6mm BR & Reloder 17

[Steve Blair]

I recently finished load development using RL17 in the 6BR. Contrary to several posts on this forum, my results were excellent.

The rifle is a Savage 12F 6mm BR, factory stock, unaltered. Optic is a Nightforce BR 12-42 using Ken Farrell's excellent rings and base. The RL17 load was as follows:

Lapua brass, NT .267 with seated bullet. 39 gn water capacity.
Wolf KVB-5.56M primers
32.5 gn RL17
Sierra 107 MK,bare) seated 2.385 OAL for .01 ITL.
2908.7 fps average, 7.9 ES, 4.1 SD.

All chrono using Kurzzeit PVM-21 15 ft from muzzle.

This load is shooting ~.3 MOA at 300 yards on my home range, South Bay Rod & Gun Club east of San Diego.

QuickLOAD says that is 96.8% capacity and predicts 2962 fps and 55829 psi. I might be able to go another .5 gn, but this load is shooting so well that I won't bother. Normal pressure signs, powder fouling is minimal and copper fouling almost nonexistent. I only went through a normal break-in with the Savage factory barrel. I was prepared to purchase a Shilen for the 12F and still will, when this one goes south.

I feel that some made an incorrect assumption regarding RL17 burn rate. They assumed it was slow because peak pressures were reduced with equivalent charges. It is more likely that the unique deterrent treatment is providing a broad,'fat' pressure curve with enhanced progressivity, producing a larger area under the curve. While I only saw ~25 fps increase over an equivalent Varget load,30 gn), the ES & SD were consistently two-thirds Varget. I attached a QuickLOAD PDF but feel that the depicted pressure curve is not accurate. Herr Broemel needs to re-characterize the powder. My opinion is that the powder is only slightly slower,if at all) than Varget and obviously denser.

Just my 2¢.

DISCLAIMER: This load was safe in MY rifle, not yours. Reduce the charge 10% and increase in 1% increments.

 

[DukeDuke]

Super detailed report, thanks! RL-17 is all I use in a 6BRX, works wonders!

 

[Forum Boss]

One reason RL17 may be working well for sleepygator is his stated 39.0 grains of H20 capacity. Quickload shows 37.8 as standard, and the capacity of my fired, FL-sized cases is 38.2.

YMMV.

Alliant says the designed burn rate is between 4350 and 4831. The powder was originally intended for the short magnums.

That's not to say it won't shoot well in the 6BR or Dasher. I'm fascinated by sleepygators results. Just shows you there are many ways to skin a cat. Some of the top Dasher shooters are moving to a faster powder,than Varget), namely H4895.

Jerry Tierney did some testing with RL17 in a Dasher, and he said it would work, but the results were not so impressive as to convince him to change from Varget or RL15.

Additionally, the two Savage 6BR barrels we've tested measure pretty fat on the inside,bore diameter) and behave a bit differently than most of the custom barrels we've tried.

 

[Steve Blair]

I read their description, too. The problem is that it does not correlate well with my testing results. I also understand that this, as most individual testing, is anecdotal and does not represent an acceptable sample population.

In the 6mm Remington RL17 gave better velocity than Varget and less than H4350. I have no recent experience with either IMR or Accurate 4350.

All loads with 80 g Berger MV, 25.5' H-S barrel

44.6 Varget - 3421 - 91.2% density
47.7 RL17 - 3490 - 90% density
49.0 H4350 - 3570 - 97.4% density

H4350 showed the least pressure signs and better consistency than the other two with 80 g Bergers. WIth 58 g Hornadys, 48.0 Varget gave 4055 at 9.90/3.95 ES/SD. I guess that is why we test.