Risks of Loading Large Batches of Ammo

I've been rereading the pet loads and other similar posts while working to test loads for my Model 14 revolver, wad gun, and (when I get my Zero bullets) my service Pistol too. 

I noticed a number of loads with variations of a few 1/10ths. I get guns like what they like and the pet loads of other guns mean nothing. 

I'm guessing different lots of power, primers, bullets, and brass can have variations. If I load a bunch of ammo with consistent components, are there any risks of the gun changing what it likes? 

And I ask this question ignoring temperature impacting the load performance.

Last summer I was preparing to relocate and was expecting to face many months without easy access to my reloading gear. So I decided to reload every piece of 45ACP brass I had. Mostly using a recipe that I had proven to be a reliable short line and training load. But I had mostly shot that ammo in coastal Oregon summer weather.

Eventually I found myself in Phoenix AZ in the "winter", very low humidity and cooler than I expected. The ammo would not cycle any of my 1911's even with softer springs till the ambient rose to about 70F. I can only surmise that the very low humidity was a factor.

To add insult to injury I then discovered that one batch had several "no powder" squibs. Unfortunately I had dumped all of the neatly 100 boxed ammo into bulk ammo cans. Nightmare! Some late night reloading sessions combined with a beverage were no doubt to blame. My bad!

I have now almost burned through that big, bad stash. I shall be very wary of undertaking bulk reloading in the future. Lessons learned.

If you're coloring near the lines with your loads a cold or hot day can cause problems if not push you into the danger zone. So don't do that.

I wonder if the number of no charge sqibs equaled the number of double charges?  Don't do that either.

I have enough trouble in my life without going looking for more.

Merick,
I do admit to one or two (only) double charges from many, many thousands of reloads. Fortunately all of my recipes are on the soft side, so nothing serious has ensued, but they do get your attention!

The bottom line is that reloading does indeed involve some risk and should not be treated casually. Pay attention, or the error will definitely get your attention!

You mention a Model 14 revolver... That is easy to load for. Those guns never stop loving a 148gr HBWC seated flush over 2.8gr of Bullseye or 2.7gr of WST.

Autoloaders can be a bit more finicky. If the load is right at the lower limit for proper cycling, it's possible that a factor like a change in temperature will make it unreliable. Instead of throwing away a large batch, it might be possible to use a slightly lighter recoil spring to make the rounds reliable again.

Thanks for the responses. I'm reloading revolver for DR. 

158gr Lead RN, 3.0g of BE +/-.2gr

Wad

185 SL and 200gr LL lead SWC over 4gr N310 +/-.2gr

Service Pistol

185gr Zeros over 4.5gr BE +/-.2gr, then 4.2gr BE +/-.2gr for SL

I know the two 45 loads shoot better than me already. I'm asking about this so I can stop thinking about this and just dry fire. Keep my mind on the important stuff.

For the most part, no. Our loads and guns are fairly forgiving. Small variations in powder weight or components does not significantly affect accuracy at 50 yards. You will hear stories, but I've never seen them. Pretty much every time I've thought something happened to my gun or ammo, when I bench it, it's fine and it's me that has changed. Pistol is a lot easier to load for than rifle.

In my experience, a good gun will shoot well with just about any ammo made with quality components, with the caveat that it must be able to run the gun. From the testing I have done on my gun, 7 different load combinations shot at least 2.5" at 50 with the favored loads shooting 1.25-1.5". During that same test session I had determined that my best matches at the time (right about when I made expert) were shot with ammo that grouped 3.5", testing is important.

With all that said, I personally load in 200-300 round batches, basically enough for a 2700 and some practice beforehand. I also do not have a short line vs long line load, gives me flexibility for match preparation and makes the loading process simpler. I would also suggest keeping notes from each loading session, that way if you run into a problem later on you can possibly identify the cause.

From personal experience, I have found that breaking down screwed up ammo is not fun.

Not pistol ammo. But yeah, big batches are normal for me.  

I agree with Wobbley. Winter is for casting, lubing, and loading. Spring & summer are for making empties to occupy the next winter.
Allen

Spot check charge weight and OAL every 50-100 rounds, then box or dump those rounds into storage. This way if you catch a problem, you've only got a small number of suspect rounds.

I put every single round into a case gage. The 100x gage made by Shockbottle is great - it lets you inspect and feel primer seating depth 100 at a time.

As for double charges and no-charge squibs - I would never load pistol rounds on a progressive press without a powder check or lockout die. I've loaded many many 1000s of pistol rounds, and I'm always vigilant and sober when loading. But still, the lockout die has stopped the press and caught 3 double charged rounds so far. We're human. It's impossible to be perfectly focused 100% of the time. I know I'm in the minority opinion here, since people on reloading forums have told me I'm wrong many times before, but I think it's dumb to count on vigilance alone when a mechanical/engineering safeguard exists. Use a check/lockout die.

Be sure and keep an eye on your powder measure to make sure it doesn't run dry. Not that this every happened to me... no, it was someone else I heard about... yeah that's it.