Headspace and semi-automatic pistols

[paulnb]

On my FN FAL rifle I know that if I change the barrel and/or the bolt, I need to recheck the headspace.

However what is the situation if I change the barrel on a semi-automatic pistol?

The reason I ask is that I have a Vektor SP2 pistol that has the 40 S&W chambered barrel. Back in the day Vektor also offered these as a kit with an additional SP1 9mmP barrel and recoil spring. The Vektor SP1/SP2 series are derived from the Beretta 92/Z88, and there are quite a few parts that are common to the Z88 e.g. the locking mechanism of the barrel is the same.

So I took my Beretta 92 9mmP barrel and installed it in the Vektor SP2, and it functioned perfectly firing 9mmP rounds, even with the stronger standard 40 S&W recoil spring installed.

The fired brass looked fine, there was no ka-boom, but in hindsight should I have considered headspace changes - hence my question?

[Adoons]

I would say "No". The headspace of the barrel should be correct as long as the slide to barrel fit (Lock up) is tight.

[Mark357]

Where can one get headspace / Go No-go gauges in SA ? (rifle)

[FNBROWNING]

SAPS Z88 barrels often ended up inadvertently swapped during cleaning. They were made to very tight tolerances.

[A-R]

The Z88 and SP1 barrels were the same part. Barrel length might have varied between different models, but the difference was at the muzzle end. Locking "wedge" and head space were the same.

With a pistol, the head space tolerance is somewhat more generous than on a bolt-action rifle. Pistols generally have no provision for adjusting the head space, the are as they came form the factory. That's why barrels are interchangeable on the same model. I have even seen a pistol assembled from parts made in 3 different countries, on 3 different continents, and it worked pretty well.

[paulnb]

I read now on the Beretta forum that the only risk of using a 9mmP barrel on a 40 S&W slide is that there is a small chance that the 9mm round will not centre exactly on the 10mm breech face - thus a small probability of a malfunction.