"Unsupported Chambers"

renaissance7697 · August 8, 2001, 03:08 PM

I am going to start loading for a Browning Hi Power in .40 S&W.
I will be using "Range Pick up" Brass, Mine and any others that I sweep up around myself after a firing session (indoors).

I have heard a lot about the dangers of reloading once fired .40 S&W cases which have been fired in guns with "NOT Fully Supported Chambers"
Is the Browning High Power ( in .40 S&W ) one of these.
(Does IT have a NOT fully Supported Chamber)

What common guns DO have a "NOT Fully Supported Chamber"?
Are the Glocks in this category?

If you load at the light end of the scale, is this a "serious" concern
( I DO understand that ANY concern in reloading is serious, but >)

Resizing the case should remove any bulges ( IF they are created)
If you load on the light side, I would hope that the cases would not be weakened enough to present a danger.

I suppose this would be one of these cases where the use of Dillon Dies with the larger radii near the base would NOT be adviseable.

Steve Smith · August 8, 2001, 04:10 PM

Yes, the Glocks definately fit into the non-supported chamber category. I've seen .40 casings with a reverse image of the feedramp on them from this...usually with hot loads. I've also seen this coming out of a Beretta Cougar.

The concern is that if you size the weirded out case, and then shoot it, and size it, and shoot it again, youll eventually start to weaken the brass where it goes in and out from the shooting and sizing. If the weak spot found it's way to the feedramp side of the chamber, you could have a KB.

Poodleshooter · August 8, 2001, 04:20 PM

Quote:

I have heard a lot about the dangers of reloading once fired .40 S&W cases which have been fired in guns with "NOT Fully Supported Chambers"

Horsepuckey. I would venture to say that there are more .40's with unsupported chambers than without. The danger is simply in shooting any old, worn out cases that have bulges, cracks or any of the other signs of excessive past loadings.

Quote:

Is the Browning High Power ( in .40 S&W ) one of these.

I'm not sure about the High Power. Stock barreled 1911's have a partially unsupported chamber IIRC.

Quote:

What common guns DO have a "NOT Fully Supported Chamber"?

Stock Glock chambers are partially unsupported.

Quote:

If you load at the light end of the scale, is this a "serious" concern

Not really. It will increase the possibility of a case failure, but if you're loading hot enough to make it an issue, you'll have problems with any barrel.

Don't resize heavily damaged cases. That will create problems, as the brass is already probably too stretched.

Basically, this is a non-issue with any ammo that is within SAAMI pressures. Many modern autos use a partially unsupported chamber to enhance reliability. Some shooters, (especially Glock shooters) will keep one fully supported aftermarket barrel for hot loads that they think might stress the brass, and save another more reliable barrel for optimum feeding.

grunewaj · August 9, 2001, 08:55 PM

For a lot of great information on KB!s with .40 S&W in general and Glocks in particular, go here:
http://communities.prodigy.net/sport...-glock-kb.html
I would say this is the first, best place to get information about this and should not be missed.

Jim

zeke · August 10, 2001, 05:23 AM

Renman-please pardon my abbreviation of your handle. An additonal possible problem from using .40 range brass from unsupported chambers is feeding reliability. Most carbide dies do not size the case all the down, and in many cases the left over buldge can cause feeding problems in tighter chambers. Apparently glocks have looser chambers, in addition to being unsupported (this increases their reliability). Have seen this problem twice, and read more than a couple of posts of similiar.

The BHP has a supported chamber, not quite sure if it is "fully supported"

Believe Lee sells a die especially made to size the whole case, can not remember distributor address?

Have never shot a glock, but is the indent left on primer a rectangular imprint?

bullet44 · August 10, 2001, 06:43 AM

I reload 40 for the Beretta 96 with no problems,
however like all things use common sense.
Most data I have read on blow ups have been with
Glock and some guns using reloads with 180gr
bullets, it would appear the 180 gr is just too
big for the pressure. Anyway I stay away from
that size.

Poodleshooter · August 10, 2001, 09:46 AM

Quote:

Have never shot a glock, but is the indent left on primer a rectangular imprint?

Yup. The firing pin is flattened on the sides, with a half round tip.

Gary H · August 12, 2001, 01:07 AM

It seems that this is an issue of how safe do you want to be. To be conservative, check your gun for support. You can simply look. An unsupported barrel is obvious when looking at a loaded round in the barrel. I understand that few, if any .40 barrels are fully supported. Many are close to fully supported. Second, don't shoot brass of unknown age and origin. Third, stay away from 180 gr. bullets. Last, load light and use powders that don't burn excessively fast. I would assume that Miwall's .40 reloads might be a good example of the load light and keep the lawyers away. All of this makes sense to me, but I haven't seen any real first hand statistics that separate each of these factors as to risk.

renaissance7697 · August 12, 2001, 05:17 AM

Gary H.

