Saturday, April 09, 2005

Hard Parts

I've had a few questions related to gun setup come by in the past few days; and I'm sure you've noticed by now, I'll take any excuse to talk about guns.

A reader on the NOR Forums asks the following question:
I just noticed that the slide stop notch is starting to round, as you've probably guessed. My question is what I should do about it.

Some background... I've installed an extended slide stop and a Wolff 18.5# spring, both of which I believe may be contributing to the problem...

...I think the slide stop is a problem as well because it seems to be harder steel than the one I replaced. I can easily swap the old one back in and just deal with doing only tactical reloads or releasing the slide with my left thumb, I suppose. This is much more of a guess than the spring/GI mag thing.
Another reader sent me this question in email:
I recently bought my first 1911. It is a Springfield milspec (not the GI). It shoots well and I like it but I do get a bit of hammer bite. So I gather the thing to do is to have a bobbed or skeleton hammer put on. Does this mean I need to get a new grip safety as well? Also, what is your opinion on ambi safeties? Are they useful? I am righthanded and don't have trouble with the stock safety but doing lefthanded drills shows me that flipping off the safety with just my left hand would be difficult.
These questions give me a great excuse to talk a little about gun setup, and a little more about technique (which is actually the more important discussion).

I'm going to address them in reverse order:

Hammer bite. The bane of the meaty hand, and John Brownings gun designs. Hammerbite is the best way I can think of to develop a flinch with the 1911 or hi-power (regardless of caliber), and it doesn't need to be; there's a couple of very easy solutions (at least for the 1911, the BHP is more expensive to fix). Glocks have a related problem called GlockBite, and it's harder to fix, usually involving retraining your grip (bad), or a trip to Robar (expensive); but for a 1911, you can fix the problem for $100 to $200.

First step: replace the hammer with a rowell or skeleton hammer (vs. the spur hammer that comes standard on mil-spec guns).

You COULD just buy a hammer for between $25, and $60 , but then you would need to do a full (and more difficult) trigger job on the gun. you don't know how well the new hammer will mate with the original sear; and msot importantly you don't know whether they will gall on each other because of differing hardness.

What I recommend instead, is buying a matched hammer and sear (or hammer, sear, and disconnector) from Wilson, Ed Brown, Les Baer, or Chip McCormick for between $50 and $100. Even better; at various times they have all offered matched sets which are sold as "drop in, no trigger job needed" for between $100 and $150. Though they seem to go in and out of their catalogs; if you call them up and ask, they may have some around, or do one for you.

I'm going to make a specific recommendation here: The Yost Bonitz Ignition system is in MY gun, and I LOVE it; plus, it's cheaper than Wilsons drop in setup, at $105.95.

First; the hammer, sear, and disconnector, are very high quality pieces; EDM wire cut and CNC precision matched to each other. Second, and more importantly; the hammer and sear are hand matched, and all parts are hardedned to 50-53rc AFTER MACHINING.

I can't tell you how important that last bit is. If the parts aren't properly hardened after final machining, they WILL wear rapidly, and unevenly, they WILL burr, and they WILL eventually fail. Light stoning is acceptable, but any major machining can cut through the hardened surfaces.

Lately it's become common for the factories to hardchrome investment cast hard parts (slide stop, safety, hammer, sear, disconnector, magazine catch, and sometimes guide rod), which can be a great finish, because it is very hard, and very wear resistant. The problem is, it results in a VERY high surface hardness (there are two processes resulting in hardnesses of 52-60rc, or 70-82rc) that doesn't penetrate very far; over very soft (around 30rc) interior metals. This is fine so long as you don't machine through the hardened layer, but a good trigger job can go down to the softer metal, which will eventually cause your trigger to fail.

Personally, I HIGHLY recommend buying a hardened steel trigger group, safety ($20-30 for plain, $40-60 for ambi), and slide stop ($30-60, from Wilson or Brown); as generally the factory pieces are crap. They are usually servicable crap, but take a look at the serrations on your hammer and slide stop; and unless you have a Wilson, Brown, Baer, or Yost; I'll bet you the serrations are cast in (instead of machined as custom pieces usually are), rounded, and not very grippy. This isn't a be-all-end-all test, but it's a pretty good indication of the quality and precision differences.

