Hot Glue Hop Up

[renegadecow]

For those wanting to bodge in a hop up that works with minimal tools, and I mean absolutely minimal, here's a guide to how I do it using hot glue for the rubber. While the methodology is pretty crude, the results speak for themselves and there's not a whole lot that could go wrong.

 

First you get your barrel down to its bare essentials. In this case we have an HFC revolver's barrel and forcing cone. The way this is set up is that it already has a way to index the barrel so a lot of steps are omitted in this particular job. Otherwise you'll need to bodge in a way to keep the barrel from rotating so that the hop window will always be pointing up relative to the gun.

 

Next you'll need a nice, sharp, square file to cut a window in the barrel that will be covered by the forcing cone (or whatever device that the inner barrel sits in). It helps to have a table vice to clamp the barrel in, but you can go at it by hand slowly or you can throw the barrel in the chuck of a drill to help hold it down. You need to cut around 1/4-1/3 of the barrel's width. When done, carefully deburr the filed edges with a sharp knife making sure to also get the front and back edge of the window. Rinse off any filings left in and around the barrel and degrease with alcohol.

 

Then you'll need a metallic shaft close to the inner barrel's inner diameter. Don't try to find something too close as you'll need to wrap it with a couple or so (how ever many it takes) turns of cellophane tape until it's lightly snug. Here I used a simple screwdriver.

 

Now comes the hot glue. Simply glob some on and clean off with a hot knife. I like to use the flat side of a box cutter which makes it easy to square off against the contour of the outer barrel. You don't have to get absolutely everything off with the hot knife, just get it square then take the excess off with your fingernail once it's cooled.

 

When cooled, carefully pull the screwdriver out. It will want to stick so take your time. It helps if you give it a slight turn left and right to wiggle it out. It's ok if some of the formed hot glue separates from the inner barrel. It doesn't need to be adhered, just don't get it torn. There may be some hot glue flashing on the inside, but it's recommended to address that after you've fitted the forcing cone back on. As this is a fixed hop, you'll need to shim the top of the hot glue with something. Personally I like aluminum sheets cut from a soda can, but often times the install doesn't need it or at worst a couple turns of PTFE tape is applied.

[ED-SKaR]

This is surprisingly ghetto, I wonder if it would work with polymorph*. I have a hsc 1903 vest pocket hammerless that may well benefit from this.

 

*a commercial product that comes as polymer dust and melts at ~80°c so it can just about be moulded by hand.

[richwuk]

I think polymorph would be too hard, at least hot glue has some give in it.

[renegadecow]

Only one way to find out. And if it isn't suitable you can always redo it with hot glue.

[ED-SKaR]

Only one way to find out. And if it isn't suitable you can always redo it with hot glue.

I don't have hotglue, I do have polymorph, hence why I wonder.

[Mitsu]

Sugru seems to be the popular choice here in Sweden.

[Cire_]

Yepp, Sugru is pretty many ppl that use in Sweden, i myself have done it aswell. It's working out pretty good for me so far.