Good afternoon everyone and welcome back to TFB’s Silencer Saturday brought to you by Yankee Hill Machine, manufacturers of the new YHM Turbo T3 rifle suppressor. We got a first look at the Turbo T3 and we will return to a second part of the review next week. This week we pull the trigger on a unique belt-fed rifle conversion – a 300BLK M249 Para running subsonic ammo. Let’s take a look.
More M249 Belt-Fed @ TFB:
- SILENCER SATURDAY#252: Five Challenges for a Beltfed Rifle Suppressor
- [SHOT 2022] Get My Belt! The FN M249S Returns For All Your Crew-Served Needs
- ALL I WANT FOR CHRISTMAS: A Belt-Fed FN M249S And More
Legal & Safety Notice: Before you modify any firearm, understand your limitations and consult a certified gunsmith when necessary. You should also understand that certain firearm configurations will fall under the National Firearms Act (NFA). Without the correct approvals, manufacturing an NFA firearm can be a violation of local, state, or federal laws. Personally, I happen to believe that the NFA is unconstitutional, but until we get it repealed, it is the law of the land.
SILENCER SATURDAY #257: Subsonic 300BLK M249 – BRM Belt-Fed Joy
SILENCER SATURDAY #258: Subsonic 300BLK M249 – BRM Belt-Fed Joy
Two Christmases ago, I publicly asked Santa to bring me a FN M249S. An while the big man didn’t deliver any crew-served weapons that year, the spirit of the season lived on. And after writing many letters (and selling off a few possessions) that Jolly Old Elf finally delivered. Now he just need to help me with the parts to convert it into a post-sample machine gun.
While we wait for the full auto transformation, I received some help from the good people at Ballistic Research and Machine to convert the M249 from 5.56mm to 300BLK. Like the AR-15 platform, the M249 only requires a barrel swap to change calibers and a bit of gas adjustment. So I bought a 300BLK barrel from BRM and they were nice enough to loan me two of their suppressors to review.
Ballistic Research and Machine (BRM):
- Manufacturer’s Page: https://brm-silencers.com/contact-us/
- Facebook: https://m.facebook.com/people/Ballistic-Research-and-Machine/100058047595696/
- Model: AR-QA 7.62
- Model: AR-QA 5.56
- MSRP: On Request
- Weight: 12.4 ounces
- 300BLK Barrels Available
SILENCER SATURDAY #258: Subsonic 300BLK M249 – BRM Belt-Fed Joy
The AR-QA suppressor is a monocore design with a quick disconnect attachment system. At the top and the bottom of the monocore, some porting and a channel diverts the gases up towards the front of the suppressor where it can vent though porting in the end cap.
SILENCER SATURDAY #258: Subsonic 300BLK M249 – BRM Belt-Fed Joy
At 12.4 ounces, the AR-QA is on the lighter side, especially for a monocore design. The knurling is a classic touch that I appreciate.
SILENCER SATURDAY #257: Subsonic 300BLK M249 – BRM Belt-Fed Joy
The flash hider and muzzle brake attachments are left hand threads and utilize a taper and detent mechanism that makes it a true one hand on, one hand off operation. (That’s what she said). Although I can’t train my brain to think “lefty-tighty”, the QD system is slick and works as advertised.
SILENCER SATURDAY #257: Subsonic 300BLK M249 – BRM Belt-Fed Joy
The Ballistic Research and Machine 300BLK barrel is basically indistinguishable from a 5.56 M249 Para barrel except from the obviously larger bore and a larger diameter near the muzzle. It also has a gas regulation system that is adjusted with a 3/32 hex wrench. Standard 5.56mm M249 barrels are auto regulated.
FN249S Para
The FN M249S is not an impulse buy for most people. At over $10K, the Para version represents a major investment in a fairly niche firearm. Price critics need to remember that FN America is the only major manufacturer to bring a civilian legal belt-fed rifle to the U.S. market. Aside from a few parts, this is a real deal semiautomatic machine gun. Expensive? Yes. But this is the only factory built belt-fed rifle issued to the military currently available.
FN America M249S Para:
- Manufacturer’s Page: https://fnamerica.wpenginepowered.com/wp-content/uploads/2016/10/M249S_OM_Rev6_151217.pdf
- User Manual: https://fnamerica.wpenginepowered.com/wp-content/uploads/2016/10/M249S_OM_Rev6_151217.pdf
- MSRP: $10,499
- Caliber: 5.56x45mm
- Operation: Closed-bolt
- MAG Capacity: 200 Rd. belt or 30 Rd. mag
- Weight: 16 lb.
- Barrell Length: 16.1″
- Overall Length: 31.5″ – 37″
- Overall Height: 9.5″
- Trigger Pul : 8 – 15.5 lb.
- Twist Rate: 1:7 RH
I have a fairly strict policy of color coding calibers – 5.56mm is black magazines and receivers and 300BLK is FDE magazines and receivers. I’m paranoid that I am going to make a 300BLK cartridge in a 5.56mm chamber mistake that could result in destruction. I will most likely spray the heat shield, ammo box, and maybe the links in FDE to keep everything straight.
SILENCER SATURDAY #257: Subsonic 300BLK M249 – BRM Belt-Fed Joy
To save time and my thumbs, I use the GunLab M27 press loader to prep belts for the M249. It’s well built and easy to use.
GunLab M27 Specifications
- Brand: GUNLAB
- MSRP: $375
- Weight – 4.75 lbs.
- Dimensions – 10.5 X 7.5
- Material – 6061 T6 Alloy, steel guide plate, neoprene antiskid base
- Caliber: .223 Rem,5.56x45mm
- Finish / Color: Unfinished
- Firearm Type: Rifle
- Material: Aluminum
- Models Fit: MCR,FN M249 SAW,FN M249S,FN MINIMI
- Tool Type: Ammunition Belt Linking Machine
SILENCER SATURDAY #257: Subsonic 300BLK M249 – BRM Belt-Fed Joy
Above, belted 300BLK and 5.56mm rounds. Be careful when swapping barrels to not use the wrong ammo
Shooting the M249S with Subsonic 300BLK
Yes, I promise you a full video, but a cold rain descended on my rain session and I had to pack it up early. Besides, I want to capture video after the post-sample conversion.
However, the BRM barrel/suppressor combination was very quiet, with the action noise being much louder than the actual report. I did have some difficulty adjusting the gas regulator to get the M249S to cycle reliably. I’ll have to give the BRM guys a call on Monday and figure out what I’m doing wrong.
Even though it is not much different than using two 20-round magazines, the two 20-round belts of subsonic 300BLK made me aware of the cost of each round as the spent brass and links hit the table. At current prices, running a 200 round belt in about a minute on full auto will cost about $500. It’s like owning a Lamborghini and not having enough budget for gas and tires.
Still, this is my most unique host to date and I look forward to sending strings of subsonic fire down range At 900 rounds per minute. Stay tuned.
Thanks for reading. Be safe, have fun, and we’ll see you back here next weekend for another Silencer Saturday.
Silencer Saturday is Sponsored by Yankee Hill Machine
