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Tactical Briefs (Volume 2, Number 2)
February 1999

Ordnance Gelatin Testing Services Available

We've acquired almost all of the equipment needed to facilitate laboratory-grade ordnance gelatin testing of law enforcement and personal defense ammunition. We expect to have this capability in place by mid-March.

We intend to offer ordnance gelatin testing services to law enforcement agencies, individual LEOs and private citizens who desire valid terminal ballistics performance data.

This service will require the agency or individual to send us the firearm and ammunition to be tested. We will test terminal ballistics performance of the firearm/ammunition combination in accordance with the IWBA Handgun Ammunition Specification.

The IWBA test protocol requires the testing of 20 rounds of ammunition: ten rounds fired into bare gelatin, and ten rounds fired into gelatin that has been covered by 4 layers of 14.5-16 ounce cotton denim cloth. We’re also considering offering a less expensive "abbreviated" test consisting of firing five rounds each into bare and denim covered gelatin.

We will perform windshield glass and automotive sheet metal penetration testing upon request.

When testing is completed, the firearm and recovered bullets will be returned, and bullet velocity, penetration and expansion data will be provided.

The cost of this service is yet to be determined. We anticipate the full 20-round terminal ballistics test program to cost between $100-$200, and the abbreviated 10-round test to cost less than $100. These anticipated prices are subject to change.

This service provides law enforcement agencies, individual officers and private citizens the opportunity to test ammunition out of their own department issue or personal defense firearms without the expense, labor and expertise that is normally required to obtain valid terminal ballistics performance test results.

We’ll publish more details about this service in next month’s Tactical Briefs.

"Statistician Dan Watters"

In Tactical Briefs 1 & 2, we pointed out that the authors of Street Stoppers, Evan Marshall and Ed Sanow, cited a person in their book whom they identified as "statistician Dan Watters of the University of South Carolina."

We described a review of Street Stoppers that was written by Martin L. Fackler, M.D., President of the International Wound Ballistics Association (Wound Ballistics Review, 3(1), 1997, pp. 26-31). In his review Dr. Fackler states:

"‘Statistician Dan Watters from the University of South Carolina’" is mentioned on page 330 of ‘Street Stoppers.’ It appears that Marshall and Sanow are implying that there exists a professional academic statistician who doesn’t burst out laughing when presented with their ‘data.’ I was especially interested in this Watters because of all the professional statisticians who I know have seen the Marshall/Sanow ‘data,’ were in clear and unequivocal agreement that the ‘one-shot stop statistics’ were so flagrantly bogus that nobody competent in statistics could believe them to be genuine. I tried to reach Watters: the University of South Carolina directory does not have any such person listed – and the Department of Statistics there denies any such person works for them, or has in the past."

We interpreted Fackler’s statement to imply that Dan Watters did not exist as a real person, and that he was fabricated by Marshall and Sanow. We were wrong.

One of our readers contacted Watters and put us in touch with him. We learned that Watters was working towards a Master of Arts degree at USC's College of Criminal Justice and taking additional classes in the Department of Biostatistics (School of Public Health) at the time he assisted Marshall and Sanow with their book.

(We haven’t attempted to verify that the person we exchanged e-mail with is in fact "Dan Watters," but this isn’t important, as described below.)

It appears that Watters was unaware of the defects with Sanow’s gelatin test data. At the time (1992), most of Sanow’s gelatin test data was produced from uncalibrated ordnance gelatin, and the samples were too small (one or two test shots of each cartridge) to be valid. This was the data used by Watters in his chi-square test that was published in Street Stoppers. Watters also was apparently unaware that the Marshall/Sanow street effectiveness data had been discredited by professional researchers.

We encouraged Watters to contact Fackler via the International Wound Ballistics Association. We also contacted Fackler and informed him that Watters had been located.

In his review of Street Stoppers, Fackler was not suggesting that Watters did not exist as a real person. Instead, he was implying that Marshall and Sanow had deliberately and fraudulently misrepresented Watters as a professional academic statistician.

We misinterpreted what Fackler was implying, and we apologize for this error.

For more details about the statistical flaws with the Marshall–Sanow data, we invite you to read the following:

Fackler, Martin L., M.D.: "Marshall–Sanow Can’t Beat the Long Odds – Wound Wizard’s Tally Too Good To Be True" (Soldier of Fortune, January 1994, pp. 64-65, and

MacPherson, Duncan: "Chapter 3, Earlier Models of Bullet Wound Effects," Bullet Penetration, Ballistic Publications, El Segundo, CA, 1994; pp. 17-48.

Product Review: SafTLok Magazine Lock for Automatic Pistols
by Shawn Dodson

(Note: Although SafTLok is no longer in business the magazine lock reviewed below can still be found for sale.)

