Just to ressurect this thread a little. I need some help and/or advice.
I measured some old factory ammo I have lying around and also pushed some bullets I have (165 Interbond, 165g Scirocco's, and 168g SMK's) into a FL resized piece of winchester brass loaded into my MCR Howa 308. After ejecting the chamberd test piece I measured with my calipers using a stony point bullet comparator (measured at ogive) and also for OAL just using the calipers. Here's what I got:
Round, Comparator Meas. Inches, OAL inches, Note.
Fed Prem. SGK 165gr, 2.125, 2.686, Factory Round.
Win SuperX 150gr, 2.178, 2.708, Factory Round.
Fed Fusion 165, 2.16, 2.718, Factory Round.
Hornady IB 165, 2.253, no meas, As Loaded into Lands.
Swift Scirocco 165gr, 2.221, 2.866, As Loaded into Lands.
SMK 168gr, 2.267, 2.873, As Loaded into Lands.
the average of the factory round measured at ogive on comparator was 2.154
Average for factory OAL was 2.704 (most of these are sp hunting rounds)
I have a couple rounds loaded up for my old Tikka with OAL of 2.802 which was almost max for the tikka Mag...measured at the ogive these are 2.182
For the IB's in the HOWA I slotted the empty case to seat the bullets by chambering the round and measured OAL and with the comparator. The average on hte comparator was 2.247"
The average for these OAL was 2.870
Average differences between factory and hand chambered to lands was .093" delta measured on the ogive and .166" delta for OAL on average...
Question is to what length do I seat these bullets for the OCW test for which I'm reloading, starting with the Interbonds...? It looks as if the factory loads are 0.1" off the lands...
The Howa is an internal drop floor mag so I should have a bunch more room than the Tikka (max was a hair over 2.8" OAL). Where do I start seating? .04" thou off the lands .02" thou, or .01" off or .09" off the lands like the factory loads?
Help or discussions greatly appreciated...
Originally Posted by BountyHunter
First off, IF it is a magazine gun you are limited to max COAL that will fit in the mag.
So no point in even figuring where the lands are!!
Start at that point and work back to see where the gun likes them.
Single shots, work with a variety of techniques listed. you can also read on www.sinclairintl.com
on their forum (Reloading Press), left hand side of the home page, how and the discussion of the tools they sell and how to use them.