I have an issue with using the A5 with green Sprinco in my SBR. I noticed after a range session that after cleaning and function testing I was getting some binding in the Receiver extension when manually cycling the action.
Build Specs:
Upper - Sionics RGP 11.5, Rugged Suppressors flash hider, geissele 10 MK3, Geissele gas block, carbine gas tube (melon its), Sionics upper receiver, Geissele airborne charging handle, BCM Ionbond BCG, Trijicon MRO/USO 1-4
Lower - DD MK18 factory lower with following part upgrades - Geissele B-GRF, Seekins safety, Geissele maritime bolt catch, BCM grip, VLTOR A5 RE, A5H3 buffer, Sprinco green, BCM Mod-0 SOPMOD stock, DD QD end plate.
After hearing/feeling the binding I went and grabbed the stock VLTOR spring and swapped it out - no binding. Pulled the buffer/spring and removed the buffer from the spring to compare to the Sprinco and I noticed the Sprinco had a slight S curve to it. As I was preparing to head to a two class this past weekend I just swapped the stock spring and ran it with no issue for the two days ~1000 rounds or so.
Ordered a few replacement Green springs for spares and to put back in the 11.5. None of my other rifles with this setup have this issue.
After putting a new green spring in the lower and cleaning, function checking (no binding), I put the rifle in the safe. Now after pulling it and function checking again prior to a range trip and function checking again - BINDING!!!
No rounds fired on spring/buffer combo and binding is evident. Pulled buffer/spring and sure as shit theres a S bend in the spring!!! Developed somehow in the safe under static spring pressure...
At a loss here as to what is causing the issue. I may pull the RE and swap in a new one. I have noticed some shiny spots in the receiver extension when looking with a flashlight indicating wear - maybe as a result of the bolt tilting and rubbing the RE?
I have only noticed this with since swapping in the A5H3. I have run the stock MK18 upper (prior to barrel replacement for gas port), 14.5 middy (no pin & weld), and the 11.5 on this lower and have just noticed the issue.
Sorry for the lengthy, rambling post but looking for feedback and possible thoughts on cause. Thanks.
Bookmarks