The Firing Line Forums

Go Back   The Firing Line Forums > Hogan's Alley > Handguns: The Semi-automatic Forum

Reply
 
Thread Tools Search this Thread
Old January 10, 2019, 11:24 PM   #26
FrankenMauser
Senior Member
 
Join Date: August 25, 2008
Location: Potatoes and Hops
Posts: 11,518
Quote:
It’s the same reason I don’t drop a round in the chamber of a controlled feed rifle.
No, not really.
Some CRF rifle designs don't have enough room in the action, and/or enough flex in the extractor, to allow snap-over. Forcing snap-over in those designs WILL damage the extractor. It's not a "maybe ... eventually". It is WILL damage, right now.

Quote:
But this does suggest that you digress that frequent engagement of said practice is not exactly... beneficial.
Know your weapon and pick your poison: Snap-over and "risk breakage". Or load from a magazine and risk bullet setback.

Which is more likely to cause injury that you prefer to avoid?

(I have chosen the option of a potentially broken extractor over hand and facial injuries.)
__________________
Don't even try it. It's even worse than the internet would lead you to believe.
FrankenMauser is offline  
Old January 10, 2019, 11:40 PM   #27
TunnelRat
Senior Member
 
Join Date: May 22, 2011
Posts: 9,154
Quote:
(I have chosen the option of a potentially broken extractor over hand and facial injuries.)
I've chambered idk how many rounds, many of them multiple times. Bullet setback is fairly noticeable. To me if you chamber a round so many times that you get setback to the level you're describing (where the round blows up on you) without noticing you're not paying attention, incredibly so. I will also say that the only rounds I chamber multiple times are defensive rounds and in my experience they are fairly resistant to setback as most have a cannelure. It does happen, but it takes a long time and by the time it does I've long tossed that round simply because the extractor has chewed up the rim more than I am comfortable with.
__________________
Know the status of your weapon
Keep your muzzle oriented so that no one will be hurt if the firearm discharges
Keep your finger off the trigger until you have an adequate sight picture
Maintain situational awareness

Last edited by TunnelRat; January 10, 2019 at 11:57 PM.
TunnelRat is offline  
Old January 10, 2019, 11:49 PM   #28
5whiskey
Senior Member
 
Join Date: October 23, 2005
Location: US
Posts: 2,939
Quote:
Know your weapon and pick your poison: Snap-over and "risk breakage". Or load from a magazine and risk bullet setback.
Ahh, but do you only fire single shot pistols? Every round fired after the first chambered round in a semi auto is subject to the dangers of the great beast bullet setback. Every round in that 15 round mag, save the first one if you plunk it in the chamber and shut the slide on it, will ram its nose into the feed ramp during the operating cycle. So, 15 out of 16 rounds will experience this violence, why cause undue wear on the extractor to lessen it in 1 out of 16 rounds?

Bullet setback is a real thing, but in normal quality ammo it is not a major concern unless you repeatedly (more than 2 or 3 times) load and unload the same round. And almost every round WILL hit the feed ramp anyway?
__________________
Support the NRA-ILA Auction, ends 03/09/2018

https://thefiringline.com/forums/sho...d.php?t=593946
5whiskey is offline  
Old January 11, 2019, 02:16 AM   #29
JohnKSa
Staff
 
Join Date: February 12, 2001
Location: DFW Area
Posts: 22,049
Quote:
As he was reloading his glock I noticed that he manually loaded the first round into the chamber instead of from a magazine.
So I said that was an unusual practice.

So, is this bad, and if so, why?
Unless a semi-auto is approved for direct chamber loading, rounds should be chambered from a magazine. The extractor can be damaged if it is forced to snap over the rim of a cartridge if it is not designed to do so.

I own a few semi-auto pistols that are designed to tolerate direct chamber loading according to the manual. Glocks are not. In Glocks, the practice can chip the extractor.

Simple solution. Unless the manual or the manufacturer says it's an approved practice, chamber only from the magazine.

