Hi. Thought I'd start another thread concerning the .17 WSM ammo. The contents have been scattered in several threads and thought I'd try to help myself and others.
I've known for may years that .22 lr target shooter weigh/sort the ammo and use head thickness guages, etc.

With the .17 WSM, I've been perplexed by the fact some shooters will get excellent groups with the 20 gr and others like the 25 gr loadings.
I realize this is not an F-Class rifle.... Once I re-floated the bbl, mine shot the 25 gr pretty good, while the 20 gr target looked like it was hit with a shotgun.
So, yesterday, I talked the gf into helping me weigh a couple of boxes of the ammo on my Chargemaster 1500.
Yes, I do know it's not a lab quality scale and the +/- .1 gr 'toggling', is not the optimum set up. I was just looking for surprises. I found some.
Weighed 50 of each, took my time. If the scale couldn't make up it's 'mind', I waited, then reweighed.

On the 25 gr ammo (which MY gun likes) the highest weight was 67.4 gr and the lowest was 67.1 for a delta of .3 gr.

On the 20 gr ammo the highest weight was 63.4 and the lowest was 62.7 gr for a delta of .7 gr.

Of course, this is just extreme spread. I am going to run the weights through a calculator to find the Standard Deviation. However, I noticed that the 25 gr ammo was more consistent through the 'mean'. What does this 'mean' (ha ha).
This is just one measure of ammo consistency. There could be:
- variations in bullet weight
- variations in case weight
- variations in powder weight (which is what I was exploring here).

Being a rimfire, there could be primer issues, OAL, and a bunch of other things to wonder about.

This is certainly not a slam against Winchester. This is just a small exercise for fun.

Your comments are welcome.....

ron