7saum not chambering.

[Lee Goodwin]

Way out there, but I had a savage 110 rebarreled. And if the torque on the bolt that held the receiver to the stock was too tight it made the ammo feed tightly. Quarter turn off fixed it and I roll with it.

 

[jdyoung]

Reads like you gotta' figure out what that chamber is. Cast the chamber!!!!! I use cerrosafe. Follow the instructions.

 

[toddlouis]

Reads like you gotta' figure out what that chamber is. Cast the chamber!!!!! I use cerrosafe. Follow the instructions.

I have some on Order.

 

[toddlouis]

I'm pretty sure the necks on my brass have to be trimmed to .312 but my caliper is current on the way so I can make an exact measurement.

 

[tgwh]

I had a 7mmSAUM with a custom chamber. It was chambered specifically for Norma 300SAUM brass necked down. I tried factory ammo, 7mm Brass f/l sized, neck turned etc. It wasn't until I measured the cases that I remembered the Norma 300 cases are slightly shorter. There was no way a standard 7SAUM was ever going to chamber without a 'good' trimming. Worth trying a 300 SAUM case necked down as a starter.

 

[toddlouis]

I had a 7mmSAUM with a custom chamber. It was chambered specifically for Norma 300SAUM brass necked down. I tried factory ammo, 7mm Brass f/l sized, neck turned etc. It wasn't until I measured the cases that I remembered the Norma 300 cases are slightly shorter. There was no way a standard 7SAUM was ever going to chamber without a 'good' trimming. Worth trying a 300 SAUM case necked down as a starter.

Oh wow this maybe the fix. I'm noticing now, no matter how much I trim down or the necks. It's not chambering. I'll have to get a 300 saum case

 

[jrock]

Cerrosafe and a micrometer/good caliper will probably tell you what you need to do to address the issue. The black sharpie method is my first go to.

 

[entropicitis]

+1 on starting with a sharpie. Answer may be obvious.

 

[toddlouis]

Ok. Far left is a sized only case. 2nd from left is sized and chambered(you can see the discernible marking and line). 3rd casing, more of the same but can still see like with sharpie. 4th is a full colored in case that was put into chamber and closed, only the one line again.

They all close with the slightest bit of resistance. Once I do a 1/4th turn that resistance goes away. As soon as I seat a bullet the round does not chamber at all. I've turned the brass to .311, .312, .313, .314 and still is not chambering at all.

I have a call into the smith, but no call back yet. I got a few cases of 300 saum brass and all though it's shorter, it still has the same problems.

 

[Ucsdryder]

Do you have a once fired? If not, dremel a slit in the neck so a bullet can slide in and out and see where it'll seat with the bullet. Maybe it doesn't have enough free bore?

 

[toddlouis]

Do you have a once fired? If not, dremel a slit in the neck so a bullet can slide in and out and see where it'll seat with the bullet. Maybe it doesn't have enough free bore?

I will try that. Thank you.

 

[L.Sherm]

Does the 2nd and 3rd case from the left have that scuff mark on the top 3rd of the neck all the way around.
I agree on the freebore as stated above if you have alot of neck tension and your trying to jam into the lands that could be why the bolt won't close ar all or when you seat a bullet it makes the neck dia bigger and you have a real tight neck chamber.

 

[L.Sherm]

I know some BR guys run down at .010 neck thick brass so if the reamer used is like that could be real tight neck chamber

 

[MNbogboy]

The shiny ring on the end of each neck makes me think a possible carbon build up at the end of the neck cut right before the beginning of the throat. A bore cam will show this easily.