Sunday GunDay: .300 WSM Hunter with Carbon-Wrapped Barrel

High-Tech Hunter in .300 WSM

Since its introduction in 2001, the .300 Winchester Short Magnum (.300 WSM), has proven very popular for hunting and long-range competition. The case has ample capacity to drive the heavy .30-caliber bullets, and with proper case prep and annealing, the WSM is capable of outstanding accuracy. When Nebraskan Greg Anderson decided to build his “ultimate long-range hunter”, he selected the .300 WSM for its accuracy and its ability to drop large game at long distances. Teaming up with Chris Matthews of LongShot Rifles, Greg developed an impressive long-range hunting rig, with high-tech components to reduce weight. The 26″ barrel is a carbon-wrapped composite over a Rock Creek stainless blank. The carbon technology saved about 3 pounds over an all-steel barrel of similar length/contour.

The Manners Composite stock also features carbon fiber construction for stiffness and reduced weight. Greg’s carbon/carbon rifle tips the scales at just 10.8 pounds, including scope and bipod. A conventional rig could easily weigh 15 pounds or more. Greg’s carbon hunter has proven accurate as well as innovative. With 175gr Sierra MKs, the gun shoots well under 1/2-MOA out to 600 yards and beyond.

The Ideal Spot and Stalk Rifle

by Greg Anderson
The purpose of this project was to create a hunting rifle that would be inherently accurate at long range and have an acceptable weight for hunting in rough country. I researched the question of overall weight with several gunsmiths. The smiths confirmed that while fat-contour barrels could deliver improved accuracy, there was a price to pay and a lot more weight. With a heavy barrel, the finished rifle would be most likely weigh about 15 pounds. That’s more than I wanted to haul around in the field. To reduce barrel weight, the suggested “traditional” solutions were fluting, which would reduce barrel weight by at least one-half pound, or going with a smaller diameter barrel.

The Quest for Reduced Weight without Accuracy Loss
Fluting didn’t promise enough weight savings, and a slim, sporter barrel probably wasn’t going to deliver the kind of consistent accuracy I wanted (particularly as the barrel heated up). Accordingly, I decided to “think outside the box”. My research on lightweight barrel options lead me to Advanced Barrel Systems, (ABS) a company in Lincoln, Nebraska that once produced custom carbon-wrapped barrels. ABS President Mike Degerness could wrap a barrel to virtually any shape and diameter, allowing great stiffness even with a huge reduction in barrel weight. As the “core” for his carbon-wrapped barrels, Mike recommends a cut-rifled blank made by any of the quality cut-barrel makers. [NOTE: ABS is not taking orders at this time. You cannow get excellent carbon-wrapped barrels from Proof Research].

Significant Weight Saving with Carbon
How much weight can you save with a carbon-wrapped barrel? Well a 24-inch, #7 contour ABS carbon-wrapped barrel will weigh about 2.5 pounds compared to about 5.5 pounds for a steel barrel of the same length and contour. So, this means that you can put a fat, stiff competition-contour barrel on your hunting rifle and save over half the barrel weight compared to an all-steel barrel. Saving three pounds is a blessing when you’re carrying the rifle all day long in the field. I placed an order for a 30-caliber Rock Creek barrel blank with an 1:11.25″ twist and a finished length of 26″. Mike wrapped the barrel and finished it to an M24 contour.

Carbon Can Also Improve Barrel Vibration Damping
One interesting benefit of carbon barrel-wrapping is that the carbon components have a vibration-dampening effect. According to ABS, the extreme rigidity of the finished composite barrel dampens the vibration nodes of the barrel making it shoot like a plain steel barrel of much greater mass. Carbon fiber has a high modulus of elasticity that has the effect of lowering the amplitude of the vibration of the barrel when fired. This is what makes the ABS barrels perform so well, according to Mike.

Impressive Accuracy For a Hunting Rifle
Looking at the targets below, one may ask, “Does the rifle always shoot this well?” The answer, not surprisingly, is: “it depends on the trigger-puller”. The rifle is capable of outstanding accuracy. But it took some time and effort for me to develop the skills required to shoot up to the rifle’s inherent accuracy. I nearly always practice prone from bipod. Initially, I was getting horizontal stringing until I changed my grip and learned to be more consistent from shot to shot. Shooting a heavy-recoiling .30-caliber rifle from the ground is not the same as shooting a .223 Rem from the bench.

3-Shot Group at 200 yards | 6-Shot Group at 500 Yards

Completing the Project Build
To smith the rifle, I selected Chris Matthews of LongShot Rifles, LLC because of his expertise with the WSM cartridges and long-range shooting equipment. Because cost was a factor, we decided to use a donor Remington long action that had been used on a Remington 7mm magnum. Chris trued the action and we had Dave Kiff from Pacific Tool & Gauge grind us a bolt to fit the action more perfectly. Chris chambered the Rock barrel and installed a .300 Badger recoil lug.

Carbon-reinforced Hunting Stock from Tom Manners
Being a fan of carbon fiber technology, I selected an MCS-T stock from Manners Composite Stocks. These stocks have an extremely high strength-to-weight ratio and the high comb of the MCS-T gave an almost perfect alignment with the scope. The finished rifle was topped off with a Leupold 4.5-14x40mm LR scope equipped with M1 windage and elevation turrets. A Harris bipod completed the package. All up, including scope, steel rings, and bipod, my .300 WSM rifle with 26″ barrel weighs 10.8 pounds.

Load Development for Accuracy
I developed a load using 63.0 grains of H4350, 175gr Sierra Match Kings with Federal 210M primers in Winchester-brand brass. This load gives 2960 FPS out of my rifle. The load would shoot sub-MOA from bipod from 100 yards to 600 yards and was adopted as the “go to” load. I have also tried the 208gr Hornady A-Max in this gun. The A-Maxs shot well but the Sierras work well for everything (paper punching and hunting) so the 175gr SMK is my bullet of choice.

Brass Prep and Annealing Are Very Important
The Winchester-brand brass is good, but you have to prep it thoroughly if you want good results. My brass prep consisted of turning the necks, de-burring the flash holes (inside and out), and chamfering the case necks. Using a Sinclair neck-turning tool, I turn the necks to .0135″ per side. That provides a complete clean-up of the necks, which run about .015″ neck-wall thickness out of the box.

One thing I’ve learned to do is anneal the brass every 3-4 firings. I started to do that after I noticed that the force required to seat bullets became inconsistent after just a few loading cycles. I also experienced flyers that were going out of the group for no apparent reason. Annealing the cases every 3-4 firings has eliminated most of the unexplained flyers and annealing has also made bullet seating much, much more consistent. I’ve also noticed a significant improvement in my groups at 500 and 600 yards now that I anneal regularly. Group sizes at 600 yards can be as much as 2″ smaller with annealed brass than with un-annealed, work-hardened brass.

Greg Anderson was successful with his .300 WSM on his very first hunt, dropping a nice buck at 364 yards. Chris reports: This was on some private land in Nebraska. As daylight faded… there were a couple of bucks, but one looked to be the best of the lot. The buck gave me a broadside shot ranged at 364 yards. I settled behind the scope and took one shot. It hit right where I aimed and the buck just folded.”