The Thousand Yard SBR, and a Little Ballistic Problem Solving

A few weeks before SHOT Show 2018, the RECOIL and OFFGRID crews all got together to participate in some cigars, whiskey, and hog hunting down at a Modern Outfitters ranch near San Antonio, Texas.

We have people all across the United States, from California to Georgia and everywhere else between. But none from Texas (we're as surprised as you). Because your zero can change significantly in different environmental conditions, not to mention the bumps, drops, and scrapes your Pelican case will get from careless baggage handlers, we obviously had to check zero before hunting.

To top it off, most of us were using different ammunition. Thankfully there was an excellent range available at the ranch for this expressed purpose.

MISSING DATA

The rifle this particular piece is addressing is an 11.5-inch barreled Grey Ghost Precision SBR, topped with a Bushnell SMRS 1-8.5x optic, with a Griffin Armament M4SDk hanging off the end. Initial zero was completed at 100 yards.

Zeroing your rifle at 100 yards is fine and good, but what if you have to take longer shots? Knowing your holds is incredibly important if you want the ability to take an ethical shot on an animal from any significant distance.

The ammunition was a known variable regarding projectile weight and ballistic coefficient. We had some Kestrel 5700 Elites on-hand complete with Applied Ballistics software to perform long range calculations, but importantly and unfortunately we were missing a pivotal piece: real velocity data.

Though the ammunition has a stated velocity on the box, that number doesn't mean all that much; SAAMI specs call for 24-inch barrels to be used for most calibers. Exceptions include 7.62×39, 30 carbine, 300BO, 350 Rem Mag, and 44 Rem Mag.

Regardless, we can safely assume the muzzle velocity on the box won't match an 11.5-inch barrel.

SOLVING FOR X

While nearly every one of us has a traditional chronograph, MagnetoSpeed, or LabRadar at home, we all* neglected to bring them on this trip. Hooray for oversights. We did have three things on our side: only one variable to solve, a range with various targets from 25 yards all the way to 1,000 yards, and a laser range finder.

Starting with a stated velocity on the box, we estimated the reduction the shorter barrel would give us. Then we plugged that estimate into the Applied Ballistics engine, and tested the solution by taking shots at longer distances.

The further you shoot, the more any incorrect data will dick everything up; what works at 300 yards may not at 400 yards and beyond. After some trial and error, we were certain we were very close to the actual velocity because we were consistently hitting targets at 500 yards.

GOING THE DISTANCE

What would be the ultimate test of data? Shooting to the longest range we had available: 1,000 yards. This is something we've done with 5.56 rifles before. An 11.5-inch 5.56 rifle is far from ideal in this situation for many reasons. Once the projectiles go subsonic the drops become tremendous. Also, the efficacy of a 77gr pill actually hitting something at this distance can certainly be argued.

The Bushnell SMRS 1-8.5x LPVO gave us no issues in actually seeing the plates at this distance, but we did nearly max out our elevation in both the turret and the reticle itself. And yet, once wind was properly accounted for–we hit, and hit consistently.

After this confirmation of ballistic data, we wrote a quick and dirty range card out to 400 yards in case a longer shot was required.

A 5.56 SBR isn't a practical 1,000 yard gun–but never let someone tell you that you can't make hits at 1,000 yards with them.

Read more about zeroing, the importance of ballistic engines, and more in our article No True Zero: Don't be a Basic Bitch–Make Your Zero Personal.

*it turns out that one of us did have a MagnetoSpeed, but unfortunately he had food poisoning and wasn't with us on the range. Bastard.