Vertical Stringing but downward

[ColonialBuff]

Yesterday, I was shooting a new (to me anyway) Mark V 338 Win, Doctor N2 scope, Leupold quick disconnect rings for the first time on a target. My string is not upward, but downward. My cool down was only about 1 minute between, but any stringing from heat should have been the other way, at least in my small mind.

Shot 1: POI
Shot 2: .5 left, 1.1" down
Shot 3: .25 right, 1.5" down (with respect to Shot 2) /ubbthreads/images/graemlins/confused.gif

I did several 3 shot groups and they were all the same. Since the first shot usually counts the most, I don't feel handicapped in the field; only the bench. /ubbthreads/images/graemlins/smile.gif

 

[ColonialBuff]

Sorry, the ammo was factory Winchester 225 Accubond. I wonder if my cool down of 1 minute was not as great as I thougth it was. /ubbthreads/images/graemlins/blush.gif

 

[Hired Gun]

Heat stringing can go any direction. What you are describing isn't stringing. String means it strays progessivly in one direction. like this ..... that would be stringing to the right horizontally. Your's apears to be random left or right and low. What model Mark V are you using? If the action screws are not tight enough or if the rear one is tighter than the front that can cause this. Is the barrel free floated or does it have a pressure point? Is your parralax adjusted out properly? Is your cheek weld and head position consistant. Is the barrel clean? On all my Weatherby's when I shoot for group I just bang off 3 as quick as the hairs settle down. This is just some of the stuff that comes to mind. I have a huge checklist I can go over if groups seem funny.

 

[kraky2]

I have a browing bar in .308 that does almost the same thing. I was at the range the other day in 35 degree weather. I was shooting lots of different recipes and found the gun is really a good shooter but the groups go downwards as you shoot. I had about 8 rounds of one recipe and was shooting out of a vise. The barrel wasn't getting too warm being a .308 but was obviously getting warmer as I went through the 8 rounds fairly rapid fire. The result was a "ladder" that looked like I took a paper punch and virtually punched 8 holes that were virtually touching with just a slight bend to the left but still an amazingling perfect pattern. I almost cut the group out cause it looked so neat but didn't think anyone else would be as impressed as I was!! Total group was probably real close to being 2" at 100 yds..maybe just a hair more.

 

[ColonialBuff]

HG I am at work so I will have to wait until I get home. I was informed sometime ago that Weatherby's were not free floaters, but had a bit of pressure at the end of the forearm. If this is wrong, then I see my first potential investigation. Also, I will look at the screws and make sure that they are torqued to spec. This weekend I am going to switch the scope to a different rifle to see how it works.

Since this is a hunting gun, I sorta wanted my first shot to be the best. I really didn't want, or need, to fire three shots so that the cross-hairs settled down.

By "kraky1", that group sounds neat; go ahead and publish it. Seems I never tire of learning about reloading and ballistics.

 

[ColonialBuff]

[ QUOTE ]
What model Mark V are you using? If the action screws are not tight enough or if the rear one is tighter than the front that can cause this.

[/ QUOTE ]

The gun was sold as a Mark V Sporter in 338 Win. I am searching to see what the torque specs are for the guard screws. Barrel was clean until the first shot and parralex was assumed to be correct as I don't know how to adjust this.