Light vs Heavy Pellets

[Gerard]

Indeed. Not a lot of grouping difference with a clamped pistol between Hobby and R10 pellets, at least in my K10. At 445fps the largest centre-to-centre measure with R10 pellets is about 6mm. With Hobby pellets it's about 7.2mm, no sorting or weighing, just whatever comes next in the tin. No way that's going to cost me more than a couple of points in a match, if that.

[rmca]

because a variance of grouping tightness can move you anywhere from 510 to 570.(9 ring: half a ring left, half a ring right).

Wrong.

Let´s just state some facts:

- The ten ring is 11.5mm across.
- All other rings add 16mm in diameter. That means the space between lines is 8mm.
- To simplify let's say that the pellet is 4,5mm in diameter.

If you hit the center of the nine ring with the center of the pellet you have something that is between a 9.7 and a 9.8. Half a ring each side (4mm) you will still have a 9.2 or a 10.2. So there is no way you drop lower than 540, nor go much higher than 545.

Remember that when you speak about groups it's a distribution all along the area, so even if it hits the next ring it will only be a couple of shots, not all!

Now to prove that the focus on the group size is wrong for those who don't score high, take the same 8mm group that you talked about (half a ring left, half a ring right center to center) and apply it to the dead center of the target.
Guess what? All your shots are still ten's!

Now double that group size... 16mm! Since the ten is 11.5mm plus 4.5 on each side (a 10.0 is still a ten) you get 20.5mm ten ring. So your 16mm group fits in there! All tens again! A perfect match score!

The point of all this is, what causes your score is how much you hobble your gun when you aim (assuming you aim correctly), plus a very tiny bit caused by a shot that could have been a 9 but was an 8... That's ONE point in the 60 point's you lost in a match (assuming a 540 score).

So you loose 59 point's due to your poor marksmanship (you and every one else for that matter) and blame it on the point that could have been...

Bottom line is, find a pellet that groups well (about 8mm total ring size max), and then start working on your technic, because that IS what makes a difference in a match.

Hope this helps

[David Levene]

plus a very tiny bit caused by a shot that could have been a 9 but was an 8...

Totally agree, and that's without considering the shot that should have been an 8 but turned out to be a 9.