Add an Adjustment Screw To the Ruger MKII’s Trigger

From the factory, the Ruger MKII rifle has what is essentially a nonadjustable trigger. I examined six of these rifles at random, and found their triggers to have a pull weight ranging from 3.5 to 6.5 pounds, with an average of 4.4 pounds. The lighter end of this range is not so bad, but most hunters and shooters find the heavier pull weights excessive, particularly for target and varmint shooting.

The Mark II trigger and sear are incorporated together into the rear of the receiver, held in position by two floating pins. The trigger-pivot pin is positioned on an integral hanger extending below the receiver. Both pins are free-floating and easily pushed out, allowing the trigger, spring, and sear to be removed.

The basic principle of the added trigger/sear adjustment that I came up with involves the positioning of a stop located beneath the trigger tab, which limits the forward travel of the trigger, thus controlling trigger/sear engagement. My method also combines the installation of a less forceful trigger/sear spring to further reduce the trigger pull. The trigger and sear spring are one and the same, positioned between the two parts.

The added adjusting screw is simply a small, adjustable threaded machine screw which extends downward from the bottom of the receiver (see photo). This screw enters a hole that’s drilled and tapped into the underside of the receiver and retained with a lock nut against the receiver. The screw-head flange engages a wide, flat surface on the trigger tab that also serves as the safety tang. In this way, the sear/trigger engagement can easily be adjusted.

This is accomplished by the precise upward or downward adjustment of the threaded screw where it engages the lower margin of a tab extending rearward near the center of the Ruger’s main trigger body. Installing the Adjusting Screw Pay close attention to depth and alignment while drilling and tapping the hole in the receiver. The edge of the tapped hole just clears the receiver wall by about .040 inches. I used a size 6-48 screw and a bottom tap. The receiver is not hardened.

A shallow half-moon groove is made in the trigger/safety tang to make room for the screw and allow somewhat more surface for the screw head below. I used a double nut at the lower end of the screw as a means of making the final trigger/sear adjustment, and used the upper nut at the threaded hole in the receiver to lock and align the screw to the receiver. Around-

The trigger is in position with a portion of spring shown. Note the half-circle slot in the trigger tab to make room for the adjusting screw. The photo also shows the rotary safety disengaged from the trigger tab. As described in text, a double nut is used to make precise trigger/sear adjustments. head machine screw could serve the same purpose, and use the threaded screw in the receiver as a means of adjustment, and the nut to lock things in place. Either method will work as long as the screw is locked in place.

Adjusting the Trigger Pull And Sear Engagement First I substituted the original firm trigger/sear spring with a lighter one of the same diameter. I then installed the threaded adjusting screw into the receiver with the double nut positioned immediately below the safety tang. The bolt handle is then raised and withdrawn to cock the trigger. A test is then made to see what the trigger pull is with the lighter spring in position before the sear/trigger engagement is adjusted.

On the rifle I worked with, the pull was at 2 pounds 11 ounces, as determined with a Lyman digital trigger-pull gauge. The Precise trigger/ sear adjusting nuts are in contact with the trigger tab. Total trigger/sear adjustment is accomplished in this way. The Lyman digital trigger-pull gauge shows a final trigger pull of 1 pound 8.1 ounces. original setup was at just over 5 pounds.

At this point, the double nuts are slowly turned upward to engage the safety tab, thus moving it upward and the trigger backward toward the fire position. This adjustment is made very slowly until the trigger releases the sear. The nuts are then backed off about one-eighth of a turn and the trigger mechanism is again cocked. Each one-eighth turn of the screw or double nut reduces or adds to trigger/ sear engagement by about 0.0025 inch. Trigger-pull weight is again tested as the sear/trigger engagement is reduced.

I tested the pull weight frecontinued on page 18)

Tech Topics In this feature, we examine new tools and tooling, tips and techniques, and news items of interest to the gunsmithing community. Field Tests Say "Yes" To the Purple Stuff Oh wow, we sighed. Yet another synthetic gun oil? According to the press release we received, it was developed to provide exceptional wear and rust protection, prevent fouling, and defend against saltwater corrosion. (Not surprisingly, it promises equal performance on fishing tackle.) But okay, we’ll bite, and we ordered a sample.

What we received in response was a dozen aerosol cans’ and more claims, of course. This oil, Royal Purple, apparently holds up and works well under a considerable range of temperatures and won’t thicken in cold weather. Reading on, we were informed that its performance We set up a four-month test to see if it could live up to its advertising hype. It did. advantages come from a proprietary chemical technology called Synerlec, and no other gun oil uses that technology.

The product sounded like a winner, but we didn’t want to offer an opinion on the product without putting it through something approaching along-term evaluation. As it happened, luck was with us. The last weekend in October and the first in November each year have been selected by a shooting club we work with as the dates for their annual "Open House & Family Fun Shoot." The club provides the guns and ammunition.

