Advice

Hendrix's rifle · March 10, 2017

Evening all, I have done some load development using cfe223 and 55g vmax in my 223. Starting at 25g to a max load of 27.8 I think it was before i started getting pressure signs. Sweet spot at 26.1g where the group shrunk down massively then opened up after that. It shrunk to about .4inch with a 5 shot group and 1 flier that I pulled(took it to .7inch) My issue is they were starting to shrink again as I was reaching maximum load. If I stuck to 26.1 and altered seating depth do you reckon I'd get where I want? Currently using 2.200 inch as my oal however it's about 2.265 at the lands. That is touching may I add. Would there be another node in there somewhere? I'm going to try but wanted a little pointer if anyone could! Howa 1500 varmint 1 in 12 twist using cci br4 primers, hornady brass and as stated cfe223 and 55gvmax bullets. Thanks

gbal · March 11, 2017

Hendrix,as ever-only actual firing can give answers-and that means several groups,not just one.I'd shoot some more with your 26.1 load as it seems a node,but by all means vary seating depth at that loading.Best use CBTO (cartridge base to ogove) as bullet length can vary. BUt you have it seems plenty throat to move forward a bit.

The second issue is; what do you want? 4 for 4 shots,if reliable is pretty good for the rifle and bullets being used.It's unlikely to be a longer range rifle (1/12),and likewise another grain plus of powder is not going to make much difference to useable trajectory,you may lose accuracy (always a poor trade at short ranges),and velocity increase is modest-say 50 fps,and here is that difference:

Fed 55g Nosler ballistic tip @ 3240 fps 100y 1.4/1.0 200y 0/4.3 300y 6.8/10.3 400y 20.8 /19.6

Nosler 55g Nosler ball tip @ 3200 fps 100y 1.4/1.0 200y 0/4.4 300y 7.0/10.5 400y 21.4/20

Both SAAMI commercial comparable ammo,same bullet BC.267,200y zero drop/drift inches 10 mph wind.

.2 inch at 300y? Hardly tempting-even if it maintained accuracy.

Enjoy the .4 groups. :-)

gbal

Hendrix's rifle · March 11, 2017

Cheers for the reply, I increased oal to 2.255 and shot some groups at 100 last night, 5 shot groups that was just 1 hole measuring about .3inch on the sides(not centre to centre) so I'm rather pleased to say the least pure luck I think

VarmLR · March 12, 2017

Well done, and not luck as you changed something that obviously affected barrel time (hence where the bullet leaves on the harmonic cycle) hence found your sweet spot. That's what it's all about. Record it in your little black book and you have that load crossed off for that bullet with CFE ;-)