What’s Causing these Grooves?

[fordy1967]

Hi all, these have appeared on a couple of my cases 223. Any ideas as to what’s causing these grooves please?

 

[Smokedude]

Need a bit more info. Take it this is after you fired them and not an action taken in the reloading process.

 

[Smokedude]

How deep are the grooves and can we have a side on pick as well as end on.
Also do you reload. If so how many times have you reloaded these cases. Bit strange that the one on the right has the marks twice?

 

[fordy1967]

Yes, after firing. I do reload, 4 times only reloaded.

 

[chriswjx]

Do you have access to a bore scope to see if there's anything in the chamber?

 

[bluesako]

first thing i would do, is to give your chamber and barrell a good clean with jb paste, you could have some debris in their, you would be suprised what crud gets in their bs.

 

[Klenchblaize]

Extraction

K

 

[fordy1967]

Thanks all, I’ll give it a good clean, been using a bore snake regularly so should be ok, but will give it a good clean. It happened to 3 out of 50 firings

 

[timbrayford]

Are you occasionally getting lube on the outside of the case neck when you resize? If so this will leave a little indentation on the shoulder, it looks like an obturation issue with the case not properly sealing, albeit briefly, against the chamber wall.

 

[gixer1]

Looks like the bolt doing it as it moves back over the next round in the mag?

 

[bluesako]

as above said

 

[Muir]

Do you use a suppressor? What is the load? Have you tried a round of factory ammo to see if does same?-Muir

 

[Will the chippy]

Why would a suppressor ever come in to contact with a brass case?

 

[long_range_rob]

Honestly bin the bores snake and get a good rod/brushes/jag/patches and a bore guide. Your barrel will thank you.

 

[Heym SR20]

May be a wee burr on the feed rails of the action or magazine, or somewhere on the feed ramp.

You will need to make up some dummy rounds - ie with a bullet but no powder or primer. Then use sharpie pen colour them completely. Then load and feed slowly and see what is causing the marks. Go slow may not show the result- you may have to run them fast, but going slow will show what happens where.

Also do you keep your rounds in a pouch, ammo card etc. could easily be that.

 

[fordy1967]

Gave it a good clean, not with a bore snake, shot another 40 today, no repeat of the grooves, will keep a close eye on it.

Thanks everyone for the input, appreciate it

 

[Muir]

Why would a suppressor ever come in to contact with a brass case?

With a light load i get occasional smokey brass and blow back....but i guess that's is mostly with semi autos.-Muir

 

[Bowland blades]

I really cannot say but something is definite wrong . Stop shooting it until its been properly diagnosed ! Can't fix this with guesses on line , get it off to a gunsmith asap

 

[Bowland blades]

With a light load i get occasional smokey brass and blow back....but i guess that's is mostly with semi autos.-Muir

These cases look mangled to me though

 

[fordy1967]

Getting it checked over early next week, getting it bore sighted as well.