9.3 x 64 B

[sambarhunter]

I have always known the 9.3 projectiles to be .366 Hornady,Woodleigh,Nosler etc all cite .366.

However a box of Norma 9.3 Alaska`s arrived today and they quote Dia of .365

Now in real life that meas absolutely sfa...but why I ask?
Is there a reason for the most minutest of difference?

 

[ndumo HUNTING SAFARIS]

Sambar, I think its just like a few old European 7mm bullets were .285 instead of the customary .284. I have shot both .366 and .365 through my 9,3 Brenneke and they all work...!

 

[sambarhunter]

I have no doubt that they are perfect,I was thinking "why"

 

[sestoppelman]

well, because...

 

[Opposite Pole]

Out of curiosity I measured projectiles in 3 factory loads in 9.3x74R. Norma Oryx 285gr, RWS Evolution 291gr and RWS T-Mantel 285gr. The first two shoot to the same point of impact in my double. The 285gr loads were both .366 but the 291gr was only .362 (I measured several). It doesn’t seem to affect shooting performance as the point of impact is same as the 285gr Oryx for which the rifle is regulated.

 

[sambarhunter]

well, because...

keeping your post count up?

 

[sambarhunter]

That is interesting Opposite Pole especially the difference as you have shown. New dies/old dies I imagine.
I would have thought that the tolerances would be higher in this day and age,we are not shooting musket balls!

 

[sestoppelman]

keeping your post count up?

No, just being a wise guy.

 

[sambarhunter]

I can see why you are an AH Legend!

Thats another one ha ha for me as well.

sestoppelman AH Legend

 

[Opposite Pole]

That is interesting Opposite Pole especially the difference as you have shown. New dies/old dies I imagine.
I would have thought that the tolerances would be higher in this day and age,we are not shooting musket balls!

I was quite surprised too, they shoot fine in my double but I wonder if a scoped bolt action would show inconsistencies in grouping on paper. Can’t really check it with a double with open sights with large bead.

 

[Longwalker]

I have also seen variations in bullet diameter of 1-2 thousandths of an inch that made me wonder, but have not had any explanation other than normal manufacturing tolerance and wear. The most accurate measurements are made with a loose bullet, laid lengthwise in the callipers. I would caution against measuring bullet diameter by placing the callipers crossways on the exposed bullet of a loaded cartridge, some bullets are designed such that nothing in front of the cannelure is full diameter. I have some old 7x64 Remington 175 gr. loaded ammunition that would measure very undersized if this perpendicular / loaded cartridge method was used.

 

[Red Leg]

Here is another little secret as well. The bores vary even more.