Introducing ShotBlock, A New Accessory Poised To Change Gun Safety ~ VIDEO

ShotBlock is an innovative, patented accessory that stops a gun from being loaded, while also providing anti-corrosion benefits to your weapon.

Greenville, SC – -( Over 70,000 firearm accidents happen each year: in the house, in the community, at the store, at the firing range and more. At times – most commonly in retail settings – a firearm is accidentally discharged. Introducing ShotBlock™, a unique and patented way of insuring a bullet cannot be loaded into full breech.


Launching in 2019, ShotBlock is working to change a large segment of the firearms industry in a positive way with its revolutionary safety product – both in the public and political eye, and for gun manufacturers, sellers and owners. An easy to use indicator that slides into the barrel of the firearm, the ShotBlock allows the manufacturer to ship their firearms to the retailer protected from loading a live round into battery but still giving the retailer the ability to allow the customer to safely hold and manipulate the firearm.

“I had the idea for the ShotBlock after visiting a high-end shooting range with my wife. I had asked to see a used Gun Site 45, and the owner brought it out of the case and held it facing my wife without clearing it,” remember Bill Masters, Founder of ShotBlock. “He finally handed it to me and I cleared it. I left there telling myself there should be an easy way to let the customer know it was safe. There must be something to prevent someone quickly loading the weapon and doing bad things with it.”

Much more advanced than the cable locks or trigger guard locks you find on firearms from the manufacturer, the ShotBlock works by blocking the ability of a bullet to go into full battery. The ShotBlock is attached to an extended protection indicator and slides into the barrel and locks into the breach lip. The extended protection indicator plays two roles: First, it lets the owner know the gun is secure and second, it helps with anti-corrosion while being stored. Having the tip of the protection indicator visible at the end of the gun barrel lets the customer and gun owner know that the gun cannot be fired.

Once the ShotBlock is in the barrel of the firearm you can easily manipulate the weapon safely, and any attempt to load the firearm will cause the bullet to be wedged inside the Shot Block, and prevent the bullet from going into full battery. This is a huge benefit and safety measure for the firearm manufacturers to reduce liability, store owners, or even private owners because they now can see – as soon as someone grabs the gun – the gun is safe.

From a retail perspective, it is also a huge upgrade to the current, restrictive trigger locks. Traditionally you would have a trigger lock on the firearm as well as a flag in the barrel as a safety measure. If someone is shopping for a new firearm, they are not able to pick the weapon up and feel the true ergonomics in their hand with these traditional restrictive devices. The trigger lock is clunky and the flag prevents the firearm from being manipulated. With the ShotBlock, the customer is able to measure fit and feel properly ensuring safe and accurate usage.

The ShotBlock One model is compatible with .380, 9mm, .40, and .223 firearm chambers . The ShotBlock Two model compatible with .45 and .308 firearms and is coming soon. For more information on the Shot Block, please visit:



ShotBlock was founded in 2019 by Bill Masters, an American engineer, inventor, manufacturing entrepreneur, and business advisor and mentor. It holds two patents (9,448,024 – Firearm Safety and Chamber Block Indicator / 9,310,149 – Firearm Safety and Chamber Block Indicator). The ShotBlock’s mission is to improve gun safety for manufacturers, retailers and private users through its innovative safety products.

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Charlie Foxtrot

I had the same question. ShotBlock isn’t so “revolutionary” after all.


Are these better, and more easy to insert and remove, than the red or orange plastic flag stops that are already in common use? The flags also hold the action somewhat open, enhancing air circulation if one stores guns in an out of ready state. This product may be good, but maybe a more or less an equivalent idea. I wonder if gun ranges that require the flag plugs during cease-fire will accept these plugs instead.

Xaun Loc

I doubt anywhere that requires flag plugs would accept this device — and they shouldn’t. While this device would work it simply provides less assurance. As you noted, flags hold the action open, this specifically does not. The only indication that this device is in use would be the orange pipe cleaner sticking out the muzzle, but you have no real assurance that the plastic chamber block is actually on the other end of the pipe cleaner. Like you, I also question just how easy this device is to insert and especially how easy it is to remove. Inserting would… Read more »


Not likely. The chamber or bore flags now in common use are nearly instant to install and to remove. In an active range situation, when a number of individual =weapons need to be cleared and safed after each course of fire for a group, the fiddly moves needed to fit, then remove, these devices twenty or more times in a day would make them unacceptable straightaway. Furthe,r to the Line afety Officers, charged wiht visually inspecting each weapon on the line prior to allowing students to move forward to the firing line, woild of necessity have tp pick up, open… Read more »


MB is correct,

my guns stay loaded and I know it. Those in the safe may or may not. But all are assumed loaded.
Rule one

I don’t point at what I don’t want to kill or destroy, or hit (target)
Rule two

Don’t touch the trigger till on target. Safeties on guns ( trigger blocks and such) since, 1964 I believe
Rule three

Don’t mix handling guns with alcohol
Forth rule.

You have to literally break all three to hurt or kill someone.