Several weeks ago the city of Boston announced that it was going to equip its entire police force with SafTLok gunlocks. According to news reports, all 2247 police officers would be issued the combination lock to install on their department issued handguns. Each officer would also receive training in the gunlock’s proper use.

Boston’s Mayor and Police Commissioner stated at a news conference that by mandating locks on police guns they hoped to protect the officers and their families from being shot, either accidentally at home or deliberately by criminals who steal or grab their guns.

SafTLok offers two different types of gunlocks, a magazine lock and a grip lock. The magazine lock is presently available for a handful of automatic pistols that use a double column ammunition magazine. It consists of a fully functioning magazine with an internal combination lock built-in to the base.

The other gunlock, the grip lock, attaches to the frame, beneath the grip panel, of revolvers and 1911-type automatics. I had the opportunity to examine the revolver grip lock at the NRA Annual Meeting in Seattle a couple of years ago. I was intrigued by the lock’s compact dimensions, which did not interfere with obtaining a solid grasp of the handgun. The lock appeared easy to use, and reliable in operation.

My local gun shop has a 1911-style handgun with a SafTLok grip lock installed that the staff uses for sales demonstrations. This device locks the gun’s own manual safety lever in the engaged position, preventing the gun from being fired. The 1911’s manual safety also locks the slide in battery, precluding it from being retracted. When the authorized user properly enters the correct combination, the SafTLok’s spring-loaded locking slide automatically unlocks, allowing the user to manually disengage the gun’s safety lever to ready the gun for firing.

After hearing about the decision by Boston police to outfit its entire force with SafTLok gunlocks, I contacted SafTLok and requested a magazine lock for performance evaluation. Having already examined the grip locks, I was particularly interested in inspecting the functional reliability of the magazine lock.

Description and Operation
SafTLok kindly sent me two magazine locks to test: one for a Glock 17 and another for a Beretta 96. I also received a law enforcement information package, Technical Bulletins for both the grip and magazine locks, and a video.

SafTLok makes the following Claims about its magazine lock:

  1. Manual Safety
  2. Locked

The operating instructions supplied with the magazine lock are simple and straightforward, and should be carefully read before you attempt to insert the lock into the magazine well of your handgun.

There are four levers on the baseplate that are used to operate the magazine lock. One lever is referred to as the "manual safety," two levers are used to enter the combination (buttons "A" and "B"), and there’s a "lock reset button."

Click here to view photos of the SafTLok magazine lock

The magazine lock’s "manual safety" can be applied to prevent the gun from firing. It works by disengaging the trigger bar. This feature adds a manual safety to Glock, SIG or double-action-only handguns, which have no manual safety, or serves as a secondary (redundant) manual safety on other handguns.

Engaging the "manual safety" also secures the magazine lock to the gun. It cannot be removed. A small catch lever, controlled by the "manual safety" button, acts as a locking bolt that extends from, and retracts into, the magazine lock’s body.

The Beretta 96 SafTLok requires minor modification to the internal surfaces of the gun’s left grip panel. A small portion of the raised rim that interlocks with the gun frame must be removed to provide clearance for the magazine lock’s catch lever.

An average person can easily modify the Beretta left grip panel. It requires unscrewing and removal of the panel. I have Hogue grips installed on my Beretta 96, and I altered the left panel with an X-acto knife. A Beretta factory grip panel can be modified with little effort by using a small file.

The Glock 17 magazine lock requires no modification of the gun to use.

The directions supplied with the magazine lock describe its function and operation as follows:

"Your SafTLok magazine allows you to keep your loaded weapon in either an ‘On Safe’ or ‘Locked and On Safe’ condition.

1. To put the safety on:

Push the manual safety in and turn counter-clockwise 1/8 turn.

NOTE: The gun will not fire and the magazine cannot be removed with the safety on.

2. To take the safety off:

Turn the manual safety clockwise allowing it to spring outward.

CAUTION: Your firearm is ready to fire with the manual safety in this position!

3. To lock your firearm:

Push the manual safety in and turn counter-clockwise.

Push the reset button fully forward.

NOTE: The gun will not fire and the magazine lock cannot be removed when locked.

4. To unlock your firearm:

Place the manual safety in the locked position.

Push the reset button fully forward.

Enter the first number of your combination by stroking button "A" forward that many times.

Enter the second number of your combination by stroking button "A" backward that many times.

Enter the third number of your combination by stroking button "B" forward that many times.

Enter the last number of your combination by stroking button "B" backward that many times.

Turn the manual safety clockwise allowing it to spring outward.

CAUTION: Your firearm is ready to fire with the manual safety in this position."

Test and Evaluation
Both the Glock 17 and Beretta 96 magazine locks appear to be quality built. The Glock 17 unit holds ten rounds of 9mm ammunition. The Beretta 96 unit holds seven .40 S&W cartridges.

