Forums.NitroExpress.com

Mac,
No you havn't disillusioned me at all but I feel you may have missed the point I was trying to make.
Barrel time can indeed influence the convergance and sighting etc, and also affect where the bullet will impact the target, and changing the barrel time will (usually) change the point of impact at the target.

My point is that you or I or most other owners of doubles would not have the faintest idea what the measured "barrel time " of their loads would be!
The point also is that they do not need to!
Most could tell you the following......
Exact powder weight in grains
Exact bullet weight in grains
Exact wadding weight in grains (if used)
Average velocity in feet per second
Average group sizes measured in fractions of an inch.
Distance in yards the groups wer shot at

But how many nanoseconds (or whatever measurement is used) of "barrel time" is there in a particular rifle/load combination?

Most folks maybe but not this one, as I am well aware of what the true use of the word regulation actually means, and rest assured that if I use the term I am talking about the physical positioning of the barrels.

The thing is that if you are building a new set of double rifle barrels, you will be either using factory loaded or handloaded ammo.
The load to be used will have to meet certain standards including.........
Producing good consistant individual barrel groups
Producing a velocity acceptable for the cartridge/barrel length
Producing acceptable pressure by double rifle standards
Using a projectile suitable for the load and the game to be hunted.
Also other things including component availability.

But nowhere is there a requirement to achieve a specific "barrel time"!
The load chosen will produce a certain "barrel time" and this will indeed have an influence on the bullets path and its impact point, and the amount of convergance required, but the barrels are then "REGULATED" and the two individual barrel groups are physicly brought together.

All this is achieved without anyone needing to know anything about "barrel time" other than the fact that it does exist!

When attempting to duplicate the load for an existing (old)double we are in fact trying to get close to the "barrel time" that the original cartridge produced in that rifle, but again we do not have any figures on the "barrel time" and we do not need any to get the job done.

Sure, "barrel time" exists and yes it affects the bullets path and yes we can alter it by changing load components,
but so long as that is understood, what more do we need to know?
If a double is shooting apart and the chronograph is showing a low velocity we can presume that the "barrel time " may be too long and we need to decrease it(the barrel time) slightly by increasing the velocity.

But the load alteration will be done by changing the figures for powder weights/types and bullet weights/types etc, not by manipulating figures for"barrel time".

When Regulating a double for a specific cartridge, factory or handload, the "regulator" can do absolutely nothing to alter or change the "barrel time".
His job is to achieve correct regulation of the barrels to bring the two groups together regardless of what the "barrel time" may or may not be.

I guess what I'm trying to say is that once a particular load is selected to be the one used in the double, yes "barrel time" is involved but it cannot at that stage be altered so it is of little matter.
The regulators job is to get the barrels and sights aligned regardless of what "barrel time" the cartridge produces.

Edited by 4seventy (21/01/04 06:38 PM)

Post Extras