Can anyone explain the dynamics that cause the point of impact to change on my rifle when I install and remove my Harris bipod each time? I have a Remington 700 SPS with the cheap factory stock so the screw is screwing directly into the plastic and the barrel makes contact with the forearm using pressure pads (which remington says is necessary for the "sporter" barrel. I'm looking at a Hogue with the full length aluminum bedding block because that is what I can afford. Any help would be great.

I had a friend with the same problem....he bought it to me and asked the same question....upon investigating we found that a screw on the bi-pod was extending through the stock and making contact with the barrel.

Once this was relieved the problem disappeared.

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upon investigating we found that a screw on the bi-pod was extending through the stock and making contact with the barrel.

That is the first thought that comes to my mind.

You can sometimes trace this to your shooting technique. If you have a tendency to lean into the rifle/bi-pod when you shooting, it can cause the plastic stock to twist and put unusual pressures on the barrel.

Another factor would be the change in the harmonics of the rifle in comparison to shooting off bags.

Does anyone think the full aluminum bedding block would solve this issue? It is a hunting rifle so I will shoot off sticks, bags, bipod, etc. I don't won't to worry about my POI changing everytime I remove the bipod and put it back on. Other than that one issue it's a great rifle! It retains its accuracy with the bipod on or off...it's the POI change that bothers me.

What is the proper technique for shooting from a bipod? Do you lean into the rifle or not?

The POI that changes should not worry you. Here in SA , its taken as a given that your POI will change with the bipod on compared to off. Dont think that there is anything that you can do about it. Have heard that there is a brand that does not affect your POI though, not sure what its called.

I'm sorry but why would a change in POI NOT WORRY ME!!????

I always free float any sporter rifle I own. Took out the pressure pad and opened up the channel on my own Rem SPS for far better results and no change of impact with or without a Harris bipod. When using a bipod I always grasp around the top of the pod rather than the stock itself and pull down firmly to stop any bouncing off the bench or ground. If shooting off a bag I hold under the forend, I don't like just allowing the forend to sit on a bipod or bag with both hands grasping the stock butt. Prefer to hold the rifle as I would in the field.

Just recently bought a Marlin XS7 which has two pressure pads at the forend tip so have taken those out as well as relieving more in the channel to properly free float the barrel. Don't believe anyone who says a sporter barrel needs pressure. I have yet to see a sporter rifle that did not shoot well when free floated and I have never had to bed any of my sporters, just free float.

I remember years ago aquiring an almost new condition BSA Hunter 7x57 off an old guy who had done a lot of reloading and target shooting with it but on first trying it out on target I was not that satisfied with its grouping. Out of the wooden stock and a good relieving of the barrel channel to get that barrel hanging in mid air. Groups came down to almost one hole with the little beauty and the rifle went on to take many an animal.

I think he meant that if it is known, it can be compensated for.

When I shoot with a bi-pod, I try to pull the rifle into my shoulder rather than lean my shoulder into the rifle. Actually, I do that whether or not I'm using a bi-pod. I look at the bi-pod as something to steady the rifle and not like it has structual value.

I didn't explain that very well but think of the bi-pod as only having the rifle resting on it and what weight is there is pressing downward.

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Originally posted by eagle27:
I always free float any sporter rifle I own.

This is sage advice....if you do this and then after affixing the bipod check again to see that the barrel is still free floating, you'll find the problem in a hurry.....and contrary to what has been said....there is no reason that a bipod should change POI.....assuming the bipod is not contacting the barrel and the barrel is free floating under all conditions!

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Originally posted by tacksmacker:
Another factor would be the change in the harmonics of the rifle in comparison to shooting off bags.

You most likely WILL have a different POI with the bipod as opposed to shooting off of a bag or other support.

There is nothing that can be done about it.

We shoot a Precision match that requires shooting from any number of odd positions with and without the bipod, canting the gun 90 degrees etc...

My precision rifle and everyone else's has a different POI at the 100 yard dot drill on the bipod and off of a backpack.

