Odd 9mm chamber

JimD · 09-30-2014, 02:16 PM

I recently acquired a 1936 S/42 with a strange chamber. About 3/4 of the way into the chamber there is a small "ridge" of metal that is a little smaller in diameter than the rest of the chamber. It seems to amount to about 1/4 the length of the chamber. Cartridges feed and chamber correctly but the fired brass shows a very slight shoulder where that ridge is. It irons out fine when I run the case into a sizing die but I've never seen a chamber like this. Almost like a larger diameter reamer was run about 3/4 of the way in then stopped.

Any ideas?

wlyon · 09-30-2014, 02:43 PM

Believe this is just the stepped chamber that is normal. Bill

John Sabato · 09-30-2014, 02:47 PM

Confirmed. The stepped chamber is standard according to the blueprints. If you want a copy of the blueprints, see the FOR SALE forum. The information is in a sticky post near the top. (YES a shameless plug for the blueprint CD!

)

JimD · 09-30-2014, 03:37 PM

Huh, I never would have thunk it. Learn something everyday. I guess I won't cut it straight now.

JimD · 09-30-2014, 09:14 PM

I just looked into the chambers of my 1908 1st Issue military and my other 1936 S/42. Both have remnants of the stepped chamber but they look to have been reamed a little to eliminate the step.

nukem556 · 09-30-2014, 09:58 PM

My 1917 Artillery had a distinct step. Where in SC, Jim?

JimD · 09-30-2014, 10:19 PM

Quote:

Originally Posted by nukem556

My 1917 Artillery had a distinct step. Where in SC, Jim?

Within 10 miles of you. North of Chapin.

wlyon · 09-30-2014, 11:59 PM

JimD; I suspect more from use than reamed. Bill

09-30-2014, 02:16 PM	#1
JimD User Join Date: Oct 2002 Location: South Carolina Posts: 184 Thanks: 0 Thanked 3 Times in 2 Posts	Odd 9mm chamber I recently acquired a 1936 S/42 with a strange chamber. About 3/4 of the way into the chamber there is a small "ridge" of metal that is a little smaller in diameter than the rest of the chamber. It seems to amount to about 1/4 the length of the chamber. Cartridges feed and chamber correctly but the fired brass shows a very slight shoulder where that ridge is. It irons out fine when I run the case into a sizing die but I've never seen a chamber like this. Almost like a larger diameter reamer was run about 3/4 of the way in then stopped. Any ideas? __________________ "Dyin' aint much of a livin', boy".

09-30-2014, 02:43 PM	#2
wlyon Lifer 2X Lifetime Forum Patron Join Date: May 2005 Location: Somewhere in Montana Posts: 2,652 Thanks: 3,210 Thanked 2,613 Times in 969 Posts	Believe this is just the stepped chamber that is normal. Bill __________________ Bill Lyon

09-30-2014, 02:47 PM	#3
John Sabato Lifer Lifetime Forum Patron Join Date: Jun 2002 Location: The Capital of the Free World Posts: 10,155 Thanks: 3,003 Thanked 2,308 Times in 1,098 Posts	Confirmed. The stepped chamber is standard according to the blueprints. If you want a copy of the blueprints, see the FOR SALE forum. The information is in a sticky post near the top. (YES a shameless plug for the blueprint CD! ) __________________ regards, -John S "...We hold these truths to be self-evident that ALL men are created EQUAL *and are endowed by their Creator* with certain UNALIENABLE* rights, and among these are life, LIBERTY, and the pursuit of happiness..."*

09-30-2014, 03:37 PM	#4
JimD User Join Date: Oct 2002 Location: South Carolina Posts: 184 Thanks: 0 Thanked 3 Times in 2 Posts	Huh, I never would have thunk it. Learn something everyday. I guess I won't cut it straight now. __________________ "Dyin' aint much of a livin', boy".

09-30-2014, 09:14 PM	#5
JimD User Join Date: Oct 2002 Location: South Carolina Posts: 184 Thanks: 0 Thanked 3 Times in 2 Posts	I just looked into the chambers of my 1908 1st Issue military and my other 1936 S/42. Both have remnants of the stepped chamber but they look to have been reamed a little to eliminate the step. __________________ "Dyin' aint much of a livin', boy".

09-30-2014, 09:58 PM	#6
nukem556 User Join Date: Jul 2010 Location: Irmo, SC Posts: 625 Thanks: 35 Thanked 168 Times in 107 Posts	My 1917 Artillery had a distinct step. Where in SC, Jim?

09-30-2014, 11:59 PM	#8
wlyon Lifer 2X Lifetime Forum Patron Join Date: May 2005 Location: Somewhere in Montana Posts: 2,652 Thanks: 3,210 Thanked 2,613 Times in 969 Posts	JimD; I suspect more from use than reamed. Bill __________________ Bill Lyon