Need help on reloading problem

[montana]

I think my case gauge and 18 inch barrel are on the tite side. I have 2 Grendel barrels from AA. The 18 inch has a harder time chambering my reloads compared to my 16 inch barrel which chambers perfectly. My case gauge seams to compare with my 18 inch barrel. I purchased some factory Hornady ammo and it is also tite in my case gauge and 18 inch barrel yet functions perfectly in my 16 inch barrel. The factory wolf ammo works in everything. This kind of problem is normal when dealing with the many types of AR-15 like I have in my gun life. The bullets that I seat may alter the case enough to cause problems. My brass is tumbled sized and trimmed to spec. I have reloaded on many types of re loaders and have never seen this happen before. This is what they call the what the #$% factor . Thanks for the reply's Montana.

[noone]

Read the thread above about shoulder flare. I think this is what is happening to you. If your seating die is set too far down, the case runs into the roll crimp area of the die. This pushes down on the case mouth, causing the shoulder to bell outwards.

You can check this by measuring a newly sized case at the shoulder, then measure a case with the bullet seated in it at the shoulder. You may not get the same problem if you just use an empty case in the seating die, because the crimp will be more easily able to push the case mouth inward. With a bullet stopping the case mouth from going inward, the force goes down, and pushes the shoulder out.

[montana]

Not to sound like a broken record, but I have tried all those idea's . This is what I meant by the what the #$% factor. Montana

[pinzgauer]

I just tried my Redding sizer die and the wolf cases came out perfect, but my Hornady cases are still having the same problem.

Wolf cases normally have thinner walls than Hornady, so not having the problem on Wolf does make sense.

You also need to check case length, it could be the wolf is shorter if the seater die might still be the problem.