Colt Defender woes

[51Cards]

Largely why I don't have a mag carrier for my 229 .

All of this explains (I think ...) why the Defender was gagging on the 2nd round. The slingshot #1 didn't have to cope with mag spring lift --- or lightspeed slide movement. (On the face of it, it would appear that the "slingshot" generates as much force --- but I'd have to think that there is some elastic collision transfer from shot #1 whamming the slide back, then to return to battery.)

I hope no one reads this and tries to put TWO mag springs in.

 

[RogersPrecision]

I agree with Tuner, once again.
The overwhelming majority of malfs I see on guns I build are directly attributable to magazines. More specifically, the mags ability to keep up with the cyclic rate. It's usually the last round, where spring tension is the least.
7 rd mags are definitely more reliable in the majority of guns. This is not to say that 8rd mags can not be totally reliable. Just the 'window of function' is smaller.
Many users try to eliminate friction where ever possible, how ever possible. Polishing the frame rails, using exotic zero friction lubes etc. I suspect a step in the wrong direction.

 

[51Cards]

FIRST: Happy Thanksgiving, folks! You guys are tops!

Meanwhile ...

Choked on a Cor-Bon DPX tonight. Given the "weird" shape of the DPX, maybe that's not really upsetting. It's still eating everything else.

My guy at the store told me originally that he thought the Wilson followers would drop the mags back to 6; the Wilson literature says "no," 7. 7 do indeed fit. But I (and you) already knew that.

Magazine recommendations??????
Dump the COlts and go with ... which is "best" in the Defender?
Or, as has been noted, just go with factory 7-rd followers (NOT the Defender orange woodpecker followers) and drop to 6 rds?

I need to add here that I hear a lot of bad stuff about Colt mags.

I'd also like to mention something else --- for some reason, I shoot this thing better than any other gun I own. I suspect that part of it is the sights (my older eyes finding those white beads pretty well). But I figure there's more to it. One might start out thinking that the Defender would be a "punishing" pistol to fire --- extremely light, big fat rounds. But it isn't. Only my back eventually suffers. The "hand" of the gun is actually pretty near perfect --- and I have arthritis in my thumb bases, and have had four surgeries on my hands. So, try and figure out why this thing feels so good (aside from the 1911-type feel, which probably explains it). I know the flat tail helps (me, at least) because it's a perfect match for my hand. The other beavers and ducks are too rounded for me.

Like I've said before --- my Sig 229 is a near-perfect machine. I'd take the "Zippo bet" with it on a thousand rounds, easy. (Same for my XD-9.) The Defender, no. But I'd really like it to be ...

Therein lies the problem.

No "art" in the Sig or the XD. Should there be? Not the point, is it? Not much "art" in the purpose of a .45 HP, either. Again, not the point.

Tonight, my last sheet, offhand at 50 feet (7+1), held two solid 10's, one breaking the 10, two 9's, and three 8's on a 7" oval target. Not great, but for a creaky 56-year-old that's been glued back together a few times, I'll take it. My friend took the sheet off the clip, held it over his chest, and said, "I think your living room is probably safe." Which is the point.

What I'd like --- in a manner of speaking --- is to be able to hit the thermostat at the other end of the house 1000 times in a row --- and have the misses be my fault.

Happy Thanksgiving to you and yours. (Or y'all .)

 

[1911Tuner]

Colt

Card wrote:

>I need to add here that I hear a lot of bad stuff about Colt mags.<
************

Send'em all to me...Metalform or Checkmate contract, as long as they're 7-rounders. I'll pay postage.

Extrapolating on what Chuck said...Magazines are at the root of nearly all feed-related malfunctions...with extractor setup running a close second for failure to go to/return to battery issues...and most magazine-related problems are traceable to the lack of enough spring tension. There's a limit, of course, and you can have too much...but there's a window of opportunity that lets you adjust a bit for that. Weak springs are pretty much useless.

On 8-round magazines. I've found that McCormick's Powermag to be the most consistently reliable of any out there...if you must have that extra round. I don't know if there's an Officer's Model/Defender flush-fit Powermag available, but the 7 rounders for that size can be turned into the equivalent by adding a Wolff 8-round extra-power spring designed for the standard-length GM magazine....provided that the magazine has the Devel-type, "folded" follower. Wilson-Rogers followers need not apply. That'll help a lot, but doesn't adequately address the
problem of controlling the last round, and preventing it from jumping the follower. More critical in the chopped variants because of the higher recoil spring rates...but workable.

