Interesting read. Some of the mentioned loads that have "no signs of pressure" show to be well over pressure when run through GRT. To be fair though GRT isnt always 100% accurate, usually a good indication though, i have found it to line up pretty close with my own real world results when all the right data is entered.
Not sure if i have just had 2 slow PRCs, or most people arent scared of just sending it with some strong brass & are running higher pressures than they think.
Superformance is the ducks nuts as quick or quicker than 26 for less powder but you dont want to be anywhere near a top and as its very temp sensitive thoughs who aren't scard or it who use it use it well it meters flawlessly threw my thrower used in my 22" creed 2800 with 147 eldm still havent finished that load d 2 years later but showed promise
Interesting one superformance, i spent some time with it in my creedmoor & ended up with wrecked lapua brass in the long run. Ive found RL26 to be better in the creedmoor, i can get to the same speed with RL26 but without the peak pressure. GRT Shows it too, Same velocity but superformance overpressure when RL26 is just on the limit.
Superformance
RL26
The most reliable "sign of pressure" is velocity, people get hung up about looking for flattened primers, heavy bolt lift or ejector stamping etc but just because you can't see it doesn't mean it isn't there (a bit like the wind) assuming all other things are equal if loading to saami spec then velocity is a fairly accurate sign of pressure. Obviously if you are seating longer or shorter that is where tools like GRT are good as a guideline, there are other variables like case volume and hardness etc. There will always be exceptions to this however I would suggest if your getting velocity that is well above book max charges there are no free lunches it isn't a magic powder or rifle chamber that is some how immune to pressure, you will end up trashing brass or eroding your barrel quicker or both or in extreme cases a failure of some sort.
Not preaching to the O.P just my 2 cents.
This of course has been said before but it never hurts to repeat it
#DANNYCENT
I would also note anecdotally that my mate's Hardy PRC stamps case heads even with 130gr factory ammo. (I told him to try cleaning the chamber, unsure whether that resolved it)
I have always respected book max but also would run a ladder, must increments of .3 of a grain would produce say 20-30 fps increase. When you get a sharp increase in velocity you are normally at pressure.
That is why you should start low and work up, every rifle is different and pressure/velocity will not be the same.
Thats why some rifles are faster than others, just because Joe Blogs rifle does 3000 fps does not mean a different rifle will be.
Superformance works well for me in the PRC but being a double based powder I backed off a bit for that reason.
Theres no such thing as a free lunch.
As stated before every rifle is different.
Remember to tune GRT with your real world chrono numbers via the OBT tool.
Can't help but think you must be wringing the piss out of your Creedmoor, if you're getting over 2900.
I'm getting ~3000 with 147's from my 26" PRC with a mild load of AR2225. Could push closer to 3100 but I see no point.
Resident 6.5 Grendel aficionado.
As ive written in previous posts, it is wringing the piss out of it to do those speeds, not arguing that, and i dont run it that hot, it was just speeds observed doing a ladder test, however not really the point of my original post. More my question from the beginning was regardless of what the creedmoor seems to be capable of, PRCs i have dealt with seem to under perform and i was interested to see what others are achieving
It does exactly what you’d expect it to, no more or less? A bigger bro to the creedmoor. It fires the same sized projectiles at a faster speed, with more powder burnt and more recoil.
Any speed you can get out of your creedmoor, the prc will smoke it by 200fps. Weather or not 12grs+ of powder more is worth it to party I guess is up to you
My experience is 143s at 3100, 147s at 3000, and 156s at 2950 2x 24” 6.5prcs. The tikka prc was noticeably slower at the same charges than my current one by a grain
Chur
I used to have a 24” 6.5x55BJAI that I ran up to 3220 or so with 140 Amaxs without obvious pressure. Settled on 3050 from memory. Tentman has it now. Dont know what he s running in it. Have 6.5Saum dies and reamers in the cupboard never used. Having a hard job convincing myself of the need to build one given the increased complexity and my experience with the ackley. The PRC s not at all inspiring.
If you wring the piss out of a PRC to the same degree with a double based powder analogous to how Re26 works in the smaller Creedmoor case (maybe Re33???), I dare say you'll still see the same ~150-200fps increase that Hornady said you can expect. I think Hornady are making quite a modest and realistic claim there as to what's possible.
Resident 6.5 Grendel aficionado.
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