130 gr Nosler Bal tip Win 270 QL Check

[Darrylth]

Could somebody that has QL, please check and correlate my data, to me it seems too far from what the somchem book says for max load ;
(54.0 gr)

Barrel Length 600mm
Case H20 Vol 70.52
S365 lot 76
54.6 gr
TPL 84mm max TPL 86mm
Nosler P/N 27130

QL Calibration was with
52.4 gr 2783fps Ave speed TPL 81.00.

I would just like some confirmation if my QL is correct, before I blow my self up.

[Piet Pille]

Hallo Darrel,

Met S365 kan jy jou te te veel steur aan die max load nie, aangesien die brandspoed baie verskil van batchno na batchno. Met Lot 72 laai ek bv 57.4gr S365 @3150fps met Sierra PH's ook vir 'n TPL van 84mm. MOET ASB NIE HIERDIE LOAD DUPLISEER NIE! Ek wys maar net daardeur dat S365 LOT 72 baie stadiger is as wat deur somchemboek voorgestel word. Ek verbeel my lot 76 is ook stadig. As jy met 52.4 slegs 2783fps kry is jy beslis nog ver van max druk af. 54.6gr behoort defnitief nie druk te gee nie. Hou jou spoed dop- dis 'n beter aanduiding van druk as somchem se voorgestelde ladings. Tot by 3000fps behoort daar nog geen druk te wees in 'n 270Win met Nosler BT's 130gr nie. Soos ek sê- ek kry tot 3150fps op die boonste node net onder max druk. Wat is jou nodespoed wat jy probeer haal met 54.6gr?

[Darrylth]

Pieter, spoed is so om en by 2800 fps. Ek jaag nie eindtlik spoed maar beter dopvullling. Op 57.4 met QL behoort ek aan 2950 te raak maar dit is nog steeds onder max druk

[tripodmvr]

Herewith 2 images showing my calcs. Lot 76 is milder than the norm and I have used your calibration COL of 81mm to calculate Node 6. This was done to not involve the change in 2 parameters as QL reduces pressure with a longer COL. Your change to COL of 84mm is a good one, as you can now decrease it to search for the sweet spot. You will however have to match the speed calculated for Node 6 and then only start playing with COL change.

Load up 3/5 rounds with 53.7gr propellant and COL of 84mm. Shoot for group over chrony and then recalibrate if speed is not true. Report back if you feel that you need more assistance.

Darrylth 270 S365 Nosler 130BT Calibration.JPG

Darrylth 270 S365 Nosler 130BT Node 6.JPG

[Darrylth]

Excellent. Thank you. I will try this and report back.