AAR: Sentinel Concepts Practical Urban Carbine

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AAR: Sentinel Concepts Practical Urban Carbine

Postby UnaStamus on Fri Sep 29, 2017 1:46 am

AAR: Sentinel Concepts Practical Urban Carbine with Steve Fisher
12-14 SEP 2017
Brainerd Lakes Area/Breezy Point, MN
Hosted by Learning Firearms

Wx: 80’s with sun on all days.

Students: 12 students were in the class, with a mix of backgrounds with LE, former military, and average earth people from all walks of life. Several students were guys we have had in previously Learning Firearms and hosted courses, so we had a class full of solid shooters.

Firearms:
Rifle 1- LaRue LT15/Daniel Defense 11.5” 5.56 frankengun SBR with Aimpoint T-1 Micro 4moa
Rifle 2 - LMT 308MWS 16” 7.62 rifle with Kahles K16i SI1 1-6x.

Gear: Mayflower GenV Split-Front chest rig



Foreword/background:
I am a metro cop with 10 years experience and 8 years military. I am also a firearms instructor with the metro agency I work for, as well as for Learning Firearms. For a while, I have been developing policies and training guidelines for a Law Enforcement designated marksman rifle/role (DMR) training and operational program. I have been expanding my training to include more precision long range courses so that I can keep pushing this DMR program forward. The Sentinel Concepts PUC course is another step on the road to developing a working program for law enforcement DMR development.


TD1:
The day started at Breezy Point PD with an introduction by Dave Timm of Learning Firearms. Learning Firearms hosted the course, and Dave laid out our training philosophy, as well as explaining our safety rules.

Steve Fisher followed next with his introduction. This is the second time we have hosted a Sentinel Concepts rifle course. Steve gave an introduction to why he created Practical Urban Carbine (PUC), which was based around the need to negotiate urban intermediate distances ranging from 100-300yds. These are distances that we often see in places like big box stores, department stores and large schools. As such, shooters need to be well-versed in engaging targets at distances longer than the typical 50yds and in. 80% of people live in urban areas according t the US Census Bureau, so the premise of urban engagements becomes very real. PUC is a “baseline class”, meaning that it’s meant to work on the “basics”. The shooting that we did was in the realms of “midrange” or “intermediate” range marksmanship/shooting courses offered by other instructors.

Steve talked about zero, and why he subscribes to the 200yd zero. He made a very poignant comment about how your zero is your zero. When you have a 50, 100 or 200yd zero, that is your only zero. Far too often people fall into the trap of believing that their zero is also has a secondary zero. What was not discussed was the concept of how trajectory works, in that when you zero, the rifle uses what is known as a “corrected trajectory”. You are arcing the bullet and adjusting to match your zero to a specific point in that trajectory. When you zero a rifle, the bullet has an initial intersect (where the bullet first crosses the point of aim upward), hits its maximum ordinate (the apex of the trajectory), and then has a terminal intersect (where it crosses to point of aim a second time downward). As a caveat to this, all rifle bullets have a specific range where the zero can be matched to the maximum ordinate, or apex of trajectory. For most rifle cartridges, this range is approximately 100yds. At 100yds, the bullet will generally not rise above the point of aim by any demonstrable distance (usually less than .15”). People often fall into the trap of believing that a 25yd zero or 50yd zero will always have a specific secondary zero like 300yds for 25yd BZO or 225yds for 50y BZO. The reality is that every zero is different based on the ballistics of the ammunition you are using, the external environments and the configuration of the rifle you are using. An 11.5” SBR and 16” rifle can both have the same zero, but the terminal intersect will not be the same for their trajectories because they will produce different muzzle velocities. When talking about zero, I feel that this is an extremely important area to discuss so that students understand exactly why their individual zeros may not match the trajectories that they see on the internet or on paper.

After student intros and a safety briefing, we broke and headed to the range.