All the matched sets, safeties, and slidestops say "fitting by a gunsmith required" but really as long as you can detail strip your gun, you're good to go, with maybe just a little bit of stoning. Yes, you should have a qualified gunsmith do any work (for liability and safety reasons), but if the piece is already machined and stoned properly, all your gunsmith is going to do is inspect it, and charge you his minimum rate (of course Yost is my gunsmith, his shop is 7 miles from me).

Next; to the grip safety: I personally recommend a beavertail, and if your gun didnt come with one already (pretty rare these days), you can get a drop in for about $40. Sure, it won't look as good as the gunsmith custom machined piece (which will run you anywhere from $100-$150 installed), but it's cheap, fast, and it works.

A beavertail grip safety isn't absolutely necesary, but in addition to absolutely preventing hammerbite; a beavertail allows for a higher indexed grip, and a deeper indexing into the palm and web of the hand. This higher and deeper indexing allows for a better grip in general, a shorter and more precise trigger pull, easier control manipulation, and better recoil control, with faster sight picture recovery. Most beavertails these days also feature a "speed-bump" (originally developed by custom gunsmiths, and popularized by Ed Brown); a feature that ensures a more positive dis-engagement of the grip safety, and helps with the muscle memory of your indexed grip (because the bump is easily felt in your palm).

After all that, why wouldn't you want one? Well, some people don't like how they look; and they add a little length to the gun, which makes guns equipped with them slightly harder to conceal. Personally, I'll take that tradeoff any day.

Now, I just recommended buying a hardened tool steel slide stop, but most slides aren't hardened to 53 rc (from 38-46 are typical). Won't that cause a problem? After all, reader number one above says: "I just noticed that the slide stop notch is starting to round, ...I think the slide stop is a problem as well because it seems to be harder steel than the one I replaced"

This is a very common issue people have with their guns; really EVERY 1911 will start to round out the notch as you go; tool steel stop, or factory stop, doesn't really matter, the bottom edge of that notch is going to round out eventually.

The bottom of the notch rounding isn't a problem; it's normal. There's only a problem if the stop either doesn't engage, or is too easy, or too hard to disengage.

If you do have a problem with engagement or disengagement, there's a process to follow (or even if you don't; it works for every gun):

First, you need to deburr, and slightly relieve the edges of the notch; to ensure consistent engagement. Make sure all three sides (and the bottom, though thats less important) of the notch are flat, smooth, and burr free; with smoothly radiused transitions between the faces.

Second, take the slide stop itself, and smooth the contact faces and top of the stop tab, so that they are even, and unburred.

Next, look at where the stop hits the notch. it should be more than half way up; if it's not, the angles are wrong. The stop tab, and the notch are machined at approximately reciprocal angles, with the slide stop machined to a slightly greater angle (when clocking the angle from the corner of the bearing face of the stop); and the final angle of incidence (which will be smaller than the difference between the machined angles) is formed by the rotation of the slide stop. This angle of incidence between the notch and the stop should be no less than 1.5, and no more than 5 degrees; really it should be about 2-3 degrees, but I've seen properly functioning guns at both ends of the range. The top of the stop shouldnt be directly in contact with the top of the notch; if it is, the stop is too high,;most likely because the angle is wrong.

This is a frequent problem with replacement slide stops in a factory gun, because the replacement part is frequently machined at a slightly different angle than the original stop; and it causes binding, slipping, or hitting the top of the notch. It is also sometimes necessary to dimple the bearing face of the slide stop, so that the slide stop plunger will engage it fully (to ensure positige engagement and disengagement of the slidestop)

Some custom makers machine their slides and stops so that they exactly mate together when the stop is at the top of it's stroke. This is very difficult to get exactly right, without causing either slippage or binding (depending on the exact angle used), but if you can do it, it looks and feels great

Finally, some folks like to chamfer, round, or multi-bevel (at a sharper angle) the back edge of the stop tab. This will smooth and ease the release of the slide stop when slingshotting.

Sometimes they also lightly chamfer the top corner of the front face of the stop tab, whcih eases engagement, and smoothes manual disengagement. This is a process you have to be careful with, because if you do it wrong, the engagement of the stop can be inconsistent or weak.

When the angles are correct, and the edges properly finished, you should be able to successfully perform the following tests:
  • The slide stop should firmly engage when the slide is pulled back on an empty magazine, no matter the speed of retraction, or if the slide is retracted fully, or jsut to the notch.

  • You should be able to smack the back of the slide firmly while it is locked back, without the stop disengaging.