I charged the Beretta magazine lock to capacity with seven dummy cartridges. The last two cartridges required a little extra exertion to overcome the resistance of the stiff magazine spring.

I installed the magazine lock into my Beretta 96 and released the slide to chamber a round, removed the magazine, topped it off to replace the chambered round and inserted it into the magazine well. Getting the magazine fully seated with the slide in battery required the application of an extraordinary amount of pressure on the magazine lock’s base to compress the stiff magazine spring as the top cartridge came into contact with the bottom of the slide.

With the magazine lock installed, my Beretta was loaded with 7+1 dummy cartridges, three rounds less than the 10+1 configuration provided by my factory Beretta magazines.

I hand-cycled the slide. The chambered cartridge extracted and ejected from the action without incident, but the first round in the magazine failed to feed. It nose-dived and jammed against the forward mouth of the magazine. This required me to retract and lock the slide, and remove the magazine lock from the gun to clear the stoppage. This particular problem happened every time I loaded the gun with 7+1 rounds and hand-cycled it. When I loaded it with 6+1 rounds (loading the magazine lock with 6 rounds, chambering a round, and replacing the chambered round), I experienced no feeding failures.

The Beretta 96 magazine lock is not a "drop-free" design. When I pressed the magazine release button to remove the magazine lock when it was empty, either with the slide in battery or locked open under pressure from the magazine spring, I had to manually remove it from the Beretta’s magazine well using my support hand.

Additionally, the magazine lock does not lock the slide like the grip lock does with 1911-type automatics. The slide can be manipulated with the SafTLok installed and locked.

To determine mechanical reliability of the combination lock, I charged the SafTLok with seven dummy cartridges and installed it in my Beretta 96. I locked and unlocked the mechanism 500 times by hand during a period of several days. I was unable to successfully open the lock 33 times. All of the failures were probably caused by operator error. The human factor seems to be the lock’s weakest link.

According to SafTLok’s Technical Bulletin, the combination can be entered in any sequence. For instance, the combination for the Beretta 96 magazine lock is 2323 (this is the combination used for demonstration samples). To enter the combination according to the instructions, the "A" button is stroked forward twice, then backward three times, and the "B" is stroked forward twice and backward three times. I found it easiest for me to hold the Beretta in my firing (right) hand, and use the thumb of my left hand to stoke both the "A" and "B" buttons, respectively, one at a time, forward twice. Then I’d quickly switch to use my left index finger to stroke the "B" and "A" buttons, respectively, one at a time, backward three times.

The bottom edge of the magazine lock base is raised to provide a protective frame that shields the buttons from impact damage. This raised rim interfered with my ability to positively manipulate the "B" button with my thumb. Additionally, the close physical proximity of the buttons also caused occasional interference. This produced a condition in which I was unable to positively detect when I short-stroked the "B" button. Sometimes I’d short-stroke the "B" button and not realize it, and sometimes I’d think I’d short-stroked the "B" button (when I hadn’t) and I’d deliberately stroke it again to correct for my perceived error.

I tried different techniques to manipulate the combination buttons, but the thumb and index finger technique I’d devised seemed to be the most natural, reliable and speedy for me.

Most of my failures to unlock were "cold failures" that were experienced during the first few attempts. Once muscle memory kicked-in, the incidence of operator error declined.

Another factor that might have influenced the results is the frequency in which I manipulated the buttons caused my thumb and index finger to become chafed, which reduced their sensitivity to touch. By the end of day 13, my thumb and finger had each developed a callous on the tip.

My lock and unlock test results were as follows:

Day 1: five failures out of 50 tries,
Day 3: three failures out of 150 tries,
Day 5: one failure out of 50 tries,
Day 7: four failures out of 50 tries,
Day 9: seven failures out of 50 tries,
Day 11: ten failures out of 60 tries,
Day 13: three failures out of 90 tries.

I performed the test every other day to allow my fingers to recover from the chafing. Also, these results do not reflect the failures or successes I encountered during my training period, wherein I was learning how the lock operated and didn’t consider myself proficient in its operation.

I also attempted to remove the magazine lock from my Beretta by pressing the magazine release button and pulling on the base of the magazine lock. With the magazine lock’s "manual safety" positioned to "on" or "locked," I could not remove it.

During this test, I noticed that it was difficult to visually detect whether or not the magazine release button had been actuated because the SafTLok’s catch lever held the assembly firmly in place. I wondered what would happen if an unauthorized person tampered with the gun while the magazine lock was installed, and pressed the gun’s magazine release in attempt to remove the magazine lock. How would this condition affect the gun’s ability to function in a self-defense situation? I made a note to test this scenario at the range.

