The Firing Line Forums

Go Back   The Firing Line Forums > The Skunkworks > Handloading, Reloading, and Bullet Casting

Thread Tools Search this Thread
Old May 28, 2020, 10:26 PM   #1
Junior Member
Join Date: November 4, 2015
Location: Western NC
Posts: 2
How to decap spent primers w/o full length resizing

New AR308 build. This rifle will always host my Omega suppressor. I put 60 rounds of Federal match ammo through it. My newly fire formed cases reveal slight over pressure. The spent primers are flowing around the firing pin such that the spent primer 'crater' exceeds the case head by about .001"

My cases won't flush up against my micrometer for an accurate reading when using my head space comparator.

I intend to measure these cases so I can bump the shoulder .002" with my die, based on my rifle's chamber dimensions. I don't want to resize these cases in the process of removing these cratered primers. How can I decap these cases without full length resizing them in the process?
Gunzer is offline  
Old May 28, 2020, 10:56 PM   #2
Senior Member
Join Date: December 10, 2014
Posts: 1,964
Get a Frankford Arsenal hand depriming tool. Maybe 30 bucks and can be used on almost any centerfire cartridge.

you may have a problem with an oversized firing pin hole.

Cratering without other indicators usually doesn't mean much.
Dufus is offline  
Old May 28, 2020, 11:04 PM   #3
Senior Member
Join Date: October 14, 2012
Location: North Central, PA
Posts: 1,487
If you have a RCBS FL die, just turn the screw down so that the decaping pin protrudes far enough to push the primer out without sizing the case at all. I have done this hundreds of times. And broken a decaping pin only once.

Once the decaping pin and expander ball are adjusted far enough. Tighten the jam nut, otherwise the pin may wobble and break.
“We do not seek peace in order to be at war, but we go to war that we may have peace. Be peaceful, therefore, in warring, so that you may vanquish those whom you war against, and bring them to the prosperity of peace.
– St. Augustine
kilotanker22 is offline  
Old May 28, 2020, 11:29 PM   #4
Senior Member
Join Date: March 18, 2009
Location: Temple, TX
Posts: 748
The easiest way is what "kilotanker" said. Just make sure you don't extend the decapping rod too far, hit the web of the cartridge, and bend the rod.

Another way is simply to buy a decapping die. Lee, RCBS, Hornady, Lyman, and Redding all make them. The cost runs from 12 $ for the Lee to about 60$ for a set of Redding decapping dies. The others are somewhere in between.

You can also buy a Lee decapping rod and base for about 8 $. You essentially set the cartridge in the base, insert the rod, and then hit the rod with a hammer. It's effective but slow. However, I've found that it is the only thing that works on military cases with crimped in primers.
hammie is offline  
Old May 29, 2020, 05:41 AM   #5
Senior Member
Join Date: April 28, 2013
Posts: 1,333
I always decap everything with a Lee decapping die before cleaning. Many many thousands of rounds and only replaced the rod once due to missing a Berdan primed 7.62x39 case I picked up at the range.
jetinteriorguy is offline  
Old May 29, 2020, 06:56 AM   #6
Senior Member
Join Date: November 14, 2017
Location: Finger Lakes Region of NY
Posts: 1,030
Every reloader should have a Universal Decapping Die. They are so useful. I have had my Lyman now for about 30 years.

NRA Life Member
NRA Certified Metallic Cartridge Reloading Instructor
USSR is offline  
Old May 29, 2020, 08:21 AM   #7
Senior Member
Join Date: November 13, 2006
Posts: 6,763
In support of those who recommend a universal decapping die : It won't have any effect on your fireformed brass. It only decaps.

Its highly recommended you run your brass through whatever cleaning process you use before you run your brass through your dies.Dirty brass will erode your dies.

If you decap before cleaning,your primer pockets will be cleaned (by most processes)
Adjusting the sequence of your process to first decap,then clean,will make your problem moot. You will have clean,decapped brass before you set up your sizing die.

So,yes,you are on the right track to decap first. The Lee universal decap die is a good,economical tool.

I appreciate and understand your target of .002 head clearance. That is the ideal for bolt guns.

For reliable full lockup on self loaders reliable sources (such as Precision Shooting's Handloading Guide for Competition) suggest a little more head clearance. I'm not the expert to tell you how much. I might suggest .004 for an AR-10. You will have some variability in the brass after sizing. Lets say you don;t want your worst case brass to have less than .002 head clearance.

