Case stretch

[nddodd]

What is a normal amount of case stretch in a rifle that is headspaced correctly. Mine is stretching .005 just wandering if this is good or bad.


Thanks fellas,

Nathan

[Mikecr]

With a stiff load, or mid to long/skinny case, narrow shoulder angle, & FL sizing, I would think it's somewhat common. I have a friend that trims his 25-06 very regularly.

In contrast, none of my cases lengthen at all. My situation is just opposite above.

[J E Custom]

Originally Posted by nddodd

What is a normal amount of case stretch in a rifle that is headspaced correctly. Mine is stretching .005 just wandering if this is good or bad.


Thanks fellas,

Nathan

You may be over sizing . After firing size just enough to be able to chamber. And then check
the growth of one of these rounds after fireing. If it still grows that much you may have to back
off on the powder charge.

If a round is sized properly and fired in a good chamber it should not grow very much unless
it is a hot load and then the chamber can grow enough that the brass will expand and
spring back will after firing and ejecting will be larger than the chamber.(This is the case when
you have heavy bolt lift.

J E CUSTOM

[nddodd]

I guess I shouldve explained it in different way, Im wandering if I have excessive headspacing or not. Using nosler brass in .243 win unfired then firing and measuring the shoulder of the 2 there is .005 diff. Of course the fired being longer. Just curious if .005 is normal or should it be less if headspaced correctly.

Thanks,
Nathan

[SBruce]

I would think that .005" is very normal for a once fired case. I've seen that much expansion/stretch in alot of factory guns.

I am getting some custom dies built for a new wildcat. The die maker requires cases that have been fired 3 times to make the perfect die. This tells me that new, unfired cases are usually alot smaller than a chamber is. I believe the allowed varience in factory chambers (SAAMI specs) is .010" between go and no go. Therefore, new brass would have to be small enough to chamber in the SAAMI Minimum chambers.

I highly suggest an RCBS Precision Mic. It is a multiple use tool that will measure your headspace (off of a fired case), aid in setting up your FL die so it just barely bumps the shoulder, it will measure the Boltface to Lands in your gun, and also provide you with a tool to measure the cartidge Base to Ogive of a loaded round (so you can adjust the seating die for maximum accuracy)

I've been using them for many years in factory chambered guns. For the simple fact that some factory chambers are on the excessive side.

[justgoto]

Originally Posted by nddodd

Im wandering if I have excessive headspacing or not.

You need to use HEADSPACE GAGES (GAUGES) to find out..

[shortgrass]

Originally Posted by SBruce

I would think that .005" is very normal for a once fired case. I've seen that much expansion/stretch in alot of factory guns.

I believe the allowed varience in factory chambers (SAAMI specs) is .010" between go and no go.

I've been using them for many years in factory chambered guns. For the simple fact that some factory chambers are on the excessive side.

The difference between GO & NO-GO in the .30/06 (and its cousins) is .006" For the .308 Win. (and its cousins) it is .004". The Weatherby Mags. is .003". The only way to check headspace is with fixed, tool steel gauges.