Cutting a 300WSM to 18.5 Inches
Hardwear and conditions
Our client rifle, a Tikka T3 Lite Stainless, chambered in 300WSM. Starting life with a factory length 24 inch pencil barrel, now wearing the same barrel cut to 18.7 inches, plus a radial muzzle brake. Prior to sending the rifle to EM Precision, it was living in a MDT HS3 chassis, with a collapsing magpul MOE buttstock.
Federal Premium 180 grain "Trophy Bonded Tip" with a published muzzle velocity of 2960 and BC of 0.500. Our data confirms these advertised numbers.
Burris XTR II 3-15x50 with the mils version of their SCR reticle
Conditions included broken sun/rain with a thunderstorm that rolled through and shut us down for about an hour. Winds while shooting were between 1-7kph. Temperature was 21 degrees Celsius, 80 percent humidity.
Before any modification this rifle shot extremely well with 3 shot groups, averaging 0.75 MOA. The 4th shot was usually loose(1.25MOA), and the 5th more so (2MOA). This can be expected from light profile barrels that heat up very quickly from magnum loads. Recoil was heavy and violent, and shooting groups slowly was important not only to keep the barrel cooler, but also to delay shooter fatigue.
After receiving the rifle back from EM Precision, my first impression was "handy". This rifle is short, maneuverable, and pointed extremely naturally. The rifle slides into our Eberlestock Operator G4 rucksack, and is nearly completely contained by the scabbard. As the barrel now only projects a few inches from the bag, it doesn't snag up on any branches when bush bashing.
" A follow up shot, if needed, would happen quickly."
The temperament of the rifle completely changed. Recoil was very manageable and this was the first time putting a box of 300 downrange that I was wanting to send another. The brake did lift other shooting mats to my left and right, and toss anything else around that wasn't secured. Personally, 300wsm is loud enough as it is that I would never shoot one without ear pro, so needing hearing protection to shoot it doesn't effect me. While I wasn't able to spot my own shots, the target never left my field of view in the glass. A follow up shot, if needed, would happen quickly.
"Muzzle velocity was 2885fps, down from 2960fps, a loss of 75fps"
The accuracy of the rifle appeared to be unaffected by the modification. After a quick boresight, the 200m zero was established in 5 shots. A confirmatory 3 shot group was fired that was sub MOA. During these shots a chronograph was used to establish an average velocity of 2885FPS. 2885 down from 2960 a loss of 75FPS.
We moved to a steel 12x18 gong that was placed at 515meters. Using the data from the chronograph, Applied Ballistics asked for 2.5 mils elevation. Miss. Spotter called to add one more click and we then had 3 consecutive hits.
We then moved to a similarly sized gong placed at 714 meters. Applied Ballistics called for a correction of 5.0 mils from the 200m zero, and we carried over the extra click we needed before. After a couple near misses with no correction, time was given to let the rifle cool. On taking up the rifle again (with no correction) 3 consecutive hits were achieved. About this time we needed to pack up for the day.
"The rifle still shoots flatter than a 6.5 Creedmoor"
Do it. The velocity lost, in my opinion, is well worth the increased ergonomics, reduced weight, and reduced recoil, in a hunting rifle. Generally the velocity lost is the same lost in 50 meters, and 300wsm has plenty to spare. The rifle still shoots flatter than a 6.5 Creedmoor that was also at the range that day.
More information will be added to this article and subsequent range data is gathered, and relevant real world applications are observed.