My gas gun load development
#15
Interesting range session today. The goal was to simply confirm that the Win 748 27.1 gr charge was going to be my most accurate charge weight and double check ES and SD’s. I snuck in a couple other CFE and LVR loads that I wanted to test all within similar velocity ranges as the 748 powder. I alternated between using Berger 109’s and the Barnes 112 Matchburners with different powder weights as well as mainly testing with once fired Starline 6.5 Grendel brass sized down to ARC. First big batch of Starline brass I have worked with.

The weather was clears skies and around 56 degrees which is also the biggest drop in temperature since honing this load in and I wanted to see how much it would throw my results off. It was quite warmer at 72 and 88 degrees the first couple of times I was looking into it. I can indeed report that the Win 748 at 27.1 gr was still by far the most accurate powder weight and favored powder for my Criterion barrel. The CFE and LEVR once again crapped the bed with .76 MOA being the best for CFE. LVR was over MOA. Both with Bergers.

The weirdest part for me is in the complete reversal of the Bergers being the most accurate when it came time to put them toe to toe with the Burners. The Matchburners blew the doors off of the Bergers. Best the Bergers could muster with 748 and five shots of the 27.1 gr loads was .65 MOA group. The 112’s dominated that with a .39” group! Same 27.1 gr load. Both with Star brass.

Here’s the downside. The limitations of having a temperature sensitive powder on top of my accuracy node being on the lower end of acceptable became clear today. Shooting at around 56 degrees Fahrenheit dragged my average velocity down to 2471 for the Bergers and 2458 for the Burners. This is still acceptable for me and for the games I plan to play. I’ll just have to work the scope dials a little longer than some. I’ll be sticking with the 27.1 for my upcoming long range course at the end of the month just because I need a proven load. There’s a qualification at the end that I don’t want to fail and this rig should be more than capable of the 600 yard distance we’ll be shooting. I’ll start testing LEVR and CFE some more when I finish the next batch of hand loads. 

I’ll obviously have to test out the mystery behind my Bergers being bested by the Burners. This is the first time I’ve shot them back to back on the same day with the same powder and brass. The other detail I haven’t mentioned is that I sorted the Barnes bullets about a week ago. Okay, not all of them but enough to take to the range! Who’s got time for that? My next range trip I can squeeze in for testing hand loads I’ll be trying to figure that out. Was it the change in Brass or sorting the base to ogive of each one of the Barnes Bullets? Maybe they were pulled into a beetle accuracy node with the slower fps and it’s neither of the first two options. Cliffhanger. All I can say is that I understand now why reloading doesn’t save anyone money! ?
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Messages In This Thread
My gas gun load development - by Burt Gummer - 09-25-2022, 10:35 PM
RE: My gas gun load development - by grayfox - 09-26-2022, 01:42 AM
RE: My gas gun load development - by Burt Gummer - 09-26-2022, 02:32 AM
RE: My gas gun load development - by CZ527 Guy - 09-26-2022, 02:28 AM
RE: My gas gun load development - by Thelaststraw - 09-30-2022, 08:18 PM
RE: My gas gun load development - by Burt Gummer - 10-04-2022, 11:06 PM
RE: My gas gun load development - by Dino11 - 10-02-2022, 09:04 PM
RE: My gas gun load development - by Dino11 - 10-05-2022, 09:06 AM
RE: My gas gun load development - by Burt Gummer - 10-05-2022, 05:23 PM
RE: My gas gun load development - by Dino11 - 10-05-2022, 09:56 PM
RE: My gas gun load development - by Burt Gummer - 10-06-2022, 01:00 AM
RE: My gas gun load development - by IALoder - 10-06-2022, 07:43 PM
RE: My gas gun load development - by Burt Gummer - 10-07-2022, 12:43 AM
RE: My gas gun load development - by Burt Gummer - 10-08-2022, 09:19 PM
RE: My gas gun load development - by Burt Gummer - 10-08-2022, 11:33 PM
RE: My gas gun load development - by GRH - 10-10-2022, 02:09 PM
RE: My gas gun load development - by Burt Gummer - 10-11-2022, 12:27 AM
RE: My gas gun load development - by Dino11 - 10-10-2022, 10:18 PM
RE: My gas gun load development - by Burt Gummer - 10-11-2022, 12:40 AM
RE: My gas gun load development - by GRH - 10-11-2022, 11:55 AM
RE: My gas gun load development - by Burt Gummer - 10-18-2022, 12:47 AM
RE: My gas gun load development - by Dino11 - 10-22-2022, 09:44 AM
RE: My gas gun load development - by Burt Gummer - 10-24-2022, 09:59 PM

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