Vertical Stringing

gillamboy

Member
Rating - 100%
5   0   0
Help with my vertical stringing please. I place 5 shots on top of each other nearly consistently when shooting groups. I noticed however, that my first shot is always in the same place (holding 5 papers together). I've read the article at 6mmbr, is this just heat in my sporter barrel? It seems I little long to wait 20 minutes to place another shot. Rifle is not bedded yet, is it time?
 
It sounds like thats exactly what your problem is. If you were to free float the barrel you shouldn't get vertical stringing. Free floating is an easy do it yourself job. A bit of sandpaper and a wooden dowl. Remove little by little until you can slip a piece of paper between the barrel and the stock and can slide it up to the recoil lug. If this is any other action than a bolt, you may have a bit more difficulty.
 
Bed it and float it.
I had some success floating a bbl on a Browning A bolt and a Win 70 as well as a Win 94... but I don't want to have to do that so now I own two Tikka T3s and I have never even taken them apart yet, half MOA with both. I have never bedded a rifle but will be trying it, I have an old Cooey .308 I want to fix up.
 
Last edited:
It sounds like thats exactly what your problem is. If you were to free float the barrel you shouldn't get vertical stringing. Free floating is an easy do it yourself job. A bit of sandpaper and a wooden dowl. Remove little by little until you can slip a piece of paper between the barrel and the stock and can slide it up to the recoil lug. If this is any other action than a bolt, you may have a bit more difficulty.

I put the wooden dowel in a drill to make it go faster.
 
Forget the drill you only need to remove a little bit of material to clear the barrel, not hog out a barrel channel. A broom handle with sand paper wrapped around it is easier to control with less chance of an "Oh sh*t".
 
but I don't want to have to do that so now I own two Tikka T3s

My T3 is doing this to me. I removed a little stock material before because I couldn't slide a paper up, but now there are some snug spots again. Will check action screws tonight, etc. I don't know if I want to try to bed this rifle, any suggestions on a 'smith to send it to? How much???
 
Are you resting the rifle in a solid rest and getting vertical stringing? Vertical stringing is usually associated with breathing and shooting technique. BTW you never indicated what type of stock you have (synthetic/wood) Bedding might not be an issue - freefloating could possibly be an issue if you are using a bipod or something that could put pressure on the barrel. How long are you waiting between shots, what type of barrel do you have? I would be hesitant to send it in to a smith if it is piling shots into the same spot be stringing because you have a sporter weight barrel and you are shooting 5 shots very quickly and heating up your barrel. If you really want to send it into a smith to be looked at call Lyle Linkaitis in Selkirk - he is really good.
 
As you yourself speculated, this problem could also be related to your skinny sporter barrel heating up. Uneven forend pressure would not be helping.

FYI, I have a Remington 700 Mountain Rifle in .30-06. It has a very skinny barrel. After experimenting, I found that it shoots best with the action bedded and with a pad of bedding material under the barrel at the forend (separated from contact with the barrel by a layer of black electrician's tape). Even then, it's only good for 3-shot groups before it begins to walk. However, those first three shots, with its favourite load, often go inside 1 inch at 200 metres. That's all I need for hunting. :)
 
My T3 is doing this to me. I removed a little stock material before because I couldn't slide a paper up, but now there are some snug spots again. Will check action screws tonight, etc. I don't know if I want to try to bed this rifle, any suggestions on a 'smith to send it to? How much???

I would contact the dealer or distributor, T3s come with an out of the box accuracy gurantee. I shot mine yesterday for the first time since last Winter. It was shooting a bit to the right, made a few adjustments and voila, 1/2" groups at 100 and that's using a gun case and an engine bonnet for a rest.
 
Just about everytime I run into a sporter weight barrel with vertical stringing problems, its simply due to a hot barrel. These light weight sporter barrels aren't intended to be used for extended bench rest shooting sessions. They're intended to fire 2-3 shots at game under field conditions at one time. Under those circumstances, vertical stringing is a none issue. If you want to fire the rifle for group, you'll have to allow sufficient time between shots to permit the barrel to cool off. Free floating may also help, but every barrel/rifle is different and some actually benefit from a little forend tip pressure as other posters have said.
 
I also should add, T3's should come from the factory free floated, if yours is not.. there is a problem.
The T3 bbl (at least on my 22-250) is definitely a sporter bbl but is a little heavier than most, while not a target bbl they are quite good.
 
Before I do anything else, start with the simple stuff, more time between shots. I was waiting a minute or two, but I'll try more. This is a hunting rifle after all and it's the first shot that counts most. Shooting at the range is more for fun and load development

bill c68, how long do you wait between shots?
 
Before I do anything else, start with the simple stuff, more time between shots. I was waiting a minute or two, but I'll try more. This is a hunting rifle after all and it's the first shot that counts most. Shooting at the range is more for fun and load development

bill c68, how long do you wait between shots?
As long as it takes to line up the crosshairs again. Serioulsy the Tikka T3 should NOT string period. I shott them as fast as I can shoot accurately.
 
What about temperature effects?? Same load everytime, etc, when it was -6 there was very little stringing, when it was -28 the most, and today I shot betwwen the two, it was -19. Is this more to do with powder or primers? Or just coinsidence?
 
Vertical stringing in benchrest shooting is a function of the load not matching the bbl harmonics. That stringing is straight as a ruler in calm (or in the wind with the best BR shooters). In 6PPC there are a couple of sweetspots, somewhere around 3250 fps and another really hot more like 3450. These guys hardly ever chrony, just watch pressure and generally "go up in powder" to eliminate vertical stringing. I used same technicque to tune 7BR. If pressure isn't already sharpening the primer craters, just go up a couple of tenths of a grain in powder at a time to close the stringing. Seating depth can affect it too but with those calibers most people jam it on the lands and tweak the powder until it tightens up. A minority will bother to find the optimum seating depth backing off 5 thou at a time from the lands with three shot groups then tune the powder so it can be an iterative process. I once followed that procedure as outlined in the "Benchrest Primer" book then wore a 6PPC bbl out 20 thou off the lands the whole way, chasing the lands along, 20 thou back. He said most will shoot well on the lands and some certain spot off of them, maybe better there and that's what I found with that combo (Maclennan bbl and a U.S. guy named Rossing's bulltes). The above may only best apply to real bottleneck cases.

In one case where I eventually resloved a real bedding problem the stringing was erratic and diagonal; that was a bolt .44MAG. and I wasted a lot of powder and bullet optimization to prove it was the bedding, live and learn.
I think that's why the Ruger M77/44 failed; they were moving around in that .22 cal stock
 
Back
Top Bottom