Chambering problems

[pyrotechnic]

Sounds like you are most likely contacting the case and pushing material around with your seating die as noted above.

Also regarding your FL seizing die setup. I haven't used Lyman dies, but the FL seizing dies I have used all came with instructions to screw down until contact with the shell holder and then another 1/8th turn. Now this will most likely size back down to minimum spec and you'll be working your brass more than necessary. But without a comparator gauge to measure how far you're actually bumping shoulders this is what I default to. That being said, if the Lyman dies have other instructions I'd would disregard the above.

 

[Rico]

Also does the die have a small vent (hole) near the top? It may be plugged. My 7 mag dies have a port and if it's plugged it will dent cases and some won't load. Been a long time since it happened. I always wipe lube off brass after sizing.

 

[Rico]

Readjust your seating die. It might be putting pressure on the case, causing a slight bulge in the shoulder somewhere. If the bullet isn’t making contact with the lands, your seating die is messing you up.

It looks like you may be right. I don’t know if you can see in these pics, but I found that the seating die is changing the shape of the shoulder, and one round developed a dent

 

[pyrotechnic]

Looks like you're buckling the case with your seating die.

 

[MThuntr]

Looks like your case shoulders are rounded. It looks like you're smashing your cases.

Get a case comparator to measure once fired brass (not resized by your tools) then adjust your sizing die to bump the should back around 0.002”. It should work on belted cases

 

[mtmuley]

How much force are you applying to seat the bullet? Does it seem excessive? mtmuley

 

[pyrotechnic]

My recommendation would be to run a sized piece of brass all the way up into your press. Then screw the seating die body down until it makes contact. Back it off a half turn or so and then set your locking ring. At that point re- set your seating depth.

 

[Dan O]

Are you applying a crimp to your cases? That could be your issue causing the case to expand in the neck area.

 

[Jbotto]

It looks like you may be right. I don’t know if you can see in these pics, but I found that the seating die is changing the shape of the shoulder, and one round developed a dent

Been there, done that. That middle case, back in on the left looks mild compared to what mine looked like. Glad you figured it out. Did almost the same process as you. Sized brass fit beautifully, bullet seated and not touching lands of the rifling, but cartridge wouldn’t fully chamber.

 

[44hunter45]

It looks like you may be right. I don’t know if you can see in these pics, but I found that the seating die is changing the shape of the shoulder, and one round developed a dent

This.

Although they are crazy expensive, Redding sleeve type seat dies will completely eliminate this issue.

This is usually from one of two things, or a combination of them.
1) Improper seating/crimping die adjustment.
2) Inconsistent brass trim length.

It is more prevalent in soft annealed brass

Adjust your seating die to not crimp by:
1) Backing the seating stem out completely in the die.
2) Just start the die a couple of threads into your press
3) Running a test round or round with a bullet ready to seat up to full ram extension.
4) Turn the die body down into the press until you feel it hit resistance at the case mouth. It will be pretty easy to feel.
5) Now back out 1/4 to 1/2 turn and set the lock ring.
6) Now adjust your seating to the determined COAL for your load.

If you want a crimp, follow up with a Lee Factory crimp die. They are cheap and worth every penny.
I never seat and crimp in one step any more. The quality of your ammo will improve exponentially if you use a two step process.

I am also concerned by the donut the pics show at the base of the neck. As I described earlier, mark that donut with a sharpie and chamber the round. You do not want any contact happening in the neck area. The neck needs room to "release" the bullet when you fire. Pressure will run up very fast and your work up loads will be invalid because of the pressure caused by this contact. When I was starting out I had what should have been light loads lock up my bolt from this condition.

 

[Seamaster]

Readjust your seating die. It might be putting pressure on the case, causing a slight bulge in the shoulder somewhere. If the bullet isn’t making contact with the lands, your seating die is messing you up.

I have seen this problem fairly often with new handloaders. It is the first thing I check when a new loader has problems chambering.

 

[nhenry]

Looks like you're accidentally crimping before the bullet gets seated.

Put a case on the press when you screw the seating die down. When it makes slight contact, back off a bit.

 

[Caseknife]

Looks like you're accidentally crimping before the bullet gets seated.

Put a case on the press when you screw the seating die down. When it makes slight contact, back off a bit.

Nailed it, crimping before the bullet is seated, causing the shoulder to bulge. Either don't crimp or re-read the process with the dies on crimping and seating in one motion.

 

[mtmuley]

Back the seating die up a full turn. mtmuley

 

[Benfromalbuquerque]

It looks like you may be right. I don’t know if you can see in these pics, but I found that the seating die is changing the shape of the shoulder, and one round developed a dent

The case with bullet on the left is definitely buckled. Seating die is too far in. If you run your finger along a case that you know to be correctly sized and seated, the shoulder angle will feel smooth. Transition easily between case and neck. A buckled, smashed case will feel rigid on that shoulder and not a smooth transition between case to neck.
And it’s ok! By wrecking components and equipment, we learn. Everyone who has responded to this thread has been where you’re at today.

 

[nhenry]

The case with bullet on the left is definitely buckled. Seating die is too far in. If you run your finger along a case that you know to be correctly sized and seated, the shoulder angle will feel smooth. Transition easily between case and neck. A buckled, smashed case will feel rigid on that shoulder and not a smooth transition between case to neck.
And it’s ok! By wrecking components and equipment, we learn. Everyone who has responded to this thread has been where you’re at today.

I threw all the mistake cases I had recently, otherwise I’d post a pic of all of them. Everyone’s been there and done that. No shame in it.

 

[antelopedundee]

Most if not all seat dies have a built in crimp feature. If the bullet doesn't have a cannelure aka crimping groove, then you shouldn't try to use the crimp feature because you will end up partially collapsing the shoulder. Since the seat die is sloppy compared to a sizing die, the collapsed shoulder will bulge the case to the point where it won't fit in the gun's chamber. It ends up even worse with Ackley Imp 40 degree shoulder cases and you may not even be able to salvage the case if you FL resize it.
Put a case in your press shellholder and run the ram up. Back off or take out the seating stem and screw in the seat die until you feel the case mouth contact the crimp ring. Back out the seat die about a half turn and set the lock ring and you should be GTG.

 

[ImBillT]

Glad you got it figured out. Don’t hesitate to buy Redding or Forster in the future even though you got it figured out.

 

[Rico]

All I had to do was reset the seating die. Simple fix. Thanks for your help guys!

 

[Laelkhunter]

I always set my seating die well off of the mouth of the case. If I want to crimp the bullet, I use a Lee factory crimp die. If you try to seat the bullet and crimp at the same, you can cause a bulge in the case especially if all of the cases are not the same length. Even a very slight bulge will cause chambering problems.