I took my Tikka 512 double in 9.3x74R over to Southern Africa as a second rifle to my .450. The plan was to use it in conjuction with Ndumo's (Karl S) own 8x68S for plains game and any plains game in Zimbabwe.

On test shooting it in Namibia we found the regulation had gone completely off, with the 286 gr SPs now crossing by about 12 inches at 50 metres. Ended up using a bit of ammo to get the bottom barrel "regulated" by shooting to the point of aim and the top barrel, still crossing and low by about 6 inches at 100 metres. Then decided to "conserve" ammo for actual use and use it mostly as a single shot with a spare "emergency" barrel.

Must say it takes a bit of confidence away. Used mostly Karl's M98 8x68S for most of the hunting except for a couple of warthog. Which was OK as I really wanted to give the 8x68 a workout as it is a calibre I have always wanted.

My thoughts is the wedge between the barrels must have shifted perhaps due to a severe bump during transport.

In Zimbabwe using FMJs I test shot it again but only at about 40 metres and while it still crossed the impact was on aim and only about an inch between the bullets.

Ended up not using it at all, as the .450 is a much better choice for elephant and buffalo. The guide had a .416 Remington in a Winchester M70 custom and when hunting a herd of buffalo we swapped rifles as the scope was much more handy to try to pick a clear shot through the scrub and other animals. He DID need the .450 handy to cover as we had several bull elephants only about 25 to 40 metres away from us at the time, but neither they or the buffalo knew we were there.

What are the gentlemen here thoughts on why the regulation changed so much?

Before going it was tested out and at 100 metres was shooting the top barrel about 30 mm higher than the bottom barrel.