Off of a backpack, my rifle shoots 1.5 MOA low. You need to do both and take note of the difference and allow for it when you need to

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there is no reason that a bipod should change POI

I do beg to differ here ......

I own 2 bipods, different heights, 9"-11" for prone and the other, 23"-27" for sitting.

Our expereince has been that a bipod used on a concrete bench and the shooting range floor and then used prone with an earth support changed POI quite a bit.

The concrete bench (when using the shorty legs) and a rear sandbag bounced shots way-y-y out of normal grouping established with a double sandabg rest.

Fairly often we get Guys who show up at the range with a bipod attached; thinking they can scrimp on using a solid front rest or sandbags. After they get frustrated becasue the concrete bench tops & bipod combo spray their shots all over the target; we'll get 'em on double sandbags and Voilá! Suddenly their rifles will shoot groups.

I shoot all my rifles off bi-pods your barrel is touching the foreend. I free float all my barrels bedding my action and the 3 inchs of the barrel in front of it.

I then put the bi pod on get into a good shooting position putting pressure on the stock and bi pod then have some body run paper between the barrel to check for tight spots.

I have had rifles with changeing points of impact off the bi-pod then did the free floating and took care of it.

All sound advice but I think you've highlighted the best thing you can do which is bin the std SPS stock for anything reinforced that'll allow that barrel to float. There's a mountain of plastic SPS stocks here that go straight to recycling.

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Originally posted by p dog shooter:
I have had rifles with changeing points of impact off the bi-pod then did the free floating and took care of it.

There's so many posts contrary to my post that it's good to finally find someone to agree.....

Evidently there's more to the story but free floating has been my trick and it's worked the few times I did it.

BTW, I recognize some fine riflemen disagreeing with me.....I'll yield to their posts but will maintian the free floating requirement.

I have even went so far as reinforceing the forend on the cheap plastic stock savage rifles to take care of the propblem of changing impact.

I couple of stiff sections of coat hanger steel and glass bedding took the flex out of them. Now they shoot to the same point of aim no matter how one holds or what one shoots off of.

If your rifle is changing point of impact it is not bedded properly.

Try what Vapo said,it will make you smile.

Why not just get a good stock??????? Pitch the toy that comes with it.

Money 5 to 6 bucks and little bit of time to bed it.

A new stock will be in the future but only if I can't get the factory stock to work...I like a good challenge and don't want to spend more money for a stock than the rifle itself cost. I'll let everyone know how it goes. Thanks for all the info!!

Free float the barrel and MAKE SURE the gap is enough so any recoil or barrel vibrations don't interfere. I've cut out up to 3/8" around floppy stocks to get things working.

I even cut out the wood clear down below the channel, installed aluminum fore arms solidly attached to the wood stock and made solid aluminum mounting blocks AND stocks to test out this bipod problem...a little bit extreme in some cases but I did learn the whats and whys.

Some solutions worked great some didn't work one way and worked another, and some were just too much trouble to deal with on a continuing basis.

Make sure the forearm is stiff enough not to wiggle like a piece of limp spagetti. I've used all thread and square key stock epoxied from the front of the mag well to the end of the fore arm length to help with the plastic garbage stocks and once the stock is fairly stiff from end to end it takes care of the POI change problem...but NOT always.

You HAVE to remember that the WHOLE rifle vibrates at different freq's and a change anywhere CAN affect the POI, but usually a person is concentrating on shooting or load development or some other problem and the vibration thing never enters the mind and/or is masked by other problems.

Depending on the way the stock is attached to the receiver you may have to experiment with the position of the bipod...moving it forward or backward until you find a null point..that's where the vibs have dampened out and it is basically NOT moving.

Swapping around different sized bipods also changes the weight points AND the node point. Tune your rifle to ONE set of parameters and quit mucking about. If you have to change things you basically have to retune to those parameters...just like when changing bullet weight, powders or primers.

