Do all semi's beat up the bullet during chambering?

Someone show me, in print, where any gun maker says their gun will feed everything. You can't. Because they don't, and never did.

The 1911 design does an excellent job at fulfilling what its original "mission statement" was. With some tweaks, it does pretty good doing more than just that.

But it was never built to be all things to everyone, and anyone who tells you different is selling something. ;)

I no longer make a habit of chambering the same round twice and if I rack out a live one I cycle it to bottom of magazine and if I ever got to the bottom I'd toss it before I chambered it twice.
Click to expand...

I'm glad you can afford to toss ammo you have suspicions about. But I do wonder why...

Because you are worried that the setback could cause dangerous high pressure? A valid concern to be sure, but is it really a practical concern?

Any set back that happens is ONLY noticed if you don't shoot that round. And, if it happens on the round you don't shoot, you might as well assume it happens to at least some of the rounds you DO shoot. Did your gun blow up with them? (no) so, ok, why are you worried your gun will blow up now?

Ok, they look scary, and could actually, under just the right conditions actually be dangerous, so tis best to avoid set back rounds if possible.

The easiest way is to simply not use ammo that has bullets set back by the feeding cycle. If XYZ brand does this, then don't use XYZ ammo. Simple.

It matters not at all to me, what the maker claims their ammo does, or what velocity it has, or anything else, if the bullets get set back in the case, the ammo was not correctly crafted.

people who accept setback as one of those "it can't be avoided", things are simply giving the ammo makers a pass on producing less than the best product they can make. If you think it should chamber twice, or 5 times with no setback, and after that it can happen you are still doing it.

Note that I am NOT saying the ammo is shoddy or defective, I'm saying that meeting a lower standard is being accepted by the public, in general, something that didn't happen (or at least we never heard about it much) if eras past.

I'll give you an example I have personal knowledge of. 1980, a fellow bought a .45 and two boxes of Federal 185gr JHP. Great stuff, worked flawlessly, shot to exact point of aim at 25yds, etc. He kept the last 7 rounds of that ammo, it was his "home defense" mag for over 20 years! That ammo got cycled in and out of the chamber so many times (thousands, probably) that the nickel cases had brass streaks on them from wear.

NOT ONE of the bullets EVER moved. (yes, I measured them, several times, years apart.) NO SETBACK!

He did, finally decide to shoot up those rounds, and replace them with something newer. Every one fed, fired and ejected exactly they way the rest of them had in 1980. FLAWLESS.

This, to me is proof that factory ammo CAN be that good. Bullet setback is NOT a "can't be helped" problem, They CAN make ammo that doesn't do that. They just don't, and don't need to these days, because the market accepts it.
 
I read somewhere, long ago that at least one ammo manufacturer made premium self-defense autopistol ammo so that it could be chambered 4 times without setback. I haven't done testing to see if that's true in general, but I wouldn't be overly concerned about chambering premium self-defense ammo a couple of times.

That is NOT a guarantee that all ammo is made the same. I have run across some practice ammo that will setback much more easily than that. Some aluminum case ammo I used at one time would setback after only one or two chamberings. I didn't worry about it because wasn't loaded particularly hot and because there was no reason to chamber it more than once.

Setback increases the discharge pressure of the round. The more the setback, the more the discharge pressure increases. Loadings that use heavy-for-caliber bullets tend to be more sensitive to setback changes. The classic example is the 180gr .40S&W in which a relatively small amount of setback can dramatically increase the peak discharge pressure of the round.
 
But when live-firing, or when slingshotting the first round, it's clearly not smooth, even though it doesn't ever seem to jam now.
Click to expand...

Went to the range this morning, and had four nose-up jams on the last round in the mag (four different mags). I had expected either no failures (like in the last half-dozen range trips), or perhaps failures to chamber the top few rounds of a full mag, if my over-zealous copper removal on the lower feedramp during cleaning had caused a hang up of a bullet on a nose-dive. It's in the hands of my gunsmith now.
 
2Aly8.png



This is a graph of .40sw. Note the huge pressure spike as length drops:eek:
 
The only 45ACP pistol that has given me issues with FTFeed is the 1911. Live fire using Federal JSWC the pistol would make a two clunk sound when chambering a round. My mod of the ramp on the frame and barrel changed the sound to like a single clunk. A faster/smoother transition of the cart. I believe.
 
Last edited:
Setback is something to be aware of, to watch for and to consider in sop's and administrative handeling of your guns and ammo. One need not live in fear of it and you sure as heck can chamber a round more than once before tossing it out.

One of the bad set back stories I read went something along these lines....

