6.5 Creedmoor load development: Semi-automatic gas gun, 130 and 107 TMK

I’m a big fan of the 6.5 Creedmoor WMD Big Beast.  In my last gas gun load development post it performed well with both the 123 and 142 gr. Sierra MatchKing (SMK).  In this post we’ll give it a shot with the 130 and 107 gr. Tipped MatchKings (TMK).

Here are some of my favorite 6.5mm bullets, from left to right, the 107 SMK, 107 TMK, 123 SMK, 130 TMK and 142 SMK.

For a test gun I am using a WMD Guns Big Beast.  Known for their proprietary coatings, WMD Guns has manufactured rifles since 2011.

The 6.5 Creedmoor Big Beast features 7075 Aluminum Nib-X coated billet upper and lower receivers, 20″ Match Grade 1/8″ twist button rifled 416 stainless steel barrel, NiB-X coated BCG, Hipertouch 24-E trigger, fixed modular stock with adjustable length of pull and cheekpiece and a low profile M-LOK hand guard (Note this rifle doesn’t have a particularly heavy barrel).

For glass, I mounted a 3-15x50mm Nightforce F1 scope in a Spuhr mount (this one also has an Aimpoint T1 on the side) that I ordered from Brownells.

WARNING: The loads shown are for informational purposes only.  They are only safe in the rifle shown and may not be safe in yours.  Consult appropriate load manuals prior to developing your own handloads.  Rifleshooter.com and its authors, do not assume any responsibility, directly or indirectly for the safety of the readers attempting to follow any instructions or perform any of the tasks shown, or the use or misuse of any information contained herein, on this website.

Since this is a gas gun I decided to use new Hornady brass with a CCI #200 primer under Varget powder.  All shooting was done prone from a bipod.  Velocity information was recorded with a MagnetoSpeed V3 barrel mounted ballistic chronograph.

The 130 TMK performed better than the 107 TMK.  While the 107 TMK worked well in my 26″ bolt action rifle, it didn’t seem to like the Big Beast as much, only one group went sub-MOA with an average groups size of 1.334″ (1.274 MOA).  The best 5-shot group I recorded was with the 130 TMK .732″ (.699 MOA).  For a gas gun with a relatively lightweight barrel that is still pretty good (note the gun liked the 142 SMK even better, see link).

If you are a regular reader you’ll note my target looks different.  I used to use 1″ orange dots on cardboard targets.  They worked in most conditions, however, in heavy rain or extreme cold the adhesive would fail and they would fall off the target.  I developed this target with Rite in the Rain.  It is on waterproof stock with true 1.047 MOA green dots.  The color provides excellent contrast and you can still see your impacts on the paper.  To learn more about Rite in the Rain and their line of targets, click here.

Between the two bullets, I’d select the 130 TMK in this particular rifle.  To read about how well it performed in my bolt action rifle, see 6.5 Creedmoor load development: Sierra 107 TMK and Varget.

I’m a big fan of the WMD Big Beast.  I’ll be reporting back as I shoot it more!