MV increases with every shot

[Mikecr]

It doesn't seem unusual that MV would go up a bit & level off as a barrel heats.
I've seen this many times, and my cold bore load development finishes with 2 shots ~30sec apart(from dead cold). Even though follow-up shots are against one of my rules, I still want to know my capability.
Not so much mv-wise, but a 10min shot rate and 200yds always seems least accurate for me. So that's where I spend the most efforts.
This is not precision(grouping), but accuracy.

You would not see a competitor(who's actually competitive) shooting for record precision from a cold bore. Given their way, they would at least shoot during a sighter period to get their barrel up to stable temps. That is where they know exactly what the gun shoots.

 

[dfanonymous]

best way to see if it really is increasing is to measure the shot in your reticle.. or measure at distance...see if your shots are getting higher...unless you are bad at keeping a group...the bullet doesnt lie....
other than that...it might be increase in pressure curve as the cooper fouling increases...keep in mind...heavy 200 gr ers copper faster in the bore. lastly id blame the chrony...
was the ammo left in the sun for awhile as you began shooting?

 

[criterionbarrels]

Just to reiterate what a few other posts had mentioned... Velocity can increase if ammunition is left in the sun, though H1000 is relatively temperature insensitive. Ball powder can increase velocity if chambered in a warm barrel as well. Check to see if there is any copper fouling and if so follow this link:

Barrel Break-In Procedure

If neither of these two solutions work to fix your issues please feel free to give us a call.

 

[elkaholic]

That seems like an awfully big increase for H1000 even if you had temp increases with barrel, powder, or what have you. I may have missed something ,but did this happen one time or always? Based on what we know, or don't know, I think I would try a process of elimination by thoroughly cleaning first and then shoot and clean between rounds. I am also wondering about your chrono? I have seen strange things happen with some of them concerning light changes?..........Rich

 

[jwing]

It's the barrel, getting copper fouled up, shoot a few groups, then it should seddle down, will shoot better fouled.. have seen it before.

 

[Wedgy]

One more thing to check is a tight neck chamber that is getting tighter as it gets dirtier and not allowing the bullet to release. Check to see if a bullet will fit into a fired case. If not you will need to turn your necks to give you a little more clearance, or use brass that has a thinner neck wall.