What/Where is/are > "Miwall's .40 reloads"

Ref your:
I would assume that Miwall's .40 reloads might be a good example of the load light and keep the lawyers away

Phil P.

Gary H · August 12, 2001, 09:12 AM

http://www.miwallcorp.com/Merchant2/...01-MR40TMJ155E

These guys run in the low 300 ftpd.

August 8, 2001, 03:08 PM	#1
renaissance7697 Senior Member Join Date: January 14, 2001 Location: Alexandria, VA Posts: 203	"Unsupported Chambers" I am going to start loading for a Browning Hi Power in .40 S&W. I will be using "Range Pick up" Brass, Mine and any others that I sweep up around myself after a firing session (indoors). I have heard a lot about the dangers of reloading once fired .40 S&W cases which have been fired in guns with "NOT Fully Supported Chambers" Is the Browning High Power ( in .40 S&W ) one of these. (Does IT have a NOT fully Supported Chamber) What common guns DO have a "NOT Fully Supported Chamber"? Are the Glocks in this category? If you load at the light end of the scale, is this a "serious" concern ( I DO understand that ANY concern in reloading is serious, but >) Resizing the case should remove any bulges ( IF they are created) If you load on the light side, I would hope that the cases would not be weakened enough to present a danger. I suppose this would be one of these cases where the use of Dillon Dies with the larger radii near the base would NOT be adviseable. __________________ An Armed Society, Is a Polite Society.

August 8, 2001, 04:10 PM	#2
Steve Smith Senior Member Join Date: December 9, 1999 Posts: 4,131	Yes, the Glocks definately fit into the non-supported chamber category. I've seen .40 casings with a reverse image of the feedramp on them from this...usually with hot loads. I've also seen this coming out of a Beretta Cougar. The concern is that if you size the weirded out case, and then shoot it, and size it, and shoot it again, youll eventually start to weaken the brass where it goes in and out from the shooting and sizing. If the weak spot found it's way to the feedramp side of the chamber, you could have a KB. __________________ Favor the X. Steve Smith NRA Life Member

August 12, 2001, 05:17 AM	#9
renaissance7697 Senior Member Join Date: January 14, 2001 Location: Alexandria, VA Posts: 203	for Gary H > "Miwall's .40 reloads" Gary H. What/Where is/are > "Miwall's .40 reloads" Ref your: I would assume that Miwall's .40 reloads might be a good example of the load light and keep the lawyers away Phil P. __________________ An Armed Society, Is a Polite Society.

August 9, 2001, 08:55 PM	#4
grunewaj Senior Member Join Date: June 9, 2001 Location: North Carolina Posts: 133	For a lot of great information on KB!s with .40 S&W in general and Glocks in particular, go here: http://communities.prodigy.net/sport...-glock-kb.html I would say this is the first, best place to get information about this and should not be missed. Jim

August 10, 2001, 05:23 AM	#5
zeke Senior Member Join Date: November 17, 1999 Location: NW Wi Posts: 1,671	Renman-please pardon my abbreviation of your handle. An additonal possible problem from using .40 range brass from unsupported chambers is feeding reliability. Most carbide dies do not size the case all the down, and in many cases the left over buldge can cause feeding problems in tighter chambers. Apparently glocks have looser chambers, in addition to being unsupported (this increases their reliability). Have seen this problem twice, and read more than a couple of posts of similiar. The BHP has a supported chamber, not quite sure if it is "fully supported" Believe Lee sells a die especially made to size the whole case, can not remember distributor address? Have never shot a glock, but is the indent left on primer a rectangular imprint?

August 10, 2001, 06:43 AM	#6
bullet44 Senior Member Join Date: February 21, 2000 Posts: 819	I reload 40 for the Beretta 96 with no problems, however like all things use common sense. Most data I have read on blow ups have been with Glock and some guns using reloads with 180gr bullets, it would appear the 180 gr is just too big for the pressure. Anyway I stay away from that size.

August 12, 2001, 01:07 AM	#8
Gary H Senior Member Join Date: April 26, 2000 Location: Texas Posts: 2,267	It seems that this is an issue of how safe do you want to be. To be conservative, check your gun for support. You can simply look. An unsupported barrel is obvious when looking at a loaded round in the barrel. I understand that few, if any .40 barrels are fully supported. Many are close to fully supported. Second, don't shoot brass of unknown age and origin. Third, stay away from 180 gr. bullets. Last, load light and use powders that don't burn excessively fast. I would assume that Miwall's .40 reloads might be a good example of the load light and keep the lawyers away. All of this makes sense to me, but I haven't seen any real first hand statistics that separate each of these factors as to risk.

August 12, 2001, 09:12 AM	#10
Gary H Senior Member Join Date: April 26, 2000 Location: Texas Posts: 2,267	http://www.miwallcorp.com/Merchant2/...01-MR40TMJ155E These guys run in the low 300 ftpd.