Bolt Lug Tolerance/Spec

[WS6]

What is the length and tolerance of that length, of said bolt-lug? I have a bolt that is "sticky" when I administratively clear the weapon (requires a weak mortar or a good YANK! on the CH).

[markm]

What is the length and tolerance of that length, of said bolt-lug? I have a bolt that is "sticky" when I administratively clear the weapon (requires a weak mortar or a good YANK! on the CH).

More likely an ammo or barrel/headspace issue... assuming the bolt is a known/good brand.

Is it factory loaded ammo?

[WS6]

More likely an ammo or barrel/headspace issue... assuming the bolt is a known/good brand.

Is it factory loaded ammo?

-Speer LE Gold Dot 64gr.
-Neither the Daniel Defense Bolt nor the Noveske bolt, in their respective guns, have this issue. This bolt does in both.
-The bolt lugs measured around 0.280" in length with my calipers. I need to measure the Noveske/DD bolts, but did not. I do not wish to discuss where the bolt came from at this time.

[markm]

-Speer LE Gold Dot 64gr.
-Neither the Daniel Defense Bolt nor the Noveske bolt, in their respective guns, have this issue. This bolt does in both.
-The bolt lugs measured around 0.280" in length with my calipers. I need to measure the Noveske/DD bolts, but did not. I do not wish to discuss where the bolt came from at this time.

Try the DD or NOV bolt in the problem gun.

Doesn't seem like the ammo... that's good stuff.

[mtdawg169]

I had one recently where the extension was slightly misaligned and had issues with certain bolts that wouldn't go into battery. I tested three bolts and only one would go into battery smoothly. That one also had the thinnest lugs, measured at 0.100". The other two had slightly larger lugs, with one feeling sticky going into and out of battery and the third would not go in at all. The one that would not go into battery was NiB coated and measured 0.103". That bolt inserted fine into other uppers. However, the additional bolt lug width combined with a slightly misaligned extension, was a no-go.

I say all that just to point out that it could be the lug length, width or extension alignment (less likely). Do you have any other bolts that you can test in that upper and then compare dimensions with your problem bolt?

[WS6]

Try the DD or NOV bolt in the problem gun.

Doesn't seem like the ammo... that's good stuff.

They are all problem guns. Both of them (dd and noveske) get sticky when this bolt is used.

[WS6]

I had one recently where the extension was slightly misaligned and had issues with certain bolts that wouldn't go into battery. I tested three bolts and only one would go into battery smoothly. That one also had the thinnest lugs, measured at 0.100". The other two had slightly larger lugs, with one feeling sticky going into and out of battery and the third would not go in at all. The one that would not go into battery was NiB coated and measured 0.103". That bolt inserted fine into other uppers. However, the additional bolt lug width combined with a slightly misaligned extension, was a no-go.

I say all that just to point out that it could be the lug length, width or extension alignment (less likely). Do you have any other bolts that you can test in that upper and then compare dimensions with your problem bolt?

Lugs miced 0.98"
Both are complete guns from dd and noveske. Neither have issues with multiple other bcg. I mainly want to know what this bolt should*** measure, and how much leeway spec allows. I'll measure the dd bolt when I get home.

[mtdawg169]

Lugs miced 0.98"
Both are complete guns from dd and noveske. Neither have issues with multiple other bcg. I mainly want to know what this bolt should*** measure, and how much leeway spec allows. I'll measure the dd bolt when I get home.

So the problem bolt lugs measured 0.098 x 0.280"?

I've got a couple of low round count BCM bolts at home. I'll try to measure them tonight for you. I'm not sure what the specs are, but maybe we can establish an estimate for you.

[WS6]

So the problem bolt lugs measured 0.098 x 0.280"?

I've got a couple of low round count BCM bolts at home. I'll try to measure them tonight for you. I'm not sure what the specs are, but maybe we can establish an estimate for you.

Correct, and thanks!

[RMiller]

In the past 2 weeks I've never heard of so many headspace and tight lug issues on AR15's. It's everywhere and enough that its strange.

The one common theme is a no-name (claimed to to mil-spec) obviously not mil spec bolt. Just an observation.