Neck tension question......I can feel a difference when seating.

[Colin78]

Hey guys is it normal when seating bullets to feel a difference in tension? I'm using RCBS FL dies bumping shoulder back .003 using a RCBS rockchucker press. Using Nosler brass reloading 28 Nosler ammo. So is it normal to feel a difference in pressure required to seat the bullets? Most will be the same but every once in a while I will get one that is noticeably harder or easier to seat.

 

[RegionRat]

Well, it doesn't help to have variations.

You will have to take a close look at performance and determine the need to chase the root cause down.

For example, if you are happy with the ammo performance, keep going. If not, then you have to determine if the cause is due to this seating force variation, or any number of other reasons.

A good starting point is to watch the group size while also taking chrono data. If the flyers are also the same as the ones that have extremes of velocity, then you will need to determine if those seating forces are the cause. Unfortunately the easy way to do this isn't cheap. Those pressure or force gage arbor presses are not cheap, but if a sort on those forces correlates to your group problem, then you can get to work on brass prep technique.

Many things can give this perception and large lever presses are not known for their sensitivity. If you can feel it on a large lever press, it is probably significant. The anneal state of the brass, the chamfer workmanship, the finish and cleanliness, etc, can all cause variations in seating forces.

What is the state of your brass and prep? Are these cases with many cycles? Annealed? Trimmed and chamfered?

 

[Colin78]

The brass is cleaned- tumbled, once fired. It is not annealed, trimmed, or chamfered.

 

[RegionRat]

The brass is cleaned- tumbled, once fired. It is not annealed, trimmed, or chamfered.

Take a real close look at the case mouths, is there any evidence of bullet jacket material being scraped up on the ones that felt harder to seat?

 

[Colin78]

Take a real close look at the case mouths, is there any evidence of bullet jacket material being scraped up on the ones that felt harder to seat?

Yes, I do see this sometimes. What does that mean? What do I need to do different?

 

[RegionRat]

Yes, I do see this sometimes. What does that mean? What do I need to do different?

Pay attention to the edge on the case mouths. If they are sharp, they scrape the bullet as you seat.

Consider using a VLD chamfer tool on the inside corner.

Also, be sure your sizing process is consistent and not trying to be too aggressive with grip. About 0.002" of sizing is a good starting point.

 

[Colin78]

Ok thanks you for all the pointers.

 

[RegionRat]

Ok thanks you for all the pointers.

Looking forward to hearing if you have a group or POI problem at all. Sometimes, that perception of seating force fluctuation doesn't matter, and sometimes it does. Good Luck in any case.