Home Forums Hunting & Shooting Ask The Gunwriters Welded Bullets and Necks

I got out some loads in 300 Weatherby that I assembled in 2016 to sight in my Elk rifle. The velocity was quite a bit higher than I remembered, and, I couldn't match it with some new loads to go with them by a few hundred fps.

I pulled a couple of the bullets with a collet puller and they were really in there! A substantial difference in force from pulling "fresh" loads. Clearly the reason the velocity was up there.

These were Barnes TTSX's loaded in squeaky clean cases (wet tumbled and my notes don't say anything about excessive seating force and I wouldn't have continued if they didn't feel normal).

What can I do to keep this from happening once again (besides shooting up all my loads!) and still keeping consistent neck tension?

I've had this happen with older military ammo.....put the ammo in the seating die and push the bullet about .030 deeper.....this will break the existing neck tension issue.

How to prevent it?.....maybe someone else knows

A squeaky clean interface between the surface of the bullet and the surface of the case-neck creates near-ideal conditions for diffusion bonding. I leave my cases grotty, doing no more than washing after use. I don't clean the case lube off before seating bullets either. It seems to work ;-)

Squeeky clean is the problem. One of the reasons I don't wet tumble. Its good to have a little soot on the inside of the cases... Never hurt a damn thing and I load some pretty accurate ammo.. Just sayin..


Nothing wrong with it being clean, as long as it's the outside. Not the inside... That or you can lube the inside with graphite before seating the bullet. An extra step for you guys that wet tumble, but it may be necessary. I'll continue to keep using media to tumble my brass... And no, I never leave case lube on my cases. That's just stupid...

I have had no issues wet tumbling...

That's one of the problems with wet tumbling, the cases get too clean and you end up with bonding/cold welding after they sit a while. You need the layer of powder residue in the neck from the previous firing or some other way of preventing it. I've read some of the target guys will dip their bullets in imperial dry neck lube (graphite) before seating the bullet to prevent it if they're not going to be using the ammo soon.

I don't know about wet polishing but after tumbling with a liquid polish in corncob I tumble in clean corn cob with a pinch or two of paste wax scrapings. Removes any remaining polish and adds a very thin layer of wax to prevent tarnishing. I suppose it leaves a layer of wax inside the neck too. Never noticed a cold bonding condition anyway.

And my ammo stays pretty.

You just got to watch out for those little stainless pins...... I found some in some of the 308 Norma brass you sent me... Get one or 2 of those going down your barrel at mach 90 and you'll (or your barrel, I should say) will have issues...

Yes, or they will load long and bump back to their OAL at the shoot, or right before the shoot...

Use powdered mica in the neck unless you are going to shoot ammo within 3-6 months.

Nah they make your bullet go faster

The big problem is not shooting up your loaded ammo fast enough.

I like JBs method, shoot dirty cases. Wax, Hornaday One shot, mica, moly, graphite all work. Graphite can back fire as it attracts moisture. Last bunch I did I wiped the bullets down with Dyna Tech Gun Coat. A shot of Corrosion X on the bullets works too but always test fire as they can act like you are shooting with an oily barrel.

Last brass I wet tumbled, I used about two jiggers of Turtle Wax "Zip Wax" which is car wash that has wax in it instead of the usual couple of squirts of Dawn dish detergent. Brass came out looking good, and hopefully there's enough wax residue to prevent tarnishing. It might even prevent cold weld, but it will likely be a long time before I have any confidence in that idea.

I shoot nothing but moly plated bullets, & I never brush or touch the inside of the case neck.

I've pulled pullets from 2,3,4+ year old ammo, and the bullets slide out like they were loaded yesterday.

Some factories use a product called "Black Lucas" in the neck to prevent cold welding(fusion).

I lived out West for 30 years never had cold welding. I moved back South, and I have seen cold welding on my own ammo twice. Moisture maybe a factor.

On hunting ammo that I want to load 100 of, I barely seat the bullets in the case, and when time comes, I measure OAL to kiss the lands(or what ever bullet jump that the barrel/bullet likes best), seat the bullets. This seems to be a good system.

Midway used to sell a little box which contained mica powder and had places to mount bore brushes in a vertical orientation. One dipped the mouth of each cartridge into the mica and then over the brush to clean out the excess. It was marketed to reduce drag on the expander button as the case was pulled from the sizing die. But also served to give e a little layer of lubes between case neck and bullet.

I do not tumble my brass to a new sheen. A couple hours in ground walnut (lizard bedding) in a vibrator, and the finish is usually still a bit dull. And I now moly everything centerfire. And they definitely do not weld to the case.

But I ain't holding my breath while we try to talk anyone into taking up moly plating. I'll just say, I love it.

Boy howdy, ain't that the truth.....gets old defending your position...........

Laffin' here....I am a moly user and have a good system so it works for me, long strings between cleaning.

As for the cold weld, yep, naked metal without any kind of lube will tend to "bond" or need to be "broken free" in a suprisingly short time if there's any force on the surfaces. I've seen it on flat surfaces where just a hunk of metal was laying upon another, and had it happen early in my handloading (before moly) when I'd loaded some "squeaky clean" virgin brass and shiny shiny bullets. Early it shot fine, but I was slow going through the batch and sure enough, I got some wild flyers and flat primers, it wasn't until I tried to pull a bullet and see what my powder charge was, that I realized there was an issue. Couldn't pull, but I could "pop" it downward about ten thousandths and the rest shot fine. But that was a lesson.

Definitely a problem. I load enough for sight-in and then to take on the hunt. Invariably I have a bunch left over, but not enough for the next hunt! These "sticky" ones were loaded in mid-2016, so they weren't THAT old.

When I wet tumble, I use a little armor-all car wash and wax as my detergent. Apparently it does NOT leave enough residue to prevent the sticky problem. I did like the 300 fps higher velocity, who knows what the pressure was. They were also really, really accurate.

I'm going to pull everything I have and start over. I need to have some loads ready at any time.

I wonder how the factories prevent this problem? JB?