7mm Rem Mag Powder Question

That's all well and good, but don't let the fascination cloud your judgment and interfere with your attention when loading. One mistake can literally [blow up in your face] If you don't remember anything else.....Always pay attention to detail...CLOSE Attention.

Good luck.

WILL.
 
Sighting 7mm Rem Mag

I realize this is an old thread but knowledge should last longer.

g-stanger wrote,
@100 Yards I had no adjustment to the scope (sighted in 7 years ago with Rem Core-Lokt, props to Leupold for holding a zero for this long)

@200 yards I have about 6in drop

A lot of people do that kind of sighting but a bit of thought finds better recipes. e.g. The height of trajectory to 200 yards for a 154 grain pointed bullet launched at 3000 ft/s is only 1.6" above the line of sight. For a 300 yard zero, the number is only 5". So, if you sight in 4" high at 100 yards, you don't have to worry about range at all to 300 yards. The vital zone of many big game animals allows holding crosshairs on the bottom of the vital zone and being on out to a very long range: 7X57 and .308 to 350 yards. 7mm Rem Mag can do 400 easily and by using lighter bullets to 440 yards, well beyond most hunting situations. If you choose 7mm Rem Mag you might as well use all its capability in sighting.

Further, bullets lighter than about 150 grains will fragment on game within 100 yards at these high velocities so I recommend passing on such shots or using heavy RN bullets at reduced velocity for that situation. In 7mm Rem Mag, I carry 170RN loaded down to 7X57 velocity on the top of the magazine. If I see game at long range, I shuck that round for the higher velocity pointed bullets. If you expect to see much more game at long ranges than short (ambush from high ground, for instance), you can zero for 600 yards and hold well under the vital zone. The flattest part of the trajectory is about 200 yards around the highest point of the trajectory so lots of meadows and gullies can be covered quite nicely. Of course, one should test rifle, ammunition and shooter at longer ranges to be reliable but 1-200 yards is not a real test for 7mm Rem Mag.
 
Why make things more complicated than necessary. Having a bullet hitting 4-5" high at the ranges where most shots are likely to take place is a recipe for disaster. A 100 yard zero is a lot simpler and requires no hold over out to 300 yards with almost any modern cartridge.

I do that with everything from 308 up. At 200 or less I simply hold in the middle and the bullet will be within 2" of my aiming point. At any range between 200-300 yards I simply hold on hair on the top of an animals back. Bullet drop with all of my rifles is 7-10" low and still in the kill zone. If someone can compensate for being 5" high then 7"-10" low ain't rocket science and is lot more natural. If rushed taking a closer range shot almost no one will remember to hold low. Remembering to hold high at long range comes naturally.

Beyond 300 yards even the flattest shooting rifles drop enough to require pretty precise range estimation (range finders) and a scope with multiple aiming points or adjustable dials. And most of those are calibrated for a 100 yard zero.

Almost no serious shooters use the 2-4" high at 100 yards method to zero rifles anymore. You gain next to nothing between 200- 300 yards, it doesn't help at all beyond 300, and just complicates things at closer ranges.
 
jmr40 wrote, "Having a bullet hitting 4-5" high at the ranges where most shots are likely to take place is a recipe for disaster. A 100 yard zero is a lot simpler and requires no hold over out to 300 yards with almost any modern cartridge.

I do that with everything from 308 up. At 200 or less I simply hold in the middle and the bullet will be within 2" of my aiming point. At any range between 200-300 yards I simply hold on hair on the top of an animals back."

Two points:
  1. It's not always possible to judge the range of a large animal far or a small animal close especially in clutter or rolling land.
  2. This recipe requires knowing the range more or less. Mine doesn't.

It is good that jmr40 specifies the point of aim. Many who use such recipes don't. Holding on the heart is natural too but it will miss badly at 300 yards. I've been using my recipe for decades and passed it on. No one has had a disaster using it. I've used it with 6.5X55, 308 and 7mm Rem Mag and it works for all and makes best use of the calibre. If one holds on the same spot every time that becomes natural. Aiming at the centre of the vital zone may be easy but it's not optimal. It throws away lots of feasible range and can miss low badly. In particular, one should know that drop increases rapidly past the second zero so shooting out there is way more dependent on range than using the flatter part of the trajectory near the highest point. It's just physics.
 
FWIW........ I always sight my rifle in to shoot 2 inches above point of aim at 100 yards. This puts it right on at 200 yards and about 3 inches low at 300 yards. For hunting you don't worry about the range. Just put the cross hairs on the critter and pull the trigger.
 
"Does anyone set a chronograph out at the target to see what the speed of the bullet is at POI? "

I do not have a chrono. Who cares how fast the bullet is going? I want to know where it will hit. Shoot to hit the target IOW.

Get a reloading manual. Take your load from the manual. Start low and work up. May I suggest the Lyman 50th? I am sorry, but I will never take a load from a computer web site.
 
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