I'm working on my first reloads having finally received powder and bullets enough to get started. I'm working on a couple of ladders to look for pressure signs and find out what's safe in my rifle. After that, I'll load smaller variations around whatever looks promising and test for accuracy.
At present I don't have a gauge to seat bullets by the ogive / position in the throat - I know that's a better way than OAL but I can't afford the tool right now. Therefore I'm using minimum OAL figures in the data to determine seating depth.
For .308 Win I've got data that shows a 110gr Barnes TSX Flat Base bullet with a minimum OAL of 2.690".
I actually want to load a 110gr Hornady SP which is also flat-based, but shorter than the Barnes bullet.
The Barnes bullet is 0.955" in length. The Hornady bullets are 0.820" in length (average).
Is it therefore reasonable to calculate the minimum OAL for this load by finding the difference in length and subtracting it from the Barnes minimum OAL, which should put the base of the bullet in the same place for the Hornady SP load?
(0.955" - 0.820") = 0.135"
2.690" - 0.135" = 2.555" = minimum OAL for Hornady 110gr SP?
In case any of this is relevant:
- in the absence of an accurate chamber / throat measurement for my rifle, I'm using the minimum OAL from the data plus 0.025" to err on the side of lower pressure. In this case, I plan to load to an OAL of 2.580".
- I'm going to load H335 in 0.5gr increments from 47.5-52.5gr and stop firing when I see pressure signs. The data for the Barnes 110gr bullet is on page 363 of the Lee manual.
Second question is related to the above - does anyone think there's anything stupid about loading to just above the minimum OAL when I don't have the information I need to load using distance from the ogive to the lands? Is the listed minimum + 0.025" a reasonable figure to use?
Thanks in advance for any insights anyone can give - this is a new rifle and I'm new to reloading, so I'm trying to play it safe.