If over time, if your measurements show .002 variability,it might be best to compensate with a target of .004.

But you are taking a very good approach. Well done!

Last edited by HiBC; May 29, 2020 at 08:30 AM.
HiBC is offline  
Old May 29, 2020, 09:38 AM   #8
Senior Member
Join Date: August 8, 2004
Location: Alabama
Posts: 278
Universal Decapping Die, definitely the way to go - I've got three since reviews led me to try the Lee after already having the small RCBS, and large Redding versions.
Some people spend an entire lifetime wondering if they made a difference in the world. But, the Marines don't have that problem. Ronald Reagan, 1985
hikingman is offline  
Old May 29, 2020, 10:50 AM   #9
Senior Member
Join Date: March 21, 2012
Location: Indianapolis, IN
Posts: 269
i use the lee universal decapping die, its on sale at midway for $12 right now.
Shadow9mm is offline  
Old May 29, 2020, 10:58 AM   #10
Aguila Blanca
Join Date: September 25, 2008
Location: CONUS
Posts: 14,199
I also use a Lee universal decapping die. It has no sizing function -- all it does is puch out the primers.
NRA Life Member / Certified Instructor
1911 Certified Armorer
Aguila Blanca is offline  
Old May 29, 2020, 11:39 AM   #11
Senior Member
Join Date: March 1, 2009
Posts: 3,067
if you want pretty and durable go with a Mighty Armory, 40 bucks but I have have had mine 3 or 4 years and never broke a pin yet. I use the 059 pin for them for small flash holes
“How do I get to the next level?” Well, you get to the next level by being the first one on the range and the last one to leave.” – Jerry Miculek
hounddawg is offline  
Old May 29, 2020, 01:14 PM   #12
Marco Califo
Senior Member
Join Date: April 4, 2011
Location: LA (Los Angeles)
Posts: 1,909
I have used the Lee universal decapping die, in a Lee hand press for years. Recently I bought 3000+ range brass and wanted something faster. I bought one of these:
Get a Frankford Arsenal hand depriming tool.
It is easy to use and faster, and can be done while watching TV.
Either one deprimes without touching the brass with any metal. The deprive rod only touches the primer. The Frankfort comes with three different sizes of plastic collets to hold the brass. $39.99 @ Brownells.
I firmly believe it is best to decap dirty brass first (you can wear latex or nitrile gloves), then wet tumble with pins to clean and scour primer pockets. When you see how much dark black filth, including lead primer residue, comes out in the solution, you will never want to handle dirty brass again. The solution includes citric acid and renders the residue safe for toilets and sewage plants. I would not put in in a residential septic system. The deprimed brass drains faster, too. I would say the separating he steel pins is more work than drying the clean brass. Use distilled or Reverse Osmosis water to clean/rinse faster and leave no hard water residue.
Dekontaminierter Glanz über alles!!
Gruß Glock!
Marco Califo is offline  
Old May 29, 2020, 01:26 PM   #13
44 AMP
Join Date: March 11, 2006
Location: Upper US
Posts: 21,561
I use the LEE "military decapper" punch and base set. No idea the cost today, but its cheaper than a die, doesn't take up a spot in your press, is virtually indestructible, and, you get to hit something!!!

OK, its slow, its 100% manual, but you get to feel the pin go into the flash hole, and so it will do cases with off center flash holes too. IF, SOMEHOW, you manage to break it, Lee will send you another.

Get the set that has two punches, one for .22 cal and one for .30 cal. They'll work for every centerfire that isn't Berdan primed and shorter than the .50 BMG

An added plus, if you have bent case mouths in .22 or .30 the punch can do a fair job "rounding" them back out so they can go in the sizer die.
All else being equal (and it almost never is) bigger bullets tend to work better.
44 AMP is offline  
Old May 29, 2020, 06:16 PM   #14
Average Joe
Senior Member
Join Date: August 29, 2005
Location: Easton, PA
Posts: 1,195
Lee universal decapping die
Average Joe is offline  
Old May 29, 2020, 06:36 PM   #15
Junior Member
Join Date: November 4, 2015
Location: Western NC
Posts: 2
Fantastic. Thank you all for weighing in.
Gunzer is offline  

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

All times are GMT -5. The time now is 09:07 AM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
This site and contents, including all posts, Copyright © 1998-2018 S.W.A.T. Magazine
Copyright Complaints: Please direct DMCA Takedown Notices to the registered agent:
Contact Us
Page generated in 0.06802 seconds with 10 queries