Too much crimp

[Adam From Africa]

I overcrimped ten or so Rigby cases with a Lee crimp die, such that when I fired the rifle a small part of the case neck blew right off. These little “brass rings” travelled all the way through the barrel with the bullets. My concern is that it may have damaged the rifling of the stainless steel barrel. Should I be concerned and how would I know? Thanks, Adam

 

[IvW]

Yes. Stop.....

Problem will arise when the ring does not go out the barrel.

Stop, pull re do.....or discard and start over.....

 

[fourfive8]

That's unusual!!! Yes, stop and re-assess. Never heard of any type of regular mouth crimp causing that. Check to make sure you have trimmed the cases for your chamber length. The crimp may have allowed the round to be chambered and fired, even if the case was too long... in effect pinching off and separating that thin ring from the rest of the case upon firing. The ring itself would cause little damage to the bore even if another bullet "ran over" it. The bigger potential is for very high pressure spikes if the bullet is being "crimped" into the case mouth at the end of the chamber from too long of a case.

 

[grand veneur]

If everything has flown without problems through the barrel , theoretically no overpressure can have arisen. One should normally see with the eyes whether a damage has arisen inside in the barrel. To be absolutely sure you need an endoscope.

Strange in spite of everything , especially if one know the deep crimp of the old Kynoch cartridges. May be something else like @fourfive8 noted.

Disassemble and reload everything before what happens.

 

[IvW]

May want to anneal as well....

 

[DrBob]

May want to anneal as well....

Agreed. The repeated reloading of a case will work harden the metal leaving it brittle. Extreme crimping will thin and potentially tear the mouth edge. For annealing, with fingertips holding the clean deprimed case base, twirl the neck of the case in the propane torch flame until: 1) the base gets HOT to the touch at which point place on thick clean old towel for cooling and/or 2) in a dim room twirl the neck in the flame until a faint dull dusky red color is seen on inner wall of neck... not red or cherry red as that means the neck is getting dead soft. Lay on towel to cool. Some stand the case in water to protect hardness of base but the neck may not be uniformly annealed. For a clean polished case, the annealing will give that faint silver green tint as seen on new cases. With good neck tension the crimp does not have to be heavy. The recoil in a Rigby can drive the bullet into the case and deform the tip. Really good rifles had a front taper on the mag to arrest the cartridge from hitting the front of the magazine.

 

[austrianhunter]

I dont think you damaged your barrel - as long as you dont shot a bullet on a stucking ring, all should be good. So shooting it should not be a problem - but after every shot, i would check the barrel if there is remaining brass. BUT THAT IS MY OPINION.

If your crimp is so severe to part off a ring from the case, you really should see it on the loaded round.

 

[fourfive8]

Work hardening that part of the case usually reveals as longitudinal splits in the mouth.... not a ring from the end of the mouth. Actually those splits are the most common indicator of excessive work hardening. Check the case length against your rifle's chamber length. Check case length after sizing. You should be trimming cases .005-.010" shorter than chamber length.

 

[sestoppelman]

How did you determine that the brass ring came from the case? Is it possible your crimp or a tight neck shaved a little ring of bullet off when seating? Either way it wont hurt the bore.

And don't buy a bore scope! You will drive yourself insane worrying about every little thing you find. Real problems can be seen with the naked eye.

 

[Adam From Africa]

Thank you everybody. Yes, I blew the mouth right off the case because the crimp was severe. You could actually notice how the mouth was almost stepped down on the bullet. It clearly weakened the brass on the very sharp shoulder of the crimp.

 

[sestoppelman]

I have never seen such occur before. The LEE crimp die is a pretty nifty rig. I can imagine it took some considerable force to crimp your rounds hard enough to cause this.

 

[Adam From Africa]

Some further explanation. Perhaps its got something to do with my tools. I use a 416 Remington Lee crimp die for the Rigby cases. I feed the cases from the top through a spacer I place over the die mouth. But I have now adjusted the die and the crimp is much softer.

 

[sestoppelman]

 

[CBH Australia]

If everything has flown without problems through the barrel , theoretically no overpressure can have arisen. One should normally see with the eyes whether a damage has arisen inside in the barrel. To be absolutely sure you need an endoscope.

Strange in spite of everything , especially if one know the deep crimp of the old Kynoch cartridges. May be something else like @fourfive8 noted.

Disassemble and reload everything before what happens.

Sounds serious, I’m not sure if he want to line up for an endoscopy.

In my limited experience many comments are making sense. Stop clean it to be sure there is nothing stuck.
Check it and see if you can see anything,
Reconsider ammo sort that out as suggested.
IF you are UNSURE seek PROFESSIONAL advice. A gunsmith might take a few minutes to look through the barrel and give you a second opinion. Presumably anything serious may be obvious to you but if it’s not get it checked out, surely they won’t charge much. Maybe. Little bulge, some insignificant markings or a clean bill of health.

Different scenario but I have seen a barrel where a bullet was fired after the first round was stuck some way along due to no powder in the shell. So I was told. The barrel was peeled back like a banana and the stock shattered into splinters.

It’s unlikely but “if” there was somehow a flaw in the barrel it might fault down the track.

There are various bore scopes some with LED screens and some that are possibly better optically being a tube with his a light and a lens. Generally none are cheap if you don’t have a use otherwise.