Like I said earlier the bigger the number the slower the burn . Good job . LarryI have shot RL22 since it's been out ..a long time...I also have shot a lot of RL25 when ever I switched from 22 to 25 they are close in burn rate with 25 being slightly slower..I have shot a lot of RL17 and recently last year or so I have been threw 2lbs of 23 and 26 now on my 3rd lbs of 26.. I am not a expert but if you are a loader you will understand what I am telling you. If you do not understand load density you are not a loader.. RL26 works by being able to load to a higher load density. just take the 6XC case for a example...25 you might get 39.0 grs in the case and it may shoot well but the velocity will be low low,low...26 you can get 42.0grs in before going to a drop tube and getting 45.0 grs in..
the slow burn rate with the dense load density allows a longer burn down the barrel before you make peek pressure
so it produces high velocity and dense load...more powder allows you to make the max pressure...that's how I see it and that's how it has worked for me...Now 26 is slower than 25...how much slower. some but I really don't know..
You could have a slow lot of 25 powder and a fast lot of 26 I guess...I think the RL powders are decent lot to lot.
but I know for sure I have seen and talked to others who have seen quite a bit of difference in burn speeds lot to lot and even humidity and moisture content of the powder can change the burn speed some...I could get in trouble for this but I once was talking to a powder co about a specific lot of powder compared to another lot of the same powder, I told them I wish all of it was like the first lot...the reply I got was. well that powder was out of spec or at the fastest side of spec we have for it and was almost another powder but we jugged it and shipped it...but it turned out to be another powder and it has had many lots and some of them have quite a bit of difference in burn speed..
I know a few guys who seem to have better luck with RL33 in the 257 WM..Certainly. There is always a price to pay for speed. The additional pressure has proven to be manageable, but, nevertheless, pressure increases. I am building a 250 Ackley and will be using RL 17. If I need more speed, i'll use my 257 Weatherby with RL 25.
Tod,
The info, I quoted are from the Quick Load program,
there are several other factors for each powder,
that come into play,
like Heat of explosion, specific heat ratios, case capacity,
bullet weights and bbl lengths etc.
I have made up a list of all the powders,
and use it to find the best powders for my SP pistols/loading,
along with all the rifles/pistols I use.
If you have the QL program, the info is there,
IMHO, the cost is well worth the $$$.
Tia,
Don
RL-17, 33, and 50, are also made in Switzerland by Nitrochemie.First thing I noticed on my jug of R26 is that it was made in Sweden. Unlike any other Reloader product I have or at least noticed anyway.
If you'll read the articles referencing the Nitrochemie RL series of powders, you will understand why the increases in velocities are possible.25-vs-26
Regarding the 6mm-06=====
Previous load was 59g of 25 and a 80gTTSX. 10rds of this load clocked 3640fps.
Powder level was just below the bullet base when seated.
I loaded 59g of 26---all the rest was same. Powder level was lower than w/ 25.
Fired 3 rds over the chrono, as follows: 1st rnd-3802fps. the other 2 were 3780 and 3787.
Brass was moved on each case head and the primers were notable flattened, but none leaked.
I guess I would put 26 in the faster than 25, category, at least in this instance.
Would like to see similar comparison referencing the 243AI case.
26 has a slower burn rate. LarryI think there is some confusion on this thread regarding the term "fast" powder. Sometimes a slower powder than another powder gives a higher velocity - but this does not make the powder "faster" than the other - it is still a slower powder.
Per QL V 3.6
RL-26
Heat of Explosion/Potential: 3905 kJ/kg (higher than H1000 @ 3630)
Ratio of Specific Heats: 1.2303
Ba: 0.3397