FINALLY I've had the opportunity to begin testing 120 NBT in my Win 70 FTWT 22"--6.5X55.
I'm using WW brass/ older, nickel plated, WW Primers, IMR 4831 powder over an Oehler 33 with NEW skyscreen IIIs.
I waited 6 mos for the bullets to come last yr and when they did it was tooo hot to mess with. Deer season came & went then we've had 3 months of March winds.
This morning I was able to graph with cloudy skies, temp @ 65*. Great conditions.
I began by checking batteries in the O 33, NO low battery indicator. I used my Ruger 10-22 and Fed ammo to verify everything was working alright. CHECK !
After months of research and comparing load data for Modern Firearms I started with 46 gr IMR 4831 and slowly worked my way upward.
49 - IMR 4831 av 2760 fps --not acceptable to me.
50 - IMR 4831 av 2825 -- not bad but I'm looking for 2900-3000.
I have another LOT of IMR 4831 I'll try next PLUS IMR 4350.
50 grs is NOT too hot for MY rifle. Primers still tight. ALSO I found this in Handloading Big Game Rifles...
Denton
Campfire Outfitter
Registered: 06/28/04
Campfire Pet Loads -- 6.5X55
49.5 grains H4350 with a 120 grain Sierra bullet and 3.000" COL gives me a measured 59.4 KPSI and 3075 FPS out of a 24" barrel. I back that one down a grain just for luck. Should give you about 3025 and around 57 KPSI,
****which is a conservative load for a modern rifle.****
47.5 grains H4350 behind a 129 grain Hornady bullet, 3.000" COL, gives 2951 FPS. I don't have a pressure measurement on that. Same 24" barrel.
Your results will be different, of course.
Edited by denton (12/28/14)
---------------------------------------------------------
IF - IF 49.5 grs H4350 gave less than 60,000 PSI--
THEN 50 grs IMR 4831 should be less than 60.000 PSI.
Next time I'll try another lot of IMR 4831 and IMR 4350
*************
Check This OUT
I shot a few rounds of Factory PRVI 140 SP over the graph.
2217, 2202, 2235, 2202 / 4 rounds told me ALL I wanted to know!!
That's good 30-30 speed right there.
For curiosity and *satisfaction* I drug out my M 6, 30-06 with 165 HBTSP and H 205, yes-- H 205
2929, 2942, 2923---The graph WORKS right
--PRVI SUX!
Jerry