It was DOE as I recall, officers report in obtain weapons from armory and load, go on duty. At end of shift go off duty clear weapons and turn in.

This occurs for some number of months... Then it came time for qualiications at the range and one of the guns kb's inspection reveals serious set back in other unfired rounds.

As I recall subject guns were 40 cal glocks.

Obviously this is a bit of an extream case. If you do some quick math with some wild assumptions with this scenario you get something like a minimum of 100 chamberings of a round. So don't do that... In a glock... In 40 cal... Change any variable and it likely is not an issue
 
Some ammo is more sensitive to setback than others.

Corbon DPX I believe will start to setback after just a couple re-chamberings. Corbon might have fixed this issue.
 
It was DOE as I recall, officers report in obtain weapons from armory and load, go on duty. At end of shift go off duty clear weapons and turn in.

This occurs for some number of months... Then it came time for qualiications at the range and one of the guns kb's inspection reveals serious set back in other unfired rounds.

As I recall subject guns were 40 cal glocks.
Click to expand...

That sounds like a perfect storm situation for a KaBoom!

Repeated chamberings from duty carry
(the setback issue)

.40 S&W
(a high pressure "keg of dynamite" cartridge)

Glock pistol
("generously" unsupported chamber)

Am not so sure about DOE, though. I spent 30+ years working at DOE guarded facilities, and never saw the regular officers, nor the TRT guys carry any GLock. Its not impossible, I have no idea what DOE used at other sites. I would tend to doubt any difference though, Govt is pretty big on standardization, at least within agencies.

Might it not have been some other alphabet agency? Or something other than a GLock? possible either way.

Stuff happens. One of the guards shot himself in the foot (and no, it was NOT a holstering accident), another fired a round from his UZI into a lunchroom ceiling. If you look at enough people handling guns over a long enough period of time, you will see all kinds of stuff.

I could tell you some stories, but then, I'd have to kill you, and I'm feeling lazy today. :D:D:rolleyes:
 
Mike_Fontenot said:
I've gotten the impression that the chambering process for all 1911's is very chaotic, with frequent bullet-push-back, and "whops" to the bullet (and also the case). I've seen that on my 10mm Kimber Eclipse, and I've also seen some copper deposits on the small FRAME feed-ramp that is immediately underneath the barrel-mounted feed-ramp ... that's a LONG way below where I'd like the bullet to be during feeding. I also occasionally see some tiny copper fragments left on the feed-ramp, and once even in the upper lug area. Since my gunsmith throated my chamber (several hundred fired rounds ago), I haven't had any more failures to feed or eject, but I still don't like that chaotic feeding precess. In contrast, when I chamber the first round by SLOWLY moving the slide forward (with only a single round in the mag), the feeding is like melted butter ... absolutely smooth and controlled. But when live-firing, or when slingshotting the first round, it's clearly not smooth, even though it doesn't ever seem to jam now.

Do other semi-auto's have chaotic feeding, with bullet-push-back, etc?
Click to expand...
I've deliberately chambered the same round in my Sig p320c for a month now to observe wear. So far all I can see is a minor blemish to the finish. No deformation to the casing at all.

Hornaday Critical Duty JHP 9mm.
 
Different guns put differing amounts of wear on a chambered round. The straighter the shot from the magazine into the chamber, the less wear and tear on the round and the less potential for setback.

Also, different types of ammo tolerate the stresses of chambering differently. Some will tolerate a lot of re-chamberings with no issue while others will setback after a relatively small number of trips from the magazine to the chamber.
 
In my experience, bullet setback is more likely to occur with non-premium "practice" ammo like FMJ than with premium self-defense ammo. For example, I've experienced significant bullet setback before with CCI Blazer Brass .45 ACP 230 gr FMJ. However, out of curiosity, I repeatedly chambered and measured the same round of premium SD ammo to see if setback would occur. I tried this experiment with Federal .45 ACP +P 230 gr HST, Winchester 9mm +P+ 127 gr Ranger-T, and Winchester 10mm 175 gr Silvertip. With all of those loadings in the guns I tried them in (S&W 1911, CZ-75B, and S&W 1076 respectively) I found a couple thousandths of setback within the first one or two chamberings and none thereafter out to 20 chamberings.
 
