Q & A

Additional questions, email info@deadfootarms.com


 1I’m having trouble with some rounds cycling improperly. What can I try

  • Try swapping different spring combinations. We suggest for rifle caliber, start with red and red and move one spring around at a time. 9mm, start with blue and blue.

 2I’m having issues with the SCW. It’s nearly impossible to close the upper and lower because the buffer is wanting to come out over the buffer detent.

  • You need to remove the buffer retaining pin and spring. 

 3. I can’t find the rubber bumper in my 9mm kit. 

  • We pre-stage them in the end cap. Check there.

 4I can’t get the bcg far enough back to reset the trigger on the brace is installed. 

  • Your springs might be binding. Rotate 180 degrees and reinstall.

 5I have an AR9 with a PSA hybrid G9 bcg. Does this bcg need to be modified? 

  • Just punch out roll pin and remove rear weight. BCG will work with our 2.5 kits.

 6. Do all your springs come painted? 

  • Yes, the colors identify the weight of each spring. Black is the heaviest.

Blue is medium. Red is the lightest spring.

 7. I’m using the SCW 2.5 and when I charge it, it doesn’t have the full charge like it’s out of alignment. What can I do?

  • Lock the bcg to the rear overnight so the plunger and springs set to working length.

 8. My bcg does not lock into battery. It’s not seating and causing light primer strikes. What can I do? 

  • You might need a heavier spring. Red – lightest Blue – medium Black – heavy

 9. If I have the Tailhook brace and want the stock, do I have to buy the entire kit? 

  • No, just purchase the stock plate in the accessory tab on our site. 

10. Can I get a left opening Tailhook?

  • No. Tailhooks for SCW’s only open to the right. 

11. Do you have a recommendation on a bolt catch release that will not interfere with the sliding/telescoping portion of the SCW4 GEN 1?

  • The Strike Industry extended bolt catch works!

12. Is the system compatible with the Gibbs side charging upper?

  • The Gibbz is compatible if you make a small modification to the lower lip of the side charger bar. You need to remove about 0.375" of the lower lip or that part will hit the SCW collar. Email us for a picture @ info@deadfootarms.com

13. Is the rear end cap, the same thread as the buffer tube?

  • No. They are different. 

14.Will a 5.7 CMMG bcg work with your 2.5 system?

  • No. We can’t modify that bcg. The SCW4 products will work though.

15. I’m having trouble with some rounds cycling improperly. What can I try

  • Try swapping the springs.

16. I’m having issues with the SCW. It’s nearly impossible to close the upper and lower together because of the buffer wanting to come out over the buffer detent.

  • You need to remove the buffer retaining pin and spring. 

17. Can I fire the weapon multiple times with the stock folded when using the MCS?

  • Yes. Our patented technology is specifically designed to allow continuous fire with the stock folded or deployed.

18. Is the Dead Foot Arms MCS compatible with fully automatic weapons?

  • Yes, the Dead Foot Arms MCS for rifle caliber weapons utilizes a M16A2 full automatic bolt carrier.  For 9mm, a full auto bolt carrier is utilized as well. Please note that although the MCS is compatible with fully automatic weapons, our system alone does not make your weapon fully automatic. Additionally, any fully automatic weapon must be registered as such with the bureau of alcohol, tobacco, firearms, and explosives. Please cite local laws as well for permit requirements within your state and county.

19. What calibers is the rifle caliber modified cycle system compatible with?

  • Currently, the MCS is certified as compatible with .223, .223 Wylde, 5.56, 300 Blkout, 7.62x39, .458 socom, 6.8 SPC, 6.5 Grendel, and .224 Valkyrie.  

20. Does Dead Foot Arms offer special pricing for law enforcement and military agencies?

  • Yes. Email us a form of verification and we will set you up with an account. info@deadfootarms.com

21. Does Dead Foot Arms sell rifles?

  •  Currently, no.

22. Does the Dead Foot Arms MCS work with gas piston systems?

  • Yes. However, to purchase the MCS for your gas piston rifle we must have your bolt carrier sent to us via the bolt carrier modification program.  Dead Foot Arms does not currently manufacture piston system bolt carrier groups.

23. How does the bolt carrier modification program work?

  • When you purchase the MCS, you have an option to purchase our system at a reduced price under the bolt carrier modification program. When you order under that program, you are providing us with your bolt carrier to be machined to MCS specifications. 

24. How long does bolt carrier modification take?

  • Approximately one week from the time we receive your bcg. Upon completion, you'll receive your carrier back along with the version of MCS you ordered in a single package.

25. I bought the MCS pistol kit, and I would like to upgrade my system to the MCS folder or the SCW 2.5.  Is that possible without buying a whole new MCS?

  • Yes. We offer a MCS pistol to folder upgrade kit, as well as an upgrade kit for the 2.5 tailhook and SCW 2.5 stock in our web store.

26. Does the right-side folding stock interfere with access to the fire control group (trigger)?

  • No. The MCS was specifically engineered to ensure easy access to the trigger well, and while doing so without interfering with the forward assist or ejection port.

27. What types of stocks are compatible with your folding stock adaptor?

  • Any stock that threads into an AR-platform lower receiver is compatible with our folding stock adaptor.

28. Can I put a pistol brace or cheek rest on your folding stock adaptor?

  • Yes. The same rules apply with the MCS and standard ar-15 setups.  AR’s with a barrel length less than 16" require a pistol brace, or, if a stock is utilized, that lower receiver must be registered as a short-barreled rifle (SBR) with the batfe.

29. What will the overall length (OAL) of my rifle be, with the stock folded, when I equip your folding stock adaptor?

  • 16" BARREL- OAL 26.5", 14.3" BARREL- OAL 24.85", 10" BARREL- OAL 20.5", 6" BARREL- OAL 16.5". These lengths also apply to the SCW 2.5 Tailhook and SCW 2.5 Stock

30. My end cap is not staying closed?

  • You can use blue Loctite to secure it.

31. Will the Gen 2 SCW work with AR Maglock?


  • No, it will not.



BCGS that will work with MCS

  • CMMG Radial Delay – Order rifle cal
  • Superlative Arms
  • Adams Arms
  • Bear Creek
  • Palmetto State Armory  - The AR-V needs to be sent in to be modified with the 2.5 or you can punch out the weight and use it as a SCW4 kit. It needs to be able to accept our plunger and with the weight in, there is not space for the plunger to fit inside. G9 version - punch out and remove rear weight and can be used with 2.5 system. 
  • 6MM ARC
  • Aero EPC – Will not work as a 4’’ but will work as BCM 2.5 without modification. Once weight is removed, it’s correct length for 2.5 kits.
  • 350 Legend


BCGS that will not work with MCS

  • Stern Defense
  • FX-9
  • Older generations of Primary Weapon Systems bcgs – the version that has an internal diameter of less than 0.62 inches
  • Gibbs arms
  • .40 S & W 


Triggers that will work with the MCS

  • Rare Breed
  • Elftman
  • Fostech
  • Franklin
  • Mil-Spec


Triggers that will NOT work with the MCS