At the very least, don't let the slide slam home from all the way back when direct chamber loading a gun that's not designed for it. Only pull the slide back just enough to let it snap over the rim.
Quote:
I'm not advocating loading manually, but trying to see if it's that big a deal.
It won't be a big deal until you chip an extractor. The real question is why do it? Glock provides a method for loading their pistols in the manual. It works just fine.
Quote:
It's having to go around the rim case to do that. So it seems the same function.
If your gun isn't working and you need it to save your life, risking a broken extractor to get it running again seems like a reasonable tradeoff. That doesn't mean it's good for the gun.
Quote:
I expained to him about bullet setback and higher pressures, but this led me to wonder if this is overblown.

If setback does happen on loading the round by manually letting the slide slam forward, then would it be true that every round loaded when gun recycles has setback also? Which then made me wonder if ammunition manufacturers take this higher pressure from setback into account in their loadings.
Some loadings are more sensitive to setback than others. Mild loads with light for caliber bullets and large cases are less sensitive to setback than hot loads with heavy for caliber bullets in small cases.

In extreme cases, a tenth of an inch of setback can double the discharge pressure. That's a real problem.

Premium ammunition with brass cases will not setback from a single chambering, or even several chamberings. I seem to recall that at one point I found some information somewhere from one particular manufacturer stating that their premium ammo should tolerate 4 chamberings without setting back. But eventually, the slamming will break things loose and the bullet will start to setback.

Fortunately, there's a simple solution. Don't keep rechambering the same round over and over. And if it's cheap practice ammo, especially with aluminum casings, chamber it only ONCE.

I have seen ammo that would setback from being chambered once. It was bargain practice ammo with light bullets loaded in aluminum cases and the loading was pretty mild. So I didn't have a problem shooting it--but you can bet I didn't rechamber ANY of that ammo. Once it got into the chamber, it was either fired or discarded.
Quote:
Or load from a magazine and risk bullet setback.
If you have ammunition that is setting back enough from a single chambering to be dangerous, then you need to contact the manufacturer and get your money back rather than adopting non-standard loading practices to try to compensate for the extreme lack of quality in the ammunition.
Quote:
While I'm not into SIGs and Glocks, I have never seen a gun that wasn't designed to have the extractor ride over the rim of a cartridge.
Come on Bill.

It might be reasonable to make the claim that: "In your opinion, every gun you have ever seen appears to be designed to allow the extractor ride over the rim of the cartridge without damage."

Implying that you know with a certainty how the extractor system of every gun you've ever seen was designed to operate is just not remotely credible.

Anyway, unless you've never seen a Kahr, the statement is false. The Kahr P9 manual tells the user: "Do not load an individual round into the chamber and then close the slide. This can damage the extractor. Only chamber rounds from the magazine as described..." Clearly there are pistols that are not designed to have the extractor ride over the rim of a cartridge.
__________________
Do you know about the TEXAS State Rifle Association?
JohnKSa is offline  
Old January 11, 2019, 04:15 AM   #30
Bill DeShivs
Senior Member
 
Join Date: April 7, 2006
Posts: 9,790
I know nothing about Kahrs, obviously.
__________________
Bill DeShivs, Master Cutler
www.billdeshivs.com
Bill DeShivs is offline  
Old January 11, 2019, 11:27 AM   #31
FrankenMauser
Senior Member
 
Join Date: August 25, 2008
Location: Potatoes and Hops
Posts: 11,518
Quote:
If you have ammunition that is setting back enough from a single chambering to be dangerous, then you need to contact the manufacturer and get your money back rather than adopting non-standard loading practices to try to compensate for the extreme lack of quality in the ammunition.
I don't use cheap ammo. I am not compensating for anything, unless you include statistical probability.

All brands and quality levels of ammunition can suffer bullet setback. Whether due to the manufacturer's loading practices, a quality failure, or negligent repeated chambering by the end-user, they can all suffer setback.

The most recent examples that I've setback with were Hornady Critical Defense 90 gr FTX .380 Auto, Speer 124 gr Gold Dot LE 9mm, and Barnes 115 gr TAC-XPD.
It happens with rifle ammo, too - and setback doesn't even have to happen inside a firearm. About two months ago, I dropped a factory Remington .300 Blk 220 gr OTFB subsonic load on a concrete floor. It landed base-first. When I picked it up, the cartridge overall length was more than 0.150" shorter.

