Did the Belgian, Austrian, Brazilian, Austrian, South African, Israeli, British, and Indian FAL's all have the same barrel twist rate of 1:12? Regardless of barrel length?

Every one I have ever checked had 1:12.

But I think Badger did some 1:10's maybe?

I think that there were some 1:11 barrels too, but that would make them odd...

Forrest

DSA's are 1:10.

The military ones all had 12 inch rifling.

The Inch pattern ones originally had 6 groove rifling and the metric ones had 4 groove rifling.

Some of the Australian replacement barrels and later production rifles have 4 groove rifling and some Canadian rifles may have 4 groove rifling.

The British went with 6 groove rifling in an effort to improve or prolong accuracy, but the accuracy didn't change from the original 4 groove rifling.

The Canadians adopted the rifle before the British and the Aussies decided to switch to 4 groove rifling as there wasn't an advantage with 6 groove rifling.

The Aussies did come with some special target barrels, that may have changed in twist rate and / or type of rifling.

Pre-1961 H&K G3's had 6 groove polygonal rifling, but in 1961 NATO standardized on 4 groove conventional rifling and most buyers of the G3 wanted the NATO standard rifling, so H&K started offering both and later sniper and target models got 4 groove polygonal rifling too.