The key to any martial skill to the point that they are practical is integrating sparring into the equation, in order to validate how your skills hold up under pressure, and against another human being. Firearms are a difficult thing to practice this with, especially if your intent to use them is for self-defense. It’s never a great idea to point loaded guns at your friends, but luckily, there exists a product for this very purpose.

The scope of this article covers FX Simunitions, and the compatible Speer Force on Force equivalent, and not UTM.

Simunitions, short for “simulated munitions,” are non-lethal training cartridges designed to simulate the effects of live ammunition in training scenarios. They are primarily used in force-on-force training exercises by military, law enforcement, and security personnel to create realistic training scenarios without the risk of causing serious injury or death.

Designed to closely replicate the size, shape, weight, and the general ballistic characteristics of live ammunition, Simunitions kits are typically compatible with standard firearms with easy, drop-in modifications. For common firearms like AR-15s or Glock pistols, this can be as easy as using a drop-in bolt assembly, or a slide and barrel combination, respectively.

Some firearms, like MP5s, Beretta M9s, H&K USPs, and others, may require additional parts that are typically included in their respective Simunitions conversion kits.

Despite being designed as a drop-in solution for a firearm, some tuning may be required out of certain weapon systems in order to attain relative reliability. Through extensive testing at work, and at training events, we have found that while the AR-15s only require a quick bolt swap in order to be compatible with Simunitions, certain tweaks needed to be made with simple, off-the-shelf parts.

The design of an FX Simunitions bolt foregoes a gas key, as the design of the projectile makes it so that your AR-15 operates more like a blowback firearm than a direct gas impingement one. With the powder charge of a Simunitions cartridge being more like a firework than a regular one, not much is needed to cycle the bolt, so we have found standard, if not reduced power Sprinco Yellow springs to work very reliably, while using a carbine-weight buffer.

Even with a fully-functioning Simunitions gun, malfunctions should be expected. Any system designed to be a drop-in solution will never be flawless, and should be tested extensively if possible.

Prior to use in various training events, I’ve found that sims bolts don’t play particularly well with conventional firearm lubrication. A quick rub-down to neutralize as much oil as possible on the bolt, chamber, and on the sims bolt itself got it reliable enough throughout.

Depending on what system you are using, barrels should also be bone-dry, or very lightly lubricated, so that the projectiles exit the barrel smoothly, and to reduce the likelihood of squibs. Read the manual, or talk to people who have run your system to figure out what works best and test it for yourself to be sure.

Malfunctions are bound to happen regardless, and for that, a full-length cleaning rod is advised. Rods that break down may work in a pinch, but are not advisable to use, as multiple squibbed projectiles may take force that a multi-piece cleaning rod may not be able to handle. If a solid steel rod in the diameter of your bore is not available, then a Dewey rod that spans the length of your barrel, plus the upper receiver, should suffice.

Simunitions projectiles still exit with enough force to cause bodily harm. Think of something small that stings of an airsoft BB, traveling at the velocity of a paintball. Naturally, you’ll want some kind of safety equipment, and luckily, specialized equipment is not required for this purpose. In higher-paced force-on-force scenarios, some altercations may also be below the minimum advertised one meter standoff distance for common Simunitions, so it goes without saying to make sure you are protected.

A full-width paintball neckguard is a must, on top of face protection. An athletic cup is also highly advisable for pretty obvious reasons! Both are easily obtainable at your local sporting goods store, or online.

Gas masks are also typically resilient to the rigors of Simunitions impacts, and we here at WO have been using Airboss Defense masks for our trips to DARC. It helps to be prepared, and while finely-grated airsoft or paintball mask may work on short notice, it’s probably a little better to be prepared, and to train with as much kit as possible, including your gas mask.

Keep in mind that using an older or surplus gas mask may preset a risk in that aging rubber may be easily penetrated. On top of that, protect your visor by using outserts that can take the brunt of the Simunitions impacts, and to not ruin the one molded into your investment.

Hopefully, your next force-on-force outing goes a little more smoothly with this primer!