04-03-2021, 12:27 AM
I believe we have a load. Varget and 105 gr RDFs were the hope and it looks like it will work quite well. 2500 fps was the target and it looks like it will fall a bit short at 2450. Nothing that that's going to impress any hunters around here, but at today's density altitude of 4050 ft at 90 degrees (spring is here!), the RDF and its 0.280 G7 will start transitioning around 920 yards and stay supersonic to 1125. From a 6.84 lb carbine with a 16" barrel and a 37" OAL with the stock fully extended. Falling short 50fps cost about 35 yards.
The weight clearly magnifies shooter error. Go soft on the shoulder? Grip too tight? Go inconsistent on the bipod? Have a brainfart while pulling the trigger? You'll see it downrange. The weight also results in more felt recoil, but it feels deep and smooth. Return to battery (which is what throws me more off target) is very light with the Ti carrier and results in not much more than a twitch in my sight picture. Learning to handle this rifle is going to make me a better shooter - unforgiving, but a scalpel in the right hands. It's reminiscent of old Porsche 911s - where you actually had to know what you were doing to drive one fast.
In my initial ladder, 26.8 gr gave me 2448 with an sd of 6. Sd was 8 at 27.0 and both had good accuracy so I loaded up 31 at 26.9 for today. One fouler then 10 over Magnetto which gave me 2455 with an sd of 10. I'll probably drop back to 26.8.
The remaining 20 were shot in four five shot groups. This isn't the best of the groups - it's all of them. The first set is bottom left and I went clockwise. The first 2 were on my Atlas bipod with a rear bag on a slippery concrete bench. The bipod slipped on one shot in the first group (circled). Annoyed with the bench, I went prone (where the concrete is still slippery (give me dirt and I don't need no stinking mat!)). I forgot to load the bipod on the first shot (circled) and reached deep into the depths of my being to concentrate hardest on the last and best group. I'll take an average of 0.94 MOA which includes shooter error and 0.78 MOA if I exclude the obvious errors - this is from a 6.84 lb carbine with a 28 ounce barrel and was shots #143-162 (so it's probably still breaking in a bit). It looks like I need to move the zero a click left, but I like that 7 of the 20 are touching the aiming dot. I haven't actually zeroed it - I just made some adjustments based upon where the Magnetto shots went and it looks like I got damn close. The little barrel heats up but there was no drift of the zero (have I mentioned how much I love Varget?). This is the internet after all, which is populated with thousands of images of tiny little groups - which are almost never clustered around the aiming point.
Off to the steel range on Sunday where I can go to 550. Fun fact: 700 yard wind drift of this load is 42% less than a 77 gr Sierra TMK launched at 2700 - which would be a hot load out of a 20" .223. From a ballistic standpoint, it almost entirely matches up to what I did with 123 gr Scenars at 2560 out of my 22" 6.5 Grendel - using CFE.
The weight clearly magnifies shooter error. Go soft on the shoulder? Grip too tight? Go inconsistent on the bipod? Have a brainfart while pulling the trigger? You'll see it downrange. The weight also results in more felt recoil, but it feels deep and smooth. Return to battery (which is what throws me more off target) is very light with the Ti carrier and results in not much more than a twitch in my sight picture. Learning to handle this rifle is going to make me a better shooter - unforgiving, but a scalpel in the right hands. It's reminiscent of old Porsche 911s - where you actually had to know what you were doing to drive one fast.
In my initial ladder, 26.8 gr gave me 2448 with an sd of 6. Sd was 8 at 27.0 and both had good accuracy so I loaded up 31 at 26.9 for today. One fouler then 10 over Magnetto which gave me 2455 with an sd of 10. I'll probably drop back to 26.8.
The remaining 20 were shot in four five shot groups. This isn't the best of the groups - it's all of them. The first set is bottom left and I went clockwise. The first 2 were on my Atlas bipod with a rear bag on a slippery concrete bench. The bipod slipped on one shot in the first group (circled). Annoyed with the bench, I went prone (where the concrete is still slippery (give me dirt and I don't need no stinking mat!)). I forgot to load the bipod on the first shot (circled) and reached deep into the depths of my being to concentrate hardest on the last and best group. I'll take an average of 0.94 MOA which includes shooter error and 0.78 MOA if I exclude the obvious errors - this is from a 6.84 lb carbine with a 28 ounce barrel and was shots #143-162 (so it's probably still breaking in a bit). It looks like I need to move the zero a click left, but I like that 7 of the 20 are touching the aiming dot. I haven't actually zeroed it - I just made some adjustments based upon where the Magnetto shots went and it looks like I got damn close. The little barrel heats up but there was no drift of the zero (have I mentioned how much I love Varget?). This is the internet after all, which is populated with thousands of images of tiny little groups - which are almost never clustered around the aiming point.
Off to the steel range on Sunday where I can go to 550. Fun fact: 700 yard wind drift of this load is 42% less than a 77 gr Sierra TMK launched at 2700 - which would be a hot load out of a 20" .223. From a ballistic standpoint, it almost entirely matches up to what I did with 123 gr Scenars at 2560 out of my 22" 6.5 Grendel - using CFE.