The range is in a quarry, and started with zeroing at 50yds. Steve talked about how the first day is going to be about establishing zeros, and he was correct in that regard. When he talked about shooting at distance, he talked about the first best sight picture, or first acceptable sight picture. When the initial sight picture is acquired during shooting, we were advised to be aware that the shot was not getting any better and to take advantage of that. Steve then talked about shooting positions and the need for maximum recoil control. The prone position affords us that ability. Sling use was covered, and Steve talked about the need to incorporate sling use into all positions, including prone. This allowed the shooter to get the rifle tight into the shoulder and maximize recoil control.

We talked briefly about how rifle cant can affect trajectory, and how LPVOs (Low Power Variable Optics) can allow you to eliminate cant. With red dots/RDS, you don’t have this ability. Using the front sight post allows you to maintain awareness of the cant of your rifle. While shooting my SBR, I used my right with both the front sight up and down. When it was down, my shooting positions did not dramatically affect my ability to hold the rifle upright with minimal cant. I have enough experience to keep the rifle from canting dramatically. For precision long range, this may be more necessary, but for a carbine making body shots, it’s not as critical given the expedient nature that carbine shots often tend to be.

When we zeroed at 50yds first, most of the class was on target. Most students were able to zero within the first two five-round volleys. I have begun to notice that as my eyes age and my vision begins to degrade, an LPVO is far more advantageous to me than an RDS. The dot of the Aimpoints I commonly use get more and more fuzzy every year. After that, we moved back to 100yds and zeroed there. I decided to keep the zero of both of my rifles at 100yds, as that is the zero my agency uses for our patrol rifles.

After lunch, we moved back to 200yds and established our zeros there for everyone who was going to use the 200yd zero. We initially shot at 200yds to see what the bullets would do with the 100yd zero. The bullets were striking a few inches low, as to be expected. Once students switched to a 200yd zero, students shot out to 300yds and saw their bullets impacting low again as the trajectory was not he downturn. We were seeing approximately nine inches of drop at 300yds with a 200yd zero. The point blank range (PBR0 is often considered to be 4-5”, which means that you point and shoot and don’t have to adjust for elevation and can hit within that established target zone. With a 200yd zero, 300yds is obviously out of the PBR. With that, we finished the first day.

While shooting, I noticed a couple things that would benefit other shooters. Several people were shooting off of improvised bags or rests. If you do not have a quality dedicated rifle rest, it would be wise to invest in a quality bipod or tripod. Also, it’s a good idea to invest in a shorter 10 or 20 round magazine for zeroing so that you can get as low as possible with the rifle. Students shooting recce rifles with match barrels had very good accuracy with both match and ball ammunition. Their groups were very tight. A contributing factor to shooter accuracy is the equipment you shoot with.


TD2

We started the day with shooting at 50 and 100yds again. For people running a 200yds zero, they were shooting about an inch low at 50yds. We then moved back to 200yds to confirm zeros and see the deviation of the trajectory. We also shot back to 50yds to see where we were hitting with 200yd zero, and in most cases, people were hitting slightly high. With a 200yd zero, you will see the initial intersect at a distance shorter than 50yds.

We discussed how lack of magnification can cause changes in sight picture to have more dramatic effect. You are unable to see shifting of the reticle on target when the target is at longer ranges. The benefit of LPVOs becomes apparent here. Further, whenever there is any change to body position, you have the potential to lose your control of the rifle and accuracy can be affected. Body mechanics and breathing are the key parts to this. Another facet was on how to maneuver the rifle around the barricade. The rifle must move first, and then the shooter should position behind the rifle. It should not be the other way around, where the shooter is pulling the rifle with them.

We broke for lunch, which like always was provided by Learning Firearms. After that, we began doing dry runs on barricades. We used VTAC walls to practice shooting positions from both standing and kneeling positions. The walls were set up at 100yds and Steve demonstrated positions and how to lower down to lowest levels in the most efficient way. We then went live and started working our way on the left and right sides of the barricades with one shot, then two shots. We shot on steel at 100yds.

