nCognitos

I got the AT-One version with the heavy match barrel but I quickly swapped the stock as it was too small. Works really well with the Form stock instead and looks very pretty. The LRP was just too ugly for me. Anyway, you can see the size comparison below. In any version, it's a lovely accurate rifle.

Don't know if this helps but these are the results of my load testing, 5 rounds at each weight. Usual health warning, these are presented for entertainment only, you should work up your own loads, these are my loads in my gun with N140 and PPU 174gn heads in PPU brass. I was aiming for 2,470ft/s which is book speed but decided to use 41gn. Its OK at 600yds, will try at 900 at some point this weekend. 40gn will be fine at 500yds

How very odd, you should complain. Affiliated club members can use the zero range on the day of, or on the day before a club shoot. I used to do it and I know non-NRA members of the club with SCC's do it now. However, no SCC and its game over. When booking as a club member, I booked through the club and toddled off to shoot on my own. To be fair, this involves a trip to the shelter behind the range office to sign in, no actual contact with range office staff these days. Anyway, not going to enquire too closely, don't want to queer the pitch for anyone else.

I have both, just need to remember that 1 Mil is about 3.5MOA, (actually 3.38 MOA but who is going to be that precise!) and that 3 clicks is about a Mil, works well enough for government work as they say. After 30 years I'm just going back to using plotting sheets I'm going to set up my turrets on the zero range tomorrow to read 0/0 at 300yds and then plot from there. It really is much simpler on TR vernier sights, which give an absolute reference but I will make it work somehow.

Here you go, I hope it's what your are after. https://serc.org.uk/assets/files/How-to-do-Full-Bore-Plotting-by-Nic-Boyde.pdf

You're not wrong but it is a bit more nuanced than that. Before I re-joined the NRA, I used to book range time at Bisley through my club and shoot on my own, but I did have an SCC. If I didn't have an SCC then I would need to have been under Club RCO supervision. NSRA isn't like the NRA, it's an afternoon so it's not so much of a ball-ache. No military range stuff.

Just had this same issue come up at Sywell, where there is an expectation that an RCO is present, fortunately the NSRA RCO course is a one day affair and it looks like all the members who shoot solo at Sywell will need to do it. At the same time it was also said that if anyone was using a magazine with their rifle, they would need to be RCO qualified or supervised but this got stomped on pretty quickly. This is Bisley, where the nice gentleman in the red shirt marked Range Safety, drives around the site all session in his white pick-up truck. It's also pretty rare that you would be the only shooter on a range, though it has happened, I've had the whole of Century to myself on a rare occasion. I think its more of an issue somewhere like Sywell, where you could be completely alone on site. I think the logic would be someone who has got the RCO badge would be less likely to do something dumb. I have mixed feelings, while I am competent to shoot on my own, I prefer there to be someone else on site. Also, I believe my NRA insurance would cover me, even at a NSRA range however there are the range regulations to consider.

The rumour at Bisley last week was that all handloaders would have to have an SCC endorsement. They would need to have done an accredited course with the accreditation body being the NRA itself. This is all due to a person whom, it is rumoured, mixed up rifle and pistol powders in a load. For those clubs that have been running reloading courses these will be assessed and, if satisfactory, a path may be put in place to get the qualification. Of course this was rumour and should all be filed under the category of gossip. The rumoured implementation date would be the end of this year. Personally, I hope it is just all rumour and gossip but if true it would be better than the alternative of factory ammo only.

Well, I could but the SE is 2.803 which if you work it out tells you very little more than the SD, so going for a 95% confidence level, thats 2,716±5.6 fps. Thanks for that, I'm using N150, I'm going to test down the other way with smaller charges tomorrow, and see if I can get that flat spot or obvious best point. Then I can focus on seating depth. I've done load testing before but I've never had a situation where the SD's and ES were so similar across a grain variation in powder, with very similar group sizes, it struck me as odd but perhaps my friend is right, the barrel just doesn't care. I'm going to shoot max 1,200yds so I have some leeway to bring the charge down and still have the speed. My daughter was shooting at 1,000yds on Sunday and getting excellent results with slightly lighter loads that I put together for her to plink with, so I'd like to explore that space a little more.

So, there seems to be a real absence of understanding of the way statistics work. There is no minimum number of samples for a meaningful results, what counts is confidence level generated by the margin of error, you keep taking data until you achieve the confidence level that you desire, and you can do this with 4, 5 or 6 samples, as long as they are representative. More samples will increase your confidence but it's not linear and quickly becomes the subject of diminishing returns. So for my data, taken at 37.2gn and running it through a stats calculator I have an average of 2,682ft/s. From that I get a confidence of 68% that the results for the population will be 2,682 ± 2.49, and a 99% confidence that the results will be 2,682 ± 6.41. I'm afraid that that is just the way maths works. Anyway, I got an answer to my question elsewhere so I will leave it at that.

I really am not interested in a discussion on methodology, but if anyone has an opinion on the original question, I would be grateful. I must say it's much more difficult with this rifle and calibre, everything else I have gives a clear answer straight away.

Dirty Barrel, I do 5 fouling shots with factory ammo before I start. I disagree with you, the MV variation across one grain of load are equivalent to about 0.6MOA, which is the difference between a V and a 5. To be honest, I'm not asking to be trolled about my methodology, simply asking for help in its interpretation as the results are so different to what I expect, as demonstrated by the .303 results.

5 rounds 20 step ladder prepared of 100 rounds, started in the middle with a view to work up or work down depending on MV and pressure signs, all looked good so worked up and stopped at 38.4, I had loads up to 39 but I thought I could see very feint pressure signs around the primer so I stopped at 38.4 Once I have it narrowed down, I will load up 10 at each increment for MV and grouping but I don't really want more than 5 increments for this. I really am a bit bemused by this, my mate who was with me said load what you like, the gun doesn't care! I did some .303 at the same time and got the results below, which are much more what I expected, the answer is obvious, go with 41gn. Charge Weight Average High Low ES SD 40.4 2370 2383 2349 34 16 40.6 2382 2421 2354 67 25 40.8 2414 2434 2400 34 12 41 2424 2437 2416 21 8 41.2 2435 2462 2418 44 17 41.4 2445 2467 2428 39 17 41.6 2459 2470 2444 26 11 41.8 2472 2486 2457 29 14

Thanks, my other problem is there was no appreciable change in group size across the entire range but that was on an Electronic target at 300yds. Will go again with 37.4 to 38 on paper and see what that tells me.

I did some load testing with my 6.5CM using N150 and Lapua 139 Scenars. From the data below, should I go with: (i) the velocity node at 37.8? (ii) the ES/SD node at 37.4? (iii) stop overthinking it, the SD's are so close it makes no difference, just load for the MV I want? GRT gives nodes at 37gn and 38gn and tells me the max load (38.4gn) is 6% below max pressure. 38gn would be 9% below PMax and 37.4 would be 15% below PMax. Charge Weight Average High Low ES SD 37.2 2682 2690 2675 15 6 37.4 2690 2694 2684 11 5 37.6 2712 2719 2705 14 6 37.8 2716 2726 2711 15 6 38 2725 2732 2718 13 5 38.2 2739 2750 2732 17 7 38.4 2751 2760 2744 16 6