ish gas piston work to bleed off recoil. I've only had it out to the trap range once and you can feel the gas piston doing it's thing. 1 oz loads feel like very light 20 gauge loads.

Does anybody know if the gas seal ring is the same as the 1100?

P.S.I wish I could figure out how to make the photos 'appear' and not be a link.

[img]https://i.imgur.com/Ldz7Ah8.jpg?1[/img]

[img]https://i.imgur.com/PVObSY7.jpg?2[/img]

[img]https://i.imgur.com/sZ7f0lK.jpg?1[/img]

[img]https://i.imgur.com/WLjOPHT.jpg?1[/img]

They are the same o ring , I suggest you purchase the graphite coated o rings , Brownells, midway,north south Has them , KEEP THE GUN CLEAN , IT WILL LAST FOREVER, VERY POPULAR WHEN THEY CAME OUT!

For the 1100 at least you need the proper O-ring. Heat eats up the hardware store variety. Carbon buildup where the O-ring seats in the gas ring too. Can be hard to see. Worked on a 1100 used for trap that kept eating the proper rings. The gas ring had a smooth, shiny but not quite right look. Attacked it with a piece of brass and with considerable force carbon broke off in chunks. Brownells sells (or did) a gas ring brush to make it easy to keep the build up down if you shoot it a lot.

Interesting! I don't understand how it reduces recoil. Does the gas piston cause a weight to counteract the rearward force of recoil?



DMc

Google dropped this in my lap. Not a thorough explanation but gets the point across. Odd, but the short video makes it look like the "870 Competition" kicks just like any other 870. There's no technical info on actual bleed off, displacement, or actual recoil reduction.

https://www.forgottenweapons.com/remington-870-competition-hidden-features/


DMc

Keep in mind that none of them actually reduce recoil but spread it out over time. First impulse when the energy from the stock goes into your shoulder, another when the piston (and bolt) stops and transfers energy into the stock/your shoulder. (Yes, the recoiling springs transform some of that into heat, but it ain't much.) Feels like less.

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Oh yeah, You loose a little energy in gas escaping through the gas ports but that ain't much either.

Happened to pick up Bob Brister's book "Shotgunning" which was long waiting to be shelved. For an iea on magnitude of felt recoil reduction I'll quote beginning page 56.

"Wayne Leek, Father of the Remington 1100, once explained gas gun's operation to me, and if anyone can give a sufficiently scientific explanation, it should be a man who developed one. Here's what Leek said translated into layman's language: 'Let's take common hunting load which we'll say would recoil against the shooter's shoulder with 25 foot-pounds of energy in a fixed breech gun. We put that load into an 1100, an the shooter pulls the trigger. Before the load and gasses leave the barrel to create full recoil force, approximately 10 foot-pounds of energy are tapped off at the gas orifice and stored into a moving mass not directly associated with the fixed gun mechanism, namely the action bars, breech-bolt mechanism, and action bar sleeve.Therefore, at this instant, the shooter is getting kicked with 15 foot-pounds instead of 25.' "

"My interpretation at this point is that the rearward-moving mass is temporarily postponing Newton's laws of motion in that whereas there is an opposite reaction to the action of gasses moving out the barrel, it is occurring within the gun rather than impelling the whole gun to move backwards with 25 foot-pounds of energy. Obviously, however, Newton sooner or later must be paid back. This is done, Leek said, as the mechanism moves rearward. When the action-bar sleeve impacts against the front of the receiver, five foot-pounds impacts the front of the receiver five foot pounds of the 10 foot-pounds stored in the moving mass are put back into the equation and an instant later the breech bolt, still moving rearward, impacts against the rear section of the receiver, putting back the other five foot-pounds, thus satisfying Newton's Laws."

"What really happens is that the shooter gets kicked three little times instead of one big time; the first kick coming with 15 foot-pounds of energy, the second with five, and the third with the final five. By the time the final foot-pounds arrive, the shooter is already recovering from the original 15 foot-pounds of recoil and does not notice them - at least, not nearly so much as he would notice the full 25 foot-pounds delivered all at once."

I buy that it softens the recoil by spreading the recoil pulse out. I can feel the mechanism moving backwards/forward within the mag tube. Doesn't hurt that that the piston weighs a couple ounzes and it is absorbed in both directions by the spring while also putting a bit of weight between the hands.

Softening felt recoil by counter-movement was also what the Ljutic Space Gun and Browning Recoiless shotguns did.

Well, springs lengthen pulses but don't violate Newton's Third Law.

Felt recoil, that is all I care about. Mr. Newton can't help me with my flinch.

I've got a few of these:

Graco mercury recoil reducer, but it's built as a magazine cap rather than fitting into the buttstock:



A compression butt plate:



A magazine cap weight. But I don't consider this to be a recoil reducer as much as simple forward weight on a shotgun to help some of the sub-gauges be less whippy:






DMc