Load development with iron sights

[Dead eye Joe]

I am going to start loading for my SMLE.
I plan to shoot no more than 150 yards since it only has the stock military sights.

How would you go about load development with Iron sights?
Shoot at 50 yards?
Group sizes do you expect etc.

 

[bigedp51]

If the wood is dry on your fore stock and you have wood shrinkage I would start first by checking your bedding. The center band screw should only be tightened until spring compression is felt, if over tightened it can pull the barrel down in the center causing the rifle to shoot high.

 

[Rory McCanuck]

I do mine at 50 yards with irons using a 4" square as a bull's eye. The 4" square is big enough that I can see it well at that range, and it doesn't get obscured by the front sight.
As for what type of groups to expect, that depends on you, your loads, and the rifle. to save on components, just make up 3 of each step up in powder charges. If they give you 3-4" groups at 50yds, they aren't worth pursuing. A 1-2" group is worth re-visiting, with a small step above and below it to find the sweet spot. Even a 2" group at 50 translates to 6" at 150, that'll drop a bunch of deer.

 

[H4831]

Dead eye, save your self some frustration. Forget about tweaking your reloads to find the sweet spot, or the silly phrase, what your rifle likes. Get 174 grain bullets which were designed for the 303, load them up to full, reccommended loads and shoot away.
The 303 Lee Enfield was designed to shoot no better than 3 inches at 100 yards. In other words, any rifle that shot 3 inch groups in testing was good to go.
I'll gamble that you can't prove, with your iron sighteed 303, that changing the seating depth, or one or two grains difference in powder, is making any change to how your rifle is shooting.