Fire formed cases

[Hoodlum]

I have been loading .223 and .308 for several years for hunting purposes, but within the last 6 months I have been leaning more towards longer range accuracy instead of 150yd kill shots.... I loaded some full sized lc cases with a load of 43gr rl15 behind a 168gr A-max which seems to be the load my model 10 savage likes the best....Shot them with excellent sub moa groups at 200 yds. I then neck sized the brass, copied the previous load, and shot them again the next day.... Groups spread to right at 1moa, and poi was 1" lower than the previous day... Has anyone else encountered a pressure drop with fire formed opposed to full resized?
Hoodlum

 

[ksthomas]

Hoodlum,

Yes, sometimes you'll see differences like this, other times (other guns) not. Personally, I'd suggest sticking with the F/L sizing, and steering clear of the whole N/S notion altogether. No accuracy advantage in the vast majority of loads, and as you've seen, in many cases it may increase group size. Beyond that, it's nothing but potential trouble that will eventually pop up, usually at a time when you can least afford it. In short, nothing to be gained, lots to risk and potentially lose, so where's the advantage?

 

[Hoodlum]

The advantage for me just seems to be less wear and tear on the brass from the full sizing. Always heard neck sizing was much easier on the brass making it last for several more cycles.

 

[ksthomas]

No, it doesn't, so long as the F/L sizing is done correctly. Need to use a case gage or bump gage, and ensure that you're not setting the shoulders back by more than .001"-.002" at most (this is for bolt guns, not autoloaders!) and you'll get very good case life. Using N/S only, you'll still need to F/L size it every fourth or fifth shot (at least) to get them to chamber reliably. Done without a bump gage, you could easily do more damage from that one sizing than by constantly F/L sizing every time with dies that are properly adjusted (using a gage, that is). Don't sweat it. Get the dies adjusted properly, and case life won't be an issue.

Neck sizing finally seems to be on its way out, and that's a good thing.

 

[Hoodlum]

Understood.....Thanks.... I have a gauge for checking headspace that I made from a chunk of aluminum.... I have a Howa 1500 in .308 and a savage 10 fcp in .308.... .002" shoulder setback for the Howa won't chamber in the Savage... Savage chamber is too tight, so instead of sizing two different lengths, I made the gauge to work for the Savage...That way, they will work in either/or.... More precisely, the howa chamber is .002" longer to the shoulder, and I size them with .002" clearance on the savage, so the Howa is using brass with .004" clearance from the shoulder.... This is the minimum setback I can go without sizing separate brass for each chamber....But, that's really no more of a problem than keeping separate batches of fire formed for each chamber..... I haven't f/l sized different lengths, and probably won't since the Howa seems to shoot very well with the .004" clearance cases....
Hoodlum