WW white box velocity

[Donaldo]

Just discovered something interesting.  As for the WW white box 45 JHP stuff.  This load in my 22-250 chrono's at a bit over 4,000 fps.  Average of several shots was 4,043 fps.  This is the 45 JHP, advertised as 4,000 fps.  Now in the 223, it is advertised at 3,600 fps.  In my 223 UV handi it chrono's just a bit over 3,400, like 3460 or so.  My 22-250 is a Shilen barreled FN Mauser bolt.  My 223 is of course the UV Handi.  Both have 24" barrels.  Why the difference in velocity?  I suspect it is the micro groove barrel on the handi, or maybe an oversize barrel or long throat.  My 22-250 has an average throat.  I can't find a load in my manuals that lists the 45 JHP at more than 4,000 fps for the 22-250, right at but not over.  Whata ya think.....any ideas?

[handirifle]

I suspect the Handi's long throat.

[Paul5388]

Win White box 45 gr clocks at 3302 fps average in my standard .223 Handi with 22" barrel.  Probably the long pressure reducing throat and 2" less barrel are the main factors.

[Ditchdigger]

I clocks 3450 fps. in my 24" Ultra. The chrono will make liars out of ammo claims sometimes.
Digger

[nipprdog]

the 3600 advertised was from a 26" barrel.