Seating Long Until Ready for Use

med358-boise

Well-Known Member
Joined
Jul 4, 2022
Messages
327
Location
Boise
Have heard people say that to be efficient they will load in large batches say 400 rounds or so but anything they don't believe they will shoot within a couple of months they seat them very long. Just prior to use, they will seat to desired length. They feel this creates more consistent neck tension and breaks some kind of "weld" between the bullet and the brass that will form over an extended period of time.

Anything to this? or is it much to do about nothing?

Thanks!
 
Last edited:
now that is a interesting question ?? I know HOT weather will make a big difference. cold will also, but how much ??? will keep an eye open on this one for sure.

I do all of my load development on hot days, 90+ F, allowing the rifle and ammunition to reach ambient….a couple of hours! This is important to me as I push my loads pretty hard, and may use my rifle at anytime during the year. I don't want any surprises! 😉

I then do out and test those loads for velocity and grouping at somewhere around expected temperatures during hunting season.

If there is a significant difference, I adjust accordingly. Not a huge deal or game changer for me as I don't shoot at the distances that some here do!

With my zero, and my self imposed range limit…..unless a pretty large summer/winter velocity differential, it's pretty easy to "mentally" adjust! Plus, my game is somewhat larger than coyotes……a few inches is pretty inconsequential! memtb
 
Anything to this? or is it much to do about nothing?
TLDR: yes the risk is real. If and when it happens, it certainly ruins the ammo performance the same way variable neck tension does. In the real world, we manage risks in terms of likelihood and consequence. This problem is well known but difficult to reproduce in labs, and the consequences are bad enough that we design for it with stuff like sealants and "other" means.

A very long time ago I was visiting a well attended match. It was either a big state match or a national one. I think it was a silhouette match but it was more than 40 years ago so you must forgive me cause I don't remember specifically the match, but one of the things that stuck in my head was....

I was still pretty young and immersed in the defense world, so by then I had a pretty good ballistics background in that respect but they still encouraged me to visit small caliber stuff since my world was mostly the heavy stuff.

I had already been introduced to a young man who was an awesome shot so I felt comfortable asking him what he was doing. He was bumping the seating on his rounds. He explained it to me and I was wondering why that had never occurred to me before. He had a tough schedule and had to load his ammo long before the matches and did this just as he arrived. He showed me and every once in a while one would "pop". He would segregate that round for a sighter or reject it if he had enough.

In the military world, most small arms ammo has a crimp, neck sealant, and "other" that prevents this issue, but since we were in a different context what he was doing made a lot of sense. I have learned a lot from folks with no formal credentials, just like I have from the heavy hitters at the national labs and defense corporations. I learned a lot from that guy and consider him a friend to this day. His name is David Tubb and he doesn't have formal letters next to his name but his CV has many championships in several shooting disciplines.

If the issue is "cold welding", does a "barrier" (graphite, HBN, etc...) help with this? What about military surplus?
The way we look at this risk in the defense world is different than those of commercial ammo. We look at things in terms of likelihood and consequences. As a result you will typically see the standardized bulk ammo has a pitch sealant in the necks, a crimp, and sealed primer. We also store ammo according to specifications to protect it from water or other ionic risks.

To judge the performance of those materials you asked about, you just have to compare the conductivity of the bare ammo to samples of your ones with the "barrier". If you can measure the resistance across the bullet to the case neck, you will find that it takes a lot of barrier to cut off that conductivity path. If there is good conductivity and we introduce stuff like water vapor, we open the door to the problem since copper likes to trade electrons pretty well. I'm not saying stuff like MoS2, HBN, Graphite, etc, don't help at all, but a dusting of those isn't going to prevent conductivity or lock out the water vapor.

If you want to protect against this risk, keep your ammo in US Mil-Spec ammo cans while you travel. If you ammo gets wet while you carry it in the field, consider putting it aside for long term testing and see how it tests after you let it sit a few weeks after you get home. As always, YMMV
 
Thank you. "TLDR" stands for?
Sorry, acronyms are a pain when they aren't universal and I assumed TLDR was one of those everyone knows... bad assumption...

TLDR = Too Long, Didn't Read....

I had to answer to lots of folks up and down the line. When I wrote memos that went up, they often asked for an abstract or TLDR version cause some of those folks were not technical and some were just always in a rush.
 
After a couple of blown primers I either dont load more than will be used or load it long To be reset before fireing! Reseting old ammo is always prefered.
Over the years I've found no ryme or reason for the weld problem but Moly helped or made it much worse. HBN may be the ticket but have not tryed it yet.
With the limited supply chain these days I just dont load untill its needed, 223 and 9mm of coarse are exempt from mass reloading.
Pic is over 10k rounds for prairie dogs back in the early 2000s. The old 1945 50bmg ammo did just fine but for some reason the 6-284 ammo from the year before blew primers without being set back.

old%20toy%20pics%20017.jpg
 
Top