During this shooting, we got to learn how body mechanics plays into recoil control and rifle stability. We also discussed how the need for effective shots on target may supersede the maintain cover. When using a barricade, people have to balance the need for tactical positioning with how they will make first round hits.

People running LPVOs were more consistent with the long range hits, and this became exponentially more prevalent as the range increased to 200yds and 300yds. When shooting at 100yds, 2-3x was the optimal magnification for a balance of speed and accuracy. Magnification will also pull the the dust clouds around the rifle and barricade out of focus. This allows the LPVOs to be the most effective at night, as was demonstrated later.

During the rifle barricade transitions, we swapped from right to left handed. This emphasized the need to maintain good body mechanics. I found myself slipping with my grip and trigger pull on the left side when I was quickly transitioning, and when I had poor mechanics, a miss happened quickly.

Steve covered sling use for shoulder transitions, and we discussed how best to do them. Some students tried full unslinging when they shot, which I am not a fan of. Being in LE, we have to negotiate the use of a pistol. In this course, we used no pistols, so it wasn’t a factor that needed to be taken into account. For LE and military use, the sling should always be be in contact with the body for maximum control.

We ran several alternating side drills on the steel at 100yds. Following that, we served dinner and had a discussion about low light/night shooting. Steve talked about types of light and reasoning for why those lights would be ideal or problematic. We also discussed when to use light, and when you wouldn’t, and the importance of light for identifying friend or foe.

Steve provided a laser demo, as well as using night vision and an IR laser. He discussed the premise behind a converging versus parallel zero. For night shooting, 3x was described as the optimal magnification for exit pupil.

Age was also discussed regarding the quality of human sight. At 14 years old, your eyes are the best they will ever be. Once you get to 45 years old, you need four times the amount of light a 14 year old would to see the same image.

Students were each allowed to flash their lights downrange once it got dark, and students were able to see what light quality did for long range visibility. Some lights were very poor, and he poorest performance came from the incandescent lights. There is a reason why we call them “Amish candles”. Students running generic lights or lower intensity LED lights saw their lights coming up short at the 100yd steel targets. The 800-1000 lumen lights being run were very effective at 100yds.

In the class, I ran a Streamlight TLR-1 HL 800 lumen weaponlight mounted on my SBR. I don’t like to use this kind of light for rifles, but the new 800 lumen lights have excellent range now compared to old pistol lights. The activation and placement of the light have always been problematic for me, and I have not been a fan of them being used on rifles. My agency requires officers to provide their own optics and lights on their rifles, and the vast majority of officers are running Streamlight TLR-1 weaponlights on their rifles. Running a pistol light on my rifle offered me an opportunity to evaluate how best to configure the light on a rifle, and how to instruct the placement and use to officers in my agency.

When we shot, we worked the barricade at 100yds and made sure to deactivate the light as we transitioned between positions. When the dust was too much for us to shoot, we were forced to move to a different height or side to get away from the dust being kicked up and obscuring our view.

We did a short debriefing, and then called it a night.


TD3
For the third day, we continued to shoot from barricades at 100, 200 and 300 yards. We continued to work to drive the rifle to the target where we looked at the target before moving the rifle. This was done instead of swinging the rifle to the target.

The class concluded after we spent some time shooting at 300yds.

At 200yds, I feel that the 4 MOA dot is at the limits of its effectiveness. You are covering an 8” area at that point. Once you get to 300yds, you are are at a 12” area of coverage for a 4 MOA reticle. We shot at 100 and 200 yards before lunch, and then 200 and 300 yards after lunch.

One student shooting a Vortex StrikeEagle 1-6x determined that his optic was of insufficient quality. He later decided to ditch the optic and use his Sig Sauer Tango4, which is a superior optic. This student is not the first person that has ditched the StrikeEagle after taking this course. When you need optical quality, you quickly see deficiencies with low priced glass.


A huge thanks goes to all the students for attending and making this possible. This was a very good class of shooters, and it helped keep the pace of the class up to where it was. I would also like to throw out a big thanks to Dave Timm for all the work he did to make this class happen.


