I "fixed" my slow barrel!

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uvausmc

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I posted a few weeks ago about my dismay that my Savage 12LRP 6.5 Creedmoor was shooting Hornady 140gr A-Max factory ammo around 200 fps slower than advertised. Well, I took it out again today with the same ammo and really paid close attention to how my chronograph was set up. Ensuring the diffusers were right and there wasn't a lot of sunlight hitting the sensors I got results much better than expected.

Instead of the average 2543 fps I got last time, now I got 2773 fps. This is actually over 50 fps higher than what Hornady advertises but I'm not complaining. As a bonus, the 1" groups I was shooting at 100 yards last time shrunk to 1/4"-1/2" groups this time. I also shot a few rounds at 250 yds (the farthest I can at my range) and from what I can tell on the steel plate 3 of 5 shots were touching with the other 2 w/in a couple inches.

Lesson learned: Always make sure your chronograph is set up for success.

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Here is the original thread if you're interested.
http://www.thehighroad.org/showthread.php?t=625460
 
Nicely done, glad you got that worked out LOL. Chronos are still kinda a weak link some times. I have a couple friends with them, so when i take mine out i always try get one of thiers also. Being very careful of how you set it up helps, and having a known velocity "base line" load, or preferably a couple loads at different velocity points, helps alot also.
 
My fold out Chrony seems to be sensitive to light direction and overcast vs clear and bright conditions. Still a valuable TOY and I use it nearly every controlled shooting session. I have found R17 to be cold sensitive rather than heat sensitive once my best warm weather load is found. What limited knowledge I gain from a mearly 100$ tool is better than knowing nothing at all. Best accuracy is my prefference to even 200 fps advantage.
 
pantannojack said:
My fold out Chrony seems to be sensitive to light direction and overcast vs clear and bright conditions. Still a valuable TOY and I use it nearly every controlled shooting session. I have found R17 to be cold sensitive rather than heat sensitive once my best warm weather load is found. What limited knowledge I gain from a mearly 100$ tool is better than knowing nothing at all. Best accuracy is my prefference to even 200 fps advantage.
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I second this.

I have the lower end Shooting Chrony. It is more of a toy than anything really, a very simple setup, but a very useful tool for the handloader in particular. Extremely light sensitive, and that is what makes it a toy at the moment. However, when mine is off kilter, it is usually something absurd like 7000fps. I'd be concerned if I had a 200fps jump myself with the same ammo, but I only shoot handloads and my chronograph is either (right or wrong, I have to assume it is right, they claim 99.5% accuracy) absurd, or it says "error" or something similar. My deviation is usually quite narrow.

Because of my lighting issues (PacNW, sometimes it is dark all day) and because I sometimes shoot at night, I'd say 70% of the time I can't use it. They make a kit now though that replaces the white plastic diffusers with small IR lights. Says it works in all light conditions, even total darkness.

The temperature of the ammo can significantly affect the velocity of the same lot of ammo too, especially if you used warm ammo one day and cold, outside ammo the next. Some serious competitors, marine marksmen unit included, use ammo warmers to keep it just right.
 
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