I picked up my 10mm 1911 from my gunsmith's yesterday afternoon, and I'll test it this Saturday. He said the problem is caused by the top cartridge in the mag (in last Saturday's jams, it was the only round left in the mag) being slid forward when the previously-fed round is fired, purely due to the heavy recoil of the full-spec 10mm. When the round is fired, the slide is closed (of course), and the top cartridge in the mag is being pressed down lower by the bottom of the slide above it than it would be if the slide were all the way back. He says the round was being slid all the way forward by the recoil until it is in contact with the junction between the barrel-mounted feedramp and the frame feedramp. It was hanging up at that point due to the upper feedramp being very slightly aft of the lower feedramp (the offset at the junction is tiny, but it's enough hang up the bullet). When the slide then comes aft and then forward, it hits the rear of the round, but because of the low position of the bullet, the rear of the case misses the extractor, and rotates up in front of the slide, and ends up getting hit by the bottom edge of the slide at roughly the midpoint of the case, pinning it against the aft end of the chamber. His fix was to re-contour the lower part of the barrel-mounted feedramp, so that it is very slightly forward of the top of the frame feedramp (instead of being in the opposite direction), and won't hang up the bullet. And if there is any subsequent buildup of copper in that area, I'm probably going to leave it alone.

That's my understanding of what he said, anyway. I'm hoping for the best at the range.
 
I wonder if you can stronger mag springs from Wolff... if you're not already using the strongest ones available? THAT extra force pressing UP on the topmost round might help, too.
 
I've thought about that, also. But the last time I looked, Wolff didn't have recoil springs in 10mm for either the original Kimber mags (Metalform, rounded follower) or Checkmate (9-round mags with a "collapsing" follower). I've previously emailed Metalform and Checkmate several times (asking about buying new (and perhaps stronger) springs for my magazines, and I've never received a reply from either of them. Likewise for Kimber, itself.

It's possible also that the "preemptive" sliding forward of the next round (due to recoil when the previous round is fired and while the slide is forward) might not necessarily be a bad thing, IF the feedramps are smooth enough (and shaped right) to not snag the bullet.
 
" His fix was to re-contour the lower part of the barrel-mounted feedramp, so that it is very slightly forward of the top of the frame feedramp (instead of being in the opposite direction), and won't hang up the bullet. And if there is any subsequent buildup of copper in that area, I'm probably going to leave it alone."

I find the lower part of the ramp on the barrel to be useless. Can be reduced substantially. Once reduced the ramp on the frame can be extended forward.

Best to keep case head support at the ramp of barrel untouched IMO.
 
745SW said:
Once reduced the ramp on the frame can be extended forward.
Click to expand...

Seems like what you'd want is for the lower feedramp to be extended AFT a bit, to make the upward slope of the ramp less steep. It's already to the point that, when the bullet is that low (with the rear of the case higher once the slide has gone aft), that the axis of the cartridge is getting dangerously close to being perpendicular to the ramp (and it won't want to go either up or down when pushed along its axis by the slide). Adding material AFT on the lower feedramp is what I'm going to try to accomplish by leaving any copper deposits on the lower ramp right where they are, instead of cleaning them off. But who knows ... maybe I won't see any more of those deposits.
 
You can open the lips on the mag a little to allow an earlier release of the cartridge. I would try a different bullet before jacking with the mag. Target shooters shoot SWC ammo, it won't feed at all in a gov. model bbl. The guys that built target guns rampped the bbl and tuned the mags so the flat tip of the bullet doesn't hang on the ramp. Some hollow point bullets hang or stub on the ramps of some guns. Of 7 1911 guns the only problem I've had is the 9MM with the Wilson mags and I'm told they have now redesigned them so they will work. Recently shot a friends Kimber with my 185 Hornady bullets, first round hung on the ramp. They work fine in my guns including my Kimber.
 
I am afraid I haven't discerned the issue here. Is the OP complaining of fairlures? If so, I am not picking that up.

If the OP is complaining about the way feeds are done during fire, then I would ask who cares, barring this being a high-end race gun of some type.

There is a lot of force, and a lot of critical timing employed with these gizmos. If it is working satisfactorily, call it a day. If you want Korriphilia performance out of a Tisas, you are gonna be working on that for a while.
 
You can open the lips on the mag a little to allow an earlier release of the cartridge.
Click to expand...
I'm not saying that adjusting mag feedlips is impossible, but it's not a simple thing. Most of the time, for most people, "adjusting mag feedlips" = "buying a new magazine".
 
JohnKSa said:
Most of the time, for most people, "adjusting mag feedlips" = "buying a new magazine".
Click to expand...

As JohnKSa notes, there's not much adjusting allowed. The metal in most mag feed lips is pretty brittle. Bend the lips too much and you break them; if you bend them too far and try to bring them back a little they'll break, too. (Once bent, they're not all easily unbent.)

Maybe using a file to open the feed lips (moving the file rom front to back) would let you open up the gap a bit....but do it carefully, as you can't replace that lost metal.
 
You must log in or register to reply here.
Back
Top