Ridge in fired brass

[B-LOT Banga]

I've got a Tikka 25-06 Ackley fixed shouldered pre-fit barrel and started fireforming some brass, On my once fired factory loaded 25-06 brass I've got this ridge that I don't see on any of my other rifles I know something isn't right but can't figure it out. I know I'm not using the correct tool to measure my brass but it's close enough to get an idea on the ridge being left behind after firing.

pic 1 the ridge

pic 2 just above the ridge on the body

pic 3 is of fired brass with non fired on the ends for comparison

pic 4 is of a 5 shot group at 100 yds off a bench (shots 40-45 total)

Pic 5 just below the ridge

this is Hornady brass, factory loaded 120 gr soft points. Velocity is around 2960 FPS around 50 FPS slower than advertised on the box which I feel is pretty good for fire forming and accuracy is outstanding for hunting. Any info would be appreciated thanks!!

 

[waspocrew]

What type of prefit - is it shouldered or a barrel nut? Did you check the headspace with gauges?

 

[SO I HUNT]

^^^^^ what he asked?

 

[B-LOT Banga]

Sorry **shouldered pre-fit**

 

[MagnumManiac]

Oversized chamber just in front of the unsupported area of the casehead.
See this a lot.
Try different brand brass.

Cheers.

 

[B-LOT Banga]

Oversized chamber just in front of the unsupported area of the casehead.
See this a lot.
Try different brand brass.

Cheers.

I have several brands of brass, this one was factory loaded so I figured give these a try first. Thanks

 

[B-LOT Banga]

@MagnumManiac is this acceptable or should I send it back for fixing? It's brand new and I was about to make a 257 wby mag with the same barrel specs. If they can't fix this one, would it be best to re-chamber? Thanks

 

[MagnumManiac]

Acceptability is dependant on how much bigger the chamber is.
Brass is generally .005" smaller than it should be in the head diameter. The chamber may be within spec at the datum .200" up from the head, but larger than it should be below this.
I have a 25-06 that expands like that above the web, it poses no problem because my die doesn't change the dimension much. If I use Winchester brass, the expansion is clearly visible and measurable, but if I switch to Remington brass the expansion is only just visible. I have 3 25-06 rifles and only one of 'em does it, my custom Ruger M77 MK II.
Without seeing it first hand, and not sure where you have taken your above measurements, it is hard to tell.
I doubt headspace is an issue, thicker brass often cures the problem if the chamber is not excessively oversized.
Remington brass is generally thicker above the web, not sure about Hornady, never sectioned one. I had a factory Sako L579 with an oval chamber, had me in fits trying to get that thing to accept sized brass.

Cheers.

 

[B-LOT Banga]

Acceptability is dependant on how much bigger the chamber is.
Brass is generally .005" smaller than it should be in the head diameter. The chamber may be within spec at the datum .200" up from the head, but larger than it should be below this.
I have a 25-06 that expands like that above the web, it poses no problem because my die doesn't change the dimension much. If I use Winchester brass, the expansion is clearly visible and measurable, but if I switch to Remington brass the expansion is only just visible. I have 3 25-06 rifles and only one of 'em does it, my custom Ruger M77 MK II.
Without seeing it first hand, and not sure where you have taken your above measurements, it is hard to tell.
I doubt headspace is an issue, thicker brass often cures the problem if the chamber is not excessively oversized.
Remington brass is generally thicker above the web, not sure about Hornady, never sectioned one. I had a factory Sako L579 with an oval chamber, had me in fits trying to get that thing to accept sized brass.

Cheers.

I appreciate you taking the time to explain, thanks!!

 

[MagnumManiac]

Welcome.

Cheers.