The public is invited to get acquainted with the shooting sports and win a frozen turkey by competing in a relay of shotgun, blackpowder, small-bore rifle, or pistol deadmark. No club members are allowed to shoot against the visitors, and there are plenty of just-for-fun events on the firing line for those who prefer unfrozen range-raised birds. The club charges a small fee per shot, makes some much needed maintenance money, and a good time is had by all.

The crowd grows from year to year, and, of course, every new shooter is supervised oneon-one by a range officer assigned to run the individual event. So we decided to hand out 11 cans of Royal Purple to the range officers, keep one for our own use, and asked the range officers to report back in three or four months with their individual opinions on the product’s performance.

The chosen officers were all good to exceptionally good marksmen (and markswomen) who’d be checking out Royal Purple in every shooting discipline’s ometimes under the added pressure of match competition. We, on the other hand, having no time to shoot matches, did our part by using the oil to lubricate guns we worked on or worked over for customers during the same period of time.

We’re pleased to note here that, by all reports received, Royal Purple performed royally, and all shooters believed the manufacturer’s claims were supported. There were even a few "rave notices," and everyone involved in our little experiment wanted to know where they could get more when their aerosol cans went dry. So this is what we told them: Royal Purple Oil, One Re, Porter, Texas 77365; $5.59.

Easily Cut Trigger Pull By 50 Percent The sign on the booth at the most recent SHOT Show in Orlando said "EZ Pull Trigger Assist." Our first reaction was pure curiosity. Now what could that be? A magic spring? A tooling fixture? Or maybe a guy with superb natural finger control who tags along to do your shooting for you? Our second reaction, after we saw what it was and how it worked was: Why didn’t we think of that?

The EZ Pull is what you see pictured here, a bracket that attaches to the trigger guard of along gun and a wide trigger shoe that attaches to the bracket. Built into the shoe is a roller

that contacts the factory trigger. The device uses leverage to cut the factory pull in half. To install the EZ Pull on a rifle or shotgun, lay the gun on its side with the muzzle to your left. Install the mounting block to the guard by tightening the four set screws just enough to seat into the mounting block. The faces of the angled "ears" on the block are positioned toward the muzzle end of the gun. Using the two small slotted-head screws, attach the triggershoe/roller assembly to the block.

Unless you can completely remove the guard, this is not easy, since you’re working with very tiny screws inside a trigger guard. You can use a straightened-out paper clip as a slave pin to help you get the holes in the shoe and those in the block lined up. And, yes, you will be using a jeweler’s screwdriver. Once you have it installed, make sure the assembly moves freely.

Move the block forward or back to bring the roller into contact with the center of the factory trigger, and tighten the block screws against the guard edge to maintain the position of the roller. Only the roller should be touching the trigger. If it moves off center, adjust it by backing off the right or left setscrew and taking up the slack with the opposite screw. Now cock the action, rotate the show forward, and pull the trigger with your finger.

Now recock the gun, rotate the shoe back into roller contact, and pull the shoe. What the extra leverage provided by the EZ Pull has done is reduce a 6-pound trigger pull to 3 pounds. A 3-pound pull would be taken down to 1.5 pounds. What you haven’t done or had to do is to completely tear down the gun, rework its trigger system, reassemble it, and possibly void its warranty in the process.

The EZ Pull Trigger Assist (about $40 retail) is sold in various sizes depending on the width of the triggerguard, in both black and clear anodized finishes. The one we received was made to fit the Browning A-Bolt and other bolt-action rifles with trigger guards of similar width.

It’s not currently available to fit lever-actions or handguns, but we have a hunch the inventor, Robert Nehrt, has something in mind to resolve these limitations in th ore info, call EZ Pull The Worldwide Web Can Mean More Business for You According to the National Shooting Sports Foundation (NSSF), 40 million Americans enjoy hunting and other shooting sports every year. Another 48 million would like to give hunting or target shooting a try. That’s a total of 88 million people.

At least some of them must live in your area. Those that do, could’and should’ be your customers. Besides offering the repair of fire- Without disassembling a rifle or shotgun and reworking its trigger system, the EZ Pull Trigger Assist uses leverage to reduce trigger pull by 50 percent. at arms, what else can you do to promote your services? Start with your computer and the internet. On your browser, type in "huntandshoot.org." This is a one-stop resource for new and experienced hunters.

It provides abroad range of information from getting started to staying active. Another hunter-oriented site is "huntinfo.org." This one delivers oneclick access to the websites of all 50 state wildlife agencies. These sites carry state-specific information on hunter education classes, application deadlines, license fees, and more. For those who lean toward feathered game, "wingshootingUSA.org" will turn up a directory of over 1,000 bird-hunting preserves in America and make it easy to pinpoint them.

By absorbing at least some of the information on these sites, there’s little doubt you can demonstrate you’re as devoted to hunting as your hunting customers are. Your understanding and appreciation of the various aspects of the sport is certain to impress them. Also not to be overlooked or taken lightly in the mix are "wannabe" or brand-new shooters. By helping them along you’ll be helping business to grow. If you’re really fortunate, you have a working range as part of your operation.

