Upgrading with Drop-In Pistol Parts

"ve I built more than a dozen 1911s for my personal use and modified many others to various extents, often without access to heavy machinery. To do this, I’ve relied heavily on parts variously known as "easyfit" or "drop-in" parts. In my experience, some parts have been just that’ drop in or easy to fit’while others have strained my muscles and tested my religion. I’ll try to share some of that experience with you in this article so you’ll know better what to expect when you order an aftermarket part.

The most common major pistol component that we replace is the barrel. I’ve purchased a variety of aftermarket barrels for the Colt 1911, Browning Hi Power, Beretta 92, and the Glock, among others. Most’but not all’were simple drop-ins. (Of course, we’re not talking about matchgrade barrels here or barrels purposely designed to be oversize, requiring a careful fit. These area subject all their own.) Recently, I have had very good luck with two barrels in particular.

The .460 Rowland conversion from Clark Custom was a simple drop-in for my Hi-Standard .45. In the other case, I needed an inexpensive barrel for a 1911, and the Roto barrel I bought from Sarco was as good as any factory barrel and no gunsmithing was required. On the other hand, I ordered anew Bar-Sto .38 Super barrel that required some fitting. This is to be expected in a pistol manufactured from 1911 to the present, and most of the time at least some fitting is required with older slides.

It only stands to reason that it will be easier to obtain a dropin barrel for a modern pistol like the Beretta or Sig, as the manufacture is far more consistent. This was proven when I obtained a .357 SIG-caliber barrel for my .40-caliber Glock. This Bar-Sto unit simply dropped in and gave better-than-expected results in this pistol. I’ve yet to meet a drop-in barrel that’s too loose or that wallows in the slide, so barrel makers must err on the side of caution.

When drop-in barrels don’t fit the slide in question, it’s usually the barrel hood that’s too large. The hood must be carefully filed and polished to remove that small amount of metal that’s keeping the barrel from fitting properly. The locking lugs maybe oversize as well. A simple rule of

thumb is to check the fit with a slide stop. With the slide removed, seat the barrel properly in the frame, complete with a link. Insert a slide stop into the slide-stop opening and through the link. If the barrel moves upwards, then some fitting will be required. When purchasing a drop-in barrel, you’re ahead of the game if the barrel comes with a barrel bushing that is fitted to that particular barrel.

The outer diameter is often okay, but the drop-in barrel may not fit in the inside diameter of your old barrel bushing. When putting together a pistol, it’s a good idea to check with the manufacturer of the frame (if possible) and ask about recommended parts. Recently, I acquired a Rock River Arms frame for a special project. I often try different parts just to see what they look like or how they perform.

In this case, it would have been unwise to use any beavertail grip safety other than the Smith & Alexander, as this is the grip safety the Rock River frame is cut for. In the past, I’ve replaced the grip safety on quite a few 1911s with King’s parts and never had a problem, although I’ve tried other brands that failed to fit properly at the mainspring In this case, a minimal effort and expense results in a worthwhile upgrade. housing. Some have been too wide, requiring careful removal of metal and polishing.

Be careful with the beavertail, and be aware that fitting anew trigger often requires anew beavertail as well, because the beavertail locks the trigger. Slide-lock safeties are sometimes drop-in items, but they often require polishing in order to move smoothly. It is a shame to have a finely polished pistol that has a clean trigger break and then ruin it with a rough safety. Variations in pistols are inevitable.

For example, the Cylinder & Slide Shop safety I prefer for the Browning Hi Power is a straight drop-in for the Browning and the majority of FMtype pistols. But the part is overlarge for the Hungarian FEG, at least most runs of them. As a result, the shooter who has added these safety levers to the Browning may scratch his head when moving to the FEG. The critical dimensions are not far off and a minimal amount of careful filing will allow assembly to proceed.

Although drop-in slide stops usually seem to fit properly, there are times when an oversize part is needed. I’ve used one of Chip Mc Cormack’s oversize slide stops to snug up a conversion upper on an M1911. The 1911 relies on the extractor for proper function in the feed cycle, and these can sometimes be a problem, although I’ve never had any serious trouble with the Wilson Combat extractors I’ve used for many years. However, I had a problem with one in a 1911 that surprised me.

The extractor was contacting the tunnel, affecting function. A bit of polish on the bump behind the extractor’s claw cured this problem. When it comes to adding a trigger, hammer, and sear, my advice is to purchase a complete kit, or at least purchase all of the parts from the same maker. I have enjoyed excellent results with parts from Wilson Combat, Ed Brown, Nowlin, Kings, and Mc Cormack among others. Most of us order from Brownells, but your life will be much easier if the parts are allin sync with each other.

Sometimes a drop-in unit is okay as far as the fit goes, but it changes the geometry of your lockwork. In other words, that nice new trigger or hammer has put the sear and grip safety out of whack. When it comes to hammers, it’s not uncommon for an aftermarket hammer to rub on the slide of a stock 1911. I would place the hammer in the naked slide before installing the hammer to be certain no work is needed for the hammer to clear the slide and strike the firing pin.

