Well we shot 600 yesterday afternoon and as expected the weather was crap. The aggregate was not great but the groups were very good for vertical and held waterline. I increased the load with the 205s by 0.3 grains to bring the velocity up to the LRP POI and shot the four targets with that. If i had to make a judgement i would say that the 308 SRP brass holds a tighter vertical with this barrel in this gun which would mean on a more compliant set of conditions it would in my mind shoot a tighter aggregate.
As for the 260 that i have been playing with in my Defiance action. Tested the 130 and 140 RDFs in both SRP and LRP Lapua cases with H4350, H1000 and Re23. With the H4350 the results were acceptable but the LRPs were holding tighter groups when the charges were around or over 42 grains. With H1000 the SRPs are a no go area at any level of charge in my view. The distinct click bang is around one millisecond away from shrapnel.
The Re 23 loads with the LRPs in the 260 with both the 130 and 140 RDFs is nothing short of extraordinary. I borrowed a Magnetospeed out of curiosity to get the final settled load velocity with the 130s from the 27 inch barrel at just shy of 3100 fps and the 140s were a little over 2900 fps. At no time were cases stressed. Accuracy was sub inch at 300 yards with both bullets where if i had to pick one, i would go with the 130s. They seemed a better balance with this case and Re23.
Unfortunately not so with the SRP cases. Re23 with the SRP cases is not as scary as H1000 but accuracy was at times atrocious with patterns rather than groups.
To try and get some sort of sense of what was going on, i went to a faster powder in 2208 and the 130s. At 37 grains both the LRP and SRP cases shot OK and were about at max load with similar grouping at something around 2800 fps. I have no doubt that with a bit of work i could get 2208 and the 130s in the SRP cases to shoot very well. But at nearly 300 fps slower speed why would anyone bother?
So unlike the 308 and the quicker 2208, the 260 with slower powders to try and get the really usable velocities needs something like the 210Ms to get things working properly in my view. I didn't attempt to drill the flasholes like i have heard and read of others doing, nor did i use the Synoxid RWS SRPs to try and get the slower powders to work. Not realistic either way and really defeats the theory of why SRPs and 62 thou flash holes are used.
I remain, once again, highly suspicious of claims of SRPs in medium sized cases and slow powders being the better option. Maybe with H4350 in another barrel. Maybe and possibly with newer lots being a fair bit quicker than the 1997 lot i used. But to me this is a variable i would illiminate before i fired a shot. Barrels have a very short window of accuracy for competition to try something that is fashionable over functional.
As a caveat for accuracy. At a 100 yards some of the initial test groups (three shot) with the SRPs and Re23 looked acceptable. But at 300 yards and multiple five shot groups the inconsistencies showed up on paper. Don't be fooled into thinking you have hit gold until you take the load out to atleast 300 yards. 500 is better still.
By acceptable i mean 1 MOA or 3 inches at 300 yards is simply not acceptable yet many of the SRP loads could better that and some did do way better than that.
This is where people are getting duped i feel. The accuracy testing is testing relevant to what? It may seem good when compared to nothing else at that time, but when things are head to head, same barrel same moment, then it becomes very clear as to what works or doesn't. The SRPs in this barrel on that day in good conditions on a mates paddock at 300 yards got its bum smacked by the LRPs. That is all i need to see. Not interested in theory, SDs or ESs. They never won a match, as Jacko often tells people.
To elaborate on this further so you know where this is coming from. You can place any clock in front of that muzzle. And i mean anything from $200 to $20,000 value. The SDs and ESs can be 0 (zero). The group will still be fucked. The reason? It is never about the numbers a bullet is doing, it is always about when the bullet leaves the barrel. The time delay between ignition and the bullets exit needs to be perfect. Its speed may vary but if it leaves at the same time, the group is accurate. If the velocity is perfect for each shot, but the exit varies, the group sucks. So it gets back to the base concept that without perfect pressure time curve, accuracy will elude you. Until some get their head around that it is about when the bullets leave as opposed to how fast, they may well continue to destroy barrel by chronograph.
This is where i believe the theory with SRPs in larger cases is flawed. I do not disbelieve the claims of smaller SDs etc, but given we know a barrel has a movement cycle during firing, i feel we need to see the time delay between firing pin strike and bullet exit. Not the exit speed. That is the easy way out and how often do we hear the stories about how it lies. I don't want to see data from it being done on a PPC or 6BR. I want to see it from a 260 Rem with H1000 and a 140 grain bullet. Real world, not selected world.
At some point i will try Re26 but feel it may be futile. Re26 would no doubt get higher velocity with both bullets but the case will most likely run out of volume long before it finds pressure. This will be with the LRP cases only. Winchester cases have a considerable capacity gain over Lapua so i may try them.
As a final note, everyone that knows me knows very well that as a competition caliber, i really really fucken detest any 6.5 cartridge. Some of the worst ever scores and groups seen on our range have been at the hands of a 6.5. Other than Pete Smiths Rogue and Old Trevs recent good results with the, hack spit, 6.5x47, i would have never tried a 260 for this test. I found it so good i will shoot it as a LG next season. Then we will see if that was a mistake
