308 Winchester Load Development Part-2: 175-grain Sierra Matchking, Varget and Reloader 15

22″ 308 Winchester Load Development Part-2.

This the second trip to the range working up a load for my 308 Winchester.  On the first trip, I shot two, five-shot groups of each load.  While it provides more data, I felt I was wasting time and money with the bad loads- last trip’s groups best group was .452″ and overall group size averaged .843″- not bad- but not great.  This time around and being low on brass, I only shot one 5-shot (or in two instances, 3-shot) group for each load.  I also worked up some Reloader 15 loads as well.

You can read about my first trip here: 308 Winchester Load Development: 175-grain Sierra Matchking and Varget

The rifle was built with the following parts from Brownells:

M700 308 Winchester 22 barrel surefire nightforce spuhr right rear 2

If you’d like to read about how the rifle was built, please see:

I selected long proven match quality components: 175-grain Sierra Matchking (SMK) bullets, Lapua brass, Hodgdon Varget powder, Reloader 15 powder and Wolf large rifle primers.

The Lapua brass I am using has been fired once in this rifle.  Cases were neck sized, trimmed to length and cleaned in an ultrasonic cleaner.  Charges were dispensed using an RCBS Chargemaster.

Ballistic information was recorded with a Magnetospeed V3 barrel mounted ballistic chronograph.  All velocity information presented below.

308 rifle black and white

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.

308 WINCHESTER 22” Barrel- 1XF Lapua Brass 2.832” OAL

WARNING: For reference, read disclaimer above, only safe in test gun

Load Bullet Powder Primer Velocity (FPS) SD Distance Shots Group size
3 175 SMK Varget 43.6 Wolf LR 2619 13.0 100 yds 5 .583
6 175 SMK Varget 44.5 Wolf LR 2672 15.8 100 yds 5 .497
6 175 SMK Varget 44.5 Wolf LR 2672 15.8 100 yds 5 .373
7 175 SMK Varget 44.8 Wolf LR 2678 12.5 100 yds 5 .280
8 175 SMK Varget 45.0 Wolf LR 2697 11.4 100 yds 5 .552
11 175 SMK RL15 42.1 Wolf LR 2453 5.5 100 yds 5 .644
12 175 SMK RL15 42.4 Wolf LR 2465 3.3 100 yds 5 1.007
13 175 SMK RL15 42.7 Wolf LR 2500 10.0 100 yds 5 .603
14 175 SMK RL15 43.0 Wolf LR 2522 8.1 100 yds 3 .274
15 175 SMK RL15 43.3 Wolf LR 2544 13.6 100 yds 3 .548
AVG .536

All groups were fired prone, from a bipod with a rear bag.  The load numbers are asynchronous and used as a reference in my reloading log books.  The first group for load #6 includes the cold bore shot.

Range conditions were overcast and 33F.  No wind.

308 winchester 175 SMK varget .280 at 100 yardsThe best 5-shot group of the day, 280″ at 100 yards (.267 MOA).  
308 winchester 175 SMK vargetThe rifle liked the higher end of Varget the best.  The lower left group includes the cold bore shot.

all 308 load trip 2

Here are all the groups I fired on this trip (above).

It appears that my rifle prefers the higher end of Varget loads.  The Reloader 15 didn’t give the velocities I was expecting, but it was pretty cold.  I’ll be conducting further testing on load #7 at distance and see how it performs.