6bra Necks Looser than other

[MDT6BRA]

I am reloading 90gr eldx in a 10twist hart. I am noticing some of my bullets seat a lot easier than others. I have measured the necks after sizing and they all measure .240 but some of the bullets seat with much less effort on the ram and in return the looser necks are measuring up to about 10thou short oal (ogive). What is going on?

 

[Bill Norris]

It's a good indication the neck tension is random. When this occurs the length will vary because of the pressure being applied on each bullet at seating is different and will therefore having a different stopping point. Swapping over to a smaller bushing to gain neck tension may help.

 

[JMayo]

I use a 261 bushing .... I can't imagine case mouth isnt shaving your bullets.

 

[MDT6BRA]

It’s not shaving bullets I have pulled several trying to figure this out. My die is a non bushing Whidden but I have never had this trouble before. Could my brass just be wore out? It’s been loaded several times but primer pockets are still snug

 

[Bill Norris]

May have to anneal it to get it to come back around to being even seating pressures.

 

[MDT6BRA]

I don’t have anneal machine or ever done it. Does it make sense to have all the same measurements and just some of the cases not as tight on the bullet anymore?

 

[Bill Norris]

Absolutely, seen it many times and usually a tighter neck bushing in my bushing die would help but not a cure.

 

[MDT6BRA]

So the only cure is annealing or buy new brass?

 

[LCazador]

What is your neck thickness,012"? Sounds like you have a random neck thickness issue. I had this recently with a .243 Sammi chamber. After I skimmed .0015" of my Lapua brass I wound up with a very consistent seating depth and neck tension. I also shrunk my groups by half. I'm not done yet as I will be trying different bushings to see if ES and groups shrink.

 

[Bill Norris]

What is your neck thickness,012"? Sounds like you have a random neck thickness issue. I had this recently with a .243 Sammi chamber. After I skimmed .0015" of my Lapua brass I wound up with a very consistent seating depth and neck tension. I also shrunk my groups by half. I'm not done yet as I will be trying different bushings to see if ES and groups shrink.

Yes good point as well.

 

[MDT6BRA]

Would a random thickness be something that could develop over several firing? The cases didn’t use to have this issue.

 

[Bill Norris]

I guess it could but normally what I've found if you have .0015 average or less runout then turning don't do much.

 

[NZ_Fclass]

I'm pretty sure that it's annealing that you need.

 

[LCazador]

Would a random thickness be something that could develop over several firing? The cases didn’t use to have this issue.

Yes random thickness will develop over several firings due to build up of carbon in the necks and brass spingback. What is your neck thickness? Measure with a ball micrometer not your calipers.

 

[Mulligan]

Just for giggles,

Run a piece of the loose brass back into the die and hold the brass fully in the die for 20 seconds or so. This will increase the "dwell time" in the die. I have seen this help with well used brass.

CW

 

[MDT6BRA]

I don’t have a way to measure runout, or a ball micrometer wow typing all this really shows me what my loading bench is missing. I’m just a hobby shooter just never in countered this before.

 

[Dusty Stevens]

A bushing die is in your future, i can see it now.

 

[MDT6BRA]

I think you probably right and maybe some new brass. I have 3 bra so it’s not like I won’t use it.

 

[Old Navy]

Pull the seating stem out for inspection. Make sure it is not flared and that the bullet tip is not hitting the bottom.

 

[Sandstorm]

You could try some imperial dry neck lube to help with seating untill you anneal your brass.