I fired over 200 rounds of handloaded ammunition through the magazine lock. I tried the 7+1 configuration that gave me problems when I hand-cycled dummy cartridges. The first two attempts produced the same results I encountered during the hand-cycle test: after the first shot, the first round in the magazine nose-dived and jammed the gun.

I switched to the 6+1 configuration and the magazine lock operated flawlessly. I fired slow-fire, double-taps and rapid fire. After successfully firing 70 rounds with this configuration, I tried the 7+1 configuration, hoping the magazine lock merely needed a dynamic breaking-in. It worked! And it worked without failure for the remainder of the test.

During the test at the shooting range, I always locked the magazine lock after installing it fully charged in my Beretta. This required me to unlock it in order to fire it.

I then turned my attention to the problem with detecting a situation in which the magazine release is tampered with when the magazine lock is installed and locked. I charged the magazine lock with 7 rounds, chambered a round, and topped off the magazine lock. With this 7+1 configuration, I locked the magazine lock, and pressed the magazine release. After successfully unlocking the magazine lock, I fired at an IPSC cardboard silhouette target. Predictably, the chambered round fired and the slide cycled, but by then the magazine had dropped out of position and no round was chambered. When I pressed the trigger a second time, I encountered a failure to fire. I immediately performed tap-rack-target, and when I pressed the trigger again, the gun would not fire.

Upon inspection, it appeared that the "tap" caused the meaty part of the palm of my hand to simultaneously press-in the "manual safety" button and actuate the lock reset button. This engaged the "manual safety" and locked the magazine lock. In order to return the gun to firing condition, I had to rotate the "manual safety" lever to "on," and enter the combination to unlock the locking mechanism.

I performed this test several times and found that I could reproduce this condition approximately 20 percent of the time.

While this might seem to be a serious flaw in the lock’s design, I believe it can be easily compensated for by firmly tapping the base of the magazine lock to ensure it’s securely seated before you attempt to unlock it. In my opinion, this is a minor design deficiency that can be overcome by technique.

Finally, I timed how long it took me to successfully manipulate the gunlock. It took me approximately 4 seconds to unlock the lock, and 11 seconds to unlock the lock if my initial attempt failed due to operator error. This timed test routine was not part of my 500 cycle lock and unlock test.

Summary
Personally, I'm very wary of using combination locks for securing personal defense firearms. My reason is because during moments of extreme stress it can be very difficult to recall the combination. For example, in 1991, my wife was robbed at gunpoint by a crack cocaine addict while she worked alone at the front desk of an upper-class hotel. The robber walked into the empty lobby and asked for change, and as soon as she had the cash drawer open he drew a Glock handgun, pointed it at her and ordered her to give him all the money. Then he made her lie face down on the floor before he fled. As soon as she heard the robber exit the lobby she reached up and locked the doors electrically by pressing a switch behind the counter. She tried calling the police, but she was so shaken by the experience that she couldn’t remember that the number to dial was 9-1-1. She says her mind went blank for several seconds, and try as she might, she was unable to retrieve the three digit telephone number from memory.

Personal feelings aside, my only concern about the magazine lock is that the small buttons could be difficult to manipulate in a high stress situation, such as when the only thing that’s keeping you from certain violent death at the hands of a criminal attacker is your ability to successfully enter the combination needed to make your gun operable. The loss of fine motor coordination and severe body tremors when facing such a dire situation could work against you

It would be interesting to assemble a group of people as testers, inject them with epinephrine (adrenaline) and challenge them to successfully work the controls of a SafTLok in a manner similar to the combat handgun tests described by Massad Ayoob in the Feburary 1999 issue of Guns magazine (p. 10).

You should keep in mind that my product review was conducted by a single person. This was not a scientifically controlled study to determine "average success" or "average failure" rates. This product review simply reports my personal experiences with the SafTLok magazine lock.

Another thing to keep in perspective is that I have no other "success/failure rate" data to share with you for other gun security devices which use a combination lock mechanism (GunVault, trigger locks, lock boxes, etc.). My personal 93% success rate might be very similar to, or better or worse than, my attempts with any other combination lock-type gun safety device.

As with all personal defense hardware, you should train intensively with the SafTLok before you use it to develop the skills necessary for consistent successful operation, and you should train with it regularly to keep these skills from becoming stale. Operator error is the weakest link for any combination lock-type device.

The SafTLok magazine lock appears to meet the claims made by the manufacturer. It is very well constructed, and the locking mechanism operates reliably. It costs $89.99 and can be special ordered with a custom combination (any combination from 0001 to 9999) directly from the factory. You can also have the combination changed, if it becomes compromised or you desire a new one, by the factory for $20.

The problems I mentioned above about memory recall under stress and operator error can be minimized by ordering a custom combination that requires a minimum of mental and physical effort (1010, 1000, 1100, 0011, etc.)..

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