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Old 16th April 2015, 10:40 PM
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RobF RobF is offline
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Originally Posted by Brian.Samson View Post
Whoever wrote that article, nicked my illustration, the cheeky bugger.

It's spot on though
Which does beg the question of how people manage to get CG to agree, when they haven't used this method...

I can generally spot something good or not so good indoors on paper at 25m... if it's good, they generally go through the same hole. Vertical patterns or flyers can be seen at that range, and indoors it's easier to not discount them as the old cold air/warm air up draught downdraught voodoo (aka nonsense).

But if you're not getting very tight groups to start with, it becomes difficult to draw conclusions.

Here's a group Helen shot earlier in the week, sitting, 10 shots, indoors, 25m with the Walther.

The 9 ring is 12.5mm wide, so thats about 10mm edge to edge, or 5.5mm CTC. I would consider this shooter/gun/ammo combo to be around where i'd start looking at going further outdoors... but if I couldn't do this, then I wouldn't. And it's surprising how a group like this can be a struggle even with quality branded ammo and rifle when one of the elements isn't living up to expectations. It can also be improved upon, but the shooter starts to become the inconsistent link (well it is if it's me)

I'd also like to note it's not central. And that could be down to a positional bias, or cant or even windage... at this range it's about 6mm centre to the left... which is an MOA... That's a lot at 50m/55yds which may, if the wind is in the right direction, convince the gun is taking less. Or if it's cant, it could be made worse.

Positional bias can show up when shooting all 10 spots on a card... doing 10 groups of 5 across the a3 sized card, even at 25m, can show reaction to the natural point of aim being forced away to the intended target.

So while you can pick out good and bad groups, it's really important (i think) to get them into context. For me, wind cheating wonders are picked out by BC... because the rest can really be shooter induced voodoo.
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