www.uline.com 
I have purchased many plastic ammo cans full of loose American Gunner Match ammo in numerous calibers. These get thrown around by UPS before I get them. I see no difference in accuracy/precision between them and the same ammo packed in boxes.
I have the same problem... my solution has been heavy duty 8mil thick ziplock bags from amazon. A 50cal ammo can will hold about 500rnds in 6x9 bags. For my factory ammo I cut the side of the box and put it in the bag. For reloads I use a 3x5 card.
What kind of neck tension do you have? When deciding not to crimp my 223 AR ammo, I put rounds in an inertia bullet puller to see how hard I had to smack it to get movement. Turned out, a hell of a lot. Trying to wrap my head around COAL changing from transportation.
Thanks for the details, I am fascinated if you are willing to share more.In my case, about 2 thou of neck tension for a .308 Win, packed inside the blue Dillon 50rd boxes. I'd trim to fit a layer or two of the thin foam that comes in boxes of Berger bullets in the top of the ammo boxes to cushion the tips (and to help keep the empties from coming out). It was absolutely solid for every day handling and bumping around, and *usually* fine for travel. Usually I had the blue Dillon boxes stuffed into a small Pelican style hard case, fitted with pick-n-pluck foam inserts. You can fit a fair bit of ammo in a case like that
Every once in a blue moon, I'd get some weirdness happening downrange on target. One such time, it just so happened that I had some 'saved' rounds left over, and while sitting around the hotel room bitching about what had gone wrong with my gun, borrowed some measuring tools. The CBTO was very much not what it was supposed to be. Knowing that the comparator I was using at the time wasn't necessarily the same as 'my' comparator at home, I wasn't betting the farm on that reading - but it was a hint. I very carefully packed up that partial box of ammo in my luggage, and checked it again when I got home with my own tools. Yup, definitely moved. After that, I started looking for ways to make sure I didn't get 'bit' by that particular gremlin again.
Some of these trips were 1000-1500 miles (each way) of interstate and highway, or flying with multiple lay-overs. Sometimes the ammo was shipped ahead via UPS, because 5 kilos / 11 lbs of ammo just wasn't enough to shoot an entire event. Some were international trips where the ammo had to be pre-loaded months in advance, shipped to a team sponsor (Berger, at the time), then shipped via container through their agents so it had time to go through customs and we picked it up from secure storage when we arrived.
By "click it clams" you mean the green or blue ect clear-ish looking 50 round or 100 round cases that store bullets vertically with the bullet facing up right? The ammo cases that are common for handloaders to use?Well, it's been a few years, so going off memory here.
Not a compressed load. Way back with the 155.5's yes. Later, with the heavier bullets, no.
Amount of change was not consistent, and was only some rounds.
No idea on the pressure change. The time I measured and 'found' the problem was a long road trip (central WA to Raton, NM) that does have some healthy elevation changes along the way... but I'd suspect vibration and/or potholes before I would pressure.
The clickit clam shells are relatively new; by the time I got mostly out of that particular rat race several years ago more people were starting to use them, particularly if they were flying to events and/or shipping ahead. I personally never went that route as I was already loading long and reseating my rounds the night before. One more unpleasant chore after a long day on the range
Ah ha..... thanks
I load 223 with 77 grain bullets. I put 223 in strippers then into cardboards then into bandoliers. I can get 1,200 into a fat 50. Its a tight fit. If I put 100 rounds of 223 into a quart ziplock bags, I can maybe 1,500 into a fat 50. Its good exercise moving those around.