I don't think anyone would classify any of the above as "low quality." Yet, they all suffered from bullet setback with minimal or single chamberings (or one drop).


Some people snap-over. Some people don't.

Some people wipe front-to-back. Some people wipe back-to-front.
Some people do both.

It's a personal choice.
(Just don't wipe side-to-side. That's not good for anyone.)
__________________
Don't even try it. It's even worse than the internet would lead you to believe.
FrankenMauser is offline  
Old January 11, 2019, 05:18 PM   #32
OneFreeTexan
Senior Member
 
Join Date: September 15, 2002
Location: West, Texas
Posts: 127
I think. That with the Beretta 92 series, that you can load a single cartridge that way.

Seems I even saw that in this thread here somewhere.?????
OneFreeTexan is offline  
Old January 11, 2019, 06:54 PM   #33
Bill DeShivs
Senior Member
 
Join Date: April 7, 2006
Posts: 9,790
Regardless, most guns are designed for the extractor to slip over the rim of a chambered cartridge. That's why they are sprung.
__________________
Bill DeShivs, Master Cutler
www.billdeshivs.com
Bill DeShivs is offline  
Old January 11, 2019, 07:32 PM   #34
HighValleyRanch
Senior Member
 
Join Date: July 15, 2005
Posts: 3,182
Quote:
Anyway, unless you've never seen a Kahr, the statement is false. The Kahr P9 manual tells the user: "Do not load an individual round into the chamber and then close the slide. This can damage the extractor. Only chamber rounds from the magazine as described..." Clearly there are pistols that are not designed to have the extractor ride over the rim of a cartridge.
I just looked and the Kahr extractor does have a beveled extractor.
Kahr states in their manuals that one should not "slingshot" the slide to chamber a round, but instead release the slide stop to load from a magazine. In fact, I've seen on many forums that many will not purchase a Kahr arms pistol for this very reason, thinking that this would not be good from a defense pistol viewpoint, i.e with a closed slide, and empty chamber you would have to first LOCK BACK THE SLIDE, and then release the slide on the magazine to chambe the round versus simply inserting a magazine and racking the slide.

But on both my Kahrs, a K40 and PM9, they work just fine with an overhand "slingshot" as long as you don't ride the slide forward.

In general, lots of stuff in owners instruction manuals are written by lawyers, not technicians.
__________________
From the sweet grass to the slaughter house; From birth until death; We travel between these two eternities........from 'Broken Trail"
HighValleyRanch is offline  
Old January 11, 2019, 07:43 PM   #35
Walt Sherrill
Senior Member
 
Join Date: February 15, 1999
Location: Winston-Salem, NC USA
Posts: 6,257
Quote:
Originally Posted by Bill DeShivs
Regardless, most guns are designed for the extractor to slip over the rim of a chambered cartridge. That's why they are sprung.
I wonder whether the fact that not all ammo is made exactly to spec might also justify the use of a slightly flexible material in an extractor? Case bases that are a hair larger than spec might eventually break an extractor that wasn't at least a little bit flexible as those oversize cases are slid under the tip of the extractor as it's fed from the magazine. Spring steel extractors might also be a bit more resistant to chips and cracks than harder steel extractors that can't give a little.
Walt Sherrill is offline  
Old January 11, 2019, 11:41 PM   #36
Rinspeed
Senior Member
 
Join Date: February 1, 2000
Posts: 1,460
Quote:
Originally Posted by Bill DeShivs
Regardless, most guns are designed for the extractor to slip over the rim of a chambered cartridge. That's why they are sprung.




Not so sure about that.

Last edited by Rinspeed; January 12, 2019 at 09:47 AM.
Rinspeed is offline  
Old January 12, 2019, 12:05 AM   #37
JohnKSa
Staff
 
Join Date: February 12, 2001
Location: DFW Area
Posts: 22,049
Quote:
Regardless, most guns are designed for the extractor to slip over the rim of a chambered cartridge. That's why they are sprung.
Kahr extractors are "sprung" and still the manufacturer explicitly states that they are not designed to slip over the rim of a chambered cartridge.

I don't think it's true that "most guns" are designed to tolerate that, and clearly, based on the Kahr example, whether they are beveled on the face or "sprung" isn't a reliable way to make the determination.

