FN Herstal Firearms banner

1 - 8 of 8 Posts

·
Registered
Joined
·
5 Posts
Discussion Starter #1
I have a FNX 40, and the spent shell casings have a slight bulge in them. The one that came with the gun has the same bulge. Is this normal? Thanks for any thoughts
 

·
Administrator
Joined
·
11,355 Posts
I have a FNX 40, and the spent shell casings have a slight bulge in them. The one that came with the gun has the same bulge. Is this normal? Thanks for any thoughts
Most short barreled auto pistols (especially compacts) in the higher caliber range has a unsupported chamber. Some are worse then others, ie Glock is worse than HK. Due to the unsupported chamber, your spent casings will have a bulge in them. This is a problem for reloaders as the bulge has to be dealt with and the brass is weakened at the bulge.

Some firearms (Glocks a-hem) are prone to kind of dismantle themselves if the ammo used is rather hot.

Do a search for unsupported chamber: http://fnforum.net/forums/search.php?searchid=1987657

Has been discussed ad-nauseum....
 

·
Registered
Joined
·
21,554 Posts
how bad is it?

I haven't noticed any bulging in my FNP-9 or FNX 45 (both have mostly supported chambers)
 

·
Registered
Joined
·
5 Posts
Discussion Starter #4
I`m not sure what is bad and what's not. You can see it. With the barrel out of the gun, a live round is kind of loose in the chamber. I think the bulge is the casing expanding to the size of the chamber.
 

·
Administrator
Joined
·
11,355 Posts
No, the bulge is caused by the unsupported chamber. It is usually a small area of the chamber that the feed ramps cut into as seen here:



This unsupported area of the chamber causes the bulge in the casing when the firearm is fired. You can see how the feed ramps are cut into the chamber.

http://38super.net/Smart Figures/big_supp-not_supp.jpg
 

·
Registered
Joined
·
1 Posts
FNX-40 Bulging Spent Casings

I have a FNX-40 that I just purchased In Dec 2014 and Im currently taking a 47 hr firearms training and my instructor noticed the same type of thing with my spent Casings. I called FNX and they said that the FNX is considered a Combat weapon and the chamber is designed to be compatible with a wide range of ammo so the clearance in the chamber is bigger than on most handguns. Does anyone that has an FNX-40, 45 or 9mm have bulging shells like mine? bulging casings
 

Attachments

·
Registered
Joined
·
21,554 Posts
My 45's aren't buldged like that. The chamber is slightly looser than my 1911's, but not by much.

What ammo were you shooting?
 
1 - 8 of 8 Posts
Top