What are the leading causes and diagnosis for Failure to Feed malfunctions.
I have an 18” (rifle gas system) upper that has run flawlessly for several years and a couple thousand rounds with a Gemtech HALO attached. After removing the suppressor I am getting Failures to Feed. The bolt is obviously not going rearward far enough to pick up the next round or lock open after the last round. Possibly under-gassed.
The upper was built by Accuracy Speaks with a Douglas 1:9 so I assume the port size is appropriate. I have tried two different bolts and BCG’s. M193 and handloads. Inspected the gas rings. Cleaned the bore. And tried a couple of newer mags that have never had issues in my other AR’s. Still getting failures to feed.
I would ass-u-me it is a “standard” rifle buffer and spring. I have run several thousand rounds through this lower and may need to replace the recoils spring. Wouldn’t a new (stronger?) recoil spring be more prone to FTF than an older worn-out one?
What type of buffer spring and buffer are you using? Rifle or carbine?
The spring for a carbine should measure from MIN. 10 1/16- 11 1/4.
Rifle spring is MIN. 11 3/4- 13 1/2. If it is below the minimum then you need to replace it.
Since you state that you have changed rings and BCG’s that only leaves one other option and that would be the gas port or the gas tube. Maybe your port has a blockage? Maybe the tube is filled with crap? I would probably try a new one at this point.
True, but it’s also easier to at least try a pipe cleaner or a trick that I used somewhat successfully before, which was a simple bike air pump with a ball inflating needle. Faster and also possible to do.
By the way, you clip the tip of the needle off so the air expells from the front rather than the hole on the side.
Not sure where you read or heard about cleaning the gas tube with a pipe cleaner, but it does nothing at all to clean the tube. In fact, the TM states that you use either Carbon Removal Compound (NSN 6850-00-965-2332) which is somewhat nasty stuff or you replace the gas tube.
My fault for not clarifying that I let some Bore Tech C4 sit in there first, but assumed most would know the desposit needs to be softened. I just blew a little air in the tube to disperse the C4 and we were good to go within about 15 min.
Also agree that they are cheap and easy to replace, but this is just another option if a new one isn’t readily available.