Advice for reloading 7mm Rem Mag?
- Thread starter saunders278
- Start date
My best advice is to use your chronograph. 7 Rem velocities are all over the place, and it is quite easy to produce ammo slow enough that it makes a 308 look good and a 30-06 seem like a holy terror. Factory ammo can be down-right dismal as well. 7828 seems to wake it right up though.
7 Rem chronograph results might even be a leading cause of suicide for all we know.
7 Rem chronograph results might even be a leading cause of suicide for all we know.
DiabeticKripple
CGN Regular
- Location
- Red Deer, Alberta
I did a ladder test using Barnes data and never saw any pressure signs all the way to max. Hodgdon data has a few more grains so I would definitely use that data.
+1 on that. Arguably the most under utilized cartridge produced.My best advice is to use your chronograph. 7 Rem velocities are all over the place, and it is quite easy to produce ammo slow enough that it makes a 308 look good and a 30-06 seem like a holy terror. Factory ammo can be down-right dismal as well. 7828 seems to wake it right up though.
7 Rem chronograph results might even be a leading cause of suicide for all we know.
I read too many Jack O'Connor stories in my youth, and think the .270 Win is the worlds best non-belted magnum.
If you want to shoot longer range small groups (not hunting) then buy Sierra 168 match bullets, rather than fancy hunting bullets. Might be cheaper, too.
And sort your brass by headstamp. There can be a significant difference in capacity and neck tension.
And sort your brass by headstamp. There can be a significant difference in capacity and neck tension.
saunders278
CGN Regular
Thanks everyone. It seems like I picked a difficult cartridge to reload. I'll keep at it though, get myself a chronograph, start sorting my brass, and try some different projectiles.
The brass I've been using so far might be all but spent anyway (4x fired), I've noticed it getting harder to close the bolt. Anyone got any advice on buying good quality stuff in bulk? Then I wouldn't even have to worry about sorting.
The brass I've been using so far might be all but spent anyway (4x fired), I've noticed it getting harder to close the bolt. Anyone got any advice on buying good quality stuff in bulk? Then I wouldn't even have to worry about sorting.
I wouldn't be too quick to decide that your brass is hooped, if you are just basing that on the 4 firings or harder chambering. Since you are just neck sizing that just sounds like its time to FL size them just enough to regain easy chambering. How are the primer pockets?
These days, getting most brass in large bulk quantities is a nice fantasy; but you don't need 1000 for it anyway.
The 7mm isn't hard to load for or shoot. Using a 700 with the 3.600" mag box makes it even easier since you can reach the lands and still have a repaeater with practically any bullet.
saunders278
CGN Regular
The primer pockets look fine, I haven't had any casings that looked suspect at all, actually. The only problem is closing the bolt on some of them. I didn't think this would be an issue with a belted magnum because the headspace is determined by the belt and not the shoulder. I thought it was only rimless casings that had this issue.
Anyway, I'll see how they chamber on the fifth firing and maybe get a full-length die.
Thanks,
-K
Two things with a belted case can cause hard chambering.
1. Not bumping the shoulder back .001 to .002 after each firing.
2. Just above the belt the case has expanded too much and is binding in the chamber.
NOTE, some full length dies do not reduce the case diameter just above the belt enough. This is where using a black felt tip marker and coloring the entire case will let you know where it is rubbing when chambered.
Chambers and dies vary in size, meaning in diameter and shoulder location. And sometimes you can have a fat die and a skinny chamber and the case is not reduced in size enough.
1. Not bumping the shoulder back .001 to .002 after each firing.
2. Just above the belt the case has expanded too much and is binding in the chamber.
NOTE, some full length dies do not reduce the case diameter just above the belt enough. This is where using a black felt tip marker and coloring the entire case will let you know where it is rubbing when chambered.
Chambers and dies vary in size, meaning in diameter and shoulder location. And sometimes you can have a fat die and a skinny chamber and the case is not reduced in size enough.
If you're neck-sizing your cases the only time they head-spaced on the belt was the first shot.
My experience with the 7mm Mag is that velocities are all over the place. I have a Winchester M70 Custom Super Grade which has had two factory barrels on it. In both cases the actual velocities using maximum loads from loading manuals were well below the book numbers. I had to go quite a bit over the book figures in order to get the velocity the cartridge is capable of. For this reason I never quote the loads I use for fear they could be overloads in some other rifle. My loads in my rifle produce good case life so I have no concern that they are over pressure IN MY RIFLE.
Also, with over 50 years of reloading I have always found that full length sizing will eventually be necessary unless you are using very light loads and these loads usually do not produce the best accuracy in this calibre.
Jim
Also, with over 50 years of reloading I have always found that full length sizing will eventually be necessary unless you are using very light loads and these loads usually do not produce the best accuracy in this calibre.
Jim
