The standard 308WIN precision bullet for Tikka T3

[Unclenick]

Rimfire5,

Thanks for the follow-up. I wondered what your working approach was.

For others interested in this stuff, Dr. Lloyd Brownell found in his studies in the 60's that when a bullet jumps to the throat of a barrel and engraves into the rifling, the fore and aft chamber stretch caused by that event produces a pressure wave in the barrel that goes down the tube from the throat. It explained the small ripples superimposed on the pressure trace itself.

Below is an example from a .30-06 pressure measurement I made. In the green oval you can see the reflected waves most clearly when the pressure has dropped to zero. The ripples in the higher pressure parts of the waveform are also the effect of the pressure wave. If you look back at the starts of the traces, the ripples don't clearly appear until about 30,000 psi, or just under 0.1 ms, which is in the range of pressure and time at which you expect the bullet has jumped to the throat of the rifle and begun engraving into the rifling, initiating the wave. If you follow the colors carefully, you'll see they tend to travel in pairs (see the dark blue trace and green trace) or in triplets due to reflections off the back end of the receiver adding themselves in, but you do get dead spots. Because the waves can distort a muzzle a few tenths of a thousandth of an inch, especially when the muzzle has a thin wall profile, best accuracy occurs when the muzzle is undisturbed by the waves (when the dead spot is at the muzzle rather than at the breech end of the barrel).

 

[Paddycakes]

THANKYOU one and all for this wonderful data. WendyJ especially; rifle buds indeed - and yes that slick bolt about beats all doesn't it. T O'Heir my friend, the T3 is a hunting rifle indeed, so I don't have any sub MOA expectations at 300 yards. But as it is my only .30cal or comparable bolt rifle, and since it was my first, I will use it in any and all capacities to the best of my (and its) ability. Sort of like myself in a way; jack of all trades, master of a good few but not all.

 

[Wendyj]

You won't have any problems with sub moa at 300 yards. Just don't let the barrel get hot. I know mine shot better than I could.

 

[Metal god]

The gun you're using at the time for what ever you are using it for is what the gun IS for . Like I said above , I have a Ruger American rifle . Many would say it's a "hunting" rifle . Well I've owned it since the first year they came out and it has never been used to hunt with . 99% of the ammo fired through it has been Federal GMM or my reloads with match bullets . It has shot plenty of sub moa holes through paper at 300yds .

I understand guys points when they say a rifle was designed for a specific purpose . What is not helpful is when a OP asks a specific question like I want to see how accurate my rifle is . What bullet should I use ? Then get answers like , well it's a hunting rifle so you should try hunting ammo to get a true idea as to how well it shoots .

Often the OP never mentioned hunting so why bring it up ? The Q/A never happens in reverse . (Q) hi I have a SCAR , FAL , AR and want to see how accurate it is , what bullet should I use . (A) well those rifles are for combat and defence use so you should use FMJ or NATO ammo to get a true idea as to how well they shoot . Why is it you never here that response but always get the hunting rifle response ?

 

[Wendyj]

You hit it Metal. I've taken game with mine but it shoots a lot more paper and steel than animals. I've shot match kings. Barnes bullets. Noslers. I want to see what mine does at any range. Only way I know how is to get a good case of scope eye. Barrels won't hold up to our bench guns but that's why we take 3 or 4 at the range to let them cool.