Ballasting speargun - how much weight?

I like my guns to just barely sink with the shaft in, and be as buoyant as possible with the shaft out. I take a mesh bag held on the gun loosely with a looped string holding it. I add weight until the gun just barely sinks with the shaft in. Then I slide the bag toward the muzzle or the butt until it sinks level, butt or muzzle first, whatever I want. I like mine to sink level, but that's just me. When I get it the way I want, I put a cable tie next to the string on the gun. Now I know how much weight I want and where on the gun it needs to be.

Next, I take the weight and calculate what size slot in the gun I want to hold the weight. I screw 2 pieces of wood together, then mill or route a slot per my calcs, melt the lead and pour it into the slot. If I like what I've got, I cut the same size slot in the gun, take the little ingot out, drill a hole in it, and install it in the similar slot I've cut into the gun. Make a removable cover plate and you're good to go. This is how I ballasted Core's gun, except I didn't make the cover plate removable. The first time Alvin needs to adjust the ballast, I'll just mill out the epoxied cover plate and install a removable one.

Advantages to this approach:
1. Lead is cheap, and a poured ingot like this can be tailored to the shape of the gun (in this case, fairly long and skinny so you don't weaken the stock) A poured lead ingot also takes up less of the stock than bb's and is quieter.
2. If you make a screwed cover plate, it's easy to adjust the ballast if you modify the gun, like adding a reel, change shaft diameter, or whatever.
3. It's simple- all you need is a router to cut the slot. I used a mill because I have one, but it's no big deal with a router.

I hunt on the bottom in what is sometimes a strong currrent. My shots are also fairly close, like 8-12 feet. Most of the time I'm more concerned about keeping the gun off the bottom and out of man made wrecks after the shot than I am about recoil. For a very slender or very short gun, I'm not sure the difference in ballast for a gun that slowly sinks with the shaft in compared to a gun that slowly rises with the shaft out would affect recoil much (It's a tiny bit more than the weight of the shaft, right?), but I've never really tried to compare one with the other, either.

:goodposting:
With Reefchiefs build coming to a end this would be a great thread for some ballasting pictures and more opinions... If all the experience here on the forum would weigh in on this topic it would be magic.
Any tips on ballasting for too much kick later on in a guns life(other than power reduction)?

hey guys , i don't want to stray but i was thinking of using a mountable lead weight maybe painted and then screwing it onto the gun so i could always change the weight as need be . also not weakening the barrel with holes . has anyone ever done this ?

I used Woodguy's method for my gun. It works really well and is pretty simple. Its usually pretty easy to figure out about where the lead is going to be before you even put it in the water.

Personally I like my gun to sing as slowly as possible, that way if I let go of it for a second it doesn't sink off into the deep.

My first gun was fairly thin with a rear handle plus layout, because of the shaft overhang and the extra wood behind the mech my gun was a little nose heavy. I ended up putting about .75 oz in the but of the gun. to balance it but because I was using a 5/16" shaft then gun sunk without much extra weight. Of course a rear handle or mid-handle layout will be different.

Tufual to answer your question yes you can. A company Ulusub makes a reel that I use and it comes with a metal plate to keep your guns balance when the reel is off. Using an external weight comes with the added intricacy of shape and aesthetics. Just make sure the shape doesn't catch the shooting line and it should be fine.

I found out pretty quickly that I don't change the rigging on my guns very often. I end up getting/building a gun for each role. I bet I'm not the only one here that does that either.

Thanks for the bump Dude George :thumbsup2: This forum always has the answer.

Im planning basically the same thing Wood Guy says. My gun is pretty massive so I am not very worried about kick at this point. I plan to ballast the gun to slightly slightly sink in saltwater shaft in. Ill be making my handles detachable so I will try to hide lead there as well.

Since you're going to put a nice big rubber loading pad on the back you have a nice spot for lead right in the butt of the gun. However, I would expect the ballast for your gun will have to go pretty close to the midway point of your gun depending on your shaft diameter and overhang.

Also just a tip when trying to determine the trim you can use less weight the closer you get to either end.

Yeah planning to do a little in the back and a slot up front. Probably in the back since the handle can't hide much.

If you don't have a good hiding place to hide all the lead, don't fret. A wooden plug does not look that bad on the underside of the barrel. I make 3/4" dia lead plugs melted in a scrap wood. Bore a 3/4" dia blind holes to the proper depth in your gun, then cut matching wood plugs and epoxy the plugs in place and sand smooth.

Buy Snappy 1 Tapered Plug Cutter at Woodcraft

Quote from Dan

How much weight should I add to my speargun? I figured I'll ask about balance in a separate thread.

My understanding of ballasting as far as weight is; to keep adding weight until the gun starts to sink (shaft out) then take off just enough weight to make it float again.

This is called Maximum Ballasting which will make the gun very heavy...i.e, difficult to maneuver...but .as everything in a speargun is a tradeoff....it will also reduce recoil substantially.

It comes down to personal preference......so my 2 cents of advise...if the gun sinks with the shaft in....you don't need to add anything...and most guns will sink muzzle first with the shaft in.
If needed...just add as much weight to the muzzle area to reduce recoil/muzzle flip...but not too much so it feels comfortable enough holding the gun under water as if target shooting for a few seconds without feeling a downward drag...I think this is what you will need to figure out more than anything else.

If you still are not comfortable enough with the resulting recoil...then its a matter of stock design/mass.

Riffe guns tend to have low profile stocks...but with noticeable recoil...to really counter recoil in that case you need a lot of ballasting weight...which defies the low profile stock in the 1st place....personally...I would have added more mass to counter recoil (instead of weight) and design the stock so that maneuvering will be acceptable....most of all...accurate gun.

Bigger guns will float with the shaft in...then it's necessary to ballast the gun with the shaft in (using Woody Guy method is good) just so it sinks with the shaft in...floats with the shaft out.

Ihab