Question on chamber size on 6.5 CM

[Shooter McGavin]

I just had a barrel attach to a R700 and I was measuring the chamber to size my loads and this looks all full small. I have to use some effort to close the bolt with factory loads factory loads. What should the chamber measure? 2.80 or more? This is for a 6.5 CM.

 

[cattleman99]

I believe SAAMI OAL should be 2.820" ish

 

[Shooter McGavin]

I believe SAAMI OAL should be 2.820" ish

Hornady has it as the COL as 2.825 in the 10th manual that I just got yesterday. Shit FML

 

[2aBaC̶a̶]

oal changes based on projectile. What really matters is bullet to ogive.

Color the bullet with a black sharpie and chamber it. Look close to see if the bullet is being jammed into the lands.
If not I would investigate the case size to chamber.

 

[Shooter McGavin]

oal changes based on projectile. What really matters is bullet to ogive.

Color the bullet with a black sharpie and chamber it. Look close to see if the bullet is being jammed into the lands.
If not I would investigate the case size to chamber.

I did that for the case minus the bullet and I can see a ring on the brass were the sharpie was removed.

 

[2aBaC̶a̶]

I was referring to factory ammo not chambering.

What is the brass from?

Once fired? Sized? Factory pulled case? factory new?

How are you measuring your chamber and how are you measuring your cases?

 

[Shooter McGavin]

I was referring to factory ammo not chambering.

What is the brass from?

Once fired? Sized? Factory pulled case? factory new?

How are you measuring your chamber and how are you measuring your cases?

It's new Lapua Brass

I was using the Hornady Lock and Load gauges to get the COL that would fit in the chamber. I just got my Hornady 10th addition saying the COL should be 2.825, so the 2.732 looked wrong.

Bullet is 130gr Norma
Case is Hornady Lock and load in the 1st pick

Just the brass pics are Lapua brass

 

[2aBaC̶a̶]

Assuming you are fairly new to reloading.

The Hornady tool above doesnt measure the chamber, it just measures how far the lands are for the purpose of seating the bullet. Different bullets will give you different case overall length depending on how far off the lands you are.

You need something along the lines of Hornady comparator or something to measure the shoulder of the case and or a case guage that measures how far off saami spec.

If you are not familiar with this I reccomend browsing through this thread.

https://www.snipershide.com/shooting/threads/hornady-brass-explosion.6970993/post-8094302

 

[Shooter McGavin]

I decided to shoot one round to look for signs of pressure. I use Norma match 130gr factory load. Looks like a little extra pressure.

 

[pabrousseau]

from what I can see that case head and primer do not show high pressure. it looks like you need to push the shoulder back from the looks of the marks on the shoulder of the sharpie colored case. a few items that have made trouble shooting and loading a lot more simple for me are bullet comparator and shoulder comparator and redding competition shell holders. good luck

 

[davere]

What you actually need here to answer the question that's underlying the post (that is, "is my chamber cut too short") is a Go gauge. That would address everything up to the shoulder. If the bolt closes on a Go gauge, then it's just a question of the throat length, basically - and that determines things like how deep the bullet should be seated, etc.

If you have a correct chamber, but it's throated a little short, that could explain your factory ammo situation - basically, you could be seating those rounds into the lands.

Brand new Lapua brass is relatively short. Does the bolt close on a new case without resistance? You'll feel it, if you're moving the shoulder by chambering the case.

 

[Shooter McGavin]

What you actually need here to answer the question that's underlying the post (that is, "is my chamber cut too short") is a Go gauge. That would address everything up to the shoulder. If the bolt closes on a Go gauge, then it's just a question of the throat length, basically - and that determines things like how deep the bullet should be seated, etc.

If you have a correct chamber, but it's throated a little short, that could explain your factory ammo situation - basically, you could be seating those rounds into the lands.

Brand new Lapua brass is relatively short. Does the bolt close on a new case without resistance? You'll feel it, if you're moving the shoulder by chambering the case.

It actually will not close on a go gauge.

 

[davere]

It actually will not close on a go gauge.

Then you definitely have a problem - that should go back to the smith that did the work for correction.

 

[Shooter McGavin]

Then you definitely have a problem - that should go back to the smith that did the work for correction.

Dropped it off yesterday. Told him to make it right. Should have just gotten a Deep South Tactical barreled action when they were available.