  • You should be able to rest your thumb on the slide stop, with our without a magazine in place, without having the slide drop.

  • You should be able to pull the slide back to full retraction off the lock without any catching, grittiness, or excessive tension.

  • You should be able to drop the silde on a either a full OR an empty magazine without excessive pressure, or any grittiness, or catching.
Most aftermarket stops WILL be much harder than the slides they are stopping, and this is OK, so long as both parts are burr free, and the angles are correct. If you do have a problem, its most likely because the steel of your slide stop is too soft, and it peens, burrs, or the edges break, causing inconsistent engagement.

This problem is very common with factory slide stops, because the factories tend to cheap out on the hard parts, as I described above; using cast steel pieces, hard surfaced, and not deeply heat treated.

I have a thinned Wilson tool steel slide stop, and a Wolff 22lb dual captured spring (my gun is set up for .45 super). I've beveled the bottom, and eased the edges of the notch, and the stop - VERY lightly. The engagement is great, and even with the ultrathin thumb surface and heavy recoil spring, it's easy to disengage.

Now, on to the technique section:

The one problem I have with using my slide stop, is that I have an extended and very thin slidestop; and extended gas pedal safety, which is thinner than competition safeties (which are DAMN wide, so you can use a full thumb rest), but not as thin as the slide stop, and which indexs my thumb a bit higher than the slide stop. This configuration makes my thumb press up on the safety if I release the stop with my dominant hand, as I move to reindex my thumb over the safety, for the shooters rest grip. I use the shooters rest grip because my thumbs tend to accidentally engage the slide stop during recoil recovery, even with a thin slide stop. The safety, stop, and grip combined, completely prevent my dominant thumb from unintentionally engaging the slide stop.

Guess what? I wanted it that way. This configuration makes it difficult to engage the slide release with the grip safety depressed, unless I use my support hand thumb to make the release. This got me out of the habit of dropping the slide before I had fully indexed my support hand grip. More importantly, it makes me automatically put the safety on the second a round is chambered, if I'm not indexed.

If I'm using a stop drop on a reload, Ill slap the mag in with my support hand, then immediately transition my hand into the support grip, and drop the slide (either with my dominant, or my support thumb. As I'm brining my gun back up, I wipe the thumb safety on as I move my thumb up over the safety. I then automatically reindex my thumb on the top of the safety to wipe it off, leaving my thumb in the upper rest position; and slowing me enough in my process (not in my motion); that I have reindexed the sight, and re-established my shooting position before I am ready to squeeze the trigger.

Yes, this slows me down a fraction of a second, but it's a hell of a lot safer in a potential mixed threat environment, where you want to make an asessment before you shoot again.

I said above this configuration broke me of the habit of dropping the slide before I was ready. Actually it did something more important: it got me out of the habit of dropping the slide at all.

Unless you are competing, you should get used to using the slingshot. For years, instructors have been saying don't do it, because it moves your support hand near the muzzle of the gun, and tends to pull the gun off to the side, which are potentially unsafe. On the range, they're right; but on the street, it's the wrong thing to do.

To perform a proper sling shot, tuck your elbows in, and wrap your whole hand over top the gun (keeps your fingers and palm away from the muzzle, and improves grip strength); then pull the slide ALL the way back and release the slide completely, letting it slam forward rapidly.

Now, take a look at the difference in clearance, and in slide speed and pressure between a slingshot, and a stop drop; it's about a half inch, and about 50% more speed, which are HUGE in gun terms. Given this, the slingshot is more likely to return completely into battery in a dirty, partially obstructed, or rough feeding gun or cartridge. Also, your thumbs aren't in the way to slow the slide down, which frequently happens with a stop drop.

Another point in the slingshots favor: if you've inserted an empty mag, or a round that won't feed from the mag (because of a bad profile, burred brass, deforemed lips, or a jammed follower), the slide is going to stay locked with a slingshot. You may think depressing the slide release on an empty mag is hard, and that you'll notice before your gun goes click instead of bang, but trust me; the second you're engaging a subject, you will have strength you didnt even know existed.

Believe me when I tell you, under stress you can EASILY accidentally load an empty mag, and you WILL be able to depress that release without even noticing; at which point your gun will go click instead of bang, and you can end up dead.

Now, in competition it makes sense to use the slide stop, because it's faster; but when your life is on the line, reliability is more important than speed.