How much is too much(headspace)

[Miseryguts]

I seem to remember a thread on here concerning excessive headspace causing light primer strikes.

So, how much headspace is excessive? Just got some once fired lapua brass whose headspace is 1.610 to 1.615, whereas once fired brass from my rifle measures 1.625. All measured with the same comparator. By my reckoning, this means that the Lapua  brass will have an extra 10 to 15 thou of headspace. Am I digging myself a hole?

M(worrying in wet Monmouthshire)

 

 

 

[gruntus]

Hi M,

First off what rifle are you shooting?

If it's a standard factory rifle I would suggest you just bring your thermometer down a few notches.🙂

Some rifles are chambered with a forgiving chamber and some are within really close tolerances such as high end match/target rifles. If you compared the two fired cases from each rifle there would likely to be a reasonable variance.

As an example my Lee Enfield battle rifle SMLE circa 1916 is a .303 and when compared to my mates Lee Enfield No 4 T you would be amazed at the physical difference with the eye when comparing them.

A grown up will come along soon to comment but rifles are chambered within an allowed variance/tolerance within SAAMI specs and that's why you see differences in cases between rifles.

Don't sweat it too much. This game will have you chasing your tail for a long time! 

All the best

G (in Fife and it's dry. Bonus!)

 

[Miseryguts]

Hi G, sorry, should have put that in - its a Sauer 100 factory rifle chambered in 308 Win

(Its all that a poor man like me can afford)

M

[gruntus]

Oh, if you can confirm what tool your using to measure (assuming base of case to shoulder?) And the case (.308, .223, 303, 300 win mag etc)  this will help determine how your headspace should be measured.

ATB

G

[gruntus]

Hi M,

If its a new factory rifle and hasn't been rebarreled / rechambered etc. it's unlikely that you would have excess headspace due to the quality control of the manufacturer. Obviously, exceptions can occur but if you're unsure you could get it checked by your local gunsmith to ensure its within tolerance.

Cheers

G

Edited September 27, 2019 by gruntus
Rephrased question

[Mattnall]

.303 is not headspaced off the shoulder so measuring and comparing the head to shoulder length with cases from different rifles is not comparing headspace.

[terryh]

Misery guts,

So if I’m correct you are saying factory brass (that is made ‘small enough’ to fit into anyone’s rifle) is coming out of your factory rifle (who’s chamber has to be cut to take any factory brass) 10-15 thou bigger. My answer would be - so what!   10-15 thou does not sound like a big tolerance for a world wide product, but I’m up for being corrected.

Have you had any light strikes? What cartridge i.e. 6.5x55 been round for 120 plus year so good chance for wide variation in rifles etc.

Are all the fired brass the same size (probably) so that is the size to work from if you are reloading, take a couple of thou off and that’s the size to size to. No issues.

Just my take on things i.e. don’t sweat it.

Terry