Bipod Placement

[whiskerer]

I was at the range the other day and I saw a guy with a unusual bipod setup. He had what looked like a Cadex Dual strike chassis, but unlike most people, his bipod was not on the front of the chassis. He had a extension on the bottom of the rifle that extended under the barrel. Near the end of the barrel, the extension stopped and had his bipod. (The barrel still appeared to be free floated) He basically extended the bottom of the chassis to the muzzle. It looked kinda like this except not attached to the barrel

http://www.google.com/imgres?imgurl=...d=0CCAQMygCMAI

At first I thought it was weird, but after I thought about it, it seemed like it might help a shooter at long range. If you move the butt of your rifle, the closer the point over which the rifle rotates, the more the muzzle moves. It looked like he thought that moving the rotation point away from himself would mean that his natural movement would cause less movement of the rifle. Besides the obvious weight, portability, and maybe looks aspect of this, is this a good idea or would it have some effect that I'm not thinking of? (thinking about trying this out for my own rifle build)

(repost from wrong forum)

[JMP]

Most of my rifles take a spigot bipod up front, have a picatinny undermount, and a bipod loop at the end of the stock, so I can stick on whatever style I want. For more stability, I like a bipod that is wide and far forward. Having the bipod closer can help with more adjustment if you are shooting at something up a hill or are shooting on a downward slope. Also, the ones that mount under the stock tend to be tend to be tighter.

[whiskerer]

Most of my rifles take a spigot bipod up front, have a picatinny undermount, and a bipod loop at the end of the stock, so I can stick on whatever style I want. For more stability, I like a bipod that is wide and far forward. Having the bipod closer can help with more adjustment if you are shooting at something up a hill or are shooting on a downward slope. Also, the ones that mount under the stock tend to be tend to be tighter.

What do you mean by tighter? Less likely to get loose from recoil?

[ar15barrels]

Your link is bad, but it sounds like a parker-hale style spigot and bipod.

http://www.expeditionexchange.com/parkerhale/

I have taken apart Harris swivel bipods and made custom spigots and then bedded the spigots into conventional composite stocks.
They come out with a much lower "roll center" when done that way.

[brando]

It's simple mechanics. Moving the pivot point of an object further towards one end will make it inherently stable (when supporting the opposite end) while moving it closer to the center of gravity will make it less stable.

For maximum stability, move your bipod as far forward as you can. But in some cases the difference is almost unnoticeable, especially for fairly lightweight (under 20lbs) rifles. Increase that weight and everything changes.


My old .408 Windrunner started out with the bipod very close to the center of gravity, which was a feature not a bug as it was designed from the get-go as a takedown rifle. And because of the bipod location, it was nowhere near as stable as I wanted.


So I had a custom bipod and shroud made so I could push the bipod out closer to the muzzle. Stability was my main concern because I was generally shooting 1000-2000m and had no concern about it being compact. I should also point out that the location of the bipod mounting changed as well. Notice in the first photo that the bipod sits under the receiver, so that all of its weight pulls down on it. This is less stable than moving the mount point closer to the muzzle, as you can see I did with the second arrangement. The most stable bipod assembly would be close to the muzzle and slightly above bore axis, allowing the rifle to hang and stabilze under the bipod mounting point. This is precisely why the old Parker Hale bipods you found on L96 and AIAW rifles weren't that stable and fairly floppy while the high bore axis mounted Sako TRG bipods were very stable.

[whiskerer]

Your link is bad, but it sounds like a parker-hale style spigot and bipod.

http://www.expeditionexchange.com/parkerhale/

I have taken apart Harris swivel bipods and made custom spigots and then bedded the spigots into conventional composite stocks.
They come out with a much lower "roll center" when done that way.

It extended significantly further under the barrel than that one, but that is kinda the idea. It looked a lot like the post above except that it did not have the tube around the barrel, but just extended a "rail" under the barrel.

[JMP]

What do you mean by tighter? Less likely to get loose from recoil?

What I mean by tighter is not flimsy or floppy. Some bipods have adjustable tension and others do not. Most designs allow a little flex from side to side to adjust your rifle's aim. If it flexes from side to side and doesn't have a lot of tension, it can be difficult getting your rifle in a stable position. Bipods like the old AI spigot don't have much tension; they are easy to move around side to side and make fast adjustments, but they are not good for high precision or long range.

My favorite bipod design that works well as an all around compromise is the Sako bipod. It's easy to adjust and loads well for stability.

You will need to try different designs to see what you like.

[bomb_on_bus]

It's simple mechanics. Moving the pivot point of an object further towards one end will make it inherently stable (when supporting the opposite end) while moving it closer to the center of gravity will make it less stable.

For maximum stability, move your bipod as far forward as you can. But in some cases the difference is almost unnoticeable, especially for fairly lightweight (under 20lbs) rifles. Increase that weight and everything changes.


My old .408 Windrunner started out with the bipod very close to the center of gravity, which was a feature not a bug as it was designed from the get-go as a takedown rifle. And because of the bipod location, it was nowhere near as stable as I wanted.


So I had a custom bipod and shroud made so I could push the bipod out closer to the muzzle. Stability was my main concern because I was generally shooting 1000-2000m and had no concern about it being compact. I should also point out that the location of the bipod mounting changed as well. Notice in the first photo that the bipod sits under the receiver, so that all of its weight pulls down on it. This is less stable than moving the mount point closer to the muzzle, as you can see I did with the second arrangement. The most stable bipod assembly would be close to the muzzle and slightly above bore axis, allowing the rifle to hang and stabilze under the bipod mounting point. This is precisely why the old Parker Hale bipods you found on L96 and AIAW rifles weren't that stable and fairly floppy while the high bore axis mounted Sako TRG bipods were very stable.

Brando is that the RND upgrade that was offered for the EDM ARMS Windrunner series of rifles? Is that still being offered by RND?

I was wanting to get that set up for my Windrunner and was waiting for the funds.............turns out the .50cal is a never ending money pit LOL.

[brando]

Yep, that's the one. My buddy Troy and I convinced Lloyd to do it and make a bipod to fit it from his other bipod designs, back in 2007. As far as I'm aware, he's still making those setups for XM04 and M96 receivers. The larger M96 receiver has a slightly different shroud where it meets the barrel nut.