I've never had a problem getting 8-round magazines to function. It's just that I've seen too many of'em run just fine for hundreds of cycles and thousands of rounds....puke once or twice...and continue run for hundreds of rounds/cycles without a hitch. Trust and confidence in the gun is the big question.

It's like a car with an electrical system glitch that shuts it down on the interstate once or twice a year. It's always in the back of your mind if this will be the day that it strands you again. Same with the pistol carried for an
"Up to your Patoot in Pit Vipers" moment. Confidence in your sidearm and in your abilities is the biggie.

So...I simply don't trust 8-round mags...or in your case, 7-round...enough to carry'em in my defensive guns. You may feel differently. My reasoning is that...if I should need to shoot for keeps...the winner and loser will likely be decided well before the magazine is empty...and I'd much rather have a higher chance of the second and third rounds that I probably WILL need as opposed to the last round that I probably WON'T need...and if I'm alive when the magazine is empty and need to reload, it would be good to be able to reload without having to clear a stoppage on the last round, which is where the extended magazines most often fall short.

It's not about guarantees, for nothing mechanical can be guaranteed to function as intended. It's about reducing the odds that a malfunction will occur at a critical moment. Chances...that's all it is. I try to stack the deck whenever possible by using the equipment that has been the most consistent
in my experience...and that's all I can do. That's why we maintain our defensive weapons and keep'em clean and lubed...to increase the chances that they'll work when we NEED for'em to work in that awful split-second of time suspended...while life hangs in the balance.

Again...Your mileage may vary.

 

[51Cards]

Before I tinkered it was almost always the second round. The Wilson springs are pretty long & strong, relative to the originals. If I could accurately measure the spring pressure on the top round of a full magazine, and compare that with an established number ... probably not even completely relevant from weapon to weapon.

When it's good, it's very, very good ...

[too much turkey...]

 

[51Cards]

There's no end to all of the info you provide, Tuner!

So, you got me thinking --- I was visualizing the 1911 operating cycle, and thinking about the stem lock. About the timing. I started thinking about the link, looked it up, and lo! and behold, there was your analysis.

So, marker in hand, a -.005 link in a few days, and another try at force-feeding!

Now, after fiddling, one choke on DPX and one on a Ranger; obviously, not good enough. The current favorite flavor seems to be Fed EFMJ. If that's where it winds up, I'll live with it.

This has become a project. (As you've mentioned, absolute confidence is an essential ingredient. The ammo industry will be the chief recipients of my research endowment. Some boxes and boxes down the road, I might feel about the Defender the way I do about the Sig. Can't complain --- this is the only pistol (or rifle, for that matter) that has ever troubled me. So, I'm ahead of the game.

 

[1911Tuner]

Link

Whoa up there!

Juggling on-center lengths of the link can have some interesting results...some of'em not good. The link times the barrel's disengagement and drop, and increasing or decreasing that length can also keep the barrel from disengaging at all...which falls into the category of not good.

 

[51Cards]

I understand.

With the slide off and the barrel pinned to the frame, there seems to be a lot of play when pushing the barrel forward. If I understand correctly, the loading cartridge strikes the rear of the barrel, pushing it forward during the loading cycle. As I've said, the distance from the ramp to the barrel was never close to 1/32". So I'm wondering if (assuming that it won't ride the pin) the barrel is starting out a) too far back; and b) is rotating up too much too soon.

Conceptually, it makes some sort of sense --- but I need correction if I'm going at it wrong.

Just to complicate things a tad, the extractor does clock slightly, but I don't know how much is unacceptable. The firing pin block is a loose drop-in/drop-out. No extraction problems --- but the extractor can interfere with proper loading, no?

(PS The last thing I want to do is have the barrel coming out of battery too soon.)

 

[1911Tuner]

re:

If the specs of the gun are right, the bullet nose shouldn't strike the barrel ramp, but rather glide over the top corner and put a light downward force on the barrel to keep it from moving forward and up as the slide moves to battery. The barrel shouldn't move forward until the breechface hits the rear face of the hood.

