Ek dink die groef is 1:9
Dankie Gawie, ja ek het vanaf 42gn begin laai en in 0.5g inkrimente verhoog tot 44gn. Ek dink ek sal 44.5gn en 45gn laai en kyk na spoed.Gawie(13mm) wrote:Wynis, as ek jou data in QL kalibreer dan wil dit voorkom asof Norma URP of 204, jou nader aan 2630 vps gaan bring.
Met die IMR 4350 moet jy die dop tot 107 % volmaak om naby te kom.
Hoogste veilige node met IMR 4350 is met 45.1 grein @ 2 538 vps. Dopvulling is dan 102.7%
Thanks Dale. If I up the bullet weight to say 170 or 175gn (because I already have the IMR 4350) are there better combinations at these bullet weights?Dale SH wrote:As Gawie correctly states.
Norma URP or Viht N550 are your two first prize options with this combo
It was a measurement after a long day at work.Dale SH wrote:Your H20 volume is now much more reasonable.
I have not measured but I suspect, I can definitely lengthen the COAL. The current COAL is close to that of store bought PMP Pro-Amm.Dale SH wrote:Just as a matter of interest, what is your jump to lands at your current TPL.
76.12mm rather short for the long taper of the SST bullet.
OK thanks Dale l, I will do! I am still new to reloading and I will ask a friend to help with measuring jump.Dale SH wrote:OK.
Please measure accurately what your jump is.
I suspect that you are well off the rifling at your current TPL.
By increasing your TPL to about 1.00mm off the rifling you could free up some case volume and generate higher MV at the same or lower pressure.
It has done duty as a bush hunting rifle to date. I am keen to get more out of the rifle in terms of speed with good accuracy, but I believe the caliber is best suited to the bush.Dale SH wrote:What is your application for this rifle ?
Plains, bush or target ?
Thanks for the advice. I believe my rifle was made in 1964 and has a strong action. BSA Royal.Dale SH wrote:I hear you but don't fall into the trap of believing that the 7x57 is a bush rifle.
If you want to load 170-5 grain bullets then yes it becomes a good bush rifle.
I have a 9.3X62 which I use for bush hunting so I have made my 7x57 (Brno ZKK 600 with 600mm barrel) into an all rounder)
Also remember that the ballistics you see from the ammo manufacturers are very mild as they have to load their ammo remembering that their are still some 120 year old rifles with weak actions out there.
Get some 150 grain bullets with a relatively high BC such as accubonds/ballistic tips or 154 grain Interbonds and Some Norma Urp or Viht N550 and you could potentially achieve 2750fps or higher at about 51000 to 53000 psi, which is above Saami spec (OLD SPEC) but in my opinion quite safe for a modern action with good quality metallurgy.
Now you have a really capable mid to longer range set up.
Dankie vir die inligting!tripodmvr wrote:Nosler 140BT. Ek het S365 gebruik. Jy kan daarmee so by 2840fps kry op 'n node. Druk is by 50K psi. Hy sal mooi platskiet.
Nee, dit is nie korrek nie, daar bestaan nie direk omskakeling van CUP na PSI toe nie. Dit verskil van kaliber tot kaliber.wynis wrote: Mon Aug 03, 2020 1:47 pm Now I have found something quite concerning in terms of my rifle.
On the receiver it gives a maximum pressure rating of what I believe to be 18.5 tons per square inch. The conversion of this rating to PSI takes it to 37000 PSI.
