Issues with some cases AFTER full length resize..Issue seems to be solved!

[rumblebee]

I'm at a loss here. I tumbled\cleaned\deprimed and ran a FL die (Hornady New Dimension) on some .223 (PMC) and some 5.56 M193. The PMC could have prevoiusly been shot out of either my AR-15 or my Tikka. The M193 was only shot from my AR-15. (Edit: all brass trimmed to 1.750)

What I am finding, after loading some of each of the PMC and the M193, is that some will chamber in my Tikka and others will not chamber (the bolt will not go into full battery on some reloads). It is not specific to the PMC or the M193 brass. They are both set at the same COL of 2.473 and both are topped with a Hornady 75gr A Max.

The only thing I can think of for the brass with issues, is that it may have been shot from my AR and is somehow not being FL sized properly by the die?

I've been reading that there should not be any issues with utilizing 5.56 brass in my Tikka .223, as long as it's been FL sized in the .223 die.

What the hell am I doing wrong here???

[Low-Pressure]

Did you trim the cases?

[rumblebee]

Yes...all brass trimmed to 1.750. I should have provided that info in original post (my bad)

Did you trim the brass?

[Low-Pressure]

You should make a dummy round and do not crimp it and see if you need to seat the bullet a little deeper.

[ojisan]

When a semi auto fires, there is a tendency for the shoulder to move forward more than you would see with a bolt gun.
Some of this can be caused by early extraction or a slightly larger semi-auto chamber.
You may need to push the shoulder back a bit more.

[rumblebee]

I made dummy rounds before the real dealio...I know I am good at COL 2.473, but I went to COL 2.302 just to see and still have these issues.

You should make a dummy round and do not crimp it and see if you need to seat the bullet a little deeper.

I understand what you are writting below and thought that may have been the issue. Would I push the shoulder back more by running it thru the FL die again or is there another process to do this?

When a semi auto fires, there is a tendency for the shoulder to move forward more than you would see with a bolt gun.
Some of this can be caused by early extraction or a slightly larger semi-auto chamber.
You may need to push the shoulder back a bit more.

[Low-Pressure]

I do not have my Reloading manual in front of me, but I recall it correctly your COL should be around 2.260".
Somebody please correct me if I'm mistaken.

[Sub95]

When a semi auto fires, there is a tendency for the shoulder to move forward more than you would see with a bolt gun.
Some of this can be caused by early extraction or a slightly larger semi-auto chamber.
You may need to push the shoulder back a bit more.

+1 for this.

[fabguy]

I do not have my Reloading manual in front of me, but I recall it correctly your COL should be around 2.260".
Somebody please correct me if I'm mistaken.

Yes, I think you are correct

[rumblebee]

I have my Horanady 8th right here and COL for the 75gr A-Max is 2.390. I also called Hornady to verify that this was for their test and I would need to find my rifles COL, so I performed the poor mans method by setting up a case with a 75gr AMax and started out with a high seat and then seated in small increments until the round chambered smoothly and was just off the lands. After litterally about 50 tests of this, I came to my rifles COL of 2.473. Some of the 2.473's chamber and feed smooth, others will not..Some of the 2.302's will chamber and some will not

These are not being loaded for mag...these will be single hand feeders

I do not have my Reloading manual in front of me, but I recall it correctly your COL should be around 2.260".
Somebody please correct me if I'm mistaken.

[fguffey]

I am a big fan of the companion tool to the press, the feeler gage, Redding has one for + $50.00, they list it as a thickness gage. When I want to know if my press, shell holder and die is/was successful in FULL length sizing, or if I full length size a case AND it will not chamber I use the feeler gage to determine if the press sized the case or the case whipped the press. With the ram up and the press jammed, crammed, cammed over or locked up I measure the gap between the top of the shell holder and bottom of the die, in the perfect world there should be no gap, if there is a gap, the case whipped the press, determining 'by how much' is a matter of measuring the gap in thousands. Others use light, me? I always have time and never in mortal combat with the press when reloading.

In the perfect world of reloading cases are new or once fired, beyond that it is down hill, I can not fire a case then neck size it 5 times THEN start over by full length sizing, BECAUSE? After firing a case 6 times, it has been fired 6 times.

F. Guffey

[rumblebee]

Ok....I had to step away from the reloading bench and have a beer. Too much time out there yesterday.

I found the below from Sinclair, which was also pointed out by some members. I now know that to bump back the shoulders on the suspect brass, I need to set the FL die up to do so. I have a feeling this pesky brass was shot from my Bushmaster\AR-15.

http://blog.sinclairintl.com/2009/02/19/setting-up-a-full-length-sizing-die/

I now have cleaned\trimmed and primed about 100 pieces of brass, loaded 25 different pieces (with different powder charges). Can I remove my decapping pin from FL die and run the brass the I have new primers in, safely? I can set the zip spindle so that the neck sizer is high enough that it won't go near the primer. I know I can not punch the new primers back out, unless I want a new and violent hairdo

Thank you for the help and for making me think!

[Hoop]

You need to bump the shoulder back some more (turn the die down a 1/16th of a turn and make sure the brass is going 100% up into it). Yes you can run them up into your sizing die if you take out the primer poker-outer...

[Fjold]

Take the sized brass with no bullet or powder and make sure that they chamber. If your seating die is adjusted to low it will bulge the case at the shoulder and give you problem chambering.

[westcoastr]

and RCBS precision mic would let you measure exactly much you are resizing...and very good investment