Well I finished load development on my new 300 WSM I built myself. I wanted to do a compact setup so I went with a 22" Benchmark carbon barrel since Im running a suppressor. The reamer is set up for 205 gr Bergers but will work for others in that weight class including the 215s. Contrary to popular belief it was easy to get my Defiance XM to feed in a mdt detachable magazine. I moved the hole forward .275 that has the spring go through it. This put more pressure on the front of the follower and would keep the round inline when getting chambered. Feeds flawless and won't go below the feed ramp like people have experienced w this combo. Very first load I tried out of this barrel to break it in shot in the .3s at 100.
After the barrel settled down for velocity I decided to do a powder charge test. ADG Brass, Reloader 23 is pushing a 205 berger at 2860 fps with an es of 12 for 10 shots. I didn't hit pressure til 2935 fps. There was another node at 2900 but I didn't wanna be that close to pressure since it was less than a gr from hitting it. Picked the milder 2860 fps node. 4 seating depths later it shot a 3 shot group that measured .195" @ 100 yds. I decided to load 3 more rounds to verify at 580 yds. Heres the group it shot at 580 in a 10 mph wind. 1.5" tall by 3.0" wide. More than happy with it in those conditions.
While breaking the barrel in with a super mild load at 2650 fps I decided to shoot two 3 shot groups in a row at 580 yds. One measured .6" and the other measured 1.2". This cartridge has been about the easiest magnum Ive seen to load for that Ive seen. While breaking the barrel in I tried 3 different neck tensions and seating depths from .015-.060 off. It shot everything 1/2" or better with most being in the .3 moa range.
Im expecting 2000+ round barrel life with peak accuracy since this will be only shot cold bore. Plugging in the ballistics of a 205 at 2860 youll see its pretty much identical in the wind compared to the 6.5 prc,saum/shermans etc with a 156. However it has 20% more energy at 1000 and way more barrel life. Very easy to keep in tune and minimal throat erosion.
Rifle has the following:
Defiance ANTIX XM length w nitride
Manners LRH
Benchmark 22" 30 cal 10 tw sendero light
Hawkins Bottom metal
Modified MDT magazines
Triggertech Diamond
Thunderbeast Dominus SR Suppressor
Nightforce ATACR 4-20x50 bedded into a set of NF Rings
Rifle weighs 11.0 lbs with optics and suppressor.
After the barrel settled down for velocity I decided to do a powder charge test. ADG Brass, Reloader 23 is pushing a 205 berger at 2860 fps with an es of 12 for 10 shots. I didn't hit pressure til 2935 fps. There was another node at 2900 but I didn't wanna be that close to pressure since it was less than a gr from hitting it. Picked the milder 2860 fps node. 4 seating depths later it shot a 3 shot group that measured .195" @ 100 yds. I decided to load 3 more rounds to verify at 580 yds. Heres the group it shot at 580 in a 10 mph wind. 1.5" tall by 3.0" wide. More than happy with it in those conditions.
While breaking the barrel in with a super mild load at 2650 fps I decided to shoot two 3 shot groups in a row at 580 yds. One measured .6" and the other measured 1.2". This cartridge has been about the easiest magnum Ive seen to load for that Ive seen. While breaking the barrel in I tried 3 different neck tensions and seating depths from .015-.060 off. It shot everything 1/2" or better with most being in the .3 moa range.
Im expecting 2000+ round barrel life with peak accuracy since this will be only shot cold bore. Plugging in the ballistics of a 205 at 2860 youll see its pretty much identical in the wind compared to the 6.5 prc,saum/shermans etc with a 156. However it has 20% more energy at 1000 and way more barrel life. Very easy to keep in tune and minimal throat erosion.
Rifle has the following:
Defiance ANTIX XM length w nitride
Manners LRH
Benchmark 22" 30 cal 10 tw sendero light
Hawkins Bottom metal
Modified MDT magazines
Triggertech Diamond
Thunderbeast Dominus SR Suppressor
Nightforce ATACR 4-20x50 bedded into a set of NF Rings
Rifle weighs 11.0 lbs with optics and suppressor.
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