Trouble with new Lapua brass

I just ran into an issue that I never have before. I’ve got a Tikka T3 6.5x55 that I’ve been loading for for a few years. I’m currently fire forming a new batch of brass. While at the lease this weekend I noticed that while chambering a round the bolt is difficult to close. Inspected the case and the shoulder is dented. Tried the next 2 in the magazine and got the same result. I’ve shot 80 of this new batch and not had a problem until today. These cases have only been neck sized. So my questions are 1) why do you think I’m running into this issue? 2) do you think they’re safe to shoot?

Thanks for any help.

Safe to shoot if you can close the bolt without breaking sometthing (as in Remington 700 bolt handles).

When you employ neck sizing, you're going to have to bump shoulders back after several firings either by FL sizing or using a body die.

Then again, after more carefully reading about your experience there could be more to it.

Lack of lubrication can make bolt closure difficult, but not cause shoulder dents. Hmmm...

The first one is because of the second one.

You are probably right JG...but if I'm reading this right it's new brass, and all the ammo loaded before chambered fine. And there's the "dented" shoulders...whatever that could mean. Kinda sounds like crap building up in the lug recesses creating a tighter headspace situation. I dunno though. Maybe we need more info.

Imma go with that.

Yes, it’s brand new brass. I neck sized them because a few of the case mouths were dented. I’ve been through 80/100 with no problems. The gun has a total of 260 rds through it. 25 or so since the last cleaning.

I think I'd just bump the shoulders on the next go round and keep on truckin.

-.002" for sure

Ok thanks guys. I’m going to pull the bullets on everything I have left and bump them back. I’m going to shoot the 3 dented ones.

It just didn’t make sense why I got through most of that batch of brass without a problem and then this. Thanks again.

Lapua makes very fine brass, but maybe they're not 100% perfect. That, and you may just have a tight chamber. Once you get your die set to a .002" shoulder bump, I would run any new brass through it from now on.

Will do. Thanks.

What do the dents look like? Good suggestions above but I would also clean the chamber just in case something got in there and is stuck to the chamber wall at the neck.

Yeah I need to take a closer look at the chamber. I looked while I was out there but I could have missed something.

Your picture shows why it's not chambering. The dents, and maybe the bullet engaging the rifling. Holy cow, those are seated long! Why so long?

I finally just got a decent light in there and there was a good amount of buildup just as kmon1 suggested. Cleaned it up and the problem is solved. Surprises me that it was like that. I thought I have a pretty good system as far as the cleaning goes. I’ll be paying a lot closer attention from now on.

Chad, this Swede has a long throat. Those are .020 off the lands.

20 gauge shotgun mop fits snug inside an action.

Very cool. Thanks! I appreciate all of the help from everyone.

Yes. It looks like you are running a Hornady SST. With them seated that long, there can't be much bullet in the case. I'd worry about the neck holding enough of the bullet to keep it secure. With that SST bullet, it's not seating depth sensitive, so there's really no need to seat it out that far. And if it's a hunting gun, those bullets won't stay straight long in the field. That would be my only concern.

Gotcha. Yes, 140gr SST. I don’t recall exactly what it was but I measured to see how much of the bullet was in the case and it was around .260. I just started using SST’s when I got the new box of brass. Before that I had always used 140gr Partitions and I’d seat them .020 off as well. I haven’t had any issues so far but I trust what you say. How deep would you seat them? And yes, it is just a hunting gun.

If you have .260" of bullet in the case, then that should be alright. My rule of thumb is atleast bullet diameter needs to be held by the neck. So, .260" is right there. And Lapua brass is known for firm necks. If it shoots good and the bullet is firm in the case, roll it!

Curiosity on my part, never loaded anything out that far. The SST's are a boat tail design, I'm assuming the boat tail is included in that .260" of bullet in the case, which isn't really held by the neck?

^^ No, I don't count the boat tail. It has to be the actual amount of bullet that the neck is holding.

Now I’m wondering so I’m going to measure them again when I get home.

Ok, so I just measured a few. Not counting the boat tail they are .224 in the neck. If I seat them to .264 that will be .060 off the lands. Again, I’ve been doing this for some time with this gun and not had a problem, but you fellas have a ton more experience and knowledge than me, so if you say I should do it then I am listening.

.224 should work and has been for you, the old rule of thumb of bullet diameter is a sound practice but there are a few cartridges that do not meet that "rule" that have enjoyed commercial success if I recall correctly, of course those are not from seating depth but neck length.

If you like that load and it shoots well then I would just keep on shooting it.

If the length you've been using is what works, don't change it for some arbitrary "standard" with no basis in fact. Some guys are loading hunting ammo with much less shank in the neck than you are, and do fine with it. IF you should discover that something is screwing up your ammo due to shallow seating, THEN address it (which might mean nothing more than changing the way you carry spare ammo, for instance). Otherwise you may be compromising your accuracy to cure a non-existent "problem."

That is one of the ones I was thinking of. Not going to look it up on the phone but isn't the 300 Win Mag also shorter necked than .308? There are a few others.

Whoa! That is one short neck!

It fathered a phenomenon.

Would that be 308?

6.5 Creedmoor