Got in some range time after work. Got time to try two laddered loads but they chrono'd at almost the same avg speed. 3053 vs 3063. First was 26.2 Varget and the second 26.5 which is still below maximum for the 60 grain Hornady HP bullet I used. Is it possible that the additional powder was just blown out the muzzle? I am going to repeat the comparison and then also do it with CCI SRM primers to see if the hotter primer makes a difference. Any other ideas? BTW I measured each charge individually so I know I added the extra 0.3 grains of powder to the second batch of 5 cartridges.

you did get a 10fps increase!!!!
maybe it just doesnt want to go any faster the primer change may be the ticket. I can see a few trips to the range in the near future coming up for you.we are talking .223 arent we??? this is about right by my manual the 62 grn with 25 grns behind would be at that speed.

Yes 223. Should have mentioned that. I need a whole day on the range. I had planned it today because of absolutely no wind but alas had to work for 5 hours instead. Another 6 months and retired "Gentleman"?

were these 3 shot groups? If so, not large enough to be stastically significant. I would doubt you have unburned powder. Run a cleaning patch down and see if any grains of powder come out. I had this happen to me with Varget with a light loaded .45-70 but not a .223. With .223, I use .3gr powder increments to ball-park a load and determine where I should use .1gr increments to find the real sweet spot.

You don't say what barrel length 20"? 16? 11"?
I have some chrono data for 77gr & varget but not 60gr yet
24.0 is running about 2530 out a 16" tube
24.5 is giving 2570 avg but with a 75gr bullet
so yeah, 10fps is not much and within SD for any given load.

My first thought was also to try magnum primers. then I started thinking more. First, I would think at least 10 rounds of each would give you a better idea of velocities. Second, .3 grains is not a very large difference (only about 1%)
Try subtracting the min load from the max and dividing by 5 for an increment. That looks like .6 gr for varget with a 60 gr bullet in the .223

44marty wrote:

First, I would think at least 10 rounds of each would give you a better idea of velocities. Second, .3 grains is not a very large difference (only about 1%)

Marty is right. Chronographing loads using a higher number of rounds per run will give a better baseline of actual velocity figures for each load. 3 rounds doesn't give enough data to address anomalies.

Faster burning powders such as BLC2 or H322 might show significant increases with .3 grains of powder, but the burning rate of Varget falls roughly in the "medium" burning rate range and .3 grains really doesn't mean much.

Your caution is to be commended, however. Too many loaders just jump right into maximum loads without doing their due diligence and create potentially dangerous conditions for themselves and others.

what he said... x1

I'm a little confused as to how you ran your tests. At first I thought you ran 2 shot strings of 5 different loads and was asking about 2 specifics of the 5 shot string. This is how I would have run the ladder to find sweet spots. But after re-reading your post, it looks like you had a different approach. A little more info would be helpful ...

You mention you have 2 shot strings and 5 rounds each (If I am reading your 1st post right).

Are these 5 each a different load or 5 of the same load. This would make a difference if your using 1 shot or 5 shots per load rung.
ie:2 ladders of 5 rungs or a partial ladder of 2 rungs of 5 shots each.

By the floowup posts and data given so far, I'm now assuming all 5 are the same charge, and your reported velocities must be averages of the 5 shots each. If this is the case then 10 fps is too small a variance between them and something else is wrong. Put a new battery in the chrono and try again. I've had this happen recently.

sorry for my confusion.

SyberShooter wrote:

what he said... x1 Put a new battery in the chrono and try again. I've had this happen recently.

Good point. Most often when I have had unexpected chrono results, it is due to something with the chronograph rather than the loads. Even a change in the amount of cloud cover can make a difference.

I doubt you were just blowing powder down the barrel !!!

I would have expected at least a 25fps increase.
I'm assuming you are referring to trying a CCI mag primer....... Personally I don't think that's the way to go.
However if your using a standard or match CCI primer I could see where a hotter primer might help.

In no particular order:

- Both loads are compressed

- Bore was really dirty but no grains of powder that I could see.

- I fired 5 at the lower load and then 5 at the higher. Each shot was chrono'd and the average of each 5 shot string taken.

- Average group for the lower load with one that I pulledremoved = 0.32 and upper = 0.31 @50 meters/yards.

- When I repeat I will ensure new battery in chrono and post results. I am anxious to start adjusting seating after I get this settled. One of these is my best load with this component combination.

BTW I well along my initial work-up for RE10X. I started at 19-0 grns and am up to 22.5 and all groups are averaging under 1 inch at 50. The best is 21.5 at less than 0.5 inches.