If the barrel doesn't sit far enough forward...viz a viz the mimimum 32nd inch gap...or the frame's feed ramp isn't steep enough to deflect the feeding cartridge high enough to glide over the top corner of the barrel's ramp...you have the makings of a 3-Point Jam/Stem Bind...or worse. If the barrel is pushed into the slide too early, the corners of the slide and barrel lugs contact and the whole cycle stops in a hard jam. A simple stem bind usually goes to battery with a bump on the back of the slide. The hard jam between slide and barrel requires racking the slide to relieve the bind. If the barrel also rides the link during the feeding process...and the link is a little too long...the hard bind is almost a certainty.

The gap is important. The barrel ramp angle is important. The frame ramp angle is critical. 31 degrees...plus a half-degree/minus zip...with the barrel ramp being much more forgiving and much easier to correct in the event of an out-of-spec condition. There are limits, though.

When you release the slide from lock to feed and chamber a round...listen to the gun. If you hear a hard "Ka-Thunk" the bullet nose is hitting the barrel ramp. It may or may not cause a stoppage, depending on just how low it hits...but you can pretty sure that the bullet is being shoved deeper into the case, and it'll cause a stoppage sooner instead of later. If you hear a smooth, metallic "Schhhhlick" The gun is feeding correctly, and it will likely eat about anything that you feed it, assuming that the ammo isn't pure junk.

Early disengagement isn't the only problem with short-linking the barrel. It can actually prevent it feom getting loose from the slide at all. The upper lugs are still partially engaged...the lower lug stops hard against the vertical impact surface...and the barrel is trapped between the moving slide and the frame, with the upper and lower lugs taking the brunt. The same thing can happen with a link that's too long, but for a different reason. Here, the link delays linkdown until the barrel stops on the frame. It never swings far enough to make it to the correct position to draw the barrel downward. Long-linking problems generally don't happen unless you really go off the scale with the length, such as installing a .290 link into a gun that's dimensioned to time correctly with a .278 link.

A field expedient check for incorrect link is to flip the gun upside down and hand-cycle it briskly. If the slide cycles as smoothly as it does right-side up, the link won't cause any damage. This in no way suggests that the particualr link is optimum for the gun...only that it won't destroy the barrel when you fire it.

 

[51Cards]

The hard jam between slide and barrel requires racking the slide to relieve the bind. If the barrel also rides the link during the feeding process...and the link is a little too long...the hard bind is almost a certainty.

Yes ... the kind of jam that you'd get in a nightmare if in a critical situation. The mag has to come out, then the slide wrestled with and the round dropping --- intact --- out the mag well. This is what happens most of the time, when it does happen. The fed round is either solidly pinned in place at the frame ramp/barrel ramp juncture --- or it pipes up.

Sometimes, it's a simple bind; but mostly, it's a hard lock.

It has improved immensley with the throat tinkering --- but I am not going to be removing any more casing support.

Am I correct in assuming that if If I install a "short" link and that in battery, everything still has some "wiggle" and "shake," in addition to the inverted-cycling, that I should be OK, at least in terms of basic function? (I understand that there are a few variables, so, no, I'm not gonna holler if I run into a jam .)

Hmmm ... maybe a Kimber ...

 

[51Cards]

I have to say again here --- in all fairness to Colt --- that this pistol probably came off the line meeting every COLT 1911 standard, i.e., ball flies through it with happy abandon. I doubt that they run a few mags of HP through it on the way through QC ...

 

[1911Tuner]

Wiggle Room

51Cards asked:

>Am I correct in assuming that if If I install a "short" link and that in battery, everything still has some "wiggle" and "shake," in addition to the inverted-cycling, that I should be OK, at least in terms of basic function?<
************

Probably...but there's also the issue of linkdown starting a little too early, while the bullet is still in the barrel, and the pressure still has the lugs horizontally locked.

Linkdown should begin...BEGIN...at about .100 inch of slide travel, and by .250 inch, the barrel should be fully down and have about .012 inch of clearance between it and the underside of the slide. The start of linkdown will vary a little, but generally, it's best for it not to start until the slide has moved rearward at least. 100 inch to give the bullet enough time to exit. FIguring that the slide and barrel together weigh over 38 times what the bullet does...and add the resistance of the recoil and mainsprings...the bullet accelerates about 45 times faster than the slide and barrel do for the first bit of travel. At .090 inch of slide travel, the bullet has moved 4.05 inches. A 5-inch barrel has 4.1 inches of rifling, which means that the bullet would still have .050 inch left before exiting...and the bullet must be out and gone before the breech can safely unlock...or you can have major problems of the kaboom variety.

