10mm-Auto

Other Ammunition Calibers => Reloading => Topic started by: ML on August 31 2017 06:10:40 PM MDT

Title: Dented Brass
Post by: ML on August 31 2017 06:10:40 PM MDT
New member here. My last batch of reloads was a step up in grains of Accurate No7 but still under max. The bulk of my brass had a dent extending down from the case mouth about a 1/4 inch on one side. Looks like case is hitting ejection port. The gun is a stock G20 Gen 2. Brass is once fired SIG.

Load: 155 grain XTP
         12.4 grains Accurate No 7
         OAL 1.25

My previous load with Accurate No 7 was the same except with 12.0 grains. Both loads shot well and did not exhibit any obvious signs of over pressure. Any thoughts on what is going on and how to correct?(http://i.imgur.com/g7kZorm.jpg)   

Thanks. Sorry for large image. Still learning the ins and outs of image posting.
Title: Re: Dented Brass
Post by: The_Shadow on August 31 2017 07:21:08 PM MDT
Was this from the Desert Eagle pistol in the other post?  It looks like the brass was trapped by the extractor as the slide ran forward.  In other words it may have been tightly held as the next round tried to rise up pushing up the spent casing and crushing on the barrel hood.
Title: Re: Dented Brass
Post by: Texashogman on September 01 2017 11:41:13 AM MDT
Quote from: The_Shadow on August 31 2017 07:21:08 PM MDT
Was this from the Desert Eagle pistol in the other post?  It looks like the brass was trapped by the extractor as the slide ran forward.  In other words it may have been tightly held as the next round tried to rise up pushing up the spent casing and crushing on the barrel hood.
his post says G20 gen 2 --- with the scrape and dent it still looks like the slide is hitting the brass--ejection port dings are not that severe, and don't have those scratches on them--almost looks like it could have been close to a stove pipe?
Title: Re: Dented Brass
Post by: ML on September 01 2017 11:46:13 AM MDT
The gun is a stock G20 Gen2. The gun should have been fairly clean when this happened and has not been fired since. I will run some factory loads thru it this weekend and see what happens as I did not have any factory ammo with me at the time when the case denting occurred. Never thought about trapping by the extractor. 

If the slide is hitting the brass what would be the root cause of this? I will do a control shoot with some SIG factory 180 grain I have that has always shot well in the gun.   
Title: Re: Dented Brass
Post by: sqlbullet on September 01 2017 02:05:59 PM MDT
When I see brass mangled to this extent I usually suspect that the brass is not fully clear of the ejection port when the slide returns to battery.  I would check extractor tension and ejector length.  Correct as needed.
Title: Re: Dented Brass
Post by: ML on September 10 2017 06:24:48 PM MDT
An updated. I replaced the extractor, depressor plunger, plunger spring and bearing. This corrected the problem of my brass collapsing at the case mouth. None of the old extractor components appeared to have any obvious defects or damage. The new spring did seem to be of a stouter construction. I think I got a little tunnel vision on the problem as it happened while working up a load.

Thanks for the help
Title: Re: Dented Brass
Post by: sqlbullet on September 10 2017 11:55:04 PM MDT
Glad you worked out the issue.