Tag Archives: BLK

What were the worthwhile SHOT week debuts?

Glorious SHOT week. Every year the depth and breadth of new product announcements gets a little bit bigger. Drinking from the firehose of flagship product debuts can be nearly as overwhelming as walking the endless SHOT show floor. There are so many shiny things to catch your attention it’s easy to miss a few along the way. So here you go- the kR-15 list of notabke new products for SHOT 2014

ATN X-Sight Day/Night Riflescopes

This optic looks awesome- switch from daylight to infrared on the same scope. HD video out, smartphone remote viewing app and more- for less than $700 retail. They are offering 3-9 and 5-12 power models to start but these will be hot items.

 Tri-Star Cobra Marine Shotgun

Stainless steel to repel corrosion, spring-loaded forearm that claims to speed cycling (I’d like to try head to head with a Remington 870 or Mossy 500 to validate this one-but it sounds good), picatinny rail and more for $360 retail . 

TacSol 300 BLK upper receiver


Tactical Solutions makes some awesome kit. Their aluminum barrels and receivers are accurate, attractive and well designed. It’s about time they tossed their proverbial hat into the BLK caliber. At $1100 retail it’s pricy just like all their stuff but if it is intriguing- the upper is ready to rock, includes a BCG and features a free-float handguard, barrel shroud that covers either your own suppressor or the tacticool fake suppressor that comes with it. They hint that the fake suppressor is required to attain a 16″ barrel length– not a big deal but be advised.

Tac-Con 3MR Fire Control Group

I remain on the fence for this one but it’s getting lots of smiley reviews from initial testers. It is basically the bump-fire concept encapsulated into a drop-in fire control group that includes a giggle switch for the rapid fire mode. The thing I like most about this is the 3rd selector position. From initial reviews it seems that the rapid fire mode shrinks the trigger reset to about 1/16″ and has a 2.5lb pull. At the end of the day bump fire isn’t accurate so is it useful? Maybe not but full auto isn’t accurate either and people seem to enjoy it- try to find a video of someone using the giggle switch where they aren’t smiling if you don’t believe me.

300 AAC Blackout Subsonic Load Recipe: 190gr SMK using IMR 4198

Count IMR 4198 (as you can see in the photo it’s an extruded powder) among the options for powders that can be used for loading subsonic rounds that cycle in AR platform rifles. Recipe was created and tuned using a Lee Precision 4-hole Turret Press with double-disc powder throw and load both factory BLK brass and 5.56 brass trimmed to 300BLK specs.

Performance: This recipe successfully cycles both a carbine length upper (and gas system) with a 16″ barrel and also a 9″ pistol length upper, w/o suppressor. No bolt hold-open on either upper in my testing. No signs of overpressure or instability. The test cartridges sounded quieter than the LilGun loads I fired afterward. Chrony readings coming soon. 

NOTE: Users assume all risk, responsibility and liability whatsoever for any and all injuries (including death), losses or damages to persons or property (including consequential damages), arising from the use of any data, whether or not occasioned by publisher’s negligence or based on strict liability or principles of indemnity or contribution. kR-15.Com neither assumes nor authorizes any person to assume for it any liability in connection with the use of any data.

Caliber: 300 AAC Blackout (300 BLK)

Projectile: 190gr Sierra Match King HPBT

Primer: Winchester Small Rifle Primers

Powder: IMR 4198

Measure: 11.0gr

Lee Auto-Disc setting(double disc): Top Disc 0.43 | Bottom Disc 0.47

Min OAL: 2.222

Max OAL: see discussion below

Regarding OAL I had to experiment to find a length that fed well. Here is my thought process to arrive at the OAL I set my dies to:

  • The standard AR-15 mag accepts cartridges up to 2.260 OAL
  • The SAAMI Specs show an acceptable range of 1.78-2.260 OAL for the 300 BLK (although 190gr SMK is a long projectile and as such will require a longer min OAL than the range defined in the SAAMI spec)
  • My personal Min OAL: 2.140 to accommodate projectile length

This seems like a pretty big tolerance but remember that the BLK supports a wide range of projectiles that are different lengths. Since the 190gr SMK is one of the longer BLK projectiles I set my seating die to give me the longest possible cartridge-about 2.220 and ranging up to 2.240. 

