Originally Posted by eddybo
Goodgrouper I guess I missed this post, thanks for sharing this info. Have you tried any VV560 in the 300 WSM with the 168s? If so can you compare the load to the RL17 as far as load density?
How about against H4350 in general, not limited to WSM cases, as far as load density? I am playing around with long throated 308s trying to push the heavy bullets faster using slower powders. I can get about 51.5 gr of H4350 in the case, will I be able to get enough RL17 in the case to equal these pressures? QL says that it isnt possible to do this with VV560, not enough capacity, I was hoping to reach SAAMI pressures with RL 17 in a 308 case with heavy bullets, what do you think the odds of that happening are?
I haven't used enough IMR 4350 or 4007 to draw any correlations as far as burn rate and bulk of this powder.
I also wonder how this would burn in a 6-6.5x47 and 243AI Lapua shooting the 115s? Right now I am using VV560 around 41gr in the 6x47 and 46grs in the 243AI. Do you think RL17 will give me some relief from the heavy compression of my loads in these small cases?
Right now I would compare VV560 to RL22 as being the closestin burn rate and bulk? Is RL 17 faster than RL22? , Less bulky?
Thanks for any info that you are willing to share.
I have never shot any N560. I have shot lots of N550 and would never use 5 series powders again. They are super hard on barrels in my experience. Super nitroglycerin infused powders are, by nature, very hot in flame temperature and keep peak pressures at longer time curves thereby roasting stainless steel to a crisp when exposed repeatedly. Triple basing the powder with another nitropolymer or nitroguandine to reduce flame temp helps but from what I have seen, it doesn't help enough. There are ways to get around this hot temp of course as some people have not noticed the high erosion rate but that is another thread.
I have found H4350 and Imr 4350 to be close in burn rate (depending on lots and calibers they are used in) but you can get more H4350 in a case because of the shorter kernel length.
RL17 is slightly smaller in size than H4350 and so far, it seems to be a bit quicker burning even though I admit I have only tinkered with one lot of RL17. So you should be able to get more RL17 in any case than h4350 and it will also be a little quicker in relative quickness. These two things should equate to higher velocities in any case.
In the 300 WSM I tested, I could easily get 2 to 3 grains more RL17 in the case than I could with IMR4350. There might even be more room than that.
Comparing N160 to RL17, they look very similar. However, N560 must be slower burning than N160 as I could never compare N160 to RL22. In my experience, N165 is closer to Rl22 than N160. But the densities of N160 and RL17 are very similar. They are similar in size, color, and even smell.
I think I put a thread on here comparing N160 and RL17 in a 30-06. Try a search if you are interested in those results. If you can't find it, let me know and I will post the specs of the experiment.
ANd yes, RL17 is smaller in size and quicker in burn than RL22 by a fair margin. But Rl17 isn't a whole lot different in density than N560/160 so it may not be the best to reduce your load density in your 6x47 or 243AI.
In any case, I was always able to get more powder in using IMR4007ssc and it is quicker in burn than RL17 by just a bit. It made the 300WSM, the 243 wssm, and the 30-06 get top velocities and also had best (lowest) velocity deviations in comparison to RL17. And it is smaller in size than RL17. It would be a powder I would try immediately in the 6x47 and the 243AI with heavy bullets.
I have been really impressed with IMR 4007ssc and it is a single base powder (ie-no nitroglycerin) instead of double (rl17) or triple (N560). It is just the perfect shape and burn rate to make lots of medium sized cases sing with heavy bullets. And it is very clean burning.
I have used it with great success in many cases.
Rl17 on the other hand was a little bit of a let down but I admit that I haven't played with it near as much as IMR4007ssc. It showed improvement over the 4350 series powders and that is what it was designed to do so I guess it is a success. But it sure as hell ain't going to give you 200 fps more velo like some of the early testers of it proclaimed. German Salazar (whom I deeply respect) must have been having chronograph problems down in Phoenix when he was testing it!
That being said, it could have just been cartridge shapes and designs giving vastly different readings. If you have done any studying on burn rates, you know that relative burn rates of powders CHANGE in different shaped and sized combustion chambers so you are bound to get varying data. Powder manufacturers actually test burn rate in controlled explosive bombs and then equate the results to cartridge combustion. That is why you see so much variation in burn rate charts. It just depends on the bomb configuration. Just this week, I tested IMR7828ssc in a 243 wssm and compared it to some tests I had run on the same gun a bit earlier with H4831sc. In every cartridge I've ever tried these two powders in direct comparison, IMR7828ssc has been quite a bit slower. But in this case, it reversed itself and was actually 150 fps faster with the same charge than h4831! Just goes to show, anything can happen. That is why I never put too much stock in Quickload, but that ,again, is another thread!