Filling hollow plastic stock for sound deadening?

[crrcboatz]

Anybody done this, a stock like what's on the Ruger American rifles, or Savage stuff?

I'm not looking to necessarily add weight, but dont mind if it adds a little. I see posts about expanding foam, and others using pourable silicone.

Some say it works great to get rid of the scratchy hollow sound, others say it doesnt. So who has personal experience here?

Yes I did using spray foam, in stages. This allowed the foam to expand in stages. Very pleased with the results

 

[Bocephus123]

use low expansion foam only expands half compared to regular foam probably denser also a little. used miles of it putting in doors and windows etc regular will bow a wall seen it happen. never filled a syn stock like how they are. can knock on it to get you deer to stop it needed.

 

[Glocktogo]

This thread makes me wonder if there's be any benefit to spraying the inside of the hollow cavity with a flexible spray like Flex Seal or Plasti Dip, then filling with expanding foam once the first coat dried? Would that provide greater sound deadening and a more solid feel?

I know I've thought before that if I had a hollow plastic stocked rifle that was too light on the back end, I'd try lining the cavity with Dynamat.

 

[Matt Giroux]

I woke up this morning with a wild hair to tackle this project and learned a few things in the process...and ended up settling (for now) with stuffing the cavity with plastic bags.

This mornings lessons:
I knew gasoline would melt styrofoam...and I've done so in the past and you can "play" with the stuff and squeeze excess gasoline out and its rubbery, or let it absorb more and its more fluid/fluffy. Leave it be and it'll eventually evaporate.
My thought was, acetone would evaporate quicker...so melted some down with acetone and that is a whole different mess. You cannot manipulate this stuff like the gasoline stuff...it is STICKY. People say both are basically napalm which I fully believe, but the acetone stuff is a whole different ballgame which promptly got thrown away and took some good cleaning to get off my hands. At that point I decided to abort mission and use the plastic bags. I may fill it with foam later but for the time being the plastic did pretty much what I wanted and has zero risk of making a mess.

At that rate if you ran out of ammunition you could always spark up the stock and use it as a flaming bat

 

[Bocephus123]

flaming bat maby Dynamat is interesting if you could get it in there

 

[delta6]

I saw this on another site.....​

I recently picked up a Ruger American Ranch Rifle 5.56. I've owned a few of the Ruger American Rifles over the past few years, and have been impressed...a lot of bang for your buck.

My only rear gripe has been the cheap-feeling stock. Inexpensive, hollow plastic...it functions fine, and I know it's how they keep the cost down, but I'm not a fan. Savage has the same problem as well...an FV-SR I have had the same issues...I fixed it by buying a Boyd's TactiCool stock.

Now that I have another Ruger, I wanted to fix the issue. Since this rifle takes an AR-15 style magazine, there really isn't a viable stock alternative on the market that I like. KRG, Magpul, and other chassis systems force you to use AICS pattern mags, and one of the main reasons I bought the rifle was because it uses AR mags. Besides, AICS pattern mags that accept .223/5.56 kind of suck.

Also, once I built up the rifle and added my old Surefire suppressor, the gun became very front heavy. So, I needed to balance out the rifle as well as get rid of the hollow sounding stock. Googled around a bit, found a lot of other people have the same issue with the stock...wanting to get rid of the cheap sound. Others have stuffed shop towels, garbage or grocery bags into the stock, but that doesn't solve my weight balance issues....and it doesn't work well for the sound mitigation, either.

My first thought was to add motorcycle wheel weights to the inside of the stock...they have a sticky back that won't come off easily. Balance solved, not the sound.

Next, I came up with filling it with expanding spray foam. Others suggested it online, but spray foam can be unpredictable and very messy. For weight, I thought about adding BB's or lead fishing weights into the foam, but that may be difficult to evenly disperse.

Eventually, I came up with my solution. Airsoft BB's mixed into suspension with epoxy resin. The BB's are uniform (6mm in diameter), don't add too much weight (0.12 grams each), and can fill up a large volume while adding weight in an easily predictable way. Steel BB's are too heavy, and would just sink to the bottom in the epoxy.

After some 8th grade Advanced Geometry mathematical calculations, I was able to work out the volume of the stock (filled it with water), and the amount of BB's needed to fill that volume. 8oz of 2-part epoxy to fill in the gaps between the 2,200 BB's, and problem solved. Epoxy doesn't expand, so it's the perfect medium for this application.

Overall, it cost about $28. I mixed and poured the epoxy/BB mix in two stages so it wouldn't generate too much heat, just in case the stock didn't like it. Now the rifle balances perfectly...plus, I'll get a little recoil reduction as a bonus.

 

[Bocephus123]

that's a very interesting combo ill have to try that.

 

[Bocephus123]

My ruger american in 300 blk is a amazing rifle

 

[adamsredlines]

For anyone who is curious, I never thought it was worth the time, money and mess of replacing the bags I stuffed in the back of my 300blk Ranch Rifle. Aside from those 3 reasons, most everything else is "permanent" and ya never know what a guy might want to do in the future.
I picked up a 5.56 Ruger American Ranch last weekend and did the same just now. It took about 20 plastic grocery bags which is quick (no cure time needed), eventually free (doest everybody have a ton of these things around?), no mess and easily reversible. It may not win me any craftsmanship awards, but it works like a charm.

 

[Bocephus123]

For anyone who is curious, I never thought it was worth the time, money and mess of replacing the bags I stuffed in the back of my 300blk Ranch Rifle. Aside from those 3 reasons, most everything else is "permanent" and ya never know what a guy might want to do in the future.
I picked up a 5.56 Ruger American Ranch last weekend and did the same just now. It took about 20 plastic grocery bags which is quick (no cure time needed), eventually free (doest everybody have a ton of these things around?), no mess and easily reversible. It may not win me any craftsmanship awards, but it works like a charm

Good idea .