These are estimates to illustrate the timing, but you'll find that they're pretty close.. It doesn't take a lot of difference in the link's on-center length to change the start of the linkdown phase during the slide's movement. .010 inch is about the equivalent of the thickness of two sheets of 20-bond typing paper. When things are moving this fast, a tiny change can make a lot of difference.

 

[51Cards]

And, since this is a 3" barrel, there's about 2.17" of rifling ahead --- so there should be ample timing?

If these numbers apply to a 5" model, and we apply that to a 3" Defender Lightweight, then the gun has less inertia --- meaning that the bullet travels a shorter distance down the remaining barrel as the slide reaches .090" of travel? At 900fps (10,800 ips), 3" would take about .0003 seconds? I see what you mean about timing!!!

Now --- suppose I have -.005" on the link, but need -.003 to -.004"? I've read in your other material that a slight enlargement of the link hole can be utilized to alter the timing.

I understand that the lugs cannot be disengaged before the bullet exits the muzzle. So the critical factor here is the slide travel distance before disengagement.

The key question that comes to mind is how this affects this particular model. I am making the assumption (on paper, waaaay before anything goes into the tube!!!) that the timing and geometry of the 3" and 5" are virtually identical, except for the inertial difference between the gun weights.

Let me tell you again how much I appreciate your wandering through this with me! I'm starting to wonder how interesting this is to any of the other folks watching ...

 

[1911Tuner]

re:

Yes. The shorter barrels can start linkdown a little earlier than the 5-inch modeld...but it's not in direct proportion to the length. About 90% of the velocity and recoil impulse that the bullet will attain occurs in the first inch of travel, so the slide is well on its way by the time the bullet reaches the end of even a short barrel. To figure how much more time the bullet has before the start of linkdown, use your formula to figure the difference between the
5-inch barrel and the Defender's barrel. One point though...900 fps is an awfully high number for a .45 slug in 2.1 inches of barrel..even for a 185-grain bullet. Was that a ballpark estimate based on the published figures for a 5-inch barrel...or was it chronographed? The reason that I ask is that...the hot rod +p+ ammo typically uses slower-burning powders to get those velocities...and slower powders aren't generally as efficient in abbreviated barrel lengths, with much of the powder burning ahead of the muzzle in a huge fireball after the bullet is gone. Powders like that...and the ammunition they're loaded in...typically get most of their final velocities further along in the barrel...say at 1.5 inch or more of bullet travel, depending on the caliber.

 

[Old Fuff]

I'm starting to wonder how interesting this is to any of the other folks watching ...

Not to worry, we've been there before, and there are a fair nmber of previous threads on this subject. Poor Tuner has to keep reinventing the wheel as new members come along.

As mentioned earlier, the sub-compacts (those with barrel lengths under 4 inches) can present a lot of issues that don't normally effect pistols that have barrel lengths between 4 and 5 inches. Anything that is even so much as a little off can really mess up the works.

Most feeding/chambering problems not caused by magazines can be blamed on the substantial increase in slide velocity (things happen much quicker) and a decrease in run-up (the distance the slide travels from the point it stops its rearward travel to moving forward to the back of the magazine). Then the bullet hits the roof of the chamber quicker and the magazine lips and extractor must let it straighten out. This I think is the reason that some cartridges run while others don't.

Learning to get a full-sized gun to run is sometimes difficult. Starting out on a sub-compact may drive you to drink... :banghead:

 

[51Cards]

Ballpark --- you nailed it --- based on 5" figures. Which means that Little Mr. Slug takes longer to get out. Lower developed velocity trading off against shorter barrel length. Without rambling through all of the math, it still looks like a slightly shorter timing window is still safe --- if I pay attention.

As far as +P goes, I don't see much need for it in this chambering and barrel length. I've put about 20 or 30 rounds of +P through it (for giggles ), but I don't think it's a really great way to treat this frame or my hand. Also, now that there's marginally less case support, it would seem that +P becomes even less desirable. (In spite of the horros you might envision while I grind-grind-grind away, I really am pretty conservative.)

One of our range officers has a scandium/titanium Smith. Told me that the Defender with +P feels like a popgun compared to the J with .357s. I declined the offer to sample ...

