Clean GP100 and .357 Cartridges

montelores · October 18, 2009, 08:55 AM

My first time firing a GP100 with .357 (only .38 Spl. previously) and the cartridges slide quite easily fore and aft in the chambers (the owner had cleaned the chambers due to advice about switching to .357 after .38 Spl.).

The .357 cartridges would slide back against the frame when the revolver was tilted up.

Question: Is there a problem if the cartridge is free to slide back and forth in this manner? I realize that the firing pin strike on the primer will knock the cartridge forward upon impact, but what happens after that?

This may only be a problem with a clean chamber, and a few rounds of residue will most likely change the situation.

As always, thank you for sharing your knowledge with me.

Monty

Rich Miranda · October 18, 2009, 09:01 AM

Monty, my Rugers have always done that to some degree. Never had a problem with them or that. I think that space is necessary so that you can get the cylinder closed after you've loaded it. Normal, I believe.

Rich

indiandave · October 18, 2009, 09:21 AM

All revolvers do this. If the chambers were really tight you would always have trouble loading her up. Don't worry your gun is fine.

robmkivseries70 · October 18, 2009, 02:36 PM

Once fired, the brass will swell from the pressure and be a bit tighter so you won't have empty brass knocking about. If it doesn't eject easily, there are over pressure problems or something in the chamber that has captured the fired brass.
Best,
Rob

GP100man · October 18, 2009, 06:28 PM

it`s neccesary to let the case heads go by the recoil shield.On the GP insert a case & ya should have between .008-.012, .010 being optimum between case & recoil shield.

what happens during firing is the firing pin drives the case forward then begins denting the primer , when the primer ignites the primer slips back against the recoil shield (this is why when ya fire a case with just a primer the revolver ties up & won`t rotate) then pressure starts to build from the burning propellant pushin the case back against the recoil shield reseatin the primer, as pressure continues to build it seals the chamber & pushes the bullet on it`s way.

wanted to add: brass is a memory metal , meaning it likes stayin the same size .
during firing the pressure makes it seal in the chambers & after that pressure is removed it releases & tries to go back to it`s original size .
when loaded to over pressures the cyl actually swells & the brass with it & when the cyl returns (hopefully) to it`s original size the brass can`t & thus a stiky situation!!!

montelores · October 18, 2009, 09:32 PM

Thank you all for the responses. I appreciate the very clear explanations. GP100Man, thanks for the "blow-by-blow" sequence.

After firing, most of the the previously loose cases would remain in the "up" position (one would occasionally fall back into the chamber) after I pushed the extractor. It was a light push to extract them, so I assume that is how it is supposed to work.

The .357 has a much sharper recoil than the .38 Spls. (my first time with the caliber in a revolver), so it took a bit of time to get accustomed to it. The sights (sighted in for .38 Spls.) seemed to be quite close for the .357s, whereas the point of impact for a rifle changed by 6 inches when one switched from .38 Spl. to .357 (6 " higher at 50 yards for the .357s).

Thanks again,

Monty

Sport45 · October 19, 2009, 04:53 AM

Quote:

Originally Posted by montelores

After firing, most of the the previously loose cases would remain in the "up" position (one would occasionally fall back into the chamber) after I pushed the extractor. It was a light push to extract them, so I assume that is how it is supposed to work.

Get in the habit of pointing the muzzle up when extracting. Give the extractor a bit of a whack to sharply drive the cases out. That way none will fall back in or hang up under the extractor star.

**JohnKSa** · October 19, 2009, 02:05 PM

Quote:

This may only be a problem with a clean chamber, and a few rounds of residue will most likely change the situation.

It's not a problem at all.

