I have frequently found box ammo to be 100fps or more 'off' from box label. Sometimes simply barrel length, other times I think it is differences in temperature or actual barrel dia/condition or chamber dimensions/headspace.
i’m new to this calibre after picking up the above rifle. i’m trying to get a factory round that i can rely on. The two main options available to me in NZ shoot well. Norma Bondstrike grouped well, but the speeds were chronoed at 2740ft/s (200 below the box speed)… has anyone else had this experience with this ammo/proof barrel combo (same barrel length)? Precision hunter seems to also group well, but haven’t put it past a chrono yet…
I have frequently found box ammo to be 100fps or more 'off' from box label. Sometimes simply barrel length, other times I think it is differences in temperature or actual barrel dia/condition or chamber dimensions/headspace.
I don't know what kind of a chronograph you have.... but I had (have-retired it) a screen type-- and it just wasn't that accurate. Sun conditions/clouds and it would spit out bad info. It's velocities didn't add up to what a ballistics solver and shooting would show.
Add in different barrels- and that higher velocity on the box sells.
I don't rely too much on chronograph data but instead use the bullet drops to tell me what the gun is doing. I do use a chronograph quite a bit but it's only one of the tools in the box.
It's better to shoot for the moon and hit the fencepost than to shoot for the fencepost and hit the ground!
Good batteries in the Chrono? How was the light? That is really low for 6.5prc. I’ve seen shooters on YouTube chrono’d the Norma Bondstrike at like 2916fps avg. from a 24” barrel.
For those reasons, and a few others, I invested in a Labradar a few years ago. Probably best investment I made other than the rifles themselves. The convenience of setting it up at the range tipped the scale from the Oehler 35P. I have been tempted to get the Pressure Trace system as well, but, I just can't justify it to myself :)
I've got a Labradar as well.. i have a bit of fun getting it to pick up, but realised it was on doppler, not the internal trigger.. will amend and try again.
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