My overall evaluation of the course is that it is an overly-basic course for my needs. My expectations coming into this course were high, and this course did not meet my expectations. 1.5 days were spent zeroing. 1.5 days were spent shooting from barricades at 100, 200 and 300yds. There was very little variety. In all honesty, this was a two day course that was extended a third day. For a novice shooter, this could be a better course. For the more experienced shooter, this may be a bit elementary.
"America is not a democracy. Your opinion is irrelevant." -Me
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Re: AAR: Sentinel Concepts Practical Urban Carbine

Postby mmcnx2 on Fri Sep 29, 2017 7:02 am

Urban carbine course shooting 200 and 300 yards. What is the practical application for this? I mean really you would have a heck of time saying it is self defense at those distances.

I'm convinced if you had a class on Zombie shooting under water people would sign up for it.
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Re: AAR: Sentinel Concepts Practical Urban Carbine

Postby Squib Joe on Fri Sep 29, 2017 7:54 am

mmcnx2 wrote:Urban carbine course shooting 200 and 300 yards. What is the practical application for this?


To neutralize a threat that has the ability to kill you at 200 or 300 yards. That would be my guess.
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Re: AAR: Sentinel Concepts Practical Urban Carbine

Postby mmcnx2 on Fri Sep 29, 2017 8:20 am

Squib Joe wrote:
mmcnx2 wrote:Urban carbine course shooting 200 and 300 yards. What is the practical application for this?


To neutralize a threat that has the ability to kill you at 200 or 300 yards. That would be my guess.


Thanks for the ridiculously obvious. My point is it was URBAN and with a carbine. Not a lot of 200 -300 yard threats that you could not retreat from, heck 100 yds for that matter. Also think for minute if you are in court defending this action, how many jurors are going to understand and believe someone 300 yards away was a threat that could not be retreated from.

Now had it been suburb then maybe, rural we get the f class boys out.

I stand by my assessment - Ninja war skills for the gullible.
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Re: AAR: Sentinel Concepts Practical Urban Carbine

Postby Squib Joe on Fri Sep 29, 2017 9:04 am

mmcnx2 wrote:Also think for minute if you are in court defending this action


There is a possibility, however slim, that you may need to defend your life one day in a situation where there isn't a court system. That may mean retreat isn't the best option. And that may mean you take somebody out before they get an opportunity to take you out.
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Re: AAR: Sentinel Concepts Practical Urban Carbine

Postby UnaStamus on Fri Sep 29, 2017 11:35 am

If you take measurements of the back aisles of a Super Target, Home Depot or Wally World, you come up with distances that are close to 200yds, and sometimes over. You also have some schools that have very long corridors. At my previous LE agency, we measured several lines of sight and corridors at close to 200yds. If you consider the possibility of stopping an active shooter, this is a potential encounter. It's not hard to justify shooting an active shooter at 200yds. I intrinsically have a problem with an average person running into an active shooter situation carrying a rifle, because it'd be very easy for them to mistaken for another suspect. This is particularly problematic if you have to run out to your vehicle to retrieve the rifle before running back inside carrying said rifle. It's even more volatile if this occurs at a school where you're basically gonna be shot on sight if you have a gun and aren't a uniform cop. This all is a whole other discussion, however.

I too have some questions about how 200-300yd engagement qualifies as "urban". For the LE game, this is legitimate issue we have to work around. For the average earth citizen, not so much so. Considering that only 3/12 students were LE, we are at somewhat of a discrepancy for the course intent I think. As much as I dislike Jeff Gonzalez/Trident Concepts, he correctly names his variant of this course as Mid-Range Marksmanship and didn't make any pretenses about it being for urban use. It was basically "we're going to practice marksmanship fundamentals at intermediate ranges using carbines". Steve is a good dude, but I think this course needs work. It's still a very new course that's about a year old, and I think that it needs more substance. 1.5 days spent zeroing and shooting groups with carbines is questionable time management.
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