vertical stringing

Holleyman

Holleyman

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Athabasca, AB
The rifle in question isn't a precision rifle but does have potential. The rifle shoots less than 0.25" from side to side but the vertical stringing can be 1 to 1.25" @ 100 yards. The groups open up to .75" horizontal and 2 to 2.25" vertical @200 yards.
Rifle in question is a Ruger M77 target model in .223. I have a Harris 3" bipod and sandbag the rear of the stock. It is a pretty plain jane rifle otherwise.
I have reloaded 55 grain VMax bullets over 24.1 grains of 3031, the brass is Winchester and weights are within .25 of a grain. The bullet seat depth is at the lands.
Any help would be great, if I can get the vertical as tight as the horizontal I would be a very happy man. Maybe it is something I am doing?
 
Bed the action, try a pedestal rest (bipods bounce and can cause alot of vertical if shot off a hard surface), reduce the powder variation to no more then .1gr. I like CCI 450 primers.

That should tighten things up.

Jerry
 
Save the bipod for prone and shoot off a sand bag front and rear while on the bench. If vertical stringing continues try shooting a group with plenty of time for the barrel to cool between shots. If this solves the stringing problem you need to free float the barrel and it wouldn't hurt to get the rifle bedded at the same time. If the stock is made out of a compressible material, pillar bedding is a good choice.

When chasing a bogey man, just change one variable at a time. Try shooting from a sand bag, then see what happens when you play with the seating depth, or adjust your loads in some other way.

Just for giggles, shoot a box. In other words put up a large target, fire a shot, adjust 6 minutes right, fire a shot, adjust 6 minutes down, fire a shot, adjust 6 minutes left, fire a shot, adjust 6 minutes up, and fire a shot. If the bullet holes form a nice square, that tells you your scope adjustments are repeatable and that the scope is tracking properly as it is adjusted. It also takes the scope out of the equation for your vertical stringing.
 
All the above and pay attention to shoulder pressure, always try and keep same hold, some peole have success with loose hold some shooters like hard hold. just be consitant and see if it works.
manitou
 
The answers above are all good, just take your time when testing. If you rush and combine tests, you'll run around in circles.
 
As a barrel heats up it will start to string the rounds vertically. How much time between shots are you allowing? It could be that you simply aren't allowing the barrel to cool sufficiently between shots.
 
Try a box of Match ammo, if the stringing disappears, concentrate on your reloading. check brass length, check bullet depth, look for inconsistancies anywhere in the reload process.
Like mentioned earlier, pull the bullet just off the lands that could help.
I've had rounds that weren't seated as deep for one reason or another and they were tighter to chamber, this bumped up the pressure and had them shoot 1.5" higher at 100.

M.
 
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