Looking for limiting rings for pump markers

Looking for limiting rings for pump markers

Thru-Hiker
Thru-Hiker

August 12th, 2012, 3:51 pm #1

Lets see if I can describe this well enough...

Back in the day, I used to have issues with how far back the pump on my Bushmaster SI would travel. The grooves on the side of the body where the pump attaches to the bolt would eventually lengthen, especially with the constant use of auto-trigger. Basically, the screws would keep pounding the end of the slot.

Eventually, this would cause all sorts of problems, because now I'd be hammering on the power tube, and they broke often enough on their own without my help.

But then Unique Sporting Goods set me up with this ring thingy that could be placed right behind the back of the pump arm. Once you measured where you wanted it, you'd screw the two halves together, and now the pump arm was limited as to how far back it could travel.

Not sure if these rings were actually massed produced or they were just an in-house thing for Unique. I can say I never saw anything like them again.

And naturally, I'm looking to get my hands on one now.

Does anyone know what I'm talking about?
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Le_KiD_Qc
Le_KiD_Qc

August 12th, 2012, 5:44 pm #2

I don't know what you are talking about the Unique Sporting Good, but one thing you can do is to put a split collar on your barrel so your pump going to stop on the split collar and not on the slot of your body. Just watch-out to not squeeze your finger or hand between the pump and the collar!

Something like this:http://www.mcmaster.com/#cadinlnord/6436k18/=ithu9h

Hope this help!

Le_KiD_Qc
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newmaticarsenal
newmaticarsenal

August 13th, 2012, 5:04 am #3

Lets see if I can describe this well enough...

Back in the day, I used to have issues with how far back the pump on my Bushmaster SI would travel. The grooves on the side of the body where the pump attaches to the bolt would eventually lengthen, especially with the constant use of auto-trigger. Basically, the screws would keep pounding the end of the slot.

Eventually, this would cause all sorts of problems, because now I'd be hammering on the power tube, and they broke often enough on their own without my help.

But then Unique Sporting Goods set me up with this ring thingy that could be placed right behind the back of the pump arm. Once you measured where you wanted it, you'd screw the two halves together, and now the pump arm was limited as to how far back it could travel.

Not sure if these rings were actually massed produced or they were just an in-house thing for Unique. I can say I never saw anything like them again.

And naturally, I'm looking to get my hands on one now.

Does anyone know what I'm talking about?
Metal clamp split rings will work but make changing the barrel difficult. They can damage the barrel and the pump. If they slip then your back to beating up the slots. Make a plastic bushing that sits between the pump and the body that limits the stroke. Black delrin would look good and wear well. You could also make a Delrin half round block that would connect to both pump arms. Position it in front of the feed tube so it will hit in the feed tube to limit the stroke. You could also drill and tap the aft end of the pump at the 6-o-clock position for a set screw. The screw could be adjusted to limit the pump stroke. Even a zip tie loop around the feed tube and the pump to hammer screws would work and not require tools or modifying the gun.

I've gotten spoiled by the pump return spring on my Phantom and truly miss that feature on my Bushmaster. I would want to add a pump return spring to the mix so I would go with a stop screw/stud at the 6-o-clock. I would give the set screw a rubber tip and a use it also as a spring guide. This just might be the next mod I do to my SC Bushmaster. Ill post pics when I get to it.
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