Seating depth changes after seating a bullet?

[seidersjoden]

Has anyone ever noticed after seating a bullet that the seating depth changes after a couple hours?

After reloading several rounds, triple checking the seating depth, zeroing my calipers and reconfirming each bullet several times that the depth is where I want it, I walk away from the reloading table then in a few hours I noticed the bullet seating depths have increased. Is this due to the trapped air inside pushing the bullet out or the compressed powder/gases inside forcing the bullet out?

I'm running a .365" bushing for 338 Lapua AI, plenty of neck tension, it takes pliers and a lot of twisting to get a bullet out so it's not like there's not enough tension on the bullet??

 

[cape cove]

I've had this happen on compressed loads. Means there is too much compression if this is a compressed load.

 

[Stammster]

I've had it happen, but only with a compressed load.

 

[DJ Fergus]

Yes, I've had it happen with compressed loads.

 

[seidersjoden]

I've had this happen on compressed loads. Means there is too much compression if this is a compressed load.

It is, it crunches the powder slightly but you can still hear it shake inside a decent amount. I've heard a slightly tighter neck tension might help with the Berger Bullets. I have a .365 bushing I could use my .364.

That being said if I just re-seat them deeper will they continue to push up a second time?

 

[seidersjoden]

I've had it happen, but only with a compressed load.

Have you guys had any luck if you re seat the bullet a second time or does it still push out?

 

[cape cove]

I would think that if you can hear the powder crunch when seating the bullet then you would not be able to hear the powder in the case when being shook. I was taught a long while ago that the way to determine if a compressed load was too compressed was to seat the bullet and measure the OAL. Leave for 24 hrs and remeasure. If it had changed then the compression was to much and a reduction in powder or change of powder was needed. JMO

 

[seidersjoden]

I would think that if you can hear the powder crunch when seating the bullet then you would not be able to hear the powder in the case when being shook. I was taught a long while ago that the way to determine if a compressed load was too compressed was to seat the bullet and measure the OAL. Leave for 24 hrs and remeasure. If it had changed then the compression was to much and a reduction in powder or change of powder was needed. JMO

You are right however it doesn't mean it is unsafe necessarily. Definitely a good rule of thumb but not unsafe. Some cases seat deep like for example the 6.5 PRC that I have quite a bit of experience with; I shot a mild yet compressed load with that caliber but because of its inherent design the bullet seats very deep and crunches powder. Same with this .338 Lapua AI, although it's compressed there is zero pressure signs and the node is great.

So back to my question, if I re seat them will they always continue to push up, has anyone had experience continuing to re seat them or use a tighter neck bushing. Basically without taking powder out has anyone ever resolved the issue?

 

[jimbires]

Have you guys had any luck if you re seat the bullet a second time or does it still push out?

I reseat them the next day . they stay at my desired length then . if you run them through the seater again you should be fine .

 

[jimbires]

are you using a drop tube funnel ? if not get one it really helps settle the powder . I use this one .

Forster Blue Ribbon Powder Funnel Long Drop Tube

The Forster Blue Ribbon Powder Funnel with 5-1/4" drop tube is the perfect funnel for a reloader looking to maximize their compressed loads. The...

www.midwayusa.com

 

[cape cove]

I did not mean to infer that they would be an unsafe load, just that if you were leaving on a hunt with max OAL loads for your mag and they increased without being noticed this would cause problems. Ask me how I know.

 

[seidersjoden]

are you using a drop tube funnel ? if not get one it really helps settle the powder . I use this one .

Forster Blue Ribbon Powder Funnel Long Drop Tube

The Forster Blue Ribbon Powder Funnel with 5-1/4" drop tube is the perfect funnel for a reloader looking to maximize their compressed loads. The...

www.midwayusa.com

I need to start using one, thanks!

 

[seidersjoden]

I did not mean to infer that they would be an unsafe load, just that if you were leaving on a hunt with max OAL loads for your mag and they increased without being noticed this would cause problems. Ask me how I know.

haha, good point, I'm awful close to mag length too, can't afford that, and you're spot on, leaving for a hunt in a week..

 

[Shane Lindsey]

I partial seat them. Put them on some type of vibration. I have used the washing machine. Then Complete the seating. This was with Barnes LRX and H1000, seated to fit in a magazine. After this they did not move.
not a 338 though, a 300 wm.