MP-Pistol Forum banner

1 - 14 of 14 Posts

·
Registered
Joined
·
25 Posts
Discussion Starter #1
The extractor is not holding the case against the slide.There is a little space between the barrel and the slide.The fireing pin drives it in to the chamber and then on firing the case slams back in to the slide.Click the image to see full size.



Ed





 

·
Registered
Joined
·
25 Posts
Discussion Starter #3
TexanAviator said:
Im going to feel like a noob for asking this... But what am I looking for


Click on the image to see it original size.Not normal flow.



Ed
 

·
Site Staff
Joined
·
9,615 Posts
The contours of the primers are nice and rounded, they sure don't look like the load is too hot.



Be glad they don't look like this:

 

·
Registered
Joined
·
319 Posts
is that a bad sign(the first pic), because mine look like that as well..
 

·
Registered
Joined
·
25 Posts
Discussion Starter #6
mity2 said:
is that a bad sign(the first pic), because mine look like that as well..


Seems to be in the design but not your normal primer flow in an auto.The pic G56 has is in the danger zone,in a glock .40 you might not have all your fingers.

Ed
 

·
Registered
Joined
·
573 Posts
I have never seen that in either my 9mm fullsize, or my wife's 9mm compact. Just a nice, round indent in the middle of the primer is all I have ever seen....sorry, no photos available. Both of those photos look terrible to me.
 

·
Registered
Joined
·
264 Posts
My 9mm full size has some flow, but I dont think its that bad. Fiocchi is pretty hot ammo for factory though. No gunsmith, but I dont think that has much to do with the extractor, but more with headspace.
 

·
Registered
Joined
·
25 Posts
Discussion Starter #10
TAZ said:
My 9mm full size has some flow, but I dont think its that bad. Fiocchi is pretty hot ammo for factory though. No gunsmith, but I dont think that has much to do with the extractor, but more with headspace.


Break the pistol down.Take a shell case and slide it under the extractor.It will be pretty loose and not held tight.Now put the barrel in with out the recoil spring.Wiggle the case and slide the barrel back till it locks up.Push the barrel back hard are slam it back.Now you can hold it up to a bright light and see a slight off set.Any way the extractor design is different that a CZ,H&K or Ruger.Also the pistol lock up is the tightest I have ever seen.The frame and rail design is such that it pulls the slide down tight to the frame.The frame has a bow in it to hold it tight.Squeeze the dust cover and slide.It will have a see saw movement over the front frame rails.

With out going in to detail it should handle a steady diet of really hot loads.I should have included a picture of some +P+ stuff.It almost fills up the primer strike.It is a winner.



Edit to add.The extractor always controls head space in an automatic.If it did not you would be in deep sh*t.



ed
 

·
Registered
Joined
·
757 Posts
Check the serial number of your pistol. If it starts with MPB or a following 3rd letter, there is a clearance cut machined in the face of the slide starting at the 6 o'clock position of the firing pin hole. This cut was introduced to increase reliability due to the striker fired system of the M&P. If you look at the breech face of the slide from the muzzle end, you'll note kind of a tear drop shape to the firing pin hole.



Some standard pressure loads (depends upon hardness of the primer cup) and most higher pressure loads will exhibit some flow into this clearance cut. Most foreign ammunition is loaded to higher pressures than SAAMI specs for standard 9mm.



In other words, quit worrying and shoot.
 

·
Registered
Joined
·
264 Posts
gdog said:
Edit to add.The extractor always controls head space in an automatic.If it did not you would be in deep sh*t.



ed


Learn something new every time. Thanks for the clarification.
 

·
Registered
Joined
·
61 Posts
I must respectfully disagree. Head space in a semi-automatic pistol is not controlled by the extractor. If it is, a potentially dangerous situation exists. If the extractor holds the case away from the breech face prior to ignition, the case will slam back into the breech face with possibly catastrophic consequences when it is fired.



The case mouth of a non-bottleneck cartridge is designed to be a specific length, + or - a few thousandths of an inch. That length will correspond to the chamber depth measured from the breech face to the forward edge of the chamber when the breech is locked to the barrel. A go/no go gauge is sometimes used to verify correct headspace. The breech will close on the go gauge but will not close on the no go gauge.



