Accuracy of the Beretta M9 or 92FS series pistols
This article is strictly intended for licensed, licensed, and insured professional gunsmiths with sufficient experience to perform work on semi-automatic pistols. Also caveat: this article is more precision oriented for conventional “bullseye” or NRA pistol than for IPSC, IDPA, USPSA, etc.
Pinpointing the Beretta M9 (or 92FS, which is the model number given to the version that’s available to the general civilian population) is something competitive shooters have been doing for a while, but how to do it is an art. relatively unknown. .
Fortunately, it’s not much different than what you’d need to do to make any weapon accurate. There are a few options that can also make the gun last much longer if you are a competitive shooter and need the frame (made of aluminum) to last 10,000 rounds or more.
The most difficult part of the entire process is the trigger work itself, which allows the shooter to accurately fire the weapon without disturbing the sight alignment. Most “out of the box” military grade guns have a relatively heavy “single action” trigger of between 5 and 8 pounds for safety reasons (ie, to prevent accidentally firing the gun). For many marksmanship competitions, the trigger should be at least 2.5 to 3 pounds. For “Service Pistol” competitions, the rule is a minimum of 4 lbs. If you are not a professional gunsmith: take the gun to a gunsmith, let him do that part of the job. You’ll be happier with the result for a variety of reasons, one of which is the fact that doing trigger work on a Beretta is a huge pain. It takes several iterations to pull the sear out of the frame and reinstall it to test draw weight, and it’s hard to get the sear in and out of the gun, even if you’ve done it a hundred times. So do yourself a favor and tell your gunsmith what your minimum trigger pull should be.
If you are a professional, qualified and insured: The trigger weight on a Beretta results from a combination of the surface condition of the sear and the surface of the hammer hook, in addition to the condition of the spring.
Gild and hammer surfaces. The sear has a return spring that must be carefully removed and properly reinstalled each time work is done on the sear. Take pictures before removing it to make sure you can replace it the way it’s supposed to be. The sear surface should be ground (buffing wheel or rotary tool) and a relief angle cut (similar to what you would do when working with the sear on a 1911), but do not alter the angle of the sear itself, or the pistol could be insecure. Hammer hooks need to be polished with a stone. Apply pressure sensitive marking material (Dykem or other styling fluid), put everything back together and test everything. Disassemble and look at the bearing surfaces of the sear and hammer hooks to ensure even sear contact across the full width of both hammer hooks.
The springs involved are: the trigger return spring, the hammer spring (main spring), the sear return spring, and the spring of the “lifting” plunger of the firing pin lock. Of all these, the trigger return spring has the greatest effect and the sear return spring has the least effect. You probably won’t see any effect from any changes to the sear return spring, and changing it may affect functionality. The hammer spring can be modified or exchanged for a lighter (read: smaller wire diameter) spring from Wolff. The standard Beretta hammer spring is about 19 or 20 pounds. A spring will give a heavier weight when pulling the trigger, and a lighter one will give the trigger a lighter pull. The trigger return spring has the greatest effect on the pull of the trigger. The stock trigger return spring is a round spring with two legs and will eventually wear out, making the trigger too light. It also cannot be easily or reliably adjusted, it is simply replaced with another standard. However, Wolff (http://www.gunsprings.com) makes a small unit that replaces this spring with a coil spring over a plunger. If you know what you’re doing, it’s possible to remove the coil spring and replace it with one of a different wire diameter (heavier or lighter) to adjust the trigger. The detent spring can be changed, but this will only change the trigger in a very small way on most guns.
The Beretta does not have an overtravel adjustment as a stock option. Having an overtravel stall is a huge performance issue. So you’ll need to buy a steel trigger to replace the plastic one (it’s about $15). Drill a hole in the trigger as high as possible, tap it for 6 x 32 tpi and install a set screw so you have an adjustable overtravel stop.
To be accurate in target pistol shooting, the barrel must be match grade. Both the Bar-Sto and the KKM Precision are good barrels for the Beretta, and you can get very good results just using a built-in barrel. Contrary to common belief, it is not necessary to use a bushing at the front of the barrel to improve the lock on a Beretta. The barrel is locked at the rear against the slide using the lock block which is attached to the barrel, so it is imperative that the lock block is tight and in good condition. If you are installing a barrel that requires adjustment, you will need to remove material from the rear of the barrel until the gun reliably enters the battery. Be sure to apply Dykem or other design fluid in between material removal to see where the contact points are. You want as much contact as possible between the rear of the barrel and the face of the chamber on the slide. Some barrels (Bar-Sto) have extra material on top of the barrel back and some of this needs to be removed slowly. The purpose of the additional material on these barrels is to achieve a tighter lock with more contact surface, as well as to center the rear of the barrel vertically on the breech face.
To improve locking, some pistols have set screws installed under the frame rails at the rear of the barrel to give additional points of contact while everything is locked on the battery.
To improve lifespan, some gun builders modify the frame rails and replace sections of the aluminum rails with steel pieces, attached with screws. This is only necessary if you’re a top-level competitor and need that extra 2% performance that comes with a super tight frame-to-slide fit, plus the durability of steel-on-steel vs. steel-on-aluminum. There are no “kits” to do this type of work, so you will need someone who knows what they are doing to do this type of work. This type of slide-to-frame upgrade is similar in nature to the “Accu Rail” upgrade that used to be done on 1911-style pistols.
Finally, places of interest. If you are replacing the rear sight with an oversized adjustable sight, it is common that you need to trim the top of the firing pin blocker riser to keep it from hitting the bottom of the scope. You will also need to get a taller front sight. The front sight can be welded on (less common) or you can get one that slides over the stock front sight and pins into place (most common) or you can mill the slide with a dovetail (uncommon). Beretta makes an adjustable rear sight that allows you to keep the stock front sight and not have to modify the blocker lifter, but it has a lower profile than most competitive shooters will want.
I hope you enjoyed this article and feel free to post questions. http://www.aafirearmstraining.com
