Buffer Tube Ridge?

[Hulkstr8]

Hey guys,

I put my lowers together over the past month and noticed on my buffer tubes that somehow a ridge has formed between the castle nut and the rest of the tube. Across the three lowers, they all have the ridge but to varying degree of severity. I'm gunna try and post a pic of it below. Is this normal?

Edit: Also, the buffer tube is LaRue (I'm still waiting for their CS to handle my problem, it's been 4 months). QD Plate is Impact Weapons (I think it's the best QD plate and the CS from Earl is fantastic). Castle Nut torqued to spec.

Also, I ran my fingers inside the buffer tube and it doesn't seem to affect the inside of the tube.

[hk_shootr]

Haven't ever seen that before.....

[Hulkstr8]

Yeah neither have I.......

I wasn't doing anything odd either, just Geissele Reaction Block, Magpul Wrench, and a torque wrench.

[jackblack73]

I'm betting the ridge was already there from manufacturing, you just didn't notice it before. LMT tubes have a similar ridge, although the location is slightly further back.

[BFS]

Looks like your tube was turned in a lathe prior to thread cutting.

Most tubes have rolled threads, not cut, hence you might never have noticed before on other tubes.

Your tube is fine.

[hk_shootr]

I'm betting the ridge was already there from manufacturing, you just didn't notice it before. LMT tubes have a similar ridge, although the location is slightly further back.

This is what I’m thinking

[Hulkstr8]

Okay, I wasn't sure. It seems strange that the ridges are either bigger or smaller depending on the buffer tube.

Is there any inherent benefit for cut or rolled threads?

[MegademiC]

Milspec tubes have thinner walls, and the threads are pressed on and are full depth.
Commercial tubes are weaker material, and have thicker walls, and the threads are cut, but are smaller and do not fully engage the threads of the lower receiver.

No clue about details on material, construction, or production for LaRue RE extensions, what I posted is for standard milspec or commercial tubes.

[Hulkstr8]

Milspec tubes have thinner walls, and the threads are pressed on and are full depth.
Commercial tubes are weaker material, and have thicker walls, and the threads are cut, but are smaller and do not fully engage the threads of the lower receiver.

No clue about details on material, construction, or production for LaRue RE extensions, what I posted is for standard milspec or commercial tubes.

LaRue tubes are mil-spec, the rest is sort of a mystery as it is with most LaRue products.

[BFS]

Okay, I wasn't sure. It seems strange that the ridges are either bigger or smaller depending on the buffer tube.

Is there any inherent benefit for cut or rolled threads?

Rolled threads are much stronger than cut threads.

Cut threads are more than adequate, but technically not correct "mil-spec"