GP 100 Problem

[elbert]

I just purchased a new GP100. I took it to the range and 38 specials worked perfectly. However, the 357 rounds (PMC) seem to be too big. They drop into the chambers easily, but the cylindar doesn't want to shut completely; it binds just enough that you have to press it closed. Then it can't even rotate. This happened right out of the box, so its not an issue of shooting lots of 38s and not cleaning. :?

Anyone have any ideas? I thought 38 specials and 357 were supposed to be the same size (except for length). Just wanting to try what I can before sending it in to Ruger.

Thanks.

 

[recumbent]

Try a different brand of ammo and see if it does it.
Sounds like the PMC ammo could be out of spec.

 

[wolfee]

elbert, please don't be offended if I am stating the (more than) obvious, but I don't know your shooting experience level. There ARE GP100's chambered 38 Special only. My favorite revolver is one of them. Last spring Davidsons sold zillions of them to their dealers. So, I assume the mark on the right side of the barrel says "357 Magnum" and not "38 Special", right?

 

[Sax.45]

Could be ammo related, also make sure no junk got behind the star on the cylinder preventing ammo to seat properly in the cylinder.

 

[Chuck 100 yd]

Maybe a .357 marked gun chambered in .38 special??

 

[IraIII]

If you shot the 38 specials first, it might just be lead in the cylinder. You should shoot the 357's first, and then the 38 specials, then clean when you get home. Sometimes it doesn't take many rounds of 38 specials to crud up the cylinder enough that the 357's won't chamber easily. Sometimes this problem shows up as hard extraction also. Before you do anything make sure it is clean, use a fired 357 case as a cleaner, sometimes it will scrape the inside of the cylinder clean when you chamber the fired case.

 

[elbert]

Thanks everyone.

Good question...but it is a 357; inscribed on the barrell.

And as for cleaning it, it wouldn't take the 357 shells right out of the box. That's why I then tried the 38 specials.

Sure appreciate everyone's help.

 

[mustang99]

They function check them with 357 dummy rounds before the leave the factory so would try a different kind of ammo and I would make sure it is not a handload.....

 

[stantheman86]

Out of spec ammo.....I bought a few boxes of A-Merc ammo years ago that did the same thing to a S&W 66. Bound the cylinder up, the rims were too thick. You also may have an SP that is fitted a hair too tight and thick rimmed ammo binds it up.

 

[Pal Val]

My GP100 came from the factory pretty tight. Any dirt under the star, or residue in the chambers that prevened the rounds from chambering all he way, caused binding. After a few hundred rounds, it loosened a bit and the problem went away. Frequent cleaning when the gun is new helps.

 

[Carry_Up]

This symptom has been discussed very recently. Before any more guessing, take your feeler gauges and measure headspace and b/c gap. A number of DA models have been arriving with next to zero headspace. .006" is a good number to expect.

It takes a lot of .38 spl shooting to clog a .357 chamber, but you can easily see and feel the buildup if it is there. If I understand the description, the OP fires some .38 spl at the range, then switches to .357. At that time, the cylinder has warmed up and expanded, tightening up the headspace and binding the cylinder. But the same thing happens if the b/c gap is too small. It will happen even faster if you start with the .357. Let's see some numbers....

-cu

 

[WrenNH]

I just want to say, this thread is filled with great information. Thanks. I have an old-ish GP100 that occasionally binds. I've cleaned it very thoroughly - star, cylinder gap, everywhere. I never thought for a second that the ammunition might be at fault. I guess I had a "revolvers can use any ammo" attitude.

I'm going to do some experimentation now.