Problems with headspace

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WestSlopeReloader

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First off, thank you for allowing me on this forum.

So, my buddy recently bought himself a T/C compass chambered in .270 Win. Since day one he has complained about ammunition being hard to chamber. So i used my hornady OAL gauge on it and came up with some interesting results. Using hornady 130gr SP the gauge shows that the bullets ogive contacts the lands at 2.629. Using a bullet comparator, the factory ammo (hsm game king) shows the length at 2.801. Whats the deal?:confused: ill try to upload a pic of the factory next to the gauge here soon. Thanks in advance for your help everyone
 
The deal: Head space is measured from the datum/shoulder to the bolt face and my cases do not have head space.

And then there is the point of contact between the bullet and beginning of the rifling.

F. Guffey
 
We need to take a step back here.

You may or may not be talking about a head space issue, all your terminology is directed to Cartridge Overall Length (COAL) . Two different things.

That is not what Ogive does or is (its a point on the curved part of the bullet)

Head space is the relationship of the case base (bolt) to the shoulder.


If he is having a problem chambering factory ammo, and the bullet sticks or has marks on it, then he has a short throat in which the lands are closer than normal to the bullet.

And you look to be mixing up two different mfgs with bullets and each one will be different for COAL. Not two mfg bullet shapes are identical even though they look the same. .

A Hornady 130 is not going to have the same shape as a Game King (sierra, not sure what HSM is? and what grain and style? )

If its truly sticking into the lands it will be hard to extract to the point of needing to tap on the handle with a wood pr plastic object. The bullet will have scarf marks on it.

If its head space, then it will come out fine, but hard to cam down when chambering the round.
 
Well this is what im dealing with. The left is what the OAL gauge shows as the bullet tip hitting the rifling. The right is the factory ammo he has been using. In my mind, that means when he chambers a factory round, he is jamming that bullet into the rifling, which surely isn't good for pressures.
 

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You need to read the breakdown on what is being determined as an issue.

What is the grain of bullet in the factory ammo?

Is the bullet in the factory ammo sticking in your friends gun?

There will be serious scruff makers or he will not be able to pull the bolt back.
Very possibly both.
 
The factory ammo is 150gr. When i chamber the factory, it is extremely hard to close and open the bolt. And there are rifling marks on the factory bullet when it is extracted. I know there will be slight COAL differences between 130gr and 150gr. But i wouldnt assume that much? Sorry, im fairly new to reloading rifle cartridges
 
Its ok, just need to be clear as this started out as Headspace and its is not.

What your friend has is a short throat. Unusual that its so short factory ammo will not work right.

You are right, its a pressure issue as well as hard on the bolt, lugs and I have had them stick so hard it took a plastic mallet to move back the bolt handle.

The best course is to contact TC and tell them what the issue is and get it corrected.

A gunsmith can fix that.

Least desirable is to just shoot reloads as you are then limited to reloads and if he does not reload that gets dicey.

A 150 grain is going to be a fair amount longer than a 130 though (assumes the same style bullet, flat base or boat tail)

As each mfg has different profiles, that can change a lot as well.

Not in this case being a factor.

Your friends gun might chamber a 130 grain ok. Its should chamber a 150 but its possible TC biases to the 130 (that is the claim to fame for the 270).
 
Thank you for your help. Ill either contact TC for him, or have him call them up. On a sidenote, my ruger M77 has none of these problems. Go ruger! Hehe
 
You are welcome. Let us know what their response is.

I was at the first test shoot for a Sig 9mm one time.

Weird extraction action, recovered brass has nasty marks.

Bad chamber. From a Sig. It does happen.

I don't know much about TC and their operation. Trying to compete in the low cost rifle arena may have some downside for them maintaining output and quality. A lot of competition. Hard to shave price and still get a good consistent build.

Pretty much hear a bad one from all mfgs from time to time.
 
When i chamber the factory, it is extremely hard to close and open the bolt.
And there are rifling marks on the factory bullet when it is extracted.
Click to expand...
Given that ...

...and if measured correctly, the pic where you've used the OAL gauge to find rifling start (bottom bullet):

attachment.php


shows a grossly mis-cut chamber leade -- irrespective of any particular bullet.
 
It's just a short throat. Great for lighter , shorter, bullets but not for heavier , longer, ones. Generally speaking reloaders want a shorter throat because of accuracy advantage. Load bullets to touch the rifling...theoretically more accurate. If a long bullet causes chambering issues...we just seat the bullet deeper.
Personally I like long throats and heavy bullets. I would want 150 grain in a 270 with a long throat . Others who prefer the 100 grain to 130 grain bullets would want the shorter throat and be upset with a long throated rifle.
It's a very simple matter for a gunsmith to extend the throat , I agree it should chamber 150 grain ammo.
Gary
 
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