JARACAL

tripodmvr wrote:Het nou net 'n lang gesprek met Dale van Gunsite gehad. Ondervinding is maar die beste leermeester. Hy het ook die lae spoed met 'n 303 gevind met beide S335 en S355. Ons weet dat die 303 gewoonlik 'n redelike vryboor het en dat ou lope se deursnee kan wissel van .311 tot selfs .316. Hierdie 2 fisiese gesteldhede maak dat druk verlore gaan met die .311 koeëls wat ons gebruik.

Om daarvoor te kompenseer kan ons meer en moontlik vinniger dryfmiddel gebruik, of 'n groter deusnee koeël aanskaf. Jou loop se toestand moet moontlik ondersoek word en die eintlike deursnee bepaal word.

tripodmvr wrote:S335
Begin 33gr en node is naby 2200vps

S355 begin 37gr en node by 2260vps

Loop is nie kort volgens QL en 99,5% verbranding vind plaas.

philipluwes wrote:

tripodmvr wrote:S335
Begin 33gr en node is naby 2200vps

S355 begin 37gr en node by 2260vps

Loop is nie kort volgens QL en 99,5% verbranding vind plaas.

Ek het die S335 ook probeer die naweek en het so 2050 gekry met 36grein. Tyd het my gevang en kon nie nog opstoot nie.
Op watter gewig grein sou mens by 2200fps uitkom volgens jou berekeninge?
Daar is nog geen druk tekens nie en die patroon doen sy werk baie goed op 2050, maar sal wel die groepering wil verbeter- daarom die node jaag.

tripodmvr wrote:

philipluwes wrote:

tripodmvr wrote:S335
Begin 33gr en node is naby 2200vps

S355 begin 37gr en node by 2260vps

Loop is nie kort volgens QL en 99,5% verbranding vind plaas.

Ek het die S335 ook probeer die naweek en het so 2050 gekry met 36grein. Tyd het my gevang en kon nie nog opstoot nie.
Op watter gewig grein sou mens by 2200fps uitkom volgens jou berekeninge?
Daar is nog geen druk tekens nie en die patroon doen sy werk baie goed op 2050, maar sal wel die groepering wil verbeter- daarom die node jaag.

Lyk asof 38.6gr S335 jou naby gaan kry

shaunbaisley wrote: Thu Apr 23, 2020 10:23 pm Thank you Sir.
So I can get back to the accuracy tweaks using S355 in my Epps, once I can get back onto a range one day.
Am I understanding correctly that S341 is better suited to the lighter side of the bullet spectrum, and S355 to the heavier?
I have both in stock but want to move to 200 or 215 grain bullets, maybe Claws, to try to get them closer to the lands in my extremely long-throated P14.
Plus I like the idea of a heavier bullet at moderate velocity anyhow.
Be safe
Shaun

shaunbaisley wrote: Thu Apr 23, 2020 10:23 pm Thank you Sir.
So I can get back to the accuracy tweaks using S355 in my Epps, once I can get back onto a range one day.
Am I understanding correctly that S341 is better suited to the lighter side of the bullet spectrum, and S355 to the heavier? S341 = S355 very closely and S341 will be the better choice if S355 is not available or the case gets too full with S355
I have both in stock but want to move to 200 or 215 grain bullets, maybe Claws, to try to get them closer to the lands in my extremely long-throated P14. The 303 in your case is for hunting. You will want to load out of the magazine (essential for a follow up shot) and not battle to chamber a round. Stay away from the lands as you should be able to get less than 2MOA which is ample for bushveldt hunting. It is a fallacy that only bullets close to the lands will assure good groups.

Plus I like the idea of a heavier bullet at moderate velocity anyhow.
Be safe
Shaun

shaunbaisley wrote: Sun Apr 26, 2020 9:55 am OK, thanks.
So now it is a wait until I can get back to the range or a friendly farmer, once the lockdown lifts.
To support your statement that 341 and 355 are similar, the velocities I recorded for each propellant and a 50 grain load were 341=2715 and 355=2689, both using 174grain bullets. The 26fps difference relates to about 0,5g of propellant. The actual burning rates of the two powders in the specific rifle is what you see here
The case capacity will not be a problem in my Epps since the node I'm aiming for is at around 2700fps or 50,5 grains 355 which is almost perfectly to the base of the case neck, which is the depth to which I set my bullets.
To change tack here, is it possible, given the data that I have already provided earlier in this thread, to determine start and probable max loads using 200 and 215 grain bullets with S355 lot 10 powder? Using the "new" burning rate for Lot 10 will get you quite close with the heavier bullets, but I will rather calculate the safest and highest node than give max charge. Speed is also a better indicator and there I can provide a upper speed not to exceed.In the past I have used Sonchem's tables for the 8x57JS as a guide for 303 Epps loads.
Thanks again
Shaun