velocity bullet 1 vs bullet 2

[bubba]

I have a question for you all...........

If I shoot a std load (whatever that might be) with a 250 sst and a 250gr barnes..............both with their original sabot..............both out of the same rifle........

would you expect much initial velocity difference?

I dont have a chrono, that is why I was asking!

thanks

-bubba

[edge]

I think that there are too many variables to say without chrongraphing both. It might not have to be out of YOUR rifle, but a side by side shooting!

Some things to consider:

1) Different sabots may be different in diameter( both OD and ID ), polymer, petal length, etc.:

2) Bullet diameters AND/OR bearing length:

3) Bullet materials, solid copper MAY change the way the sabot reacts under pressure;

4) Even the radius at the base of the bullet will interact differently with the sabot. perhaps pinching it to the point of weakening the petals or letting the bullet sink into the sabot material.

I'm sure there are dozens more things to consider, but just an ill fitting sabot CAN mean a difference of hundreds of feet per second!

edge.

[RBinAR]

;D I would not expect much difference if they fit the bore about the same. If one sabot was loose then I'd expect that to lower pressure and reduce efficiency and speed. The looser the fit in comparison the bigger the difference.

The effect is also different with powder choice. With standard single powders of large pistol or reduced rifle case speed a loose sabot would change speeds as much as 150fps. With the slower rifle powders it is much worse with speeds falling as much as 350fps or more.

This is the reason with all the newer three hole vent liner loads I've specificied a SNUG sabot and HOT primer. If pressure is lowered efficiency is lost.

[mike3132]

i shot the 250 xtp and the barnes 250 mz one day with same load, 48grn 4759. the barnes is about 50fps faster thru my chrony. 2400fps for the xtp and 2450fps for the barnes. ive shot them with other powders too and its the same results. not sure as to why it is. mike

[edge]

Mike,

Do you remember if this was in heat, or in the Fall?

edge.

[mike3132]

edge,
it was this spring, in march or april. the temp was probably in the 60's. i noticed this a year ago or so. i use xtp's for testing because they are cheaper, then switch over to barnes for hunting. barnes are usually 50fps or so faster. mike