Pressure signs or not?

[Multi-Tool]

Here are some cases from recent .270 Win loads I tested in a bolt gun. I am concerned about the appearance of the ridge near the case head. Note that the brass was new, run through an FL resizing die, and chamfered, resized, and trimmed to consistent length. The load was 44.0 g of 4064 - a full grain below Hogdon’s published max and 1.5g below the max in my Sierra manual. The bullet is a 145 g ELD-X. I worked the load up starting with 43.0 g and I saw the ridge in those loads too.

What are your thoughts? Is this an aspect of the chamber having an irregularity or a serious pressure sign? The barrel is a factory Remington, 20”.

Thanks!

 

[hafejd30]

If what your referring to is the rough to smooth look about 1/4” above the case head that is normal. If from your chamber/die. Everything else looks good

Note: A line on the case in that area can also be a sign of case head separation. Which you can use a sharpened bent paper clip to test. Usually occurs from brass flow and over sizing with FL sizer

 

[Multi-Tool]

Thanks for the reply. Those are fired cases and there is a ridge at that rough to smooth transition.

 

[hafejd30]

Thanks for the reply. Those are fired cases and there is a ridge at that rough to smooth transition.

Bend a paper clip and sharpen the 90° bent portion. Run that inside the case where the line is. See if that catches on what feels like a ridge or crack in the case

I’m going to guess this is on every case, likely just a transition from new brass to wear marks from your chamber

But others I’m sure will comment with info as well

Is that line what your referring to?

Just to note a FL die will only size so far and cause similar “issues”

 

[nn8734]

Thanks for the reply. Those are fired cases and there is a ridge at that rough to smooth transition.

How much did you bump the shoulder back relative to a fired case?

 

[918v]

Here are some cases from recent .270 Win loads I tested in a bolt gun. I am concerned about the appearance of the ridge near the case head. Note that the brass was new, run through an FL resizing die, and chamfered, resized, and trimmed to consistent length. The load was 44.0 g of 4064 - a full grain below Hogdon’s published max and 1.5g below the max in my Sierra manual. The bullet is a 145 g ELD-X. I worked the load up starting with 43.0 g and I saw the ridge in those loads too.

What are your thoughts? Is this an aspect of the chamber having an irregularity or a serious pressure sign? The barrel is a factory Remington, 20”.

Thanks!

thats normal case expansion

 

[Multi-Tool]

Since the brass was new, I didn’t bump the shoulder. I was simply straightening the necks and trying to make the cases consistent.

 

[RegionRat]

Check your cases both before and after firing against the above dimensions and this should give you a better idea of the issues.
If your chamber is generous near the case head, you will see the same pattern no matter what ammo you feed it. That 0.4708" diameter is at 0.200" above the case head.

I have had some factory barrels that did this to brass on the first cycle and it was due to a generous chamber. It didn't result in any issues, but it isn't pretty.

 

[spife7980]

Normal. You’re seeing where the brass expanded to meet the chamber.

 

[Dot3]

Here are two examples of case head separation

. Note the location of the separation in relation to where the FL die goes to. Btw, these cases have 14-15 loads on them and are checked with a bore scope before loading. Not over pressure, just overdue for tossing.