Hi guys,
Managed to test a 4451 / CCI450 / 147 ELDM / Lapua 6.5CM SRP brass combo at bisley.
I used a magnetospeed v3 on my 24" Tikka Tac A1 using an MK Machining mount, so the chrono wasn't attached to my barrel.
The wind 10 to 20 MPH from all angles, air and ammo temp was 21C, measured with a kestrel and laser thermometer respectively.
All loads grouped well despite the wind, so I focused on SD/ED and will shoot for groups another day in more favourable conditions.
The below 40.6 grain load had excellent figures, but is quite slow - however Tikka barrels can be known to be slow, however given the relatively warm ammo temperature of 21C, on a more common, cooler day I may see a lower MV, although the IMR Enduron range are meant to be relatively temperature insensitive.
Unfortunately the other shots of the below series were not recorded, however they grouped very nicely at 600 and seem to have good SD/ES.
I did however notice some marks on the Lapua brass after their first firing, I am unsure whether this is brass wipe or smear from the virgin brass on the bolt face during fireforming, from bolt unlock and cartridge extraction, or from excessive pressure.
In the picture below the 41.2 load cartridges have been arranged to place the ejector marks at the 6 o'clock position.
What are your thoughts?
brass.jpeg
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Managed to test a 4451 / CCI450 / 147 ELDM / Lapua 6.5CM SRP brass combo at bisley.
I used a magnetospeed v3 on my 24" Tikka Tac A1 using an MK Machining mount, so the chrono wasn't attached to my barrel.
The wind 10 to 20 MPH from all angles, air and ammo temp was 21C, measured with a kestrel and laser thermometer respectively.
All loads grouped well despite the wind, so I focused on SD/ED and will shoot for groups another day in more favourable conditions.
The below 40.6 grain load had excellent figures, but is quite slow - however Tikka barrels can be known to be slow, however given the relatively warm ammo temperature of 21C, on a more common, cooler day I may see a lower MV, although the IMR Enduron range are meant to be relatively temperature insensitive.
Unfortunately the other shots of the below series were not recorded, however they grouped very nicely at 600 and seem to have good SD/ES.
I did however notice some marks on the Lapua brass after their first firing, I am unsure whether this is brass wipe or smear from the virgin brass on the bolt face during fireforming, from bolt unlock and cartridge extraction, or from excessive pressure.
In the picture below the 41.2 load cartridges have been arranged to place the ejector marks at the 6 o'clock position.
What are your thoughts?
brass.jpeg
Quote Edit
Reply to this topic...