The cartridge actually under the firing pin is the only one that really matters and it doesn't have nearly as much play as some of the other cartridges. The two loosest cartridges are the ones that are most visible--the two on the left side of the gun.

montelores · October 19, 2009, 02:43 PM

Thank you for the pointers -

Monty

October 18, 2009, 08:55 AM	#1
montelores Senior Member Join Date: January 2, 2009 Posts: 239	Clean GP100 and .357 Cartridges My first time firing a GP100 with .357 (only .38 Spl. previously) and the cartridges slide quite easily fore and aft in the chambers (the owner had cleaned the chambers due to advice about switching to .357 after .38 Spl.). The .357 cartridges would slide back against the frame when the revolver was tilted up. Question: Is there a problem if the cartridge is free to slide back and forth in this manner? I realize that the firing pin strike on the primer will knock the cartridge forward upon impact, but what happens after that? This may only be a problem with a clean chamber, and a few rounds of residue will most likely change the situation. As always, thank you for sharing your knowledge with me. Monty

October 18, 2009, 09:01 AM	#2
Rich Miranda Senior Member Join Date: May 4, 2008 Location: San Antonio, not San Antone... Posts: 1,203	Monty, my Rugers have always done that to some degree. Never had a problem with them or that. I think that space is necessary so that you can get the cylinder closed after you've loaded it. Normal, I believe. Rich __________________ Read this!: I collect .38 Special and .357 Mag cartridges and I will PAY CASH for the headstamps I don't already have! Please PM me. Please donate blood, plasma, and platelets - people's lives literally depend on it.

October 18, 2009, 06:28 PM	#5
GP100man Senior Member Join Date: August 1, 2007 Location: Tabor City , NC. Posts: 1,969	head space it`s neccesary to let the case heads go by the recoil shield.On the GP insert a case & ya should have between .008-.012, .010 being optimum between case & recoil shield. what happens during firing is the firing pin drives the case forward then begins denting the primer , when the primer ignites the primer slips back against the recoil shield (this is why when ya fire a case with just a primer the revolver ties up & won`t rotate) then pressure starts to build from the burning propellant pushin the case back against the recoil shield reseatin the primer, as pressure continues to build it seals the chamber & pushes the bullet on it`s way. wanted to add: brass is a memory metal , meaning it likes stayin the same size . during firing the pressure makes it seal in the chambers & after that pressure is removed it releases & tries to go back to it`s original size . when loaded to over pressures the cyl actually swells & the brass with it & when the cyl returns (hopefully) to it`s original size the brass can`t & thus a stiky situation!!! __________________ GP100man Last edited by GP100man; October 18, 2009 at 06:35 PM. Reason: addition & spelun

October 18, 2009, 09:21 AM	#3
indiandave Senior Member Join Date: January 17, 2008 Location: Pennsylvania Posts: 214	All revolvers do this. If the chambers were really tight you would always have trouble loading her up. Don't worry your gun is fine.

October 18, 2009, 02:36 PM	#4
robmkivseries70 Senior Member Join Date: November 15, 2005 Location: free territory Posts: 203	Once fired, the brass will swell from the pressure and be a bit tighter so you won't have empty brass knocking about. If it doesn't eject easily, there are over pressure problems or something in the chamber that has captured the fired brass. Best, Rob

October 18, 2009, 09:32 PM	#6
montelores Senior Member Join Date: January 2, 2009 Posts: 239	Thank you all for the responses. I appreciate the very clear explanations. GP100Man, thanks for the "blow-by-blow" sequence. After firing, most of the the previously loose cases would remain in the "up" position (one would occasionally fall back into the chamber) after I pushed the extractor. It was a light push to extract them, so I assume that is how it is supposed to work. The .357 has a much sharper recoil than the .38 Spls. (my first time with the caliber in a revolver), so it took a bit of time to get accustomed to it. The sights (sighted in for .38 Spls.) seemed to be quite close for the .357s, whereas the point of impact for a rifle changed by 6 inches when one switched from .38 Spl. to .357 (6 " higher at 50 yards for the .357s). Thanks again, Monty

October 19, 2009, 02:43 PM	#9
montelores Senior Member Join Date: January 2, 2009 Posts: 239	Thank you for the pointers - Monty