What might be possible causes? I am pretty sure it is because I tookthe pressure point out on the forend, but would like to check all possible causes. Rifle was grouping around an inch, took pressure point out and it went to stringing the shots. (I took the point out because it was located on the side of the barrel, not the bottom, thought this might not be a good thing.)

Put a pressure point back in. Paper matchbooks work well, but I use gasket making matrial from NAPA to do this. You will soon have the answer.
It would not hurt to check/retorque screws either.
Check yourself too -a change in your cheek weld will cause verticle stringing. It happened to me.

Every now and then I've also found loads that string either vertically or horizontally in a gun that normally doesn't do that--just the forces of "shooting gods" at work I guess.

how does removing a pressure point cause stringing..??? it has been my understanding that floating a barrel (removing the pressure point)eliminates stringing.

Sometimes in free floating a barrel flaws in the action bedding are allowed to enter the picture. When I float a barrel I at the same time will glass the action. It saves taking the barreled action out of the wood/stock twice. Jim

When you put pressure on the forend, it separates the barrel and stock slightly, and may let the barrel settle down on a "rub" that wasn't an issue before.

quote:

Originally posted by WVBlue:
What might be possible causes? I am pretty sure it is because I tookthe pressure point out on the forend, but would like to check all possible causes. Rifle was grouping around an inch, took pressure point out and it went to stringing the shots. (I took the point out because it was located on the side of the barrel, not the bottom, thought this might not be a good thing.)

I concur with buckshot. You fixed something that wasn't broke!

Thanks to one and all. I figured I was the culprit, but I just had to try and shrink those groups. Live and learn i guess.

I had the same problem with a rem 700 in .270 win. I called a gunsmith friend and he said I should probably go ahead and bed it. I used the score high pillar/glass bed kit and bedded it to 2 inches in front of the recoil lug and viola. Groups went from 1.4" to just under .6" with the same load. I couldnt believe it. He also said to let my barrel completely cool between shots because there are stresses put in a barrel in the manufacturing process that can cause a very small amount of bend and can cause stringing. My rifle will still string if I fire back to back shots but it isnt near as bad as before the bedding job.

just my $.02

quote:

Originally posted by bill smith:
how does removing a pressure point cause stringing..??? it has been my understanding that floating a barrel (removing the pressure point)eliminates stringing.

IF the pressure point is dampening excessive, erratic barrel vibration, removing it will result in what's happening here. Don't think EVERY rifle responds positively to free-floating the barrel, because many don't. And you never know which will and which won't until you free-float it.

NEVER FREE-FLOAT A BARREL IF IT IS SHOOTING ACCEPTABLY AS IT IS NOW!!

El Deguello,
I just wish I knew that a year ago. It would have saved me months of aggrevation do to a scope that finally went bad.

Of course if I had realised it was the scope I wouldn't have tried to float the barrel...

Great thread as Ive always wondered what causes stringing. My friend and I both own the same rifle a 700 BDL, mine in .338 WM his in 7mm RUM. Mine by the grace of the accuracy gods shot slightly better. By slightly I mean I can consistantly get sub moa groups, where as he was always at or 1/8" above. As most here know a 700 synthetic stock has two pressure points that slightly contact the barrel located near the end of the stock. My friend asked me what I thought of him removing them to free float the barrel in his quest to acheive accuracy on parr with my 700. I said I thought it a bad idea as he was getting many groups that were only 1/8 to 3/8" larger than mine and I felt he should be over joyed with this out of a factory rifle and most likely he would do more harm than good.

Guess what, he did it anyway and his group size near doubled. He wound up talking it to a smith and getting it bedded. His 700 is now on parr with mine.

El Deguello said it best. Dont free float a rifle thats shooting well.

FWIW,

A couple rifles I own will begin to string vertically as the barrel heats up from repeat firing. From what I've been told, some of the Lee-Enfields were pretty bad about that too.

There are several possible causes of vertical stringing. The information you have received above is certainly good stuff and will deal with the majority of instances.

If the rifle was shooting well (and I know yours was), then if it strings with the same ammo after your modification, there is little doubt you have caused a bedding problem of some sort.

Just for info, another cause of vertical stringing, particularly at longer ranges, is a load which does not operate within the full, designed, burning pressure range of the powder used.

Every powder has a pressure range in which it burns cleanly and consistently with certain weights of bullets (and primers), and with relatively repeatable pressure curves from round to round.

If a load is too hot, or too mild, it may be right on one or the other the ragged edges of that proper burning range.

Then, some shots fired will result in the powder burning fully and consistently (and cleanly BTW). Those rounds will have an acceptably consistent velocity and trajectory.

In other shots the powder may not burn as it was designed to do,because it is not operating within the correct pressure parameters. Those shots may have higher or lower (generally lower) velocities and different trajectories. The result? Vertical stringing.

That why benchresters, particularly long range benchresters, sometimes find changing group shapes while working up loads. Naturally, they tend to prefer round groups over vertical ones. Round groups mean they can concentrate on trying to read and hold off correctly for the wind, without having to guess how much to hold off vertically from shot-to-shot.

Your rifle's problem is probably bedding, but some other folks who have tried several bedding approaches with no success, may get a little profit from re-evaluating their loads.

quote:

Originally posted by WVBlue:
What might be possible causes? I am pretty sure it is because I tookthe pressure point out on the forend, but would like to check all possible causes. Rifle was grouping around an inch, took pressure point out and it went to stringing the shots. (I took the point out because it was located on the side of the barrel, not the bottom, thought this might not be a good thing.)

Put the pressure pad back on and fire lap that barrel if it's a factory tube.

quote:

Originally posted by HP Shooter:
fire lap that barrel if it's a factory tube.