WKR
WKR
- Joined
- Jun 14, 2019
- Messages
- 1,505
Do you count your cold bore shot muzzle velocity when calculating your extreme spread and standard deviation?
Why or why not?
Why or why not?
Thank you for this, I’ve been wondering the same thing. Was shooting a new gun this weekend trying to figure it out before sending in for the cds dial.Do you count your cold bore shot muzzle velocity when calculating your extreme spread and standard deviation?
Why or why not?
Not in my experience, the differential factor being the heat of the barrel. Even my fouled cold bore shots have a substantially different muzzle velocity than a my subsequent hot barrel shots.Cold cleaned bore will give a different velocity/POI, but a cold fouled bore should be the same as the rest of the shots, yes? I.e. as long as you aren't cleaning the bore between range sessions, the only reason the first shot wouldn't fall in your usual 10-shot grouping is if you aren't as ready as a shooter? So for load development, be sure not to include a clean/oily bore shot in your calculations, but as long as you dry fire a bit to get yourself ready, no reason to exclude it? Not a pro or bench rest competitor, just a hunter who loves shooting, which is why I've posed these as questions rather than hard claims. I'm not new to shooting, but newer to reloading, so I'm still figuring a few things out. But I'm finding that doing a lot of dry firing, and not cleaning the bore at all, I don't seem to have "cold bore shots" any more, and no more vertical change from the first shot compared against subsequent shots. I've been paying close attention my last dozen visits to the range, and noticing the first shot is the same as the rest.
Depends on the rifle, load, environment, etc. perhaps?Not in my experience, the differential factor being the heat of the barrel. Even my fouled cold bore shots have a substantially different muzzle velocity than a my subsequent hot barrel shots.
I have spent some time doing LR but I appreciate your approach makes sense..I'm a hunter, not a PRS guy. When I'm working up loads I honestly don't even really care about ES and SD. I do collect them as data points, but only after I've figured out the load I'm going to hunt with. I shoot three shot groups that start with cold bore and I put the next two shots downrange fairly quickly as this is the most realistic hunting scenario in my experience. I look for barrel harmonics by figuring out charge weights that give me same/similar POI's to give me some room for error.
Whatever load in the harmonic range gives me the tightest groups is the load I go with. After that I start shooting through the chrono in order to work up my dope chart.
Do you count your cold bore shot muzzle velocity when calculating your extreme spread and standard deviation?
Why or why not?