This POI change with bipods has been run through a dozen or more forums, forever seems like and there is more mis-information and dis-information that solid good ways to solve the problem...mostly because whatever worked for some people gets scattered all over the net and if it doesn't happen to work for another person, the fight is on, instead of realizing that what happens in one rifle WON'T necessarily work in another rifle...JUST LIKE FAVORITE LOADS...each rifle is an individual and you have to treat it as such.

Changing POI's from the bench to the field is a well know phenomonen, most often attributed to the stock touching the barrel or stock flex and, depending on all the factors, can be easy as shooting the way you would shoot in the field and adjusting the sights and LEAVING THINGS ALONE until you notice another change in POI, to a complete restocking/rebedding jobby.

Then again I've bought a couple of Savage rifles with that POS plastic stock, opened up the barrel channel just a bit and them shoot as well as I can hold while developing an accurate load, and it continue to shoot with and without a bipod, on or off the bench and in the field using whatever was handy as a steady rest...so if you have a problem with POI changes with bipod changes you have to work throught the different solutions that have been offered by the various knowledgeable people until you DO find a solution.

Start with the easiest and quickest, like the sight adjustment, and work through the rest.

Funny thing tho', I never used a bipod for the first 30 odd years of my shooting and never seemed to need one, but now almost all of my shooters from 30 cal and down have one of those ugly things hanging off the end of the stock, but I seem to use a rabbit ear bag in the front more than not even WITH a 'pod hanging there. Go figure.

Sometimes it just ain't easy being easy.

Luck

Another thing to consider is muzzle rise. A bipod adds weight ahead of your balance point and supresses muzzle flip a little or a lot depending on the weight. It is much the same (although less pronounced) as shooting the same load with and without a muzzle brake. It can be exacerbated by poor technique.

In your equation, the cheap stock the SPS comes with is the culprit.

Look at the Bell & Carlson stocks on Stockystocks.com

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Originally posted by craigcampbell:
I'm sorry but why would a change in POI NOT WORRY ME!!????

Because you're rifle is not an exception. They all do it.

As long as the barrel touches the stock you will have issues. Oddly enough the four SPS rifles I shoot are free floated and the bipod doesn't make a POI change on them.

I will shoot groups with a bipod but will get a tad smaller ones using sandbags but not noticeably bigger. 1/2 MOA is about the best I can do with my 223's and 204's using stock adjusted triggers and my handloads no matter how I shot with bags or bipod.

Greg

Gerry said it.

Resting the gun on a hard surface compared to the same surface but with your hand between the gun and rest usually give a similar effect. The gun bounces, and less from a softer platform. I always sight in my guns with no rest and verify with the hand between gun and rest.

Many thanks to all who have responded with their experience and advice. The results of my experiment are as follows. I glass bedded the action and stiffened the forend of the stock with white MarineTex. Then I removed the front swivel screw and ground down the threads both on the screw post and in the hole of the stock. I then reattached the swivel screw using JB Weld. Then I sanded the barrel channel so that I could slide a folded up dollar bill the entire length under all conditions. Next I sanded away the pressure pads on the forend, and again, tested with the dollar. The only concern I had was whether the gun would continue with its accuracy after removing the upward pressure from the pads. A trip to the range and my concerns (happily) vanished. The rifle will still shoot 1/2 MOA with 168 MK's and THE POI DOESN'T CHANGE WITH THE ADDITION OR REMOVAL OF THE BIPOD!!!! I shot once on bags and then added the bipod for shot #2 and continued to switch back and forth for several shots. I have to say that being an amateur gunsmith (when it works) is a great feeling Thanks again everyone!

Don't it make you feel warm and fuzzy when things work out.

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The rifle will still shoot 1/2 MOA with 168 MK's and THE POI DOESN'T CHANGE WITH THE ADDITION OR REMOVAL OF THE BIPOD !!!!

For me, what I suspected happened is that the barrel was contacting the stock, and the bipod changed the harmonics. When I free floated the barrel, the change in impact was much less.