Reply With QuoteThe cold can have an effect on your velocities. Definitely check the chronograph with a factory load. Next load test , have the rounds in your pocket to warm them before firing.
I'm trying to work up a load for a 243 and I'm not getting anywhere near the velocity I should be. What am I missing. First things first. Chronograph readings are consistent, (within 30 fps). I'm using Varget, Winchester brass, Remington primers, Remington 100g core lokt bullets. All rounds had a COL of between 2.652 and 2.658. I started with the following loads of 31.4g, 32.2g, 32.8g and 33.7g. The load data I have lists 33.7 as the max load with a velocity of 2838fps. I weighed each charge to make sure I was consistent. The heaviest loads averaged 2452fps. Could cold weather mess with the velocity that much (in the 20's)? Barrel length is 22". The only thing I didn't do was shoot a factory round over the chronograph. I plan on doing that tomorrow as well as shooting the heaviest loads again. Am I missing something obvious?
Thanks for any help.
The cold can have an effect on your velocities. Definitely check the chronograph with a factory load. Next load test , have the rounds in your pocket to warm them before firing.
Vietnam Vet, Jun 66 - Dec 67
Primers, as well as powder, are affected by cold temps. For cold weather shooting, I use mag primers exclusively. I find velocity and consistency improves with a hotter longer burning primer flame when the temps are below freezing. Of course load work up has to be done in the same range of temps that the ammo will be used to get proper results.
Hummmm Sump'm sounds a little strange, so I'll ask ...did you verify your clock? I know it sounds stupid, but its why I own standards for measuring tools, check weights for scales and two chronographs. ;D I like to be able to verify the tools (and myself) especially if I'm seeing or getting some weird measurements.
Just a thought.
Bill
Thanks for the input everyone. I'll let you know how things go today.
Well, it's not the temp. All rounds were kept warm. Factory loads were 4.3% (130fps) slower than published velocity, handloads were 11.9% (400fps) slower than published data. I've verified the accuracy of my scale. This is very frustrating. ??? What's next? This is a brand new 1# container of powder, I've never had this problem with Varget before, I use it in 22-250 and 308.
Maybe you just have a slow barrel. Even if you were able to get that velocity more often than not that is not where the gun is going to be the most accurate.
If you have checked the scale and kept the barrel/rounds warm than its either a very slow lot of Varget and/or you got a slow barrel.
How are the groups? You cant miss the target fast enough!!
".......... Factory loads were 4.3% (130fps) slower than published velocity"
That makes sense as you are using a 22" barrel. I would suspect your can of Varget and try another powder, preferably a faster burning one. (4895 or 4064) If that fails, I would try another chrony, but your results with the factory ammo seem to indicate that it is in line.
Keep us informed.....inquiring minds and all that.
uj
What chronograph do you have?
"As long as there's lead in the air....there's still hope.."
I'll say this
#1 your book I bet said your load was shot in a 24 inch barrel.
#2 move on up in more powder the new books are stated low maxes because of lawyers.
# a lot of rifles will shoot a lot more powder charge that books say the max is.
increase your load until you see presure signs you may still be 3 or 4 grains under what your gun will take,
then see where your fps go.
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