I use superformance. All load development rounds I put in my truck with climate control on 30 degrees and leave them in there for at least an hour before taking them out and firing one by one. The chrony data is not a hell of a lot different between the warmed up rounds and shooting them on a cold night/morning, around 40fps which makes bugger all difference out to 243 ranges anyhow
270 is a harmonic divisor number[1]
270 is the fourth number that is divisible by its average integer divisor[2]
270 is a practical number, by the second definition
The sum of the coprime counts for the first 29 integers is 270
270 is a sparsely totient number, the largest integer with 72 as its totient
Given 6 elements, there are 270 square permutations[3]
10! has 270 divisors
270 is the smallest positive integer that has divisors ending by digits 1, 2, …, 9.
I believe the problems come with heat when your at the top end iv not used it in 243 with 90s so I don’t no if 46gns is hot just going off the pressure signs the op has already mentioned so my comments are uneducated with this particular combo few people on this forum have had it blow the primers in 08 based cases though with loads worked up hot in winter come summer time fair few frights I know that much I wasn’t the only one .
Good idea warming the cases while doing the load development I’m guessing your loads not so hot gaining some velocity without a huge pressure spike mine were over 100fps and came with primers spat out the back/pierced . That’s what you get though when your young and think everything has to go warp speed
If you are using the term “warp speed” you probably ain’t young!
My barrel was pretty warm but the time I got to the 46.5 rounds, does that count?
Yes temperature stability and being close to the line is on my radar, it's one of the reasons why I wanted to keep pushing up the charge weights to see where it was, otherwise I might be next to the line and not even know it.
The last thing I want is a locked up rifle
Here lies the issue though max now will not be max summer so 46.5 might be ok in winter and 44 might blow primers in summer again not real world figures just watch it Ryan’s load work up using warm cases is a brilliant idea you’ll need not worry using that method most rifles can hack a couple of primer blow backs
On a side note I’m keen to see how you find those 90grainers when the start hitting flesh keep us posted mate
So I used @ryansonghurst trick today, had the ammo on the floor by the A/C vent and had them nice and toasty by the time I got the range. Plus it was actually a pretty warm winter day here in the Manawatu.
I've dropped back to 45 grains of Superformance and shot this group first up. 1st shot is low and then 3 more into one hole at 100 yards. I'd say I'm done now even though speed is a bit on the low side, just shy of 3000 fps.
Then I had some 95 grain nosler ballistic tips with IMR 4064. These did something similar, I shot this group before setting up the chroni.
I was pretty excited after that so I tried the next charge of IMR 4064 and I chronied these and they were up at 3100, 3108 and 3108. Es of 8! Unreal, sorted.
I didn't think IMR 4064 would be this good in the 243 but there you go.
Hopefully get these onto some animals in the near future
Also I forgot to ad I reduced my cartridge overall length by 30 thou with the ELD-X so they're now jumping 60 thou.
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