tight chamber

[canuck4570]

just bought a tikka T3 in 30-06.....
when chambering factory amo I have a smal resistance
measured the shoulder with a stoney point
took my redding bump die and bumped the shoulder until it entered freely in my chamber...
from the factory measurement and the bumped case there was .005 difference
asked around and all of them told me to keep the rifle its good to have a tight chamber it will be more accurate and better for cases....
would like some opinion on that.....
thanks Michel....

 

[Mikem]

Having a tight chamber is fine, but a factory cases should fit in the chamber. But it sounds like your chamber is a little short on its head spacing. It can be longer, and you fire form to make your brass fit the chamber. But as your chamber is short and the rifle is a Tikka, it would take a gunsmith to reset the head space out about .006. If it were a Savage you could do it your self.

But as it is, you will have to bump the shoulders back about .006 the first time, to get them to fit the chamber, with .001 slop.
After the rounds have been fire formed, the brass should fit the chamber fine. But you will need to keep an eye on this problem, or send the rifle back and have it corrected.

Its desirable to have the brass about .001 short on its headspace, this will make a nice tight fit, improve accuracy, and extend case life.

 

[canuck4570]

when I bumped the case .005 I meant that I bump them with .002 of clearance...
in other words .003 is hair tight and I bumped 002 for easy chambering....
will go .001 clearance has you say....
thank you Michel.

 

[Mikem]

That's even better, so its only about .003 short. After you fire form the brass, set your die to give about .001 shoulder clearance,,case headspace) and you will have virtually no brass movement, and that's about as good as it gets, and the brass will love it.
That's what I do.
Mike.

 

[canuck4570]

thanks Mikem
its appreciated.....

 

[canuck4570]

when shooting with my tight chamber Tikka today
very accurate with 2 different reload and one factory
case did not change dimension after shooting, measured before and after firing and stayed the same
so I have a rifle that will be soft on brass.
my seizing die was adjusted just on the spot .001 below chamber has you prescribed
thank you Mikem for the help
thought you would like to know.... Michel

 

[jb1000br]

My Tikka 595 243 chambered tightly but smoothly on sized Lapua cases as well...seems they keep a good min. headspace on their chambers...

JB

 

[Mikem]

Canuk4570 It seams your chamber is a bit short, but you have worked through it, and it should work well with your bumped cases and reloads. You would still have a problem with factory ammo, not bumped, however, but if your like me, I only shoot my reloads.
Good luck, and keep shooting.
Mike.
PS: BTW do you shoot a 45-70?