How does your Duplin bipod track?

[ballison]

When you slide your rifle back and forth on the bipod and rear bag, does it track perfectly up and down, with no side-to-side movement? I am talking about just sliding it fore and aft, not what happens with recoil after firing. I have a Duplin bipod, Masterclass stock, and Edgewood minigator rear bag. I'm running the bipod on a piece of tight carpet. When I slide the rifle forward, it tracks down and to the right. When I slide it back, it tracks up and to the left. I understand the vertical, but not sure about the horizontal.

I put levels on the bar that attaches to the rail, and on the skis, and they are not parallel. If I slide the rifle 3-4" in the bag, the horizontal movement on target is at least 1-2 MOA. Am I making a big deal out of nothing?

Thanks.

 

[Va Jim]

Yes. Once all the white stuff goes away and you get back to shooting you will be ok.

Va Jim

 

[ballison]

Thanks for the help Jim! You can put this on the list of "best excuses for shooting bad"!

I was at Reade Range in western PA this weekend for a shoot, and there was still some white stuff laying around! 72 today so should be good to go!

 

[6BRinNZ]

I'm happy with my Duplin. I found a rear bag change to a SEB fixed a bunch of stuff

 

[280man]

How square is the bipod to your rifle? Is your forarm and buttstock straight?

 

[ballison]

Rick,
The rail is straight (put a level on the forend and rail) but not quite sure how to determine the rest. I measured from each bipod ski to the butt plate of the rifle, and they are within 1/4" of each other. This would lead one to think it is fairly square. It does look like the butt of the stock (where it rides in the bag) may be a little more tapered on one side, but not much. It would help explain the lateral movement, because it would be pushing the rifle in the same direction as the bipod skis. On a forward push, the skis are moving the muzzle to the right, and the more tapered right side of the stock is pushing the butt end to the left. The compound effect might be why I'm seeing so much horizontal shift.

Based on Jim's response, I guess my question should be "does it matter"?

Thanks for taking the time to help out!

 

[dcali]

I've got a masterclass prone stock with exactly your setup -same bag, same everything. The rifle hops to the left when fired. I'm new to the duplin (just one range session), so I haven't figured out if it's my bipod setup or something to do with the rear bag setup. I do think it matters, though - even if it's just because follow up shots take longer.

 

[ryanjay11]

If your bag is too low, the feet will ride on the rear portion, instead of sitting flat. This could be causing your problem. You may need to experiment with different spacers under the bag and/or front mat to find out what works best for your application. Try different styles of carpet for your front mat as well. You might find that a looser or tighter weave helps with your issue.

 

[Scott Harris]

My understanding,

A right twist barrel creates a little leftward thrust on the barrel when the bullet exits. Physics, "every action has an opposite and equal reaction." The bullet is given right spin and a slight right drift. The reaction is a little left movement/torquing of the barrel. My barrel has always slid left and I see that as natural. Use tight nap carpet which allows the bipod to slide smoothly and be reset quickly. Sliding is ok in my book, hopping is not. Fix hopping with a heavier barrel and adjusting body-rifle contact.

 

[ballison]

What I'm experiencing has nothing to do with the firing of a rifle, so let me see if I can better explain my question .

If you're in your living room with your rig set-up, and you slide your rifle fore and aft, do the crosshairs move vertically only, or is there some horizontal movement also? I would assume that a perfectly tuned setup would track straight back with no horizontal movement in the POI. This is NOT what is happening with my setup, and I'm wondering if it is an issue, or if I'm making something out of nothing.

Thanks.

 

[280man]

If its in your head its real. If you are going to be competitive today you must have absolute confidence in your equipment.

 

[seb]

I'm no expert, those guys above are!
But if you slide the rifle back & forth and get side to side movement (not perfectly straight) you may check your setup! I know Duplin by a bit, it's a fine machine/bipod, it should track straight under recoil if most of the things are correct.
My back ground is benchrest shooting, I wouldn't shoot if my setup is not correct, yet.
You might need to check if your rear bag is straight & settled, and if your shoulder is "really" square with the rifle/buttstock. (Hint: stand up and check the straightness of your setup, rear bag etc in relation with the target. It is difficult to check this thing if you are in prone position).
Not sure how you move your rifle forward, if it's by your shoulder and it's then moving to the right (or to the left), try to squaring your shoulder. (Hint: try to move the rifle forward by pushing the back of the bolt shroud or the back side of the trigger guard, not by your shoulder, it's more inline!).
I prefer to move my rifle back & forth by holding the trigger guard with two fingers only (thumb finger at the back of the trigger guard and index finger on the front side), it gives me more consistent & straight back-forth movement. Sometimes we make mistakes when we push the rifle forward with our shoulder or when pulling the rifle rearward by our hand-grip. That's one reason (of some reasons) why our rifle "does not come-back" to the bull / original point of aim everytime.
And btw, probably some stocks are not perfectly straight. It's no way you get a perfect straight back & forth (or under recoil) if your stock is not really straight/parallel.
Reading from your post, personally I don't think it's about your Duplin.
Again I'm not an expert, but hope this help.
seb.

