39 gn blitz king and CFE 223

[JRWhit]

204 Ruger loading 39 gn blitz king atop 29 gn of CFE 223. Using data from Hodgdon for 40 gn Hornady vmax.
Working up to 29 gn and group size is just starting to tighten, ".8in 4 shot group". Plan to work up further to find the sweet spot as it is pretty obvious that it's under powered and not getting that longer blitz king spun up. Wanted to check with anyone else using this combo before proceeding. Shooting out of a Savage 12 FV 1:12 twist.


?1. Anyone loading a 39gn Sierra Blitz King with CFE223, where did you end up?

 

[JRWhit]

Doesn't look like there are many 20 cal loaders in here.
After finding multiple sources siting that the 204 likes to jump,"ton a free bore for such a tiny pill", I re-thought my OAL and shortened to the Sierra's suggested 2.25" and reworked from staring weight to max. 4 shot group started at 2" and shrunk to .8 at max. Things got better but its still under powered when compared to factory load 32s. I'm gonna work up in .1 gn increments and see if it tightens further. If the data translates then an extra .38 gn should be NE for the 39gn. I know .8 is not bad but it is a scattered .8".
The same rifle groups 3 32gn Dog Town factory loads at .4" regularly with the 4th and 5th shot opening it to a .7" overall.
Tell me if I need a sanity check.

 

[Blue68f100]

If your not seeing pressure signs proceed with caution. If it doesn't get over .8 with a large sample pool call it good. Since your other loads opens up with only 4-5 shots it's actual group size is probably close to 1". If these are shot a lot at a time then you want your average over the large pool to be small, not 3-4 shots.

 

[JRWhit]

Well I'm hoping to get the Blitz kings to match the 32s in a 4 shot group before I kick a lot more out.

 

[cfullgraf]

I also have a Savage 12FCV in 204 Ruger. I've been using the Savage and a 26" barrel, 204 Ruger AR-15 for prairie dogs for all of my four outings over the past number of years.

My main load has been 29.0 gr. CFE223 with a 40 grain Hornady V-Max but I have also tested the Sierra 39 grain Blitzking. I tested the Sierra as a hedge against supply shortages in the 2012-2014 time frame.

This load probably is not optimum for either rifle but I get reasonable accuracy results in both the Savage and the AR-15 such that I am comfortable having one load on the prairie dog fields. My 5 shot/100 yd groups range from 0.6 in. to 0.9 in. in both rifles. Velocity is around 3800 fps.

With the 39 grain Blitzking/29.0 grain CFE223 load, I did get a .538 in. 100 yd group with the Savage.

More recently, I've been dabbling with dropping the charge to 28.5-28.6 grains of CFE223. I'm getting comparable accuracy at 50 fps or so lower velocity. I'm seeing if I can extend the life of the cases used in the AR-15. This has not been a priority at the moment as I have other projects higher on the list including replacing the barrel on the AR-15.

I've done a little shooting with Berger 20 grain bullets and the accuracy has been better than the Hornady or Sierra offerings. At the time, Berger bullets were in very short supply so they were not an option. I currently have a good inventory of Hornady and Sierra bullets that I have to consume before stocking up on something different.

I generally have gotten a bit smaller groups with the 32 grain bullets but I elected to work with the nominal 40 grain bullets to eek out a bit better cross wind resistance at farther ranges. The 32 grain bullets seemed easier to work with.

 

[JRWhit]

During the work up, 28.3 gn was the first group at just under 1". I guess it doesn't get any better it'll go back to 29gn.

 

[brasscollector]

I'm getting right around 3700fps with the 39gr BKs and Alliant Power Pro Varmint. Biggest 10-shot group I've measured was around .75". It's been a while since I've played with the 204 though. I had some excellent accuracy with RL10x but it wouldn't cycle the action even with the higher end loads.

 

[JRWhit]

CAUTION: The following post includes loading data beyond currently published maximums for this cartridge. USE AT YOUR OWN RISK. Neither the writer, The High Road, nor the staff of THR assume any liability for any damage or injury resulting from use of this information.
Well finally got back to the sand bags. Work up showed a best at 39.3 gn. no signs of over pressure. Worked ladder up to 39.5 going 1/10th at a time, 5 shots total for each charge weight. Grouping above charge weight of 39.3gn gradually opened up to right at 1 in. Please forgive the random tears on target. Had it too close to the burm and rock splatter marked it up. If I can ever get them over a Chrono I'll edit to include.
Final recipe:
39gn Sierra BlitzKing
CFE 223 Charge weight 39.3gn
Hornady Brass at trim length fire formed and neck sized.
Primer Fed #205
OAL 2.37"
Rifle: Savage 12FV 26" bull barrel 1:12 twist.