Popsbengo

Settings>units ?

Can we have some pictures of it please?

It's meant to be like that, normal for a turning tool. May I ask why you feel the need for turned necks ? Do you use variable brass as I've always found Lapua to be nominal across a batch

plus one for cheese board, my one is marble

I'd say the most important thing is a good reloading manual and/or attend a course. The Lyman manual is excellent.

EGR & Carb Cleaner - it works to decoke engines and muzzle brakes

CLR is lactic acid plus another ingredient. That's correct, Zep is phosphoric acid - same as in rust converter. I've used Holts de-coke spray, it attacks the carbon so you can just wipe it off

you may wish to review this MSDS https://clrbrands.com/CLR/media/PDF/proline/sds/CLR-PRO-Calcium,-Lime-Rust-Remover-SDS-2-12-21.pdf It's basically lactic acid

Never used OBT, I don't think it's helpful. The only way to get statistically relevant data is to shoot a sufficient sample. A small sample may indicate a poor performing load but the converse is not true ie a small good group is not indicative - or more precisely, not sufficient to draw a conclusion from. The sixth shot of a five shot group may well open up that otherwise tight group... I have read that for each load increment a 5 shot group, repeated 5 times on separate targets, and then overlaid will give the best indication of optimised loads. ( 5 targets so as to avoid rounds going unmarked through a ragged hole). Or: shoot some five shot groups and take the best ! It's unlikely to be the optimum load but it may well be good enough !

Assuming you shot your groups at a standard Bisley TR 200yd target the 5 ring is 3.5" and the 'V' 2.1" (According to Bisley Handbook 2020). The 5 ring is 3.37 moa and the V is 2.02 moa diameters. From what you say it would seem any variance in dispersion made through load development increments may be hidden in the general dispersion due to other factors. Load development within a maximum of 1 moa dispersion for five shot groups should begin to reveal variations due to load matching to the barrel.

agreed but I'd add at the distances you want to achieve. 250 Scenars are great at 1500yds and useless at 1 mile out of my 1:9 32" barrel. ES won't tell you that.

We've had this debate before and it would seem that the law is as above post however our local FEO (Staffs & W.Midlands) says that primed cases are to be considered as ammo. As I don't think it's worth falling out with our FEOs I abide by their "rule". Maybe someone else wants to test the law in court - good luck.

Your MV is low for the charge weight and the sooting is indicative of a failure to effectively obturate. This suggests to me that you're starting pressure is too low and failing to get a complete burn. Poor obturation means high pressure gas is coming back down the chamber and that's not something you want to ignore. N160 seems a tad slow for a 139. I’ve run your load through Quickload and 44 gr N160 is right on the limit at 2726fps. Your 41.5gr load is calculated as OK with 2589fps. I’ve used standard SAAMI data for dimensions and a 24” barrel N555 45gr is close to max pressure but gives 2698 fps N150 is too fast according to QL

That explains why the bolt look very similar to my Swing

try 300gr Lapua Scenar