.308 OCW Load testing results
Posted: Wed Apr 08, 2015 9:22 am
Now my rifle round count is up to 900 (.308 Howa 24" bbl) and having used various testing processes I've decided to develop a load for the 175 Sierra MK's with Viht N150 and got the following results using the OCW method (files attached):
Now using the criteria, it's not the best group per se but the most consistent POI that is the sweet spot. Then changing the seating depth for grouping. So a couple of questions for those of far more experience than I:
Where are the nodes in this example? My reading is between 41.5 and 41.8 then 43 - 43.3?
Supposedly the SMK's are very tolerant of jump - will the seating depth really change the grouping that much. How much should I look to change it by?
As side note, having reloaded at least 700 rounds and having gone through most of the "go to" bullets I've learnt the following:
The advice I got on developing a load for 155's a few years ago on FB was very helpful (thank you Tim ENS).
The Howa .308 24" Varmint bbl is a 1:10 twist and not 1:12 as I'd thought. In fact I only discovered this a few weeks ago, bored one morning with the cleaning rod.
Sierra 155's both the 2155 and 2156 shoot well. In fact a reasonably "middelish" load of N140 (43.7 gr) worked out to a 1000 yards. I've no doubt that it was subsonic at that range but it was Ok accuracy wise (ie once dialled in it constantly hit the v-bull/bull on Stickledown). I'm sure not competitive in any sense but very satisfying to be able to shoot at that distance with something you've loaded.
Lapua Scenar's - never really got them to group below 1 moa. More work required.
Cheers
Now using the criteria, it's not the best group per se but the most consistent POI that is the sweet spot. Then changing the seating depth for grouping. So a couple of questions for those of far more experience than I:
Where are the nodes in this example? My reading is between 41.5 and 41.8 then 43 - 43.3?
Supposedly the SMK's are very tolerant of jump - will the seating depth really change the grouping that much. How much should I look to change it by?
As side note, having reloaded at least 700 rounds and having gone through most of the "go to" bullets I've learnt the following:
The advice I got on developing a load for 155's a few years ago on FB was very helpful (thank you Tim ENS).
The Howa .308 24" Varmint bbl is a 1:10 twist and not 1:12 as I'd thought. In fact I only discovered this a few weeks ago, bored one morning with the cleaning rod.
Sierra 155's both the 2155 and 2156 shoot well. In fact a reasonably "middelish" load of N140 (43.7 gr) worked out to a 1000 yards. I've no doubt that it was subsonic at that range but it was Ok accuracy wise (ie once dialled in it constantly hit the v-bull/bull on Stickledown). I'm sure not competitive in any sense but very satisfying to be able to shoot at that distance with something you've loaded.
Lapua Scenar's - never really got them to group below 1 moa. More work required.
Cheers