"I'm now using Winchester silver tips as a member just stated they are the closest to original specs."
Actually, as Winchester currently loads them, the 175gn STHP barely qualifies as a mid-range 10mm load.
MCNETT, among several other 10mm users who've posted chronograph results for the STHP, recently registered only
1165fps from a stock G20 (with 4.6" barrel). I believe this was the "grey box" STHPs he tested. (The older "white box" stuff was somewhat hotter, but often demonstrated inconsistent velocities among lots).
Winchester claims the 10mm STs does 1290fps/647fpe, and that's as measured from a
5.5" factory test barrel. So over the years they've clearly been downloading this ammo. Even adding 100fps to 1165fps for the extra inch of Winchester's test barrel (i.e., from G20 4.6 tube to 5.5 test barrel), that's still only 1265fps. And I don't know of any 10mm pistols having (stock) 5.5" barrels.
Original Norma 10mm specs were:
* 200gn FMJ-FP @ 1200fps/640fpe;
* 170gn JHP @ 1400fps/740fpe (later reduced to
1300fps/638fpe).
Yeah,
IF Win really loaded the STHP to 1290fps-1300fps, it could then be considered in the same energy range as the early Norma stuff (mid-600 fpe).
No need to fret, though. There are quite a few ammo companies around (more so than in past years) that produce 10mm loads approaching, meeting or exceeding original Norma ballistics - and they do it with better bullets.
Check out:
* Double Tap Ammo
www.doubletapammo.com
* Texas Ammo
www.texas-ammo.com
* Corbon
www.corbon.com
* ProLoad
www.proload.com
* Georgia Arms
www.georgia-arms.com
* Reed Ammo & Research
www.reedsammo.com
* Buffalo Bore
www.buffalobore.com
* Power Strike Ammo
www.powerstrikeammo.com