Decided it'd been too long since I flipped a bang switch so I linked up with a buddy I shoot PRS with that needed to zero his newest match rifle configuration. We went to a nearby public range which was mysteriously nearly bereft of shooters. I wanted to do another zero-shift test since my barrels are all still pretty new.
Here's the target. Each of the black shoot-n-see's has at least 15 shots on it. Depended on how much ammo I had on-hand which was mostly what was in the magazines already. For each one I'd shoot a string of 5 shots, pull the barrel out, reinstall the barrel and shoot 5 more as fast as I could at the same aim point, at least until I obliterated the aim point... then I'd guess where to aim as best I could.
- Starting at the bottom is 3 groups from my 26" (pretty sure it's SAC made) 6XC barel firing David Tubb's retail ammo with HBN coated 115gr DTAC's. Zero shift is inside the normal group size so it passes muster. You can see 3 distinct sets of impacts forming. The middle stripe was first so it doesn't bother me that it walks side to side 1/4moa.
- Moving up and to the left we have 4 groups from my 26" .338WinMag tube shooting Federal Premium Safari .338WinMag 210gr Nosler Partition. This is shots 21-40 out of the barrel. I've never seen a .338WM that could stack 'em like this. Great job SAC! The couple flyers are very likely my fault. Zero shift is bigger than the group size but the group size is TINY so for what this barrel is meant to do, meat shooting inside 400m, it's totally satisfactory. The walk is ovate and mostly lateral.
- In the very center is 3.6 groups from my factory DT 26" .338 Lapua Magnum barrel shooting Prime 300gr retail ammo. I wussed out before finishing the final group. The brake on my .338LM is factory Desert Tech and sucks absolute monkey dick. I was flinching like a weakling kid wearing no green on St. Patricks Day. Recoil with the factory brake is enough to shake my brain around and after 20 shots from a bench sitting up in a non-optimal position I was not feeling entirely well, a little punch drunk really. Return to zero was better than my ability to not be a flinchy beyotch.
- At the far right is 5 groups from my 26" SAC-made .308Win pipe running 175gr Sierra Match King's from Sierra's own M118LR clone. Return to zero with that barrel is well inside my group size. At some point around round 14 or 15 I lost focus and obliterated my aim point and the overall multi-group size started to open up, then the barrel induced mirage started to get properly severe and it opened up a bit more. I think of that barrel as having no zero shift.
- The24" SAC-made .223 barrel put 35 rounds of Hornady Black 75gr JHP through a ~.75" hole on a separate paper target but that target got shredded by wind mid-relay and it flew over the hill before I could snap a pic. I was pretty stunned at the return to zero on it.
Barrel install procedure is slide it in (yeah, say those words again... "sliiiiiide it in"), close the bolt, set the lock, point the barrel up, hold the barrel at the brake and put clockwise hand-tight torque load on it while setting each clamping screw finger tight top to bottom, let go of the muzzle device, set full torque with Seekonk driver top to bottom using one clean motion from turn initiation to the click for each screw, unset the lock.
I suppose few of us have done this kind of testing in a careful manner. The results both were and were not surprising. Or, should I say, some of the results were more surprising than others.
In other news, the latest iteration of case foam came in. Really liking this version. It's a lot easier to deal with as far as weight distribution and having things where I need them and them being easy to remove. Really nicely finished out the whole "deployment kit" aspect.
Yes, it's over 100lbs with loaded mags in the bottome shelf and extra ammo in the top shelf but it's only about 85lbs as shown. It's fiercely heavy, true, but it's a lot lighter than 4 gun cases with 1 rifle each and the whole thing fits in the back seat of my 2001 Mustang Cobra.
www.shoot-long.com
