ok, multiple sourced loaded rounds all showed the same behavior it's gotta be your barrel/bolt. I'd suspect headspace. You have test gauges????
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Groves in 223 cases
- Thread starter WhiteJEEPSmatter
- Start date
If not the boys over at Franklin's can test it for ya, they have gauges.
I do have head space guages, I can check then before I take it apart. I have spacers to add if it's out of tolerance. But would headspacing cause the groves?
if headspace is too large you'll get case stretching. Although stretching occurs in all directions if headspace is too long you'll get excess length specifically. Under 50,000 PSI+ pressure the brass will stretch out and it'll be hard visually to see (unless it stretches to the point of a rupture) but when you resize it'll push the shoulder back and those thin spots will tend to bunch up a bit. Think of this.....take a thin dish cloth and lay it flat on your table. That's your stretched case. Slowly push the two edges inward with your hands.....that's resizing. It'll naturally form ridges. Microscopically that's what happens to your case when your headspace is off. The act of resizing causes those thin spots to bunch up making them visible. If they are really bad, tactile ridges both on the inside and the outside of the case. The inside you can check with a little DIY feeler gauge, just takes a minute of practice.
Didn't read the thread beyond your first post. But you sure you know what the barrel is chambered in? I think you are shooting the wrong caliber through it. If you have a set of calibers I'd measure the case mouth and report back with the numbers. Might just be the pictures but looks like the case neck is significantly different on the fired case vs the live round.
It could be as simple a buying a finishing reamer. Sometimes the chamber will be rough cut in increments to check go and no go. Once the proper depth is achieved a finishing reamer is used to for a lack of better words, polished with finishing reamer. It just simply smooths out the rough cut. Sort of like honing a engine cylinder bore. Once it's cut to spec it honed to create the crosshatch that helps the rings seat properly. I am no saying this is exactly what it is but it sure sounds like it. The rough cut would have groves in the chamber and when the round is discharged the chamber is transferring those groves to the case. Its possible that might be it. . Send it to them and ask them to tell you what they found so you can log that info and recognize later if you see it again
Wait it's a Noveske barrel. Its a wise idea to use a new bolt with a new barrel. They seat together and shouldn't be swapped out like that. I would buy a new bolt. Not that expensive I just bought a Noveske 6.8 bolt for that very reason. Also buy a finishing reamer and use that. Neither one of those should be a huge expense and you can rule out two problem areas that way. You can use the same carrier but swapping bolts around from barrel to barrel is not highly recommended. I try to keep the bolt and barrel together throughout the life of a particular pair. Nothing else you did should effect that. Like the upper reciever shouldn't be a problem.
The barrel is labeled 5.56, I'll measure the chamber to make sure.
Someone else recommended getting a polishing reamer for this caliber. Worse case I mess the barrel up, at this point I'm not going to shoot it so it'll be a tomato stake. I'll order the polisher of the Amazon, they are 47.99, I've already ordered another barrel and as another gentleman said I'll order another bolt to rule that out too.
If you have a bore scope inspect the chamber for similar patterns as you see on the spent brass. If they look similar you found your answer. Then use the corresponding reamer to dress the chamber. If you don’t have a reamer a diy piece of foam wrapped with 1200 grit abrasive material/ paper with Flitz polish will further finish the chamber and remove the reamer imperfections.
