Bullet Seating Problem

[MOA or bust]

Can't figure out why bullets are loose in case when there should be adequate neck tension.
28 Nosler, Peterson brass twice fired. After sizing OD neck is 0.310. Charged case and loaded HHT 170 bullets and OD neck is .318 or so. Should be lots of neck tension but after seating the bullets, I note that I can push and pull the bullets a few one hundredths in the case, like they're moving from one bullet ridge to the next. I've loaded these before and not sure what's different now or what to do next. Help!

 

[crashlanding]

Im loading 7prc with Peterson brass right now, I'm using a .310 bushing, finished diameter with a 175 eldx in it is .313, your neck is .318 finished, something is definitely off, there shouldn't be that much of a difference

 

[26Reload]

Looks like you are going to need to 'crimp' to keep it from moving....
Checkout the 'crimping boys'
..with hammer bullets...

 

[Phil Rizzo]

Mic the bullet OD for fun, if you just opened a new box.
Rule that out.

 

[MagnumManiac]

Something definitely doesn't compute, no way it should measure OD of ..318". If the neck starts .002" smaller, it should only be .002" larger after seating.

Cheers.

 

[Bob Wright]

Mic each bullet over the drive bands. Those should be identical to each other.
How are you sizing these? (Details of dies, neck sizers, etc.,
Give us your process in case prep.)
Something is way off.

 

[Tiny Tim]

Hard to imagine bullets being that loose with .008 interference fit. That's well beyond the yield point of the brass. Agree with others, check the bullet diameter and see if there is a difference between the base and near the ogive.

Is it possible the bullet is going in "cocked off" to one side and over expanding the neck? I'd think if it were off that much there'd be bullet shavings.

Is the case neck diameter out of round? Is the case neck cracked? Neck thickness seems on the high end and a lot of overworking of it in the resizing stage.

 

[dgp3006]

Following

 

[Varmint Hunter]

Using .008" of neck tension is extreme and not needed even for Hammer bullets which have very little bearing surface in the neck. It sounds like you measured something incorrectly.

Are you using a neck lubricant?

 

[VinceMule]

I think that Phil hit the nail on the head, tapered bullet shanks.

 

[MOA or bust]

Sorry, this is ADG brass in the 28 Nosler (I used Peterson in my 7PRC).
I have mic'd the HHT bullets and they seem to be a uniform .284. I measured the high points on the "ridges" individually and they are .284. No cracked cases. I have annealed after each firing.
I'm using a Redding seating die with a mic head. Sizing die is Redding Master Hunter FL. Resizes neck to .310 OD, no bushing.

Just seated a Berger 180 and the neck measures .316 OD, but it's not "loose". The Berger bullets mic at .284 OD.
Interestingly, this same Berger bullet seated in my 7 PRC (Peterson brass) goes from .309 before to .312 OD after seating.

I don't know what's going on, had no problems with loose bullets loading same components recently.
Hope I'm just making some goofy mistake, but I won't mind the embarrassment if I can get this remedied.

 

[WapitiBob]

I had that problem when I used a torch to anneal; turned the necks to jelly. Probably not your issue if the Bergers will seat. Maybe the neck isn't sized down towards the shoulder far enough ?

 

[MagnumManiac]

If your necks are thicker, it will change the measurement, but I am baffled as to why the bullets move in the neck.
First thing I would do is pull all of your dies apart and check for anything amiss. I even have spare expanders of different sizes just for this type of situation. I have got 6.5mm bullets that measure .263" instead of .264" and this changes tension…

Cheers.

 

[MOA or bust]

My wife has out of town girlfriends at our house for some function tomorrow. I've retreated to our fish camp. When I get home tomorrow, I will reevaluate the dies and Re measure everything.
Remains a mystery.