Choosing a suppressor is a daunting task. Deciphering what you need for your application versus what you are being sold is hard to digest. Trustable data and information are also hard to find within the flashy marketing from the firearm industry. The purpose of the Choosing a Suppressor Series is to help you make the most informed purchasing decision possible. Which will result in the most satisfaction from the end user (YOU). I will be referencing Griffin Armament suppressors and accessories. However, these concepts are not exclusive to our product line and can be applied to nearly every manufacturer’s product. I hope you enjoy.
Bore Diameter
Let’s start out by defining Bore Diameter. Bore Diameter, in the context of suppressors, is the aperture size of the baffle stack that will accommodate a predetermined bullet size/caliber. The commonly available Bore Diameters for suppressors are 5.56MM (.22Cal), 7.62MM (.30Cal), 9mm (.357Cal), and .45Cal. The Bore Diameter of your suppressor will determine the compatible calibers you can shoot through your suppressor. This is not to be confused with the construction of your suppressor. That determines the compatible cartridges, minimum barrel lengths, and rates of fire for your suppressor. For example, the Resistance 22M can be used on .17HMR but cannot be used on .17INCINERATOR (Pictures below)
Why is this important?
Bore Diameter is important to the overall performance and modularity of the suppressor. The performance can be defined as the efficiency of the suppressor. A dedicated 5.56 suppressor (like our Recce 5) on 5.56 will be more efficient in suppression than a .45cal suppressor (like our Bushwhacker 46) on 5.56 (Pictures Below). Your suppressor will be more efficient when the bore diameter of the baffles is as close to the bullet diameter as possible. When the bullet is in flight, the baffles inside the suppressor siphon off and slow down the expanding gasses from the fired cartridge. In common terms, the less hallway you are throwing your hotdog through, the more efficient your suppressor will be. This efficiency is directly correlated to the sound and flash reduction performance of the suppressor. The smaller Bore Diameter suppressors also tend to be shorter and lighter on average.
A larger Bore Diameter, in terms of modularity, can allow you to shoot a wide variety of calibers through one suppressor. It is a common practice of end users to choose a “one size fits all” suppressor as they will only have to pay the unconstitutional tax stamp and wait for the form to be approved once. Examples of this is using a universal suppressor like our Bushwhacker and Optimus suppressors to suppress all the firearms that an end user owns. The modularity does come at a cost. Universal suppressors or suppressors with a larger Bore Diameter tend to be longer and heavier on average. Also, you will need to purchase additional muzzle devices or accessories to be able to run a multi-use suppressor on all your host firearms. Additionally, you may see less sound and flash reduction as the suppressor may not be optimized for the cartridge you are shooting. A larger Bore Diameter does have a few obscure advantages. If you are running a shorter barrel, like our 9.5” .223Wylde barrel, a .30Cal or larger Bore Diameter suppressor will have a longer service life. The high velocity unburnt gunpower, that basically sandblasts your blast baffle, will take the path of least resistance out the front of the suppressor. Within that same aspect, if you have a semi-automatic firearm that is terribly over gassed, using a suppressor with a larger Bore Diameter will induce less back pressure into the system.
End Caps, End Caps, End Caps
A popular option for an overbored suppressor is picking up an endcap that is more optimized for the caliber that is being used. The optimized end caps will bring you closer to the performance of a dedicated suppressor without having to buy multiple suppressors. Are they necessary? I’d say no. Do they do something? Yes. You will see approximately a 2-5db sound reduction with using a caliber specific end cap. The human ear is believed to perceive sound changes at around 5-6db. I suggest going with the optimized endcap if you plan on using night vison or thermal sighting systems. (Ratchet-LOK end caps pictured below)
My Recommendation
When anyone asks me what my take on what suppressors to get to outfit their rifles, I go off personal experience. The first suppressor I chose was the M4SD-K, a dedicated 5.56 suppressor. As I wanted the most compact option that gave me the best signature, flash, and sound reduction. To give a little bit of context, my “main squeeze” is an 11.5” 5.56 AR15 built for use with night vison. The second suppressor I chose was the Bushwhacker 36, a universal suppressor, as the other firearms I could suppress in my collection are 9mm pistols and .22LR. Since suppressed Glocks and .22LR firearms do not have any real tactical purpose, the added overall length and weight is a non-issue. The benefit of the Bushwhacker, and Optimus, suppressors are that they have much more centerfire rifle applications than traditional pistol suppressors. This will satisfy the other 90% of firearms I have in my collection as well as other firearms my friends have on the range. This also comes into play for us Wisconsinites as I can just throw the Bushwhacker on a random hunting rifle for the one week out of the year for gun deer hunting.
I also break down my recommendations down to simple rules.
Rule #1 Get a dedicated suppressor for your main squeeze firearm
What I mean by main squeeze firearm is the firearm that you will grab in a self-defense or “SHTF” scenario. Whether it is an AR15, AK, PCC, Pistol, Bolt Gun, ETC. This firearm should be maneuverable, reliable, efficient, and simple. It has everything you need and nothing you don’t. I lump a dedicated suppressor in the same category as getting a good optic for your firearm.
Rule #2 Invest in a universal suppressor or keep getting dedicated suppressors
As I alluded to in one of the earlier paragraphs, all the other firearms in my collection besides my main squeeze rifle do not have a real tactical purpose to be suppressed. Should I hold those firearms to the same standard as the main squeeze in terms of getting a dedicated suppressor? Most likely, no. That is why I recommend going the route of getting a universal suppressor as the second suppressor purchase. However, you could have a couple main squeeze firearms that span multiple applications and use cases. For example, sub guns, carbines, SPR, DMR, precision rifles, ETC. I think you would be better served to get dedicated suppressors for each of those firearms if they serve a real purpose.
Conclusion
Bore Diameter is one of the aspects in a suppressor that can be one of the most stressful decisions. It can all be boiled down to a balancing act of what features the suppressor has and the overall performance it produces. With all things in the firearm industry, it is a tradeoff. I hope my breakdown and explanations help you with a purchasing decision of a suppressor. If you have any questions on this topic or need further assistance, hit up our customer service team at CS@GRIFFINARMAMENT.COM.
About the Author
The article was written by Jack Rapala. Jack is a USPSA carry optics shooter, night vision enthusiast, firearm salesman, suppressor connoisseur, and a customer service representative for Griffin Armament.