Ok, so here we are for Part 2! Lemme bring y’all up to speed on the rifle…
The action is a Surgeon 591 that started life as a 7WSM, so it already has the appropriate boltface for a SAUM based cartridge. The 591 is a ‘one piece’ push feed action, having integral 20moa base and recoil lug. Bolt is also a one piece unit, with a plunger style ejector, and claw extractor on the WSM version.
The trigger is a CG Xtreme Mod22, a verrrry nice 2-stage! I have three of these same triggers and have grown quite fond of them. The takeup of the 1st stage is smooth and consistent, and the 2nd stage breaks crisp at just under 2 lbs.
Stock is a McMillan GameScout, cut for an adjustable cheekpiece. I had Joe Ducos in CA install KMW’s excellent adjustable hardware. The color scheme is apropriately RED, with a flame/fade pattern I enjoy using with different colors on my other McMillan stocks. I put an Atlas rail up front, so as to allow quick attach/detach of an Atlas bipod.
Bottom metal is KMW’s MK-1 DBM system. New to using this kit, it has the same footprint as Surgeon’s DBM, so figured I’d give it a try this time around. So far, so good! Magazines fit nice & tight, with little/no wiggle at all. And the mag release tab requires a good bit of force to operate, I like that to prevent inadvertantly dropping a magazine.
Here she is, all up & ready! (dont’ mind the huge scope, its just for working up loads)
Now, lets get to the meat & taters! NECOs Quickoad program has been a great help for researching viable powder / bullet combinations. Based on QL predicitions, I settled on two powders, Retumbo and RL-33.
Bullet selection would be from various 69-80.5grain bullets on hand, from Hornady, Berger, Sierra & ‘Swampworks’ line of custom JLKs. First to test would be the 80gr Amax. I chose this bullet in particular as a control of sorts, in that, if the 1:9 twist barrel would stabilize this tangent ogive bullet in my AO, it’d be very likely that any/all of the other potentials would be fine as well…
Turns out, the first shots of the 80Amax with a ‘mild’ load of Retumbo all keyholed on paper. Accuracy was in the 4″ range @100yds, and:
Granted, these tests were done in 30 degree temps, with a Density Altitude measurement in the -700 ft range. So, that is some thick, cold, heavy air to shoot through! Could only hope now that the more sleek, secant ogive VLD and JLK bullets would fair better in the 1:9 twist Brux, at even the heaviest air. And, they did!
Here’s a 75gr JLK, 69gr TMK, and 75gr VLD, all seated to ‘jam’ length:
From the get-go, all three of these bullets exhibited encouraging signs of accuracy! Nice, round holes in target and ladder test loads of varying charges clustered into acceptable groups.
The 75JLK showed great signs of accuracy with Retumbo during a small ladder test, and speed was eye opening to say the least! These measurements are from Magnetospeed V3, 0.5gr steps:
NICE SPEED! I was hoping to net somewhere in the 3850fps range with a 75grain bullet, and we got that hurdle cleared…and then some! Now that I had something tangible to work with, I stepped over to see what RL-33 might allow? By all I’ve read on these new Alliant powders, and my experiences with RL17, ’22, and ’25, I know they can make some big gains in velocity. So, let’s step away from Retumbo for just a sec, and see where the ceiling is with RL-33!
The 69gr TMK ladder test with RL-33 topped out @ 3875fps, with absolutely zero pressure signs.
The 75gr VLD topped out @ 3883fps, also with no signs of pressure.
Then, I set out about seeing how fast a 75 JLK might go. Turns out, RL-33 yielded a whopping 4088 fps! That load showed obvious signs of pressure…heavy bolt lift, primer crated. Based on that data, I ‘tuned’ Quickload’s parameters to match measured velocity and that load calculated to be in the 69K psi range. TOO HOT for my liking! Backed off a bit and shot another small ladder, that topped out here:
WOW! The .220 REDLINE is clearing 4,000 fps by a good margin! UNBELIEVABLE!!!
Still, that load showed a bit of pressure signs, so again re-visited QL and dialed down to a more safe pressure window, that would be ‘safe’ to use out on the warm Summer woodchuck fields…
Had the chance to get up to our farm and do some shooting with this latest ‘test’ load, and it was averaged right in the 3970 fps range. No heavy bolt lift, and sub MOA accuracy. Not a “one holer”, but I figured it’d be good enough for some terminal bullet testing on Nature’s greatest ballistic dummy…the Eastern Groundhog!
With that current data input in my Ballistic AE calculator, out we went in search of chuck #1! First willing participant was an easy 195yd chip shot. Exploded fur lingered in the air above the throttled chuck for a few seconds after impact…WOW!
Chuck #2 was spotted @ 512yds. Figured I’d soon learn how accurately AE data was doing, so dialed up 1.3MILS from my earlier established 100yd zero, held a couple inched of wind, and let ‘er rip. WOW…again! That chuck helicoptered up & outta the thick grass like a prairie dog! And the audible report was quite distinct!. Holy schmokes, we got a killer on our hands here…
On to next farm, in search of a ‘long-ish’ shot. Again, wanted to test/prove Ballistic AE data & have some fun! Well, a big fat chuck was loafin’ about in the 740yd range. Got the video camera zoomed in, checked AE for dope, dialed 2.5MILS of elevation. The wind was zippin’ along, and turns out I made a good call…because that chuck FLIPPED when that 75 JLK hit him!
At that point, I felt like a proud pappa. My lil’ REDLINE that could, just made me proud! The investment of time & effort had just come around, full circle….
On the way home, I pulled into on more farm, that is loaded with chucks. I had ONE round left to shoot, and found a willing participant @ 260yds. After thumpin’ the last one @ 737yds on video, this poor critter had NO chance. Held for a head shot, and just stoned it. And just like that, my new .220 REDLINE is 4 for 4 on woodchucks on its maiden voyage!
Here’s a graphic shot of what a 75gr JLK does @ 260yds:
On that note, I’ll wrap up Part 2 here!
Still have to re-visit the 69gr TMK and 75 VLDs. But, for now, I’m gonna continue to burn up these 75gr JLKs and see how the throat holds up after a few hundred rounds down it.
Here video links to the first four shots in the field with the .220 Redline:
Stay tuned for Part 3! Will be more testing, more chucks, and maybe even a coyote & deer or three…
Thanks for reading along!