Today I went to the range with a brand new Ruger GP-100 and 3 boxes of Winchester White Box .38 Special and 1 box of Winchester White Box .357 Mag 125 gr WinClean Jacketed Soft Point (WC3571)
Decided to break in the gun with the .38 special and resulted in a great experience, the ammo showed a great deal of accuracy.
Then I opened the .357 Mag box and noticed that some rounds will require some pressure with my thumb to go all the way in into the cylinder, and after firing, these rounds will jam in the cylinder, forcing my to have to push them out with a punch.
The Range Master saw my problem, looked at an expent case and indicated that these rounds had very high pressure, and the primers were "flat" after being fired.
Also suggested not to continue firing those reounds.
Any one has any experience with WWB .357 mag WinClean?
Thanks

Cuba,

First, that "rangemaster" is an idiot! .357 Magnum factory loads nerly always flatten primers, it is just a matter of degree.

Second, you have just discovered the reason that the advice is frequently given to not fire.38 Spl. in .357 Mag. revolvers. This advice is faulty, but does have some basis.

What happens is that a hard ring of carbon/graphite/and other powder constituents is deposited at the mouth of the .38 case which is shorter than the .357 by a nominal .135" If you fire several and then try to chamber the .357 this ring of deposits interferes with the longer case. Since it does effectively make the chamber diameter smaller you can see a pressure increase at times, but it should not be of any great concern. The second thing that happens is that the longer case fire-forms around the deposit ring and the mouth of the case is then larger than the "ring" causing hard extraction.

There are two ways to avoid this problem. The first is the simplest, don't shoot .38 Spls. during the same session as .357 Mags, at least not first. The second is to dry-brush the chambers at least every 1-2 cylinders which will largely keep the "ring" from forming. Brushing while the deposits are still soft (they harden considerably on cooling) will pretty well eliminate the problem.. While you are at it, if you are shooting lead bullets, run the dry brush down the bore a couple times too and you will remove most of the leading easily.

To dry-brush the bore and chambers use a .375 rifle brush, not a .35 cal. pistol brush! This is big enough to clean the chambers well and does a much better job on the bore than the smaller brush will. The bristles lay back to a degree and the sharp edge of the wire then cuts the fouling better than the .35 brush which will not even contact the chamber walls. USE A BRONZE BRUSH, NEVER A STAINLESS STEEL ONE!

Hope this helps. Brushing with a tight brush immediately after shooting will clean a gun with much less work than waiting until hours ar days later when the gun is cold and the fouling has hardened.

This also works with .22 revolvers which can get hard to chamber after 2-3 cylinders full. I use a 6mm brush for them.

Yup, good advice. Long ago I started loading my '.38 special' loads in .357 brass, got tired of cleaning chambers.

Chucking the brush in a battery-powered drill will make short work of cleaning the chambers, also.

Clean the gun's cylinder good and try the 357's again. I bet they will drop in. If they don't the ammo is defective.

Alk:
That make's a lot of sense. Thank you for your valuable info.
I guess the same could happen with a .44 mag shooting .44 sp. before .44 mag.

500 mag:
I already cleaned the cylinder and the .347 drop in nicely.

I can't wait to go to the range again and try it.

Thank you all !!!

I shoot the Winclean ammo you mentioned. It does just what it's supposed to do. If the primers didn't flatten a bit, I'd be worried.

I think your rangemaster has inhaled too much lead smoke. :rolleyes:

Enjoy that new Ruger.......It'll outlast you AND your kids. Just don't abuse it. No gun deserves that.

PJ :p

I just finished a box of WinClean 357's today. all the primers are flatter than pancakes

I just finished a box of WinClean 357's today. all the primers are flatter than pancakes
Me too....I have used the Win Clean ammo myself...no issues and there is a definite flattening of the primer. I stopped shooting 38 spl. I like the boom of the 357. :p Enjoy....that GP is a great firearm and accurate as heck... and if ya need a hammer .....mack