I have searched the board, but can't quite find what I am looking for. I am starting to reload for a friend's 7mm rem mag and need a place to start. I have checked websites, boards, and books and they all seem to say something different. He is wanting to shoot 120 gr Barnes or 140 gr Barnes. I currently shoot the 120's out of my STW under IMR7828, but I have seen a lot of bad PR about IMR powders with temperature variation. Which powder to use? Is IMR7828 too slow burning? What about H4831 (is there a difference between H4831 and H4831SC) or Reloader 22? I believe that is only a 24inch barrel.

Re-22 + 120gr XBT in a 24" 7mmRemmag ='s a shit eatin' grin.

One of my favorites and the 120 V-Max doubles nicely for practice...................

All powders are temperature sensitive. Until I see HP White do a test I am going to ignore marketing from Hogdon. Hodgdon and Accurate are the only powder companies who ever gave me incorrect data or the powder was made wrong.

This is why I always try to use IMR powder.

With the 120 gr bullet in the 7 MM Mags RL 22, IMR 7828 are both very good. I am testing Hodgdon 1000 right now and so far it's ok. I have to break out the chronograph to confirm it's exact velocity.

In my 7 MM WSM the 120 gr Hornady V MAX and RL 22 is a very good load.

I get 3425 with 130's using RL22. That load is probably too hot during regular weather, but "almost reasonable" during elk season.

The muzzle blast, however........ Wow! Rings my ears, even with one shot at an elk. Dutch.

I've tried the 130 gr. XBT in my 26" barrel 7mm Rem Mag.

Here is a fast load.

----
130 gr. Barnes XBT
77.3 grs. RL25
CCI 250 primer
W-W Super case
~
3425 fps avg
----

This a hot load, back off 10% and work your way up.

For the 120's:
RL-22 From 58.7 grains to 73.0 grains
CCI-200 Primer

For the 140's:
RL-25 From 66.5 grains to 71.5 grains
CCI-200 Primer

The 7mm mag, my favorite load with

140 Nosler Part
IMR 4350 or RL 19 at 65.0
Fed M215GM Primers
Fed cases

Excellent Deer/Sheep/Antelop/Goat load

Thanks for the help. I think I will try some IMR7825 (since I already have a couple of pounds) and maybe some reloader 22 or 25. This board continues to provide me with some great help/advice that I can't get anywhere else.

74 gr. WMR 3540 f.p.s. (warm load in my A-bolt ). Shot three in wet newsprint at 50 yds. All three shed all four petals.
Thanks, Mike

If a Partition looses some from it's front section that is bad bad bad but if a X bullet looses it's petal's (as they do when I tested them) we are told they are designed to loose petals at HV impacts.

I launched a lot of 120XBT's out of my STW's at over 3750fps and never had an issue regarding projectile integrity on critters.

Though of course I never recovered one to examine either. It is a stone cold hammer.

I love that bullet in all 7mm's,from the 7-08 on up............

There is no difference between H-4831 and H-4831SC. The SC means [short cut] and the grains are shorter in length. The 7MM Remington magnum shoots best with slow burning powders. Every Reloading manual has the 7MM Mag listed. Every rifle is unto itself as to the load it will shoot best. Most hunting rifles will give their best groups with a midrange load below maximum load listed. No two rifles shoot the same with the same load. REL-25, IMR-7828, REL-22, REL-19, IMR4831, IMR4350, N-160, H-4831, H-4350 and the list goes on.
IMR-7828 is no more temperature sensative than any of the other slow buring powders. Stay away from hot loads and you will not have a problem. Hot loads in any rifle mean shorter barrel life and stress on the action. You show me a guy who uses hot loads in a hunting rifle on a regular basis and you dealing with an idiot. If two reloading manuals show different starting and maximum loads listed for the same powder and bullet. Start at the lowest starting load listed and don't exceed the highest maximum load listed.
The only short cut method I know when working up loads is the ladder test method by Creighton Audette. I use it all the time and save much time and ammo. Hunting rifle accuray requires a rifle produce MOA groups at 100 yards.