Is there a CB Cap or similar type (around 750 fps) .22 round that shoots straight? Can't really shoot anything larger in the back yard. Don't understand why these things won't group at 25 yds or so, whereas 700 fps .22 airguns are doing 0.5". The rifle's a CZ and shoots everything else just fine.

I can't help you. Some Remington CBs gave me the highest standard deviation I'm seen in 12 years of chronographing. Accuracy, what accuracy?

Bye
Jack

You might consider trying some CCI CB Longs. They have a full-length case, and put the bullet as close to the lands as possible. Velocity is roughly in the range you specify, and accuracy in my own rifles has been very satisfying.

Let us know what you find!

God Bless,

Some rifles just won't group them...long or short case, the just won't. An Anshultz has so far patterened every CB cap I've tried into about a weak modified pattern...a cheap beat to dirt Reminton 511 groups them inside an inch at the same range....every thing else is inbetween these two....why" haven't a clue, it's just the way it is.

Nothing has had as much lot-to-lot variation as CB caps. One lot of CCI will group great (you can substitue any other brand for CCI as they all have show a wide variation betweeen lots) and the next won't shoot for sour road apples.
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If i had to put the finger on one the reason for CB cap variations, it would be the tiny pinch of powder in a mostly empthy case and the variation in crimping between rounds.

There just isn't enough pressure in most loadings to bump up the heeled part of the bullet (the part that fits inside the case). Recovered CB's will show uneven bases, well below groove diameter. IF they are all consistantly sub diameter OR if they are all consistantly bumped up to groove diameter, accuracy is good....but if (and this is what happens most of the time 3with CB caps) they are variable at the base...which is the steering end of a bullet...you can exp[ect variations in groups.


Mostly it's a verticle shift...if the worst cases, can HEAR the variation in report as well as see a major velcoity spread on the 'graph. The ones that actually do bump-up and seal seem to be the fast ones.