Reloading Help

[ashland]

Last Wed. I started loading for a new rifle I got in 260. I loaded 42 grs of 4350 pushing a 139 Lapua seated at 2.80 OAL. It was averaging 2,830 fps. The temps were around low 70's. yesterday I shot those same loads and was averaging about 3,011 fps. Temps were aroun 68 with 60% humidity. I'm shooting over an el cheapo Chrony but why would the velocity change that much? About a month ago I shot some Black Hills 175s over that Chrony and the rounds were pushing about 2,650 fps. The next week I shot round from the same box that were about 100 fps faster than the week before. Temps were close to the same. Gonna try a different chronograph when I get the chance but was wondering if anyone has had this problem.

Thank you.

 

[jasonk]

Re: Reloading Help

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ashland</div><div class="ubbcode-body">I'm shooting over an el cheapo Chrony
</div></div>

I think you nailed it.

Same distance from the chrony both times? Muzzle blast can screw with stuff too if you're too close, but I'm guessing it was the chrony and/or the lighting tricking it. Light conditions the same both times?

 

[EddieNFL]

Re: Reloading Help

I've witnessed two different Chronys with the same problem.

 

[deadly0311]

Re: Reloading Help

I had a chrony tell me i was pushing a 175 SMK at 4100 fps before.

 

[Lumpy Grits]

Re: Reloading Help

Was it the same time of day?
Same location.
The Sun was, more or less, in the same location/place etc.
Fresh batteries?
Respectfully,
LG

 

[Victor N TN]

Re: Reloading Help

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: jasonk</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ashland</div><div class="ubbcode-body">I'm shooting over an el cheapo Chrony
</div></div>

I think you nailed it.

</div></div>

I've HAD 2 different models of Shooting Chrony. Neither worked repeatably and / or reliably. I have shot a PACT for over 15 years. It has served me well. But I think I'm going to get a new one soon. Probably a CED ME2

 

[ashland]

Re: Reloading Help

It was two different places, early in the morning the first time, no sun and cloudy on the second time. I know you get what you pay for. Just couldn't figure out what was wrong with my reloading. I did turn the thing off and on a couple of times to see if it needed to be reset. I'm shooting prone too. I don't know if that makes any difference. Anyway, thanks for the comments. I'll have to try a better chronograph.

 

[johndoe]

Re: Reloading Help

Sounds like a chrony. I had one of the fold
in half models read about 400 fps higher.
Been running with a now discontined model
that doesn't fold but was significantly more
expensive and you get what you pay for.

 

[ashland]

Re: Reloading Help

10-4. My buddy has a chrono that I will try to get some better numbers. Buy cheap, buy twice. One day I will learn.

 

[308sako]

Re: Reloading Help

Deleted in protest!