Working up a load?

I had the pleasure yesterday of taking my ersatz M41B Swedish Mauser to the range and using an electronic target at 100m to work up a load. I fired 10 batches of 5 rounds, going up to the max. recommended load. I was mighty impressed to see the change in group size when as little as 3/4 grain is added to the load.
So, my question is this: From forummers' experience, when working up a load for my No 4 (T) where should my loads start and finish, and in what size increments should I go up?
I use 174g FMJBT bullets and Vihtavuori N140 powder, and the reloading tables Rifle reloading - Vihtavuori indicate a starting load of 38.4 grain and a maximum load of 41.7 grains.
Is a batch of 5 rounds per load-increment meaningful, or do I go back to my best 2 or 3 loads and try larger batches?
Thanks
Rob

Personally, I like to shoot 5 shot strings in four to five relays. From that, I look at the consistency (from the chronograph) and overall precision. That way, I can figure if a load is going to be a dud or not. So my worked up handload batches are about 20-25, before I increase (or decrease) powder.

In your case, I think .5 grain increments would tell you plenty. That's how I load mine, so it's a matter of personal preference (for my smaller reloads, 223 rem, I increase in .2 grain increments).

My only suggestion is to seat the bullets as far out as possible. I use a load similar to yours, with the exception of iMR4064 in lieu of N140. I seat my bullets to around 3.075-3.080, just a few thousands off from hitting the front of the magazine. I get some pretty decent groups out of my T's.

Best of luck!

With the same components I worked up a nice load. 39,5 grains of powder and 78,0 mm OAL. No real differences up to 40 grs., nust a tad less regular, I noted. I switched to Lovex S060-2 since then and am happy with 38,0 and same OAL.

I have a load that seems to work well in any enfield it’s used in. From a Lithgow HT to a No4T and a very nice NZ savage no4, try 41.0 grains of RE-15.

As long as your using a 174 grain Sierra or Hornady it just works. I have had some excellent results in all of the above rifles, just can’t seem to get any results close from 4064/2208.

I found that N140 tops out at below 2400 fps using the Vihtavuori data. The load I settled on is 40grn N140 under either a 174 or 180grn Spitzer, and that gives 2370 fps (ish).

I have not had much to do with developing loads with a .303 (Thought I need to), BUT with reference to an old Lyman book I have on reloading one of the things that a few of their writers had to say about reloading was "It is more about the consistency of your shells, the seating, and mostly the environment which you reload in as well as how you reload than the amounts of powder you use".

They went no to say that they grouped their shells into their weights, and made sure their reloading area was spotless, and that they used the same amount of force in each primer and each re-size and seating. You can spend a lot of time worrying about how much powder you use but if you are not paying the same amount of attention to the cleanliness of your station and hands or exactly how and when you reload then the purpose can be lost.

That being said I know how much difference a tiny increase or decrease in powder can make, but at the same time I have seen primers make even bigger differences, and I don't even have any authority with .303 loading or shooting, but I reckon competitive shooters like the guys they had write for them might know a thing or two. Best of luck.

Some grouped as you say by weight others by rim thickness so the close up was the same on each cartridge there are plenty of theories out there about wringing the best out of the Lee's including black magic stuff thing I find with some "F" class shooters is "Their Secret Load Stuff" give me a break guys your not part of the fraternity keeping secrets and only fearful of being beaten!

"...batch of 5 rounds per load-increment meaningful..." Yep. You always start with the minimum load and go up. Half a grain per load up is good. However, you should slug the barrel first. Sierra use .311" for their 174 grain Matchking. Hornady uses .312" and they don't make a match bullet for .303. Your barrel may or may not be even close to .311".
Keep the loads separate(charger clips are good for that if you have 'em). Shoot for group only slowly and deliberately with barrel cooling time between strings. Sighting in comes after you've found the load. And change targets for each load.
It's critical to be shooting off a solid bench rest too.