Neck too long?

[mousegunner]

I was looking at some FC .308 once fired brass and noticed a slight ridge of brass around the opening that pointed inside. It doesn't look normal. This is once fired factory ammo that probably came out of my 40X. I say probably cause doesn't look like it came out of my .308 M1.

I'm thinking the neck was too long and the case mouth made contact and peened in brass around the circumference. I made a chamber length gauge and will check the 40x and M1 tomorrow.

I tried to take a picture but it didn't show up well. What signs do you get when the front hits the ledge at the end of the chamber?

 

[IdahoSharpshooter]

how long does the case measure? I always trim to 2.015" and have had zero issues in the last 50+ years

 

[243winxb]

Standard- Trim to 2.005" Maximum length is 2.015"

once fired brass

This is once fired factory ammo that probably came out of my 40X

Could it be from a factory crimp?


What is its current trim length, after full length sizing.

 

[6MMsteve]

what you can do if you have a borescope is drill out the head, chamber the round or push it in and use the scope through the base and see how much you have...I done this on some cases..but a blueprint will also show if it's custom chamber I think

 

[varmintshooter]

Factory crimp. Trim to length and load.

 

[Grimstod]

Standard- Trim to 2.005" Maximum length is 2.015" View attachment 1094509


Could it be from a factory crimp?


What is its current trim length, after full length sizing.

That picture is a factory crimp.

 

[mousegunner]

This was New Federal ammo, 150 gr Nosler ballistic tip bullet with cannelure and a smooth taper crimp, not like the picture, smooth.

The ridge is towards the inside, not noticeable at first glance. If you drag a bent paper clip out the opening you feel it. The fired length is 2.020-2.022.

I also found some Winchester brass, same thing. New, had a 168gr SMK, taper crimp, 2.001-2.009 long.

These had to come out of my 40x. Haven't shot it in a long time and I found this when I was doing an inventory of my brass.

I would think the inside would be ironed out as the bullet is being pushed out so I'm curious how this small inwards ridge formed. I know this wil get fixed when I run the case through the FL die and trim, still I'm curious. I'll check the chamber length later today but that's what I have for now.

 

[mousegunner]

FYI My 40x has a Kreiger barrel that was installed over 15 years ago. Since I was provided ammo by my department I never reloaded so didn't look twice at it. Barrel has 800 rounds through it then I switched to the AR for across the course.

 

[biggen0_8]

Has the brass been cleaned with stainless media? That will cause a very small inward lip. Normally it's so small that it's hard to see, but you can feel it with a sharp tool.

 

[mousegunner]

Has the brass been cleaned with stainless media? That will cause a very small inward lip. Normally it's so small that it's hard to see, but you can feel it with a sharp tool.

No, still dirty inside a baggie, inside an ammo can.

 

[243winxb]

The fired length is 2.020-2.022.

This is growing into the "safety zone" Your custom chamber needs measuring.

This 30-06 Federal factory ammo has a taper crimp of about .0015" The fired brass shows some spring back on the very edge of the mouth.

I would guess not a problem after fl sizing and trimming. Hard to say without seeing and measuring.

If the loaded rounds neck was pinched in the chamber , at the time of firing, pressure should have been high. Trim length would grow faster and become longer from high pressure.