AAR: Semper Paratus Ar15 Armorer's Class in DFW area, TX, Sep 10 & 11, 2018


Fighter of the Daychief
I attended the Semper Paratus AR15 Armoring Course in the DFW area. The instructor was Will Larson.

The Haltom City PD hosted the class at the Haltom City FD station #1. The HCFD were great hosts!

The student make up of this class was a total 12 students. 9 were LE from various DFW metro departments, 2 were sales employees in the firearm retail business, and 1 was a civilian firearm enthusiast.

Day one

The first day included lots of technical info and the instructor. We discussed the AR15’s cycle of operation; Standards for the M16A2/A4, M4A1, Mk18 CQBR, Mk12 SPR, including barrel lengths, gas systems and gas port sizes; and other Mil-spec component standards.

We also spent a significant amount of time discussing the many cost cutting measures certain manufactures resort to that result in malfunctioning AR15 weapons. Mr. Larson displayed many examples from his “box of shame” to highlight many issues with the AR.

His description of important components such as the barrel was both informative and entertaining. Less than quality or out of spec parts are often not marked with their manufacturer. I have always referred to these types of parts as “stealth” components. He referred to unknown origin barrels as “CIA barrels” as they offer plausible deniability to their origin.

Day two

Mr. Larson asked the students to discuss their takeaway or "Ahh" moment from day one.

For me, it was the instructor’s first hand knowledge and experience, including several specific examples of highly regarded AR makers also sacrificing quality and why this has occurred. Additionally, specific examples of why certain companies have inappropriate sized gas ports on their barrels was interesting and enlightening.

Some additional discussion followed on malfunctions and how to diagnose their cause was discussed.

The remainder of day two was hands on repairing and breakdown of the students rifles.

Some of the highlights included:

Two LE carbines got new gas key screws and some proper staking with the MOACKS tool. Both rifles were dept issued Bushmaster rifles.

Several carbines received proper castle nut/end plate staking, including a couple from so-called "Tier-1" makers.

During the gas tube/carrier key check, several guns (including factory "Tier-1" and homemade) were found to be in need of the TM 9-1005-319-23&P field alignment . Mr. Larson had his TM 9-1005-319-23&P adjustment approved gas tube adjustment tool (a large flat head screwdriver) on hand and made sure every rifle that needed it was good to go.

Mr. Larson did a demonstration of building two uppers,including one using the GI barrel nut and delta ring. He said this is his “favorite” type of upper receiver installation, discussing the difficulties in getting everything in the Delta Ring/barrel nut assembly lined up correctly and torqued properly. Mr. Larson walked us through a complete install and highlighted why, after 30+ years of working on AR's, this particular part is still his “favorite” type of build

This was a great course and I cannot recommend it enough for those who wish to have more than cursory knowledge of the AR weapon family or wish to build their own rifles.