 

[ballison]

If its in your head its real. If you are going to be competitive today you must have absolute confidence in your equipment.

Rick,
There are so many demons running around in my little head that I'm just trying to eliminate those that truly matter!

 

[Va Jim]

OK serious answer. I use a different brand Bi-Pod and if it doesn't track straight I move the rear bag until it does left or right. Once it tracks straight I make sure it is smooth and the work on my position. My recoil is always to the left about 1 target.

VA Jim

 

[mysticplayer]

What I'm experiencing has nothing to do with the firing of a rifle, so let me see if I can better explain my question .

If you're in your living room with your rig set-up, and you slide your rifle fore and aft, do the crosshairs move vertically only, or is there some horizontal movement also? I would assume that a perfectly tuned setup would track straight back with no horizontal movement in the POI. This is NOT what is happening with my setup, and I'm wondering if it is an issue, or if I'm making something out of nothing.

Thanks.

There should be no lateral movement in your cross hair if you are simply moving the rifle back and forth by hand. If there is, I would rearrange my rear bag as I am obviously not set up properly

If there is, the normal forces under fire is only going to make things worst.

I would check the bipod and rifle for plumb to each other and to the ground. Maybe something is tilted someplace allowing the rig to cant as you move it. Sounds as if the rifle is tracking in a spiral.

If you have a bubble level on the rifle, see where it ends up as you move the rifle back and forth. It should stay right where you set it through the range of motion of the stock.

If it moves around, something is not square.

Jerry

 

[willbas]

With my Duplin it is all about the alignment. Once I get the scope on target I stand up make sure the rear bag ears are aligned with the center line of my rifle. I then get my body behind the rifle with my shoulders square to the rifle. Now half the time my scope stays on target the other half I am out of place, my left shoulder to far back.I have not moved the rifle back forward in the rear rest or I have moved the rear rest out of alignment. The more I shoot the better I get hope this helps.

 

[ballison]

Based on the advice I received here from some very experienced shooters, I'm going to chalk this up to "making something out of nothing". I appreciate all the input and look forward to getting out and shooting here in the northeast. Finally getting some nice weather.

I would like to give some kudos to Clint at Duplin Rifles. I called him about the problem I "thought" I had, and he went well out of the way to correct my "issue". He measured several of the bipods he had in stock to determine if mine was out of whack somehow, and offered to send me a new one and take mine back. At no time did he try and BS his way out of it if there was a problem. Nice to know he stands behind his product so well!

 

[6BRinNZ]

Based on the advice I received here from some very experienced shooters, I'm going to chalk this up to "making something out of nothing". I appreciate all the input and look forward to getting out and shooting here in the northeast. Finally getting some nice weather.

I would like to give some kudos to Clint at Duplin Rifles. I called him about the problem I "thought" I had, and he went well out of the way to correct my "issue". He measured several of the bipods he had in stock to determine if mine was out of whack somehow, and offered to send me a new one and take mine back. At no time did he try and BS his way out of it if there was a problem. Nice to know he stands behind his product so well!

This has been my experience in all respects with dealing with Clint - I've never had a problem with my Duplin but did have a couple of requests - he helped me out big time with no issues..probably the best vendor I have ever had to deal with....communication is way ahead of anyone else.

 

[willbas]

My experience with Clint has been different I sent him some pictures of the poor quality of his product. The adjustment spokes still showed tool marks and was shape enough to cut your fingers. His response was if I did not like it send it back and get a refund.

 

[dcali]

My experience with Clint has been different I sent him some pictures of the poor quality of his product. The adjustment spokes still showed tool marks and was shape enough to cut your fingers. His response was if I did not like it send it back and get a refund.

What would you expect him to say? That's how they're made. It's not like you got a defective one.