If a case is too short to maintain proper head space, it may be possible to establish correct head space by seating the bullet out far enough so that it contacts the throat of the chamber and seats the case firmly against the breech face, effectively insuring safe head space. You can tell whether or not a cartridge will properly head space in a chamber by removing the barrel and dropping a cartridge into the chamber. Your finger is sensitive enough to feel whether or not the base of the cartridge is level with the flat of the barrel hood. If the cartridge is below the flat, seat the bullet further out. If the cartridge is above the flat, seat the bullet deeper. This works particularly well with LSWC bullets used for range target practice. Of course, this assumes that the flat of your barrel hood is flush with the breech face of your slide when they are locked.



It should be apparent that crimping the case improperly can easily create a condition of improper head space. A gentle taper crimp can be used but you should use a venier to make sure that you do not over crimp the case and thereby allow it to seat too deeply into the chamber. I never apply a roll crimp to cartridges that are designed to head space on the case mouth.



Ideally, the retention of a bullet in the case is maintained by using a properly sized expander plug mated to the proper size bullet. Sometimes a cannelure is applied to the case to prevent bullet set back if the case tension is unable to hold the bullet in place.



Reloading your own ammunition gives you the ability to control many of the variables that go into making up an accurate, reliable load for your pistol. However, you must first understand those variables and how they work together.



The above is my opinion based upon my life experience and is offered in the spirit of sharing experiences that may benefit someone. What goes around comes around, as they say.
 

·
Registered
Joined
·
2,408 Posts
I must respectfully disagree. Head space in a semi-automatic pistol is not controlled by the extractor. If it is, a potentially dangerous situation exists. If the extractor holds the case away from the breech face prior to ignition, the case will slam back into the breech face with possibly catastrophic consequences when it is fired.



The case mouth of a non-bottleneck cartridge is designed to be a specific length, + or - a few thousandths of an inch. That length will correspond to the chamber depth measured from the breech face to the forward edge of the chamber when the breech is locked to the barrel. A go/no go gauge is sometimes used to verify correct headspace. The breech will close on the go gauge but will not close on the no go gauge.



If a case is too short to maintain proper head space, it may be possible to establish correct head space by seating the bullet out far enough so that it contacts the throat of the chamber and seats the case firmly against the breech face, effectively insuring safe head space. You can tell whether or not a cartridge will properly head space in a chamber by removing the barrel and dropping a cartridge into the chamber. Your finger is sensitive enough to feel whether or not the base of the cartridge is level with the flat of the barrel hood. If the cartridge is below the flat, seat the bullet further out. If the cartridge is above the flat, seat the bullet deeper. This works particularly well with LSWC bullets used for range target practice. Of course, this assumes that the flat of your barrel hood is flush with the breech face of your slide when they are locked.



It should be apparent that crimping the case improperly can easily create a condition of improper head space. A gentle taper crimp can be used but you should use a venier to make sure that you do not over crimp the case and thereby allow it to seat too deeply into the chamber. I never apply a roll crimp to cartridges that are designed to head space on the case mouth.



Ideally, the retention of a bullet in the case is maintained by using a properly sized expander plug mated to the proper size bullet. Sometimes a cannelure is applied to the case to prevent bullet set back if the case tension is unable to hold the bullet in place.



Reloading your own ammunition gives you the ability to control many of the variables that go into making up an accurate, reliable load for your pistol. However, you must first understand those variables and how they work together.



The above is my opinion based upon my life experience and is offered in the spirit of sharing experiences that may benefit someone. What goes around comes around, as they say.


I have to agree 2000% on that one. That's how I was taught to reload and never had any problems. I use a very mild taper crimp and also keep an eye (random mic) on case lengths, do to the (even) slightest possability of improper head space.



Learned from another persons "hard way" experience. He over taper crimped a slightly long 45 case, that wedged past the cases head space in the barrells chamber. ...wasn't a pretty sight.
 
1 - 14 of 14 Posts
Top