High pressure signs in a 270

[charliehorse27]

This image is once-fired brass. On the top side of this casing, near the case head, you can see the ever so slight bulge and accompanying "shinier" ring I'm wondering about.


This last picture shows the ever-so-slight difference in primers I was originally asking about. Not at all primer smear or total flattening, but the primer on the right is more flattened than the two on the left. Could very well be just from being seated at a slightly different depth. Also, I have not seen any bolt marks on the faces of the casings, indicating either over-pressure, or cases with excessively long headspacing.

Also, thank you everyone for your input and advice with all this.

 

[243winxb]

over repeated firings, the brass will slowly grow to fit it?

Yes. Start with a .005" gap between shell holder and full length die.. Adjust as needed to make brass fit the chamber.

Brass and primers all look normal.

 

[savagedasher]

This image is once-fired brass. On the top side of this casing, near the case head, you can see the ever so slight bulge and accompanying "shinier" ring I'm wondering about.
View attachment 992565 View attachment 992566 View attachment 992569 View attachment 992570

This last picture shows the ever-so-slight difference in primers I was originally asking about. Not at all primer smear or total flattening, but the primer on the right is more flattened than the two on the left. Could very well be just from being seated at a slightly different depth. Also, I have not seen any bolt marks on the faces of the casings, indicating either over-pressure, or cases with excessively long headspacing.

Also, thank you everyone for your input and advice with all this.

I don't see any real pressure sign on any primers. Larry

 

[RonAKA]

This last picture shows the ever-so-slight difference in primers I was originally asking about. Not at all primer smear or total flattening, but the primer on the right is more flattened than the two on the left. Could very well be just from being seated at a slightly different depth. Also, I have not seen any bolt marks on the faces of the casings, indicating either over-pressure, or cases with excessively long headspacing.

I don't think those primers or head of the cases show signs of any excessive pressure. In fact the one on the left suggests under pressure to me.

 

[ireload2]

When the little corner radius on the edge of the firing pin indent starts to get sharp your pressures are getting too high. I agree the left primer is a bit rounded and the other 2 are about like factory ammo. You can also check the diameter of the pressure ring in your reloads vs the pressure ring on Winchester factory ammo.
If you own an use a wide array of factory rifles and all the possible varieties of factory brass you will find your rifle is about normal for a commercial hunting rifle.
An older rifle with a sloppy chamber and thin brass can be much worse. Check out some of the images of .303 British brass fired in the typical military chamber of a Lee-Enfield.

 

[jlow]

Hard to believe it is headspace with those numbers....

 

[charliehorse27]

Thanks everyone for your input on this. I've never had that ring form on new brass like this, but I'll keep reloading them and watch for more significant signs.

 

[charliehorse27]

There could be a number of potential problems that cause what you are seeing.

1. 7 thousands off can be pretty close depending on how accurate you measure touch distance i.e. you could actually be jamming. Jamming = significantly higher pressure.
   
   
2. Any possibility of a carbon ring in your chamber – that can cause pressure problem.
   
   
3. Lube on your case can also be a problem.

For the first two, manually insert (with your fingers) a loaded round or better yet a dummy round into your chamber, push it in gently (so that it does not get stuck hard), and see if it will come out by gravity. If it gets stuck, you have one or two of the above problem. The round can be pushed out with a wood dowel.

I tried this, and the rounds would get stuck in the chamber. They came out just fine when the bolt was reinserted, but they did not drop out on their own with gravity.

1. This could very well be possible. I'll try seating the bullet a hair bit deeper in small increments and see if this changes anything.

2. What is a carbon ring, and how would I check for, or remove one?

3. Cases are clear of any lube. They all get wiped down after the resizing.

 

[Brians356]

I measured the headspace on a group of 5 random new cases, never been fired or sized, and found the average length to be 2.046 in. It varied +/- .001 either way. Another random lot of once-fired cases from this gun had average length of 2.0466. After resizing them in the press, the average length was 2.0465.
... I've measured older, used several times brass, and usually get fire-formed measurements between 2.047-2.049.

Wow. I've got an old Ruger M77 "round top" in 270 Win, and for a long time never full-length sized, only neck sized, and with stiff loads. I've changed all my dies and now FL size, etc. But I have lots of old cases, reloaded up to 8 times and never FL sized, with datums measuring (using SAAMI .375 bushing) max 2.042". Recent new cases, fired with moderate loads only, measure up to 2.041".

What diameter bushing are you measuring with?

Edit: I check again, I have some old cases measuring 2.045, but they are difficult to chamber. Still I guess your numbers are not out of school compared to mine. There's a .010" range between min and max headspace. My chamber seems tight, SAAMI min chamber is 2.0487".
-

 

[fredhorace77]

Probably not a problem but I did once have a die that wasn't cut correctly and would not resize the case properly and was causing premature case head spliting.

 

[jlow]

I tried this, and the rounds would get stuck in the chamber. They came out just fine when the bolt was reinserted, but they did not drop out on their own with gravity.

1. This could very well be possible. I'll try seating the bullet a hair bit deeper in small increments and see if this changes anything.

2. What is a carbon ring, and how would I check for, or remove one?

3. Cases are clear of any lube. They all get wiped down after the resizing.

Anytime your loaded round get stuck, it’s not a good sign especially if you are just using once fired brass that has been FL sized, and not a hot load. FWIW, your primere do not look like trouble to me and that “shinier” ring is pretty normal from sizing. So I am not sure you really have a pressure problem.

Carbon ring is a ring of carbon in the chamber at the location where your case neck ends when it is chambered. It’s from carbon build up from firing, and when it builds up enough, it can impinge on the bullet and neck to cause pressure problems. To check, a borescope is the best way but if you don’t have one, you can color a dummy round with a sharpie and insert it in, push it out and look for scrapes on either the bullet and/or the case in that location.

 

[John Russell]

Probably not a problem but I did once have a die that wasn't cut correctly and would not resize the case properly and was causing premature case head splitting.

A proper FL die is SAAMI minimum... if your chamber is SAAMI longer, up to SAAMI maximum, then YOU have to adjust the die so you don't get head separations - it was NOT the die's fault.

 

[fredhorace77]

A proper FL die is SAAMI minimum... if your chamber is SAAMI longer, up to SAAMI maximum, then YOU have to adjust the die so you don't get head separations - it was NOT the die's fault.

Don't tell me whose fault it was...the die was sent back to RCBS and they did confirm it was a die that wasn't properly cut.. they sent me a new one and all is well.
Why does everyone act like a die company can't make a mistake....assuming it's always the users fault. They are human also and sometimes make mistakes.

 

[John Russell]

Don't tell me whose fault it was...the die was sent back to RCBS and they did confirm it was a die that wasn't properly cut.. they sent me a new one and all is well.
Why does everyone act like a die company can't make a mistake....assuming it's always the users fault. They are human also and sometimes make mistakes.

Sorry... Lemme rephrase it then.
If the FL die was cut too shallow, then it is still adjusted the same way. The possible difference between a properly made FL die, and a max SAAMI chamber (and fired case) is 14 thou.
So, even if everything is in order, if you have a rifle with a chamber on the long side (but within SAAMI), you can make FL sized cases 14 thou shorter than the chamber that they will be fired in - and the heads will fall off in a few reloads.

With FL dies, you still need to adjust them down on the case a thou or two at a time, until you are just kissing the shoulder.

Forster Bump dies are 3 to 4 thou SHORTER than SAAMI minimum, so even more care is required with them.