A range and an NRA Certified Instructor Classification sets you up to give those new to the shooting sports their first experience. But if you don’t have a range or classification, you’re still not out of the game. Enter into an agreement with a combined gun shop and range or with a gun club in your area, preferably one well populated with NRA Instructors. In the unlikely event you’re not aware of any gun clubs, go to "wheretoshoot.org" on the web.

It locates shooting facilities offering quality instruction in the shooting disciplines, be it shotgun, rifle, or handgun. Then there’s "firstshots.org," that provides information and opportunities for beginners, ranging from learning how to shoot a handgun to learning the requirements for handgun ownership. ¨

Experience has shown that, if you help a person to become interested in the shooting sports, guide them intelligently, and serve them well, you’ll have a customer for as long as you’re in business. Getting folks into target shooting is a good example. The best starting-out handgun for this is probably a .22 LR pistol. The Ruger Mark Series is not terribly expensive, more than reasonably accurate, and decent ammo for it is both abundant and reasonably priced.

For most new target shooters, once he (or she) becomes comfortable with a .22, he’ll develop a yen for the larger calibers he sees on the firing line. Since you’ve been so helpful already, who has the inside track for providing additional guns and the maintenance, repair, and modifications that go with them? It’s a bit different with hunters, but not much.

Most hunters favor one specific caliber for varmint hunting, another for deer-size game, another for larger prey, and still another for the pursuit of really big, really mean animals. The hardware can mount up nicely, so can keeping the hardware in working order or upgrading it. By now, you may be wondering who’s the moving force is behind these websites? Mentioned in the opening paragraph, it’s an outfit that’s been around over 40 years called the National Shooting Sports Foundation.

Non-profit in its operations, its membership includes over 3,000 manufacturers, distributors, retailers, sportsman’s organizations, publishers, and individuals who support NSSF programs. Their mission is to benefit and ensure a positive future for the shooting sports and the firearm industry.

By the way, the SHOT Show is under the wing of the NSSF, as are such organizations as the National Association of Firearm Retailers, the National Association of Shooting Ranges, and the Hunting and Shooting Sports Heritage Fund. America’s top producers of guns, ammunition, and components. Founded in 1926 at the request of the federal government, S. A. A. M.

I. was tasked with creating and publishing industry standards for safety, interchangeability, reliability, and quality, as well as coordinating technical data and promoting safe and responsible firearm use. In 1961, in order to focus more fully on their technical responsibilities, S. A. A. M. I. formed the NSSF. The charge: Concentrate on measurably advancing participation in and understanding of the shooting sports.

Though the two organizations are not joined at the commodations Newtown, CT carries on its g rnment-assigned responsibility, S. A. A. M. I. continues to address its task as the accredited standards developer for The American Standards Institute. As such, S. A. A. M. I. sets parameters for industry test methods, and defines proof loads and ammunition performance by utilizing two product task forces. One is for ammunition, and the other is for firearms. Does S. A. A. M. I. have a website?

Indeed it does: "saami.org." There you will find a list of publications offered including five on chamber pressures and ammunition, plus velocities for ammo for centerfire pistol and revolver, centerfire rifle, rimfire, and shotshell. Official cartridge and chamber drawings are included. You’ll find something else all gunsmiths should have on file’along list of unsafe arms and ammunition combinations.

This list (it is downloadable) can spare you wearying discussion and great concern about a rifle blowing up when its owner wants his .30-06 rechambered for 7.61 x 39mm, 8mm Mauser, .32 Remington, or .38-55 Winchester. This list is but a sample of the data in the download that can settle arguments and, more importantly, keep you out of court. The cost of membership in either or both organizations is moderate. Worth it? Heck, the glossary and definition of technical terms on saami.org ought to convince you it is.

Oh, and lest we forget, the website that can be the most valuable to your ate for could there ility than to tell a prospective customer to "check out my website to see some of my work and the services I provide." I

quently during this procedure. In this way, I was able to produce a controlled, safe trigger pull as low as 1.5 pounds. Cocking of the trigger was accomplished by simply lifting and lowering the bolt handle. Opening and closing the bolt several times in a slam-fire maneuver did not cause the gun to fire. At the final trigger setting, the safety was tested and functioned perfectly. Pull the trigger repeatedly When and how did the NSSF come to be? You’ve no doubt have heard of S. A. A. M.

I., The Shooting Arms and Ammunition Manufacturers Institute. This is an association made up of with the safety in the on position to be sure the safety is working properly. Conclusion The work described here on the Ruger MKII resulted in a positive trigger adjustment from a little over 5 pounds to a safe pull weight of about 1-1/2 pounds. This work can be performed by a competent gunsmith in a couple hours using common shop tools. Perhaps best of all, the cost of the materials is almost negligible. I