If you have some other evidence to support your assertion, I would be interested to hear it.
Quote:
All brands and quality levels of ammunition can suffer bullet setback.
This is absolutely true.

HOWEVER, it is absolutely NOT true that chambering a round a single time will setback properly manufactured, good quality ammunition sufficiently to be dangerous. It doesn't even require a lot of thought or careful consideration to realize that good quality, properly manufactured ammunition can safely be chambered and fired.

It is also not true that all ammunition WILL setback even a small amount from a single chambering--in my experience the ammo that will set back from one chambering is in the small minority.

In addition, when we do see setback from a single chambering, the fact that there's measureable setback from a single chambering does not automatically imply that there's a dangerous situation. The setback needs to be significant, not just detectable. A detectable amount of setback from one chambering DOES, however imply that ammunition like that should NEVER be chambered more than once.

What I stated was correct. "If you have ammunition that is setting back enough from a single chambering to be dangerous, then you need to contact the manufacturer and get your money back rather than adopting non-standard loading practices to try to compensate for the extreme lack of quality in the ammunition.

Good quality ammo is safe to chamber normally and fire. Period.

There is no need to direct chamber load to avoid setback with good quality ammo. Period.
Quote:
Kahr states in their manuals that one should not "slingshot" the slide to chamber a round, but instead release the slide stop to load from a magazine.
If you have proper technique, slingshotting the slide actually makes the gun more reliable in the general case because it results in slightly more slide energy than dropping it from the slide release. If you don't have good technique, it can cause misfeeds, particularly in small guns. So Kahr decided that consistency is better than the small amount of extra energy and they tell people to use the slide release instead of slingshotting. However, the whole slide/slingshot is a red herring in this discussion. Kahr doesn't state that slingshotting the slide can damage the gun. They do state that dropping the slide on a chambered round can damage the gun. Two very different things going on here.

Look, if you want to direct chamber load, go for it. It's probably not going to result in rapid breakage--it just stresses parts in ways that they aren't normally stressed and that can cause parts breakage over time.

Don't feel like you have to gain a consensus here before you can do it or feel like you need to convince people who know better that it's actually a good idea.
__________________
Do you know about the TEXAS State Rifle Association?
JohnKSa is offline  
Old January 12, 2019, 09:58 AM   #38
USNRet93
Senior Member
 
Join Date: October 23, 2018
Location: Republic of Boulder, USA
Posts: 545
Quote:
with a closed slide, and empty chamber you would have to first LOCK BACK THE SLIDE, and then release the slide on the magazine to chamber the round versus simply inserting a magazine and racking the slide.
I'm a fairly new 'returnee' to handguns but how is 'locking slide back and releasing with slide release', any different than pulling slide back and letting go of it?
__________________
PhormerPhantomPhlyer

"Tools not Trophies”
USNRet93 is offline  
Old January 12, 2019, 10:02 AM   #39
OhioGuy
Senior Member
 
Join Date: August 11, 2016
Posts: 769
Here's some "science" for you. Because I'm data-driven (and a big nerd) I once went to the range to test this. I ejected and reloaded (from magazine) the same hollow point round 50 times. I did get a few funny looks and one "do you need someone to show you how to shoot?" offer

But after 50 repeated runs, I fired the round. It fired. Don't know what else to say.

Can't say that necessarily establishes anything, but in at least that case, 50 chambering of the round didn't appear to cause any problems.
OhioGuy is offline  
Old January 12, 2019, 10:17 AM   #40
TunnelRat
Senior Member
 
Join Date: May 22, 2011
Posts: 9,154
I'm not really surprised. I haven't gone so far as to use my calipers, but in a visual comparison in terms of bullet exposed even after a number of times with both Speer Gold Dots and Federal HST there is little difference. Again in my experience the case body and rim are chewed up before setback becomes noticeable. However, I acknowledge care should always be taken when it comes to setback and that each ammunition type and individual cartridge need to be examined.

Sent from my Pixel 2 using Tapatalk
TunnelRat is offline  
Old January 12, 2019, 10:21 AM   #41
Walt Sherrill
Senior Member
 
Join Date: February 15, 1999
Location: Winston-Salem, NC USA
Posts: 6,257
Quote:
Originally Posted by OhioGuy
But after 50 repeated runs, I fired the round. It fired. Don't know what else to say.