Some 1911s seem to have tight slide dimensions around the firing-pin stop, so a little trial and error is called for. Some armorers and gunsmiths feel comfortable adjusting tension on the

searspring. At one time, a special sear spring was manufactured that had a twisted spring hand on the left side. When I installed one in one of my pistols, it would sometimes connect the disconnector and prevent the firearm from firing. This spring did give a nice action, but it didn’t work properly’I took it out and threw it away. If you understand the action of the sear spring, then you know that this is the last part you want to try to save a dollar on.

The problem is, there is often some adjustment needed for perfect function, and this is a place where some finesse is needed. The left rear (long leaf) of the sear spring contacts the sear. While a lighter tension here can produce a lighter action, too little tension can allow problems such as the hammer following the slide down in recoil. The middle leaf resets the trigger. I once put together a 1911 that fired one time, and the trigger was very nice’but it didn’t reset until I racked the slide three times.

The far right or short leaf maintains tension on the grip safety, and is an important part in the scheme of things. The inside of the 1911 is far from delicate, but certain rules must be adhered to. One of my rules says that, when a truly light trigger action is desired, fit an aluminum trigger. The decrease in weight makes it much less likely the trigger will bounce the sear in recoil and fire the pistol when we don’t want it to.

Almost all triggers, drop-in or not, must be fitted, or they won’t glide smoothly in the frame. GI triggers are the only ones that don’t require fitting and these are seldom used these days. While there are lots of real drop-in parts for the 1911-type pistols, there seems to be many aftermarket parts for other pistols that are advertised as "drop in" that don’t quite measure up.

A friend recently purchased a full-length guide rod for his Glock that was advertised as a high-quality unit designed to tame recoil and keep the recoil spring straight. This unit quickly was beaten on the end, and I have seen full-length guide rods for the 1911 that suffer from the same problem. The Clark system seems tome to be the best all around, with its robust two-piece construction, and the full-length guide rod used by Hindman’s as part of the .45 Super conversion is also very robust.

There are a number of drop-in sight options available. Caspian makes a nice adjustable sight that fits in their custom slides with a minimum of fitting. I like it very much. And there are a number of sights that simply fit in the beavertail of the standard GImodel .45. I’ve used a set from Maryland Gun Works (MGW) that require the front sight be staked on, which is a straightforward operation. Installation of the rear sight is also a simple matter, and these sights work well.

The front and rear sights are sold in matched pairs. Some sights are sold as rear sights only. They look similar to the Novak, with a large body over a small piece that slides into the dovetail. A screw through the body locks these sights down. This is okay as far as it goes, but when used with the standard frontsight, the pistol inevitably shoots 4 inches or so above the point of aim at 15 yards. Drop-in they are, but they’re less than satisfactory. Even something as simple as grips can require fitting.

They almost always fit the grip frame, but sometimes the screw holes don’t line up exactly. The holes must therefore be carefully reamed out. I’ve also seen supplied grip screws that were too long and protruded into the magazine well, binding the magazine. Overall, my experience with drop- Left top: Be certain whether or not the pistol’s slide features a firingpin block before ordering parts. Left bottom: Locking lugs are commonly left oversize to allow for proper fitting.

Even if the part is sold as a "drop-in," be prepared to do some fitting here, and advise the customer to expect an additional charge for labor.

Considerable fitting is usually needed, except on models of the GI-type. in parts indicates that they are more likely to drop in a GI-type pistol than in a high-grade production piece. As an example, I recently acquired a Caspian slide. This is a nice slide, with a sight cutout and front cocking serrations, and set up for an external extractor. I expected to do some fitting. I first tried it on my Hi-Standard G- Man, and it wouldn’t budge on the rails. I also tried it on a Wilson Combat pistol as a lark.

Again, no dice. But When making upgrades and ordering parts’be they drop-in or otherwise’we need to keep the customer’s needs and expectations in mind. For example, installing a drop-in Bar-Sto barrel on a Glock will always result in better accuracy. But a drop-in aftermarket barrel in a mil-spec 1911 will not normally show much improvement’unless the old barrel was worn and thus giving poor service.

Sometimes, drop-ins are used to change caliber, as in converting a .40 S&W pistol to .357 SIG or a .45 ACP to .400 Cor Bon or .460 Rowland. But make sure the customer understands that only a custom fitted barrel can give match-grade performance. By the same token, a modest improvement is realized with a drop-in beavertail safety, but a true custom beavertail will require fitting and cutting the slide.

The bottom line here is that while drop-in parts might not give matchgrade results, they can produce significant improvements in performance at a modest price. I then I tried the slide on a Parkerized mil-spec Springfield, a stainless-steel Springfield pistol, and a Rock Island Armory pistol. In each case, the Caspian slide was a perfect fit in all respects.