Small Ridge Around Brass?

[nhglyn]

I use a Dillon 550B (loading 38 Super) and have the following dies installed:

#1- Redding Sizer/decapper die

#2- Powder die

#3- Redding Competition Seating die

#4- Lee Crimp and Sizer die

I have noticed lately a ridge around the finished ammo. It goes around the case a short ways up from the case head. Almost like the die is not sizing all the way to the bottom of the case anymore. I have checked and the bottom of the die does contact the shell plate at the bottom of the stroke. The rounds still fit into my case checker and fire fine.

Any ideas as to why this is happening now? Didn't notice it until a few weeks ago. Is there a better full length sizer/crimp die on the market now that people are using that will prevent this ridge from appearing and size the finished round all the way to the casehead?

Thanks for any help/suggestions.

[ihatepickles]

Has this recently changed or are you unaware of always happening?

If you size further down the case, the die has less funnel to accept the case. This will result in crushed cases at station 1 occasionally. You can have the bottom of a die ground down to make it size further down the case. A lot of folks use U-dies but I think this overworks the brass, I don't use them unless the pistol has a super tight chamber.

[newshooter]

Hello i think i had a similar problem as you did. I asked the same question a while back and just found where i posted up my question with a few pictures. Take a look at it and see if your brass looked similar to what mine was doing. Hope this helps you some. Heres the link to my question on sizing

http://www.brianenos.com/forums/index.php?...38+super+sizing

Joey

Edited November 19, 2006 by newshooter

[nhglyn]

This seems to have "crept up on me" in the last few weeks/months. Never noticed it before, and I have not changed the setting on any of the dies since this has shown up.

Ridge is not nearly as defined/pronounced as those in your photo. Brass is not raised into a ridge you can feel, something visible but not raised.

What is the difference between the EGW u die and the Lee factory crimp die I am using now? Plusses and minuses of each?

Thanks.

[Allgoodhits]

This seems to have "crept up on me" in the last few weeks/months. Never noticed it before, and I have not changed the setting on any of the dies since this has shown up.

Ridge is not nearly as defined/pronounced as those in your photo. Brass is not raised into a ridge you can feel, something visible but not raised.

What is the difference between the EGW u die and the Lee factory crimp die I am using now? Plusses and minuses of each?

Thanks.

It appears (no pun intended) that if the issue is visual only with no dimensional issue at all and the ammo is accurate and feeds then there is no problem.

Clean the brass thoroughly and wipe your sizer die out. Load some more and "see" what you get. Also, you may try some new brass to see if there is any difference. A long shot "may" be that the shell plate is "rocking" too much thus you are sizing slightly more on side closest to the bolt than the outside position.

Good Luck,

MJ

[Flexmoney]

What is the difference between the EGW u die and the Lee factory crimp die I am using now? Plusses and minuses of each?

Thanks.

The EGW U die goes in station 1. The FCD goes in the last station.

Did I read that your dies aren't set to touch the shell plate?

[nhglyn]

No, the dies do touch the shellplate.

[ParaJoe]

I have that same line on my 40 brass. In about the same spot although I am using a Lee Sizing die. When I am able to feel the bulge in the case at that spot, the case goes in the trash. I think of it as a weak spot in the brass and an invitation for a case head separation which I something I cannot afford nor would like to experience. IMHO YMMV

Joe

[big_kahuna]

I have that same line on my 40 brass. In about the same spot although I am using a Lee Sizing die. When I am able to feel the bulge in the case at that spot, the case goes in the trash. I think of it as a weak spot in the brass and an invitation for a case head separation which I something I cannot afford nor would like to experience. IMHO YMMV

Joe

+1. The brass is wearing out due to case head expansion, and you should throw it away before you get a case head separation.

Theory and application:

Measure the case head diameters (just forward of the extractor groove) on some of this old brass BEFORE YOU SIZE IT and compare it to your new brass. Use a micrometer if you have one, much better tool than calipers for this measurement. Then, size the old brass and look for the telltale line/ridge... if you have a line/ridge then measure the case head again. If there are any significant differences between the case head measurements (new case versus old unsized versus old resized case with line), that's evidence that that your old case heads are expanding beyond the point of the case's safe life... your sizing die is squeezing the case walls down, and then encounters a sudden increase in resistance as it reaches the expanded case head area. The brass is getting worked at this junction point (the line or ridge area), getting embrittled as it gets thinner and weaker. Continued use of the case will result in case head separation.