Can't say that necessarily establishes anything, but in at least that case, 50 chambering of the round didn't appear to cause any problems.
The round will almost certainly fire -- that's not the issue. That you had a round go off wasn't surprising. But you obviously didn't understand that what you were doing was potentially very dangerous.

With round setback, the pressures generated inside the round can increase, sometimes substantially, and that increased pressure can lead to a damaging explosion that could have damaged both the gun and YOU!!

It would have made far more sense to simply measured the round after it had been chambered so many times, but since you didn't understand what the consequences of bullet setback could do, you weren't concerned.

If setback is an issue, it can be measured by using a micrometer (or in some cases, a ruler.) Setback rounds need to disposed of safely or disassembled and reloaded.

Last edited by Walt Sherrill; January 12, 2019 at 10:35 AM.
Walt Sherrill is offline  
Old January 12, 2019, 10:35 AM   #42
Rinspeed
Senior Member
 
Join Date: February 1, 2000
Posts: 1,460
Quote:
Originally Posted by OhioGuy
Here's some "science" for you. Because I'm data-driven (and a big nerd) I once went to the range to test this. I ejected and reloaded (from magazine) the same hollow point round 50 times. I did get a few funny looks and one "do you need someone to show you how to shoot?" offer

But after 50 repeated runs, I fired the round. It fired. Don't know what else to say.

Can't say that necessarily establishes anything, but in at least that case, 50 chambering of the round didn't appear to cause any problems.



I wouldn't try that with a .40 S&W, it only takes 1/10th of an inch of bullet setback to double the chamber pressure.
Rinspeed is offline  
Old January 12, 2019, 03:34 PM   #43
JohnKSa
Staff
 
Join Date: February 12, 2001
Location: DFW Area
Posts: 22,049
Quote:
But after 50 repeated runs, I fired the round. It fired. Don't know what else to say.
As others have pointed out, the issue isn't that setback renders the round inert, it is that it can result in the discharge pressure skyrocketing. Fortunately, in your case, either the round didn't set back much, it wasn't a loading that was especially sensitive to setback, it was a round that was very mild to begin with, the ammo manufacturer had taken precautions to minimize or eliminate setback (e.g. case cannelure), or some combination of the above.
Quote:
I wouldn't try that with a .40 S&W, it only takes 1/10th of an inch of bullet setback to double the chamber pressure.
The data I have seen suggests that some 180gr loadings in .40 S&W can double in discharge pressure from a tenth of an inch of setback. I haven't seen data indicating that all .40S&W loadings, or even all 180gr .40 S&W loadings are that sensitive.
Quote:
...in a visual comparison in terms of bullet exposed even after a number of times with both Speer Gold Dots and Federal HST there is little difference...
I remember reading information from one particular ammo maker that claimed their self-defense ammo would not setback at all from 4 chamberings but that they wouldn't guarantee it past that. Unfortunately I can't find that cite any longer and I don't remember which company made the claim.

Anyway, based on that information, IMO, premium self-defense ammo shouldn't set back at all from being chambered a few times. If it does, the ammo maker in question should be contacted.
__________________
Do you know about the TEXAS State Rifle Association?
JohnKSa is offline  
Old January 12, 2019, 05:58 PM   #44
Nanuk
Senior Member
 
Join Date: January 2, 2005
Location: Where the deer and the antelope roam.
Posts: 2,431
A pistol is not a car or truck. Being a mechanic does not make one an armorer or a gunsmith.

The primers can actually disassemble themselves from repeated chamberings. It has happened to cops who loaded/unloaded the same round over and over over a period of time.
__________________
Retired Law Enforcement
U. S. Army Veteran
Armorer
My rifle and pistol are tools, I am the weapon.
Nanuk is offline  
Old January 13, 2019, 01:57 PM   #45
44 AMP
Staff
 
Join Date: March 11, 2006
Location: Upper US
Posts: 19,109
Quote:
All brands and quality levels of ammunition can suffer bullet setback.
It certainly seems to be the case, these days. However, "can" does not mean "will" or "should".