Update: my new approach to 300 BLK Zero

Awhile back I thought I knew everything and decided to blog about it. Case in point: what distance to zero your 300 Blackout (BLK) rifle. Quite a bit of what is written there makes send and is pragmatic. However as I have grown into my kit and decided what works and doesn’t work well a new approach has taken shape- and it’s worth sharing.

Let’s refer back to this handy trajectory chart for common 300 BLK loads:

Although I enjoy shooting subsonic rounds out of my BLK it’s cheaper and more enjoyable to fire supersonics when you’re at a range and your buddy is firing his 5.56. So for a supersonic zero I have changed to a 25/150 yard – as illustrated by the red line above. This leaves me dead on at 25 yds, about 2″ high at both 50 and 100 yds, back on zero at 150 yds and 5″ low at 200 yds. That’s not too much to remember and even without doping shots hits will deviate by about 2″ or less at any range from 0-250 yds. 

Now to compare the blue line to represent subsonic rounds to the red line- big trajectory difference as one would expect. Figuring out holdover on the fly (and without a dual-reticle optic) is a nonstarter in this case. For the subsonic zero range: 10/100 yard zero. That setting leaves me 2″ high at 25 yds, 3″high at 50 yds, back to 2″ at 75 yds and zero at 100 yds. Again this not much to remember and 2″-3″ is not a lot of deviation without doping.

The sighting system I’m using now is flip-up BUIS for supersonics and my Aimpoint T1 for subsonics. If you take that approach make sure to use a rear sight with a narrow aperture so you can see through the optic and stay on the sight plane. My Troy di-optic rear site proved to be too wide for that task so it has returned to the interwebs from whence it came and I replaced it with a KAC. If you ever switch to BUIS and don’t remove your optic be wary of that problem- It stumped me when I sabotaged a range outing that way.

Function Check Procedure for your AR

This is a pretty solid refresher- although you should perform the function check every time you reassemble a rifle. It doesn’t matter if you removed the bolt for a quick field lube or if you just installed parts in the lower receiver– this is an important part of confirming that the rifle is in good working order before firing it. 

Maybe the giggle switch pictogram on the lower is just for show but in case you’re interested the procedure is the same as the semi check except after the first trigger/hammer check you pull the charging handle 3 times before you release the trigger.

 

AR Pistols: fireballs and headaches

Hijak86 discovered some of the warts you get with a pistol-length AR configuration.  It’s a good watch though- the photo at the end is tremendous. 

I can confirm that the concussion that people on either side feel is worse than the experience behind the trigger group. Muzzle concussions are notorious for giving your range buddies headaches and this is a great example. A kit like that really needs a supressor to be comfortable for the user and bystanders. Also there is the issue of barrel length. 5.56 rounds tend to tumble easily out of shorter barrels. They don’t spin enough times to stabilize before they exit the barrel. These are all reasons that drove development of the 300 Blackout (BLK) over at AAC. 

If you’re interested in a kit like this or want to weather the wait times and signoff requirements for an SBR you should look into the BLK- it solves most of the problems shorter 5.56 encounters and performs better in many cases. They also don’t breathe fire like a funnycar.

Meze 88s: Sort of like clay pigeons

Why yes, it IS a 300 BLK rifle, rocking a KAC rail system no less. The high speed camera work on the BT projectile is pretty cool too.

 

MAC.

Buckle up for an intense 150 seconds of MAC showing off an impressive array of NFA items. Tactical Beard not required.

Can't you just smell the cordite?

