Re: Reloder 17
Ok, the velocity test is in. The verdict: mostly hype but still some things are possible. Why? Read on.
Before I give out the results, I wish to give some background on the test and rifle. All loads are measured out to .1 grain accuracy and dropped from a 6" drop tube. The Winchester 300 WSM cases have all been turned and fully prepped right down to the last detail. Every bullet was measured for seating depth variance by an ogive to base checker and there was not more than .001' variation allowed. All primers were seated by hand. The 168 grain Berger VLD bullets used were measured for bearing surface length before seating and segregated.
The chronograph used was an Oehler 35 on a 4' rod placed 10' from the muzzle to the first skyscreen.
Air temp was 49 degrees with 40 percent humidity (quite humid for Utah but I was only 50 feet from a river). No wind, no mirage. Elevation 5150'
Rifle was a Rem 700 CDL SF with a 24" barrel. A Tubb's Final Finish kit has been fired down the barrel previous to this test.
Powders tried in this barrel are: IMR 4007ssc, IMR4350, RL15, and RL17 all with FED 215GM primers
IMR 4350 never cracked 3000 fps with as much of it as I could get in the case and still seat bullets to fit the short magazine of a REm 700. When using this lot of IMR 4350 in other cartridges, I have found it is a tad slower than average for most IMR 4350 lots I've used.
IMR 4007 data next: All three shot groups
67.5 grains (slight ejector marks)
Accuracy was under 1 moa with every load of IMR 4007 and some went to 1/2. The deviations were unusually high for this powder as I have used this powder in several other 300 wsm's and never had deviations over 10 fps with them. For whatever reason, this gun didn't like it as well.
RL17 data next since it is the direct comparison with exact same charges of IMR4007
68.5 grains (as much as I could get to fit with 6" tube)
SD 18 (started to get a sticky bolt lift and small ejector marks on case head)
Accuracy with this powder was worst of the four and the SD's were among the worst IN THIS ONE PARTICULAR BARREL of course!
SD 6 (still appears to be mild)
I don't have to use a drop tube to get 63.5 grain of RL15 in the case and accuracy was 2nd best with this powder however it did shoot the smallest group of all at .310" at 100 yards CTC. It yields the best deviations, second best accuracy, and is the easiest to throw. I would bet the next grain of powder increase would give even better accuracy and velocities around 3150 to 3200. More testing is in order with this powder.
OK, so that is how it played out between the powders. In order of burn rate, they would be RL15, IMR 4007 ssc, RL17, and IMR4350 a distant fourth. Grain for grain, IMR 4007 SSC provides more speed than RL17 in this particular gun and this particular cartridge. I must emphasize that this is just one gun and only one gun. Results may differ.
Now I get to the point I mentioned earlier, "mostly hype but some things are still possible". By that I mean several things. One, if you look at the chart that Alliant has put out and 6mmbr.com has posted in their archives, it shows RL17 and the 300 wsm as gaining near the least speed of all the other cartridges when compared to IMR 4350. I believe it was somewhere around 50 fps or something. For the smaller more overbore cartridges, the increase was much more dramatic. So from my test, I would say that I agree. RL17 yeilded at least as much as 50 fps more than IMR 4350 when identical charge weights are used. Perhaps even more. So I have no reason to doubt (or believe) that RL17 will skyrocket a 243 wssm or a 6xc. However, the only reason I could see a serious boost in velocities over what IMR 4350 can offer is simply because I can get more RL17 in the case. SO is it a super powder? I doubt it. But is it quicker than IMR 4350? Yes! Is it faster than IMR 4007ssc? Nope.
This brings me to my second "possibility". Whenever a Tubb's kit is fired through a barrel, I have noticed about a one to two grain velocity decrease (so these above loads should not be duplicated if fiiring down an UNTUBBED bore). SInce I could not get more than 68.5 grains in the case without it effecting the seating depth, I stopped there. In a non tubbed gun, the pressure I experienced at 68.5 may be closer to 66.5 grains. So if you loaded more than 66.5 grains in that non-tubbed gun, you might see a big velocity increase. Some powders kind of "ho-hum" along until they get near max and then you see huge pressure increases. RL17 could be one of those powders, I don't know. One thing I do know, I have not given up on it yet. I will try it in a 243 wssm and a dirty ought six next week and see if they can give me the famed 200 fps increase!
If it's not far, it's boring.