Chambered 50 time?? piffle!

I knew a fellow who bought some Federal 185gr JHP .45ACP in 1980. He kept the last magazine full as his home defense ammo. Between 1980 and 2002 when he finally shot them off, those rounds were chambered and rechambered HUNDREDS, if not thousands of times. The nickeled cases had brass stripes on them. All the nickel was worn off the edge of the rim. The bullets NEVER set back on any of those rounds. And, yes, they were measured quite often, to see if it happened. It never did. The gun was a Sig P220.

And when fired that ammo performed exactly the same as it had done over 20 years earlier when new. Function was flawless and accuracy was perfect point of aim at 25yds.

I mention this, not to imply in any way that today's ammo will do this, or should be expected to do this, but to show that bullet setback is not something that HAS to happen, rather something that usually does happen, these days. And, I say "these days" because, to the best of my recollection, while it has always been a possibility, it wasn't enough of an issue back in the 60s & 70s that much was written about it, then.

Clearly something has changed over the years, probably quite a few things.
__________________
All else being equal (and it almost never is) bigger bullets tend to work better.
44 AMP is offline  
Old January 13, 2019, 04:02 PM   #46
Walt Sherrill
Senior Member
 
Join Date: February 15, 1999
Location: Winston-Salem, NC USA
Posts: 6,257
Quote:
Originally Posted by 44 amp
I mention this, not to imply in any way that today's ammo will do this, or should be expected to do this, but to show that bullet setback is not something that HAS to happen, rather something that usually does happen, these days. And, I say "these days" because, to the best of my recollection, while it has always been a possibility, it wasn't enough of an issue back in the 60s & 70s that much was written about it, then.

Clearly something has changed over the years, probably quite a few things.
Not the least of them being the internet and the existence and wide participation in forums like this.

It may be that ammo is just as well made as ever, but we now have a place to rant, warn, or say what we believe. In the '60 and '70s darned few gun magazines paid that much attention to semi-auto handguns (they had NOT really caught hold back then) -- and there wasn't many other places to share experiences.
Walt Sherrill is offline  
Old January 13, 2019, 10:09 PM   #47
44 AMP
Staff
 
Join Date: March 11, 2006
Location: Upper US
Posts: 19,109
Might be the ammo is as well made as it always way, might not be, I can't say, but logic does suggest that if the public is willing to accept ammo that is good enough to stand a few chamberings, then making ammo that will stand unlimited chambering is a waste of money.

Maybe the newer semi auto designs, so popular in large numbers slams the rounds harder than the older designs, perhaps with the intent of increased reliability. We know Glock deliberately uses chambers that aren't fully supported, for increased feed reliability.

There's nothing morally wrong with that, nothing says guns intended for military use have to be reloader friendly. Few are, these days. And, ammo that sets back (or has the bullet pulled by recoil) needs to be replaced, which means you buy more ammo, sooner. Good for the ammo companies, I'm sure.

If I missed reading a single issue of Guns & Ammo, Shooting Times, and the American Rifleman from the 60s through the 90s, its a very small number. And, I have nearly complete collection of American Rifleman from 1948 through the 90s when I decided to stop accumulating them, because I couldn't afford a bigger house.

I think there were a lot of articles about semi auto pistols, its just that in before the wondernine explosion there weren't a dozen makers producing 30 different variants of 3 basic designs, each...

Bullet setback? Reloading manual, and articles would all tell you about pushing the nose of the loaded round against the bench (firmly), or something similar, to check for setback, as part of the QC for your handloads. Don't recall much else ever being said about it, even in the Q&A columns. Maybe it existed as a problem back then, but if it did, why not talk about it, we talked about a lot of problems back then, though not nearly like we can today.

And that is probably part of it, as well, with our internet instant communication, and nearly unlimited space, it is quite different from a monthly, printed magazine.
__________________
All else being equal (and it almost never is) bigger bullets tend to work better.
44 AMP is offline  
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 08:35 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
This site and contents, including all posts, Copyright © 1998-2018 S.W.A.T. Magazine
Copyright Complaints: Please direct DMCA Takedown Notices to the registered agent: thefiringline.com
Contact Us
Page generated in 0.09212 seconds with 10 queries