While loading ammo last night I ran into something I have not encountered before. Loaded 50 rounds of brass I have been using for load development and about half were very difficult to seat bullets in. I was actually denting the jacket where the seating plug makes contact, and the OAL was way off. I just loaded and shot this brass last week without issue. Any ideas?
Difficulty seating bullets?
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Dumb question, How would I get to much neck tension? I would expect to have to little since this brass has been fired several times. I plan to pull those bullets this evening, I would be afraid to fire those rounds.
neck tension is set from your die. if you have a bushing die, you can change it by getting different size bushings. if your die is fixed, it is what it is from the manufacturer. most of us reloading precision ammo like around 1-1.5 thou of neck tension. the way to measure it is measure the neck diameter of a resized piece of brass before you put the bullet in it. then measure it again with the bullet seated. the difference between those two numbers in the neck tension.
the only two things that change seating pressure/force is neck tension and friction. if your brass is super clean (think "squeaky" clean) you can actually increase the frictional force in seating the bullet. sometimes the left over carbon residue can act as a lubricant. we actually found this out on some new brass where when the metallurgy of brass cup was changed they were coming out super clean brand new and gave a false feeling of to much neck tension. but when they were pinned we confirmed that it did indeed only have 1.5 thou of neck tension (really good for virgin brass). once we started putting the brass in a media tumbler with some flitz media polish, the seating force came way down and everything seated very consistently. and shot awesome as well
Thanks, The brass actually had not been cleaned which is why I was surprised. I have noticed that super clean brass can be sticky, I noticed this with pistol brass after cleaning it was more difficult to resize. I am not using bushing dies so that as you said should be a fixed. I took another piece of brass and made a dummy round and the bullet seated perfectly. I also checked the first 50 I loaded last night from a different batch of brass and the BOL were all within .001".
I dont use 143 eldx but at 2.850 the bullet bearing surface is at or past the end of the case neck. It is possible you have a doughnut inside the
case neck. Seating would start normal but as the bullet gets near the shoulder it gets harder to stretch the brass making seating difficult.
case neck. Seating would start normal but as the bullet gets near the shoulder it gets harder to stretch the brass making seating difficult.
That sounds like a possibility, I will look when I pull the bullets and see. This brass has been loaded several times, I don't know what would cause that problem but your description sounds about like what I am seeing.
I think you may have given me the answer. I pulled one of the offending rounds apart, which was very difficult. running a pick along the inside of the case neck I hit resistance at the junction of the neck and shoulder.
Also the brass work hardens, that’s why people anneal. If you don’t seat with a arbor press you will be amazed on the feel. I know once I switched over to a arbor press it was a eye opening for me. I would seat on a single stage and sort by feel, then seating with a arbor the seating feel was way more then I ever thought.
That really made me pay much more on the neck tension side of things...
Hope that helps any
Also get some pin gauges, you can check your neck tension with the pins. They will tell you if you need more or less depending on how much tension your looking for.
