Anyone have a bore scope near Howell?

[doslitros]

I need to figure out what the deal is with this 11” 9mm barrel. The rifling seems to be blown out about 3-4” in front of the chamber. Enough that a jag or brush just slide right through that area without resistance. There’s another ring of sorts about 3/4” from the muzzle as well.

Looking at the throat with my old Mark I eyeball it looks dull and the rifling is pretty weak there. I wouldn’t be surprised if it had a lot of erosion but I’ve never seen a barrel blow out the rifling further down. Any ideas or someone who could take their borescope to this would be appreciated.

[Moleman-]

Sounds like it's had a few bore obstructions. Do you shoot subsonic ammo especially reloads through it? If you don't find someone with a bore scope close by, teslong sells a decent endoscope version on Amazon for $55. Pics from their NTG100 (.20" dia, works fine with 22 on up) of a .50" CVA express rifle that the cleaning jag stuck in for some reason. Turns out there's a gap between the breech plug and bore on both barrels that shouldn't be there and the ID of the breech plug is larger than bore dia. Barrel in pic#1 the jag slightly snags the gap. Pic #2 this breech plug has a bevel to it for some reason and lets the jag slip into the gap. You can see the brass colored transfer from the brass jag in the area it was getting hung up on. You can even see some of the red wheel bearing grease in the bottom of the gap in pic #2 from me using a M6x1mm grease zerk and grease gun to force the jag out.

[Ol` Joe]

I agree, as inexpensive as the Teslong is every shooter should consider one if interested in how their bore looks or how well their cleaning regime works.
These are photos taken with my Teslong of my AR’s throat and gas vent.

C4401455-F6DC-47D7-A015-A17F18AD3A41.jpg

9A354A15-1D49-440D-AA0C-76AF5425137C.jpg

[joepistol]

From the OP description, sounds like a new barrel is in order..
Looking at it with a bore scope isn't going to change that...

[gman]

...

[doslitros]

Yeah I pretty much concluded I needed a new barrel just from the feel of the cleaning rod falling straight through a section of it and eye ball exam.

I just had no idea what could cause the section of rifling to get eroded away so far down the barrel.

I pretty much only shoot reloads in it. 9mm cast 135gn, Ford blue coating in front of 3.7 gn of titegroup. This particular barrel leaves that load with cratered primers so I know they’re hot for that gun. I just didn’t think that hot. My 1911 and M&P9 both shoot with no pressure signs. Could be this was a .355 barrel and I didn’t realize it while sizing my projectiles to .357.

[Moleman-]

Shooting a .357" lead projectile in a .355" bore won't blow out the rifling. The usual reason for rings in the barrel is a barrel obstruction of some sort. If you reload the common reason is a squib load. I'd look at the firing pin fitment on that gun if you're getting crating on only one gun with that load. I've got a section from a 16" 9mm AR15 barrel that had a squib load through it. If I can find what I did with it I'll post up a pic. Ended up just cutting off the bad section, rethreading/repark and using it for a SBR.

Found it. Shooter though he had 1 failure to feed (was actually a squib) then took two more shots before stopping. It made two bulges in the barrel. Shot 1 Squib, Shot two bulged the barrel and pushed the first shot 4" down the barrel. Shot 3 made a second bulge and pushed out all three bullets. The shooter remarked that the last two shots kicked much harder than the other ones.

[doslitros]

Well that’s a good idea there. I love cut aways. I think I might just do that.

What you’re describing sounds pretty much like what I have going on there but with more damage toward the chamber end.

Thanks for explaining that!

[Moleman-]

The squid rounds still had some powder. The powder measure had a burr partially break off and was randomly blocking off some of the powder. Just a primer can still push a bullet several inches into the bore. The rest of that barrel lives on a SBR and shoots fine.

[joepistol]

I just read you're using cast bullets, & powder coating them ?

I use a lot of polymer coated bullets, but wouldn't use any powder coat...why ?
Powder coating produces a hard surface ..very hard. I only use HyTek coated bullets, they claim there is a lubricant in their coating.

I had my Harley tanks & fenders powder coated back in the 80's..rode it with those tins for many miles & years.
The finish didn't chip or wear at all despite bugs,stones, road debris, etc.... the finish just faded, from exposure to the sun.

Firing a bullet with powder coating ( w/o a lube) down a barrel seemed to me like a good way to wear out a barrel,
when I read about many using HF powder coat on their bullets.
My suspicion is that your barrel may be a result of this..