The Nosler 185gr RDF bullet is a fairly recent entry into the long range 7mm projectile arena, and one that deserves consideration. Given the case capacity and previous experience with the 7mm SAW, we feel like the RDF is the upper limit of the balance between speed and bullet weight for this cartridge in a magazine fed rifle. Nosler was kind enough to supply us a few boxes of the new RDF for testing, and we’re happy to provide the results below.
Test Rifle: Bighorn TL-3SA #1717, 26” Bartlein MTU contour barrel, 1-8.5” twist rate, 5R rifling profile
This is Clayton’s current PRS barrel, and has shown to be consistently accurate. In our experience, this barrel runs in the middle of the pack with regard to muzzle velocity in this cartridge, so it acts as a good test subject that doesn’t skew results up or down. There were approximately 900 rounds through the barrel at test time, and around 250 rounds fired since it was last cleaned.
Max COAL in new SAW II chamber: 2.947”. This equates to 2.259″ cartridge base to ogive when measured on a Forster Datum Dial tool.
The test barrel shows approximately .020″ of throat wear since new, so the decision was made to begin testing 2.950″ COAL for simplicity. On test day we had a variable full value right to left wind, ranging from 7-15 MPH. Minimal consideration was given during firing to wind speed; our main focus was to establish a charge weight with minimal vertical dispersion.
Brass: WTO/Alpha Munitions 7SAW
Primer: CCI BR-4
Powder: H4350 lot 5814
All loads 2.262”BTO/2.950” OAL
Charge weight/velocity, 200 yard range
44.0: 2577/8.5Sd, .856”vertical over 5 shots
45.0: 2638/7.0, .819” vertical over 5 shots.
45.4: 2660/11.0, .88” vertical over 5 shots
45.8: 2661/7.2, .604”vertical over 5 shots. Most accurate of all charges, .712” total group
46.2: 2682/12.0, .872” vertical over 5 shots
46.6: 2701/9.2, 1.138” vertical over 10 shots. Slight resistance at top of bolt lift on 3 rounds, established max for this barrel
255 degree Direction of fire/65 degrees/60%RH/27.15Hg station pressure(approx. 2700′ ASL)
Test load for field firing was 45.8gr H4350, 2661FPS Average muzzle velocity.
840: 6.3 Mil, 1” vertical dispersion
1070: 9.35 Mil
Notes: Nosler publishes a .357 G7 BC for this bullet, which was used to calculate initial firing solutions. The published BC lined up relatively well with the field data produced, although a custom drag model would be even better. At 840 yards, the bullet consistently shot .1 mil flatter than predicted. At 1070, it required .05-.1mil additional elevation versus predicted.
100 yard seating depth test(3 shots per string)
2.272”: 2674/6.3, .452” group
2.262”: 2678/4.0, .593” group
2.242”: 2661/12.5, .487” group
This seating depth test was not exhaustive, but rather intended to determine whether or not this bullet would show major signs of seating depth sensitivity. We found the 185 RDF to be tolerant rather than volatile, and were very pleased with it’s overall performance.