[90JS]

Just wanted to provide an update. Been playing around with seating depth to try and squeeze a bit more accuracy out of these bullets. Moving from an CBTO: of 1.895″ to a 1.885″ using a Hornady Bullet Comparator Ive been able to shink my group sizes down from an average of ⅞” to an average of just over ⅝” in the .68″ – .72″ range.

I also dropped my power charge from 26.5gr CFE223 to 26.2 and still yield the same MV from my 18″ Criterion Core Barrel. Still using a Caldwell Lead Sled and 10 shot groupings.

Im sure Im limited by my Nightforce 1-8 LPVO at this point. Will try using a higher magnification scope that has parallax adjustment when I finally get one.

[90JS]

Just wanted to update everone with my testing. I was able to take this bullet out to 875 yards today at human torso silouettes.

At an average of 2900fps muzzle velocity out of my 18″ Criterion Barrel, the BC that holds the most true to my dope I used at 550, 675 and 875 yards today is G1 .37

[90JS]

CFE223 Ladder from 25gr – 26.5gr. Max charge was my pick. Moved in .3gr at a time
CCI 450 Primer
LC 5.56 Nato Brass Annealed after every firing
OAL: 2.245″-2.255″, the meplate is a little inconsistent, as expected from open tip
CBTO: 1.895″, this was consistent across my loading
Ring Crimped with Lee FCD
Using Criterion 18″ Core Bbl.
Average MV: 2919fps

My worse groups were at the lower end of my ladder testing. Worse group was around 3″ in the 25gr-25.6gr range. Things started to tighten up as I approached 26gr. Shot my best 10 shot group with a max Hornady load with their 75gr BTHP under 26.5gr. Got a little under .875″ with my best grouping. Other 10 shot groups under 26.5gr was slightly under and slighly over 1″ with my max being around 1.375″. 10 shot groups are hard, even when using a sled so I could have been my technique. I still have more testing to do for consistency.

In my experience CFE223 performs best at max charges and honestly I’ve only seen it get better past max if you’re confident enough. I went all the way up to 27grs just to see what pressures would look like and see if I had a generous margin of error. Groups were around the same size as 26.5gr but I started getting raised ejector smears on the brass. No blown primers though.

I understand CFE223 is temp sensitive but I live in Hawaii so its pretty much always summer here and not too concerned.

• This reply was modified 1 year, 3 months ago by 90JS.
• This reply was modified 1 year, 3 months ago by 90JS.

[Author]

Posts