Finished breaking in the barrel on the new Cooper today, very pleased when I started shooting test loads. Not much time so I loaded unfired Norma brass with 47-49 gr. RL-22, Win. primer, 140 A-Maxk seated so that the base of the bullet is in line with the base of the neck (not very sophisticated, I eye-balled it and did not even bother to write down the measurement. The seating die is still set so I will make some more and do a measurement). After break-in my buddy shot a three-shot group with the last three break-in loads, 44/RL-22/140 Amax and they went into 0.276". Cleaned the barrel for a last time during what I might call breaking-in and started shooting five shot groups. Buddy shot 47, 48 and 49 gr. loads of RL-22, 47 grain was the best with four into 0.266", one shanker called out. I shot the remaining five 47gr. loads into 0.270" for four, also shanked one out but did not call it. Believe that this load will shoot good enough for what I want, might try some more loads but... not sure I should expect any better from this beautiful little rifle. Have only shot 40 rounds so far and I have a feeling this is going to be a fine long range deer rifle. Now to get some drops and kill some steel plates.
With all the current interest in the 6.5-284 it makes me want to have another one. I had a rifle like this back in the mid 60's. in my inexperence then I had it made on a Arisaka (jap) action it had a Apex barrel Built by Sam May with a 10 twist air gauged broached barrel.It would shoot in the 3's with 120 gr Sierra's.I used some data from Ackley books with 4350(don't Use) real primer poppers. this is a post from an old guy who would like to have one again with a 8 twist heavy barrel and bench type stock and the new wonderfull optics that are now available.
I took the 6.5x284 to 500yards yesterday evening with slightly modified loads from my last post. Breezy intermitant conditions and I'm not a great judge of wind speed (that's the excuses out of the way) [img]/ubbthreads/images/graemlins/wink.gif[/img] 142 Smk's seated .0010" off lands with 49g H4831SC best group 2.973". Berger 140 VLD seated 0015" into lands under 49g H4350 3.125". Haven't been able to chrony these as the CED we use seems to have given up the ghost, it isn't registering just displays 0000fps [img]/ubbthreads/images/graemlins/frown.gif[/img] The VLD's were shooting at 500yd point of aim with just 9MOA elevation from a zero of 170yards. At this range the SMK's were 6inches low and required another 1.5 MOA to bring them to POA. This adjustment Raised the VLD's POI another 10 inches! they sure are slippery fellows [img]/ubbthreads/images/graemlins/smile.gif[/img]
I have not chronographed the load that is shooting so well in my Cooper (47/RL-22, 140 Amax) but I expect it is pretty mild compared to what you are running. I may pay the price in bullet drops way out there, but hope to make the barrel last longer and recoil is really comfortable. Shot five into 0.348" in a fairly strong, gusty wind this morning at 100 yards. If the Oehler says this is way off the mark I will look at bumping it up, but right now I am enjoying shooting it a lot.
Thanks, unfortunatly my chrony seems to have died. The last time it was working, I checked the 6.5x284 with 48.5g H4831SC, which was giving 2674fps with a es of 9. I thought that it was a bit slow so have upped the load to 49g, this gives identical accuracy to 48.5g. I did some development work and took it up to 52g H4831SC in half grain increments, (that was the day the chrono stopped working) Up to 51.5g showed no and I mean no pressure signs and then at 52g I got lots of pressure, sticky bolt, case head imprint of ejector and sako extractor and some "flow" of brass. Accuracy from 49.5g to 51.5g was decreasing i.e from just under an inch at 300yds with 49g to 1.8 inches with 51.5g. This is the reason I have stuck, for the moment with my load of 49g H4831SC. I have H4350, RL22 and some Vit 160 but as yet haven't had the time to play.
As soon as I have fettled the chrony with a "large hammer" I will do more dev work as I am looking for 2800 - 2900 fps if possible, which I think is realistic with a 26 inch Kreiger tube? I would rather sacrifice some MV if I can attain best accuracy, with barrel longevity to boot. [img]/ubbthreads/images/graemlins/smile.gif[/img]