PDA

View Full Version : Why do I have bright spots on the case rim?



Mad Man
February 28th, 2016, 11:28 PM
I just bought a new rifle in 6.5 creedmoor. This is my second rifle in this caliber and when I shot it today I noticed bright spots on the rim of every case. Is this over pressure? It's the same loads I used in my other rifle and this never occurred. I'm using a 120 gr. nosler ballistic tip with 38.0 grains of Varget and a Winchester LR primer. Max load is 40 grains. The primer is not flattened or cratered so I'm not sure what to do. Any help is appreciated.

JMW4570
February 29th, 2016, 06:22 AM
It could be.. Do you get the shiny spot just by closing the bolt on on a live cartridge? Is the bolt sticky or hard to turn after firing? Is the mark a surface mark or indention?

Airgator0470
February 29th, 2016, 06:59 AM
What rifle?

Maybe the case is not square with the bolt face...?

Rough bolt face?

NJC
February 29th, 2016, 08:12 AM
Chamber and eject a round without firing of you can and see if it's due to part of the process there or something that happens when the round is fired ?

Mad Man
February 29th, 2016, 08:42 AM
I just chambered and ejected a round and it did not do it. The bolt is a little hard to turn after firing but it's not real bad. The rifle is a Ruger Hawkeye Predator.

Mad Man
February 29th, 2016, 08:43 AM
The mark is just a surface mark.

Jafar
February 29th, 2016, 10:32 AM
Since the fired round is "gripping" the chamber after expanding from firing, it sits stationary while the bolt rotates to unlock. The mark left is the steel ejector making a drag mark. The brass is softer than steel, so it will mar a little bit. The reason it doesn't do it with an unfired round is due to the casing being able to rotate with the bolt during feeding and extracting.

JMW4570
February 29th, 2016, 12:36 PM
Since you are running reloaded cartridges, could the head spacing between the two chambers be a little different? I've see that before.

Other ideas: New rifle: Strong ejector spring leaving a mark?

Jafar
February 29th, 2016, 05:09 PM
Other ideas: New rifle: Strong ejector spring leaving a mark?

It definitely amplifies the situation, not to mention the sharp, new edge on the ejector that will develop a radius after a few hundred rounds.

Mad Man
February 29th, 2016, 05:44 PM
Thanks for the help I think yall are right I just wanted to make sure it was safe before I loaded any more ammo. I will drop back to the starting load and see if it still does it.

0utlaw
February 29th, 2016, 08:03 PM
Wait you didn't "start" at the "starting load"???


Man you're gonna fit in just fine around here :yup:

Mad Man
February 29th, 2016, 09:35 PM
Starting loads are just there so hodgdons lawyers can sleep at night.

Tack Driver
February 29th, 2016, 10:56 PM
Somebody help me understand why we give a shit about this "bright spot". :dunno:

Mikec2003
February 29th, 2016, 11:09 PM
Somebody help me understand why we give a shit about this "bright spot". :dunno:
It can be a sign of an overpressure condition

JMW4570
February 29th, 2016, 11:23 PM
And too much over pressure is like Tack at a sorority. Boom. Big, badda boom.

ironhead7544
March 1st, 2016, 09:02 AM
I have had start loads stick in the chamber. Did you check velocity? Did you try some factory ammo? I hate to do it, but I always try some factory first in case there is a problem with the rifle/handgun.

You will find that some firearms just dont "like" some bullet and powder combinations.

Jafar
March 1st, 2016, 09:22 AM
Somebody help me understand why we give a shit about this "bright spot". :dunno:

It can be indicative of a sticking bolt and pressed cartridge. It's one of the classical signs of a load that's too hot.

FBPA.