We inspect and test fire every DSG Duty and Precision Series complete upper receiver for function before being shipped to our customers. To assist users in diagnosing function issues or to aid in the pre-purchase decision process, below are some specific details about the components we use.
1. Ammunition: Each complete upper is test-fired with five rounds of Federal 5.56 XM193 (or equivalent). With that in mind, we've found that using a military standard 5.56 ammunition provides a good baseline for functional verification.
2. Bolt Carrier Group: We use DSG brand bolt carrier groups during our five round test-fire for our verification shoots. Both our standard and enhanced BCG's are guaranteed to run trouble-free in all our uppers.
3. Lower Receiver: We mount the completed DSG upper on a Colt LE6920 lower for our test fire. The lower consists of a standard semi-auto trigger group, standard carbine spring, and an H weight buffer. The use of a Colt lower is not an endorsement of Colt or a statement about any other particular brand of lower. Still, we've found this type of lower is 1) common among many of our customers and 2) Colt is one of the original holders of the Technical Data Package (TDP) for the AR weapon type and like other choices in test components, it gives us a consistent baseline.
4. Magazine: For our verification, we use DSG's Teflon coated magazine with a MAGPUL brand follower and stainless spring. DSG can also recommend with confidence MAGPUL, Lancer, or any other U.S. Government Issued magazines for reliable use with our complete uppers.
5. During the test, ejection patterns are visually verified as acceptable, and we also verify that the bolt carrier locks back on an empty magazine.
Frequently Asked Questions:
1. Will 'brand x' ammunition work with a DSG upper? The best answer is probably. Any good quality, in-spec 223 or 5.56 factory produced ammo will likely work. There are too many variables for us to answer for every combination out there. If you are having a function issue, please see item 1 above. If the upper were here for us to assess, we would begin at step 1 above and repeat the original verification test with the ammo and components listed above.
2. Can I use a suppressor on my DSG upper? Generally yes, but some items need to be considered are listed below -
a. Short barrel users (less than 14.5") will need to verify the minimum allowed length or recommended length for their specific suppressor manufacturer and model.
b. Suppressor use may require special consideration in the choice of buffer spring and buffer weight in some weapons.
c. Adjustable gas blocks can be added to DSG uppers (.750 diameter in most cases), but should not be required for most applications. Adjustable gas allows the user to fine-tune a weapon for their specific ammunition type or for use with heavy or light operating systems (bolt carriers, buffers, springs, etc.). For a weapon that uses good quality, standards-based components, it is not necessary (see the list of components we test with above).
d. Calibers like 300 Blackout, which come in SubSonic as well as SuperSonic velocities, also require some considerations. Cycling is generally not an issue with both types of ammo in DSG Brand Complete Uppers except in cases like our 16 inch 300 blackout barrels, which by design are not meant to cycle subsonic ammunition without a suppressor attached. All other length DSG 300 Blackout barrels and uppers are designed specifically with suppressor users in mind and should work well with quality; factory manufactured ammunition of both types in both suppressed and unsuppressed configurations.
3. Will brand 'x' bolt carrier or bolt work with DSG brand uppers? That is a firm maybe. Any in-spec, quality manufactured bolt carrier group should work okay. But keep in mind that if the upper were here for us to test-fire, we would add one of our proof DSG brand BCG's for the test process. If you are adding a different brand or type of BCG to the upper, the responsibility will fall to the customer/user to verify function and diagnose any issues the BCG may introduce.
With the growth of the manufacturing base in AR components in the last few years, there is a large selection of seemingly low priced components available. Unfortunately, this large selection has also introduced many components with questionable adherence to specifications and quality control. If you choose to bargain hunt when purchasing core components like AR bolts, we recommend a great deal of caution. Seek competent reviews from high round count shooters and at minimum, use bolts that are lot or individually magnetic particle and high pressure tested (MPI and HPT markings are usually visible). A broken bolt can ruin your day and maybe your weapon (or worse).