 

[51Cards]

Fuff ---

I never really had a problem with drinking to --- it's always come naturally, so to speak .

My XD sub-compact never hesitates --- one look at the internal geometry tells a lot. The round doesn't have to do the mambo to get where it's going.

I realize that this is reiterative. There's a big difference between spending 100's of hours reading about something, and actually having to hold onto the thing you've just worked on. The hand-holding is appreciated. Hopefully, I won't have to be in a position where I can mail it to you .

 

[1911Tuner]

Here's To Ya

>>Learning to get a full-sized gun to run is sometimes difficult. Starting out on a sub-compact may drive you to drink...<<
*************

*hic*

 

[Old Fuff]

*hic*

I know..... I know......

 

[gamachinist]

I'm reading and learning from all this.

I've probably read it before in some of the other threads.but with allmy other worries,I tend to forget things and have to relearn things like this!

 

[51Cards]

OK, I have to bring up an ugly topic --- the "unsupported case."

With a standard load (not +P), how much of the case can be unsupported?

However, due to the low operating pressure of the .45 ACP, a small amount of unsupported case is not usually a cause for concern.

(from Wikipedia)

So, what is "a small amount?"

(No, I am not trying to find the Outer Limit . I'd just like to know what dimension is , and what is .)

 

[1911Tuner]

Non-Support

Anything more than just a smidgen past the web...

Seriously, it depends on several things, including the brass case itself. I've seen chambers with badly overcut ramps that caused cases to bulge almost to the point of failure...and practically zero bulging with other brands of ammo. Thick, tough brass...GI-spec...will tolerate it much better than some commercial brands. Federal and Remington-Peters are two brands that do best with a lot of support. PMC and Winchester are more forgiving.

Headspace is another factor. Excessive headspace can come from two causes. Deep chamber isn't dangerous. Worn, deformed, or out-of-spec
barrel to slide lug fit is. You can seat the round to the chamber stop shoulder and have a fully supported case, and if the locking lug fit throws the headspace too far out of tolerance, the case will back out under pressure
and cause the case to lose support. If the case is weak or brittle...or if the chamber has been compromised by over-zealous "throating" you can have a problem. Checking the amount of support by dropping a round into the chamber isn't a reliable litmus test. Neither is the fact that that same round
sits flush with the chamber hood.

Quick explanation:

If you start with a .010 inch short chambered barrel that has a theoretically perfect fit to the slide...and use a chamber reamer to deepen the chamber enough to allow the slide to just go to battery on a minimum "GO' gauge, you have all the support that the design will allow.

On the other hand...if you take that same barrel and file .010 inch of thickness off the front faces of the barrel's locking lugs, the slide will again just go to battery on the minimum gauge...but you'll have .020 inch of unsupported case...even though the headspace checks at minimum, and the barrel fit is theoretically "perfect."

Why?

Because with the second barrel...when the gun fires, the slide is driven rearward while the bullet passing through the bore holds the barrel forward until the locking lugs make contact. The case backs out of the chamber until it stops against the breechface, and the case loses that amount of support because the breech essentially opens .010 inch during the pressure peak.
Straight-walled pistol cases aren't nailed to the chamber walls like a high-pressure bottleneck rifle cartridge. They slip unless they have something behind them that holds them in place. In other words, the case follows the slide, and if the lug fit allows the slide and barrel to separate .010 inch before the lugs engage...the breech is open by that amount and the case head is kissing air instead of chamber.

 

[51Cards]

Kinda makes you (me) appreciate JMB even more.

They call baseball "a game of inches." What an easy sport ...

 

[orionengnr]

Tuner--
Post #34 was a gem. I learn something every time I read one of your posts.

I wish you would write a book. I'd buy at least three copies. One for me, one for my 1911 enthusiast friend, and one ...just 'cause.

51--

They call baseball "a game of inches."

Actually, football is called "a game of inches". Baseball is called...ah, never mind, this is The High Road, after all...

 

[51Cards]

and some days, time at the range seems more like "a game of yards"

Funny --- one of the things I like about this place, things come to mind with everything folks say ---

--- like orionengnr's post about #34 above brings to mind another question, Dr. Tuner: With or without a link change, the field-expedient test makes sense; does it also make sense to live-test with the magazine out on the first round? If there's a cycling problem (or the K-word ), it seems like it might be better to leave things as open as possible.

Work for the best, plan for the worst ...