Good afternoon everyone and welcome back to TFB’s Silencer Saturday brought to you by Yankee Hill Machine, manufacturers of the YHM Resonator R2 30 caliber rifle suppressor. Last week we got a look at the Otter Creek Labs OCM5 5.56mm – an AEM5 alternative that offers a weight bonus over the original design. This week I wanted to test out every subsonic 300 Blackout round in my ammo fort. Does all subsonic 300BLK share the same levels of quiet? Let’s take an unscientific, yet fun, look at some market leaders.

Always bet on 300BLK @ TFB:

• SILENCER SATURDAY #157: 300BLK Vs. 7.62×39 – The Dead Air Nomad LT
• SILENCER SATURDAY #137: The Best 300BLK Suppressors Available
• SILENCER SATURDAY #124: 300BLK Subs Vs 308 Subs With Labradar Data
• SILENCER SATURDAY #123: Innovative Arms Integral Bolt Action In 300BLK
• Subsonic 300BLK Tipped Hunting Ammunition from SIG Sauer
• Supersonic or Subsonic 300BLK SBR Defensive Ammo?
• YHM ULTimate AR15 Upper Review – Subsonic 300BLK Metering
• SILENCER SATURDAY #37: Subsonic 300BLK Shootout

SILENCER SATURDAY #203: Is All Subsonic 300 Blackout Created Equal?

My favorite rifle caliber is 300BLK. While it isn’t perfect, it handles 90% of my use cases with style. Optimized for shorter barrels, each suppressor/weapon system can be compact and light. With the right supersonic ammunition, 300BLK is accurate enough for hunting and defensive purposes out to about 300 yards. It excels in the AR-15 platform, as long as you keep it away from .223 chambers. And subsonic 300 Blackout can be whisper quiet (see what I did there) while providing better ballistics than pistol cartridges.

We have talked at length about 300BLK platforms and suppressors, focusing on utility, enjoyment, and of course noise reduction. As I have stated many times in the past, the perfect 300BLK silencer is the one that fits most of your intended needs. Long, short, mounting systems, and more are the characteristics that will help you spend your money wisely. What we don’t talk about often enough is ammo choices. For the most part, subsonic rounds mean heavier bullets, but there are a few other variables that come into play when optimizing a subsonic round.

Here’s where I wish that I was a reloader – smokeless powders come in many flavors, primary centered on burn rates. The chemical composition, the shape of the grains, fillers, and case volume all play a role in how fast the powder deflagrates (burns) inside the case and barrel after being ignited by the primer. For the best chance at excellent suppression levels, all of that powder should be burned as the bullet crosses over the crown of the muzzle and into the suppressor. Any extra powder burns inside the suppressor is observed as heat, flash and noise.

This is not my area of expertise and I won’t pretend to understand the finer details. But ammunition choice does play a role in noise reduction levels. How much of a role is difficult to determine without the proper measuring equipment. Until we can get Jay at Pew Science to do a Pepsi challenge with the major ammunition manufacturers,  we’ll just have to rely upon my ears.

As a reminder, as bullet weights increase, so do bullet lengths. To properly stabilize these long projectiles, they need to spin faster which means a higher rate of twist. A 1:5 (one turn for every five inches is preferred over a 1:10 rate of twist. Also, David from Discreet Ballistics let me in on a little known fact – some of the Remington Model 7 and Model 700 300BLK rifles are mis-marked and actually have 1:10 rates of twist – barrels normally reserved for .308 rifles. If you want to test your barrel, properly clear your gun and then use a cleaning rod and patch to push with the rifling. Mark your rod and push until it makes one full rotation. Then measure the difference in the amount of rod from where you started and where you ended.

Let’s take a look at today’s line up.

Discreet Ballistics:

• 190gr Discreet Ballistics Target – 1000fps (two barrel length options)
• 188gr Discreet Ballistics Selous Copper – 900-1050fps (two barrel length options)

Hornady:

• 208gr A-MAX Hornady Black – 1020fps
• 190gr Hornady Sub-X – 1050fps

SIG Sauer:

• 205gr SIG Sauer Subsonic Tipped Hunting & Tipped Duty – 1000fps
• 220gr SIG Sauer Elite Match Grade – 1000fps (not pictured).

Nosler

• 300 AAC Blackout 220gr Match Grade – 1020fps

A superficial look at the powders shows that they all have about the same grain size and shape. None of them contained any fillers. The SIG Tipped Duty ammo appears to be sealed with a lacquer whereas the Tipped Hunting rounds are not. A more knowledgeable person can offer insights on cannelures, polymer tips and bullet shapes. I’ll just say that they all look very pretty.

I used the disputed leader in 300BLK suppression  – the Dead Air Nomad L – for today’s testing. To me, this is the current silencer to beat if you are looking for extreme quiet.

To my semi-trained ears, the Discreet Ballistics target rounds and the SIG Elite match grade rounds were the quietest out of bunch. The Norma round may have been the “loudest”.  But they were all incredibly quiet in my 16” barrel with the Nomad L. Interestingly, the Selous bullet was just a little louder than its target counterpart. Don’t forget, to maximize your noise reduction, you can order ammunition for two different barrel lengths: 7-11” or 16”.

Honestly, an untrained ear probably can’t tell the difference between any of these rounds. Your main focus should be on accuracy and what is the most accurate out of your gun. But if you are worried about what 300BLK ammo is the quietest, relax, all quality subsonic ammo will leave you impressed. Of course, you have to find some in stock first.

Thanks for reading. Be safe, have fun and we’ll see you back here next weekend for another Silencer Saturday.

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