300 wsm grouping

[thork91]

I have a vanguard, it has McMillan stock, timminey trigger, barrel is floated, has aluminum bedding and I had it skim coated. I can shoot 3/4 to a inch group at 100 and sometimes smaller. I shoot berger VLD hunting 168 grns . MY question is when I shoot 150 and 200 yards I can touch with a 3 inch group. Why can't I do this at 100. I have shot 1/2 inch and one time 3/8 at 200. I have tried many times this summer.I am real happy with this gun just qurious what is happening. I also reload and I'm pretty new at this. I had score high gun smithing accursize my rifle, did a great job.

 

[elktaker]

Sometimes VLDs needs distance to stabilize.

 

[thork91]

Thank you

 

[Bart B]

If you can shoot an inch or better at 100 yards, you're doing something different at the 200 yard line. At 200, your groups will be about 10% bigger MOA wise; 1.1 MOA (2.2") or there abouts. Bullets stable at 100 yards remain so at 200, unless they drop down through the sonic barrier.

If you're shooting only 3 or 4 shots per groups, they're going to have a 2X to 4X spread in extreme spread anyway. That may be why those at 200 were much bigger than expected. None of us humans shoot few-shot groups the same size all the time.

 

[elktaker]

If you can shoot an inch or better at 100 yards, you're doing something different at the 200 yard line. At 200, your groups will be about 10% bigger MOA wise; 1.1 MOA (2.2") or there abouts. Bullets stable at 100 yards remain so at 200, unless they drop down through the sonic barrier.

If you're shooting only 3 or 4 shots per groups, they're going to have a 2X to 4X spread in extreme spread anyway. That may be why those at 200 were much bigger than expected. None of us humans shoot few-shot groups the same size all the time.

He is saying the 200 is smaller than the 100.

I have been told VLD particularly berger often will not group well at 100 but become better at 200 to 300 yards.

Could be my error, but my 7mm wsm w/ 168 Bergers does a similar thing. Groups of about 1" on average at 100 yd but groups of 1.2" all day at 220 yd (1 MOA at 100 vs .52 MOA at 200). Read about stabilization issues VLD a close range and figured that was it.

Now thinking about the "aim small, miss small" theory may have something to do with it since I use same size target at 100 and 200.

 

[Bart B]

elktaker, yes, I mixed up the 200 yard group size change.

Meanwhile, back to comments about bullets grouping better at longer ranges than shorter ranges where they're unstable and not spinning perfectly on their long axis.....

There's only one way that'll happen. Positive compensation caused by faster bullets leaving at a lower angle than slower ones to compensate for down range drop. All the bullets leave at some place on the muzzle axis upswing; slower ones at a higher angle, faster ones at a lower one. This has been observed for over 100 years.

If a bullet is not stable and in the lower right-hand corner of a group at 100 yards, how does it know that and have some internal mechanism to alter its trajectory up and to the left to strike center at 200 yards? Same thing for other bullets at all other places off the center of the 100 yard group.

 

[thork91]

I meant smaller group at 200, I also notice three shot group at 200 the bullets hit in a 45 degree angle and the ones at 100 string almost touching horizontal. I shoot of bags on bench. It probably is me. But it's all good. Very interesting when you try to figure out. Thanks agin

 

[Bart B]

Horizontal shot stringing is common hand-holding a rifle against their shoulder a bench with it resting on something. Right handed people tend to end up with a zero one MOA or so to the right when getting one so positioned when shooting; compared to a zero attained from standing or sitting/prone with a sling.