If I have an established load for a given rifle and for whatever reason need to change powders, due in actuality to the variable supply situation here in the UK, would it be safe to assume that the OAL of the round to be worked up would be set at the same as the previous known good load?

The second question is whether or not OAL and powder charge are independent of each other in accuracy terms.

This one is a little more complicated so let me give an example. If I am working up a load should I establish an OAL first and then tweak the powder charge of should I first work up a charge and then tweak the OAL?

I am thinking it makes more sense to establish the OAL first as it keeps the working volume constant for the charge work-up?

TIA,

A

I've never found rules of thumb worth anything, generally. However, for a particular rifle you MAY find that a particular bullet "likes" a certain OAL. If you have that established, then you might find powders don't matter that much -- just have to find what charge is accurate/at the desired speed (all within published data values for loads).

Mostly I stumble into good combinations for my individual rifles using published OAL's for the data set I'm trying out.

What I've done in the past is find the powder first, then tweak the OAL a bit to see if anything improves.

2 cents there

The answer I've gotten from 40 years of reloading is "MAYBE".

Since you already have your kit set up for loading a bullet at a certain depth, why not use it as a benchmark and start from there. Once you have established your most accurate powder charge, then you can tweak it around a bit.
When I'm starting from scratch, I usually begin with the COL at the longest length that will still ensure faultless function thru the magazine.

Thanks lads, as I suspected the answer was "The reloading god moves in mysterious ways"....

Shall of course try with same OAL but I hoped someone else had tried this before and could save me the components.

Best,

Amir

The overall length can have several functions:

1. Set it to work through the magazine if any.

2. Make sure the bullet is seated deep enough to be retained in the case neck.

3. Make sure the loaded round will chamber.

After all of that you can worry about accuracy.
The OAL by itself does not mean a lot on a precision basis since bullet point form can vary from one lot to the next as well as from one manufacturer to the next. I have even found a good bit of point form variation in the same box of bullets.

I usually start by seating the bullet to touch the rifling and write this down as a maximum reference. I recommend that these records be taken with one of the tools that measures off of the ogive rather just checking off the point.
I seat the bullet just enough to clear the rifling and I make sure the bullet is seated deep enough in the case neck.
Then I start shooting.