A more affordable option for BLK optics

I found an interesting tip at 300BLKTalk recently- way back in 2011 someone did the math and confirmed that the trajectory of my personal favorite of the 300 BLK projectile options, the 220gr Sierra Match King (SMK), is nearly the same as a .22LR high velocity round. Check it out here or below:

Yes, you're reading that correctly- with a 50 yard zero there is a difference of about 3″ at 200yds between the two. Finding a 22LR scope with a drop reticle may not be easy but if you stick to subsonic ammo you could get a long life out of a $200ish scope on your BLK in the meantime save pennies for a nice ACOG with a lame old Crosshair of Death, reticle porn below:
What great mind at Trijicon decided to skip both the Doughnut of Death AND the Chevron of Death options??? Either of those is more Trijicon than the sideways X. I may have to actually look at an Elcan optic.

 

300 AAC Blackout Load Recipe: 220gr SMK using LilGun

When I started researching recipes for 300 BLK subsonic loads the recommended powder was Accurate 1680. The Interweb phenomenon took hold and now there is a false impression that 1680 is the only powder that works for subsonic AAC Blackout loads.

Slowly the truth is getting out there- and I can now personally confirm success with LilGun as an alternative to 1680 for subsonic BLK loading. Also LilGun requires less charge per round than 1680– so it’s even more efficient– it’s my new preferred powder. More alternatives here– I plan to work on IMR options next.

Recipe created and tuned using a Lee Precision 4-hole Turret Press with double-disc powder throw and load both factory BLK brass and 5.56 brass trimmed to 300BLK specs. I recommend using LC brass when possible as I find its the most consistent. I still use CCI #400 primers, although you should note that these primers are a little soft so CCI #41 primers are best.

Performance:This recipe successfully cycles both a carbine length upper (and gas system) with a 16″ barrel and also a 9″ pistol length upper, no suppressor. No bolt hold-open on either upper, but that could be the PMAGs I used. No signs of overpressure or instability. Chrony readings coming soon are here and I had no problems dinging a 100yd target with these without hold-over.

NOTE: Users assume all risk, responsibility and liability whatsoever for any and all injuries (including death), losses or damages to persons or property (including consequential damages), arising from the use of any data, whether or not occasioned by publisher’s negligence or based on strict liability or principles of indemnity or contribution. kR-15.Com neither assumes nor authorizes any person to assume for it any liability in connection with the use of any data.

Caliber: 300 AAC Blackout (300 BLK)

Projectile: 220gr Sierra Match HPBT

Primer: CCI Small Rifle Primers (no. 400)

Powder: Hodgdon LilGun

Measure: 8.8gr

Lee Auto-Disc setting(double disc): Top Disc 0.30 | Bottom Disc 0.30

Min OAL: 2.140

Max OAL: see discussion below

 

Regarding OAL I had to experiment to find a length that fed well. Here is my thought process to arrive at the OAL I set my dies to:

This seems like a pretty big tolerance. I set my seating die to give me the longest possible cartridge-about 2.220 and ranging up to 2.240. Some factory ammo I purchased didn’t feed well due to FTC (Failure to Chamber). It turned out that they were the short end of the SAAMI OAL specs. Some scouring on forums and experimentation proved that longer OAL fed better : no FTCs on any of my BLK cartridges since this change.

 

The beauty of using these high mass projectiles in a modern sporting cartridge is that they pack a serious punch and don’t use much powder– a nice bonus when supplies are scarce or you’re on a budget.

 

1 Person Room Clearing Techniques

Watch this helmetcam of a room clearing exercise at Trident Fitness. Red targets are friendlies and yellow targets are bad guys.

It's an interesting video and shows how fast things happen- especially at beginner speeds. In under 2 minutes rooms are clear and we hear from Rich Graham. My thoughts after watching this:

  • Room clearing is a complex task – especially when working alone as you are in most home defense situations. The trainee in this clip is pretty green but is also a good example of how easy it is to make mistakes. More practice leads to fewer mistakes.
  • Good shooting- not missing is a good thing
  • The trainee should have changed levels- his movements were dangerously predictable. Practice helps with this too. If you act in a predictable way in this or many other situations you are asking for an ambush.
  • It would be a scream to run this drill with an integrally suppressed 300 BLK SBR