It is probably good to stick with the four top rules that most people seem to have adopted, to avoid confusion: 1. Always assume that the gun is loaded. 2. Never point a firearm at anything that you are not willing to destroy. 3. Keep your finger off the trigger until you are ready to fire. 4. Identify your target and what is behind it (and anything potentially in the line of fire) before you fire. Beyond that, there are all kinds of other good and important rules, like securing unattended firearms, using the right ammunition, not shooting in an… Read more »

Charlie Foxtrot

I am always amazed how many people do not know Jeff Cooper’s four basic rules of gun safety (which you mentioned).

Even the NRA came up with their own version, which’s inconsistency has maimed and killed gun owners. “ALWAYS Keep The Gun Unloaded Until Ready To Use” is in direct conflict with Jeff Cooper’s “Always assume that the gun is loaded.” Hence, “I thought it was unloaded” is a common explanation for negligent discharges.


An organisation with which I have been deeply involved for years now has four safety rules…
always keep the muzzle in a safe direction is the first. If THAT ONE RULE is upheld, no one would ever get hurt by a discharge, intentional or negligent.

FInger off the trigger until sights are on the target is just as important.. if your finger is not on the trigger, the gun can NOT discharge, no matte where the muzzle is directed.


While I am not inclined to use this as a chamber flag, in guns stored in my safe, etc., I could see this being beneficial to certain non-gun specific, sporting good type stores, like Dunhams for example, who insist on keeping the trigger lock/chain lock on the gun while a customer checks it out. The people working there are not necessarily going to be “gun people” as the store mostly sells other things than firearms so they are always going to be more uncomfortable with and take further, arguably unnecessary, precautions on the firearms in their stores, when compared to… Read more »


If I understood how these work, seems like they leave a glaring issue. While rare that a firing pin sticks forward in a modern firearm – it happens. More common in C&R guns, to which I’m partial! So if the cartridge partially loads, just not far enough to go into battery – if the gun lacks out-of-battery-safety or if the FP is stuck forwards, primer may still go off when slide or bolt closes. As the device is plastic, I imagine the bullet can still go down the barrel while simultaneously there is dangerous discharge out the breach. Not really… Read more »


If the round isn’t chambered, even IF the primer is struck be a protruding firing pin ( a problem with improperly assembled AKs and SKSs) the bullet can go NOWHERE with velocity that could cause any real harm. The case ruptures like popcorn – and with about as much power – and the bullet typically falls or tumbles harmlessly away. Also, ammunition in a fire is NOT a hazard in any way in a fire unless it is chambered. Rounds chambered in a semiautomatic will go off, but, typically, others will not feed and fire because they most likely have… Read more »


I think the 4 rules of firearm safety is all anyone needs. If you never violate the rules, you never have to worry about a negligent discharge hurting someone. Most guns already come with chamber “flags” use them if you feel the need.


You sound like a leftist by saying “if you never violate the rules, you never have to worry”. The fact of the matter is rules WILL be broken either on purpose (which is what the lawmakers don’t account for), or by idiotic negligence (which is what you aren’t accounting for).


@K&B – Statement was “if you never violate the rules, you never have to worry”. Implicit in that statement is that if/when one violates the rules, there is risk. Part of why there are 4 rules – is for multi-dimensional safety. If you break one or two rules, you may have an ND, but you won’t kill anyone – which is the ultimate goal here. Even breaking all the rules may or may not result in an accident as I have been lucky enough to have witnessed. By lucky I mean I wasn’t show when someone tripped and pirouetted while… Read more »


Xaun Loc made my point more eloquently and perhaps less offensively (apologies to @MB; my “sound like a leftist” comment was unnecessary. I was just really mad at liberals yesterday morning.): No one obeys all four rules all the time.

Saying that “the 4 rules of firearm safety is all anyone needs” is akin to saying “if you just pull out, you won’t get your girlfriend pregnant”. Going with the sex analogy, the shotblock is like abstinence: there’s no way there can be a pregnancy (negligent discharge) if there was no sex (chambering of a round).

Xaun Loc

NO ONE (not even YOU) obeys all four rules all the time. If you did it would be impossible to holster or draw any gun or to put any gun into a safe or any other storage. As for chamber flags, I suppose some gun from some manufacturer might come with one, but I have yet to see whatever gun that is. Personally I think this particular device is a bit silly and certainly less useful than the maker’s press release wants to make it sound. I cannot see any reason I would use one, but I can see some… Read more »


I applaud the simplicity of the innovation. … I would like to know how the pipe cleaner is secured in the thimble, and suggest a pull tab on the chamber end of the thimble would be desirable. Sticking a rod down the barrel starting at the muzzle seems undesirable, not a routine one should to become accustom with. (Yes, I know should one have a squib …)

Separately, I see no reason to use live rounds in the demo; and from a marketing perspective suspect it detracts from the information content of the offering.

Phil in TX

Uhhhh, Sisu, the “round” in the photo is NOT a live round. It is a “Snap Cap”, or dummy round designed to allow full manipulation of the firearm with no damage to the firing pin or other parts of the mechanism.
Phil in TX

Xaun Loc

Are you sure about that, Phil? Sisu is talking about the demonstration in the video, not the single photo you seem to be talking about.

Watch the video.

The round she handles in the video was a dummy but I didn’t see anything to make me think the rounds in the loaded magazine she used later in the video were snap caps or any other sort of dummy rounds. I have very rarely seen anyone who keeps a magazine fully loaded with dummy rounds.