Bipods can have a negative impact on accuracy. I didn't belive it the first time I was told that but it has proven true for me as well as almost every person I have told that to. I was told it has to do with it causing harmonics in the firearm, specifically the barrel. Now I make sure to shoot off of something other than a bipod.
Nice looking rig. When you built it did you square the front of the upper receiver? I generally do because the "flat" surface that the barrel mounts to is generally off by several thousandths. And think about it, being off by .001 equates to .1 off at 100 yards and is only compounded by the additional harmonics when the surface isn't flat.
Almost every custom bolt action builder squares the front of the receiver as well as the recoil lug. The same should be done to accurize a AR because they are rarely square.
Here are pictures of a recent one I did for myself:
First I start out with a round tube that is cut to allow for a very tight fit into the receiver where the barrel goes. And I clearance it to allow my cutter to get a full width cut. I make sure to cut a new tube each time to make sure it is true.
Next I start to surface the front portion:
You can see where it starts to cut at the 12 o'clock position. And because this is the high spot it tilts the barrel down and you loose up on your scope. This is normal for the high area to be here first.
This is about 1/2 way there and now the high spot is on the left of the receiver, pushing the barrel to the right:
And finally all cleaned up:
And the reason I do this is because when the gun fires the barrel shifts back against the receiver against what is supposed to be a flat area. And the first void is everything except at 12 o'clock. This creates additional harmonics. Then is settles into the right side of the receiver because the left sight has a high spot and again more harmonics. And it is all these varying harmonic frequencies that can cause a gun to seemingly never be accurate.
After doing this the barrel doesn't shift or squirm around upon firing or at least not as much, it comes straight back squarely on the receiver. This reduces the harmonics to only what is inherently in the barrel.
And the 20 minutes to do this put me in bed for the rest of the day. Damn I hate my back.
Questions are welcome.
Edited by Dolomite_supafly, 08 April 2012 - 11:04 PM.