Stock weight system project

[AlNyhus]

Recently, @jimmymac and I worked up a weight system for his LV gun (10.5 lbs) to bring it up to HV weight (13.5) and better balance it. Jim sent his butt plate and a piece of .750 O.D. tungsten copper rod 8" long to use as the weight. Here's what we did, in case someone is looking at doing something along these lines.

First thing was to drill and tap the tungsten copper rod for 1/4-20 threads. Not a great pic but you get the idea.

Jim had marked the butt plate where he wanted the weight to go. Milled a .250 hole in it at that location and did a 82 degree counter sink. Then, a stainless flat head Allen cap screw was used. The O.D. was reduced and it was faced it off to be well below the butt plate. In progress:

Final product with the weight bolted to it:

Having used this before for weight tubes, a piece of 3/4" Schedule 'M' hard copper tube (.875 O.D. and .811 I.D.) got the nod. This gives right at .061 clearance between the weight and the I.D. of the tube....more on that later. To close the end of the tube, a brass plug was made with an .875 O.D. flange at the end. The inner part of the plug is recessed and a piece of 3/4" thick anti fatigue mat is epoxied in as a 'bumper' for the weight. The plug is then epoxied into the tube.

The tube is cut to a length that allows about 3/16" of the 'bumper' to be compressed before the butt plate contacts the tube. The front of the weight is always in compression and the weight is pulled backward in recoil by the butt plate...not shoved backwards by the stock. Here's the amount of compression.

Stock tube and weight ready to be epoxied into the stock. The copper tube was hit with some 60 grit for the epoxy.

In use, the weight will be wrapped with tape until it's a slight interference fit into the tube. This stabilizes the weight and spreads the load of the weight out over the entire length of the inside of the tube.

At this point, I stuffed it in the satchel of the next Pony Express rider that stopped at my sod hut to water his horse. "Head it towards where the sun comes up." were his instructions. Off he went.

Jim then did the hard work and ended up with a slick installation into the butt of the stock. He'll pick up the narrative from here and bring it home.

Good shootin' -Al

 

[gunsandgunsmithing]

Nice work Al and Jim! That's the right stuff and the right way to do a weight system, IMHO. I have a bunch of aluminum tubing that I use to make flag poles, so I use it vs copper but both should be great. Like you, I don't want weight free to move inside. I've seen a stock pretty much destroyed by a loose weight in there. Attaching to the butt plate is how I do them as well. Again, good work! Ya'll pay attention to Al. He's a master at this kind of thing and is a sharp guy that pays attention to every detail.

 

[JFrank]

I need one.

 

[jimmymac]

First things first. Thanks to Al and Mike Ezell. Al did a great job with the weight system and he explained everything to me to get me moving in the right direction. Mike was also involved in this project and encouraged me to make a jig out of some wood and add a drill bushing so I could get the the bit lined up when it came time to make a hole. It worked like a charm.

Here is what the things looked like when I got started. That was my first crack at figuring out where I wanted the hole. This ended up not being the final location. I bumped it up a bit to take advantage of the greatest OD.


Here is the fixture I made. Probably not exactly like Mike would do, but the concept is the same. It utilizes the existing threads in the stock. The drill bushing was epoxied and hammered in since I could not locate a SP bushing.



After that, it was a matter of drilling the hole, so I secured the fixture to the butt end of the stock and gave it a go. I drilled a bit deeper than the tube length, because I wanted to get a good epoxy bed in there. I was fortunate to run into minimal resistance in the way of fiberglass, so I drilled most of it by hand. It was only at the end where I ran into some glass and needed powered assistance.




To be continued.

 

[jimmymac]

After drilling, I determined that the existing foam was sound, so I worked with what was already there. If it would have been compromised, I was prepared to remove as much of it as possible, re-foam, the re-drill. I cleaned up the hole to get the tube to fit nicely then coated the butt plate and stock with paste wax. I also put some wax down in the tube and on the butt plate screws.


Once satisfied with the release agent, I made up a big portion of JB Weld and poured it down the hole. I trial fitted the tube to make sure the end of it was pressing firmly against the epoxy and I was getting some resistance on the end of the tube as I tried to push it in. Once satisfied that there was a good epoxy bed in the stock, I smeared epoxy on the walls of the hole and the tube, slid it all in, cleaned up the stuff that squished out, attached the weight to the butt plate, then screwed the whole thing down and let it be.





Once that was all dry. the only thing really left to do at this was to clean things up and bed the butt plate to the stock. Al suggested this to me and it made perfect sense. I broke out the dremel and roughed up the fiberglass and removed a bit of the foam above the tube. Once that was accomplished, I mixed up some more epoxy, plugged the holes, gooped the thing up with epoxy, re-waxed the butt plate, unplugged the holes and screwed it all back down tight.



To be continued.

 

[jimmymac]

Once dry, I removed the butt plate , cleaned it up and it looked like this. The project was complete other than just buttoning it back up. Not a perfect bedding job, but hey...I'm just a hack.


At that point, I wrapped the weight with some tape to provide a slight friction fit inside the tube and that was it. In the end, the gun came in in a couple ounces less than the weight limit I shoot. The balance point was also moved rearward a good bit by this addition. This was an enjoyable project thanks to Al and Mike. They made my life easy.

 

[gunsandgunsmithing]

Looks real good! For those that have never done this, it's easier said than done. Not rocket science but it's full of pitfalls if you fail to think it through well first. Kudos! Job well done sirs!

 

[AlNyhus]

I need one.

Send me the weight and the butt plate with the location marked. Pony Express runs toward where the sun sets, too. -Al

 

[Judd]

Y’all did an awesome job, looks great! We always just did them with lead and epoxied in in the stock…doesn’t everyone want theirs loaded up

 

[AlNyhus]

We always just did them with lead and epoxied in in the stock…doesn’t everyone want theirs loaded up

I've made some lead weights using the squirts and leftover cores from my bullet making. Melted it up and poured it in a piece of capped Schedule 80 PVC for a mold....works good.

I mentioned doing that on here a while back and was told it wouldn't work. Glad I didn't know that before doing it.

 

[Judd]

We always used a plugged copper pipe and then poured it with a plug then drove it all out. Not near as purdy as your way.

Seriously guys, looks awesome! Y’all did good work.