7mm RM loading frustration

[skeeter 20i]

Guys do the reloading manuals / powder manf. websites show as big of a spread in other calibers as they do in the 7mm RM?

 I'm was working up loads for my newish Tikka and am relatively new to reloading having just started this last year.  I started with one powder, bullet etc and built up to sub MOA loads with a couple of bullets checking / cross referencing a couple of different info sources. 

Ok so having a couple goods loads  added to the book i moved onto the next new bullet and i added a new powder to try, heres where i wasted a trip to the range by not double checking another source.

Im trying the139 grain SST,H4831sc, COL 3.29, CCI250 Primer.

I pulled up the Hornady book and found my range of 55-65 i loaded up 3 shot string from 60-67 increasing by one grain increments.  The results really weren't impressive and had me puzzled, things were starting to come together but hadn't got there when i ran out of rounds. It isn't until i got home and double checked the Hogdon website and saw that they say a spread of 64.5-68.8.  One source pretty much ended where another source started.

So my question is first does anyone have experience with this combo that could share what they've found and do other calibers show the same wide spread of loads between bullet /powder manf. Sources?

[jrebel]

If you had a load shooting sub MOA, why would you buy another powder and bullet?  Stick with what works...at least that is what I do.     

[skeeter 20i]

If you had a load shooting sub MOA, why would you buy another powder and bullet?  Stick with what works...at least that is what I do.   

Oh I hear u I'm just getting started in reloading and am in the "well let's try this one" stage.  Besides if I stopped when I found a load I would have to buy a new rifle every time I wantedt o try a new bullet.......wait.........THATS BRILLIANT! 

Just learning and starting out.  Seems I enjoy reloading, that's why I asked.

[jrebel]

    Buy a new rifle everytime you want to tinker with a load!!  That is what I do...  Now you are catching on.   

[DaveMonti]

Load ranges will vary quite a bit from publisher to publisher.  Generally, the publishers of the reloading manuals are going to be conservative on the loads they publish.  There is a lot of variability in firearm design, so their published max loads will be the max for the "weakest" action rifle. 
To determine where the max is, increase the powder by small increments (.2 or .5 grain) until you start seeing your primers flatten out, or start to see brass cracking, fatiguing, etc. 
I have a 7mm RM myself, and once I settled on a good load with Nosler Partition (140 gr), I pretty much settled on it as my deer and elk load.  I'm not using the rifle for tinkering with loads to get real tight shooting loads, but the load I have will certainly be accurate out to the ranges I am comfortable with (400 yards or so).  I also worked up a very hot load with 100 gr bullets for longer range antelope hunting, but now that I'm settled on two good loads, I'm pretty set.  I do mess around with loads with my .243 and .25-06 (both heavy barreled rifles), but I find the most accurate loads are not near the max powder charges.

[KNOPHISH]

I get the max loads from all the different sources & average them out. Then back off from there to start.

[bobcat]

The best thing to have for working up a load is a chronograph. It will tell you what your max is, and take the mystery out of everything.

However, if your components are all exactly the same as the recipe in your book, you are generally safe with the max load shown. They're usually a bit on the conservative side so you can often safely go a couple grains over the book max.

But again, if you want to take the guesswork out of it, use a chronograph.

[DaveMonti]

Bobcat,
I realize the chronograph will tell you the velocity, but how does it indicate the max load?  Do the velocities from shot to shot become inconsistent as you go beyond the "max" load?
Just curious, I never heard of using the chrono to determine max load. 

[BULLBLASTER]

Once I get a good load I spend the time and money practicing and confirming dope on that ammo. Instead of trying new bullets. I don't change unless price or availability forces me to.

[tonymiller7]

If you had a load shooting sub MOA, why would you buy another powder and bullet?  Stick with what works...at least that is what I do.   

Oh I hear u I'm just getting started in reloading and am in the "well let's try this one" stage.  Besides if I stopped when I found a load I would have to buy a new rifle every time I wantedt o try a new bullet.......wait.........THATS BRILLIANT! 

Just learning and starting out.  Seems I enjoy reloading, that's why I asked.

Reload a lot of the round that works well and shoot more.  I never understood tinkering once you've found a round that works well.

[Curly]

Bobcat,
I realize the chronograph will tell you the velocity, but how does it indicate the max load?  Do the velocities from shot to shot become inconsistent as you go beyond the "max" load?
Just curious, I never heard of using the chrono to determine max load.

You could graph velocity vs. powder charge and it should look like a fairly linear increase.  Then as you reach max powder, you will see the graph flatten out.    There does come a point where more powder does not result in much of a velocity increase.  (There may even be a point where increasing powder results in less velocity.)

[huntnphool]

Load ranges will vary quite a bit from publisher to publisher.  Generally, the publishers of the reloading manuals are going to be conservative on the loads they publish.  There is a lot of variability in firearm design, so their published max loads will be the max for the "weakest" action rifle. 
To determine where the max is, increase the powder by small increments (.2 or .5 grain) until you start seeing your primers flatten out, or start to see brass cracking, fatiguing, etc. 
I have a 7mm RM myself, and once I settled on a good load with Nosler Partition (140 gr), I pretty much settled on it as my deer and elk load.  I'm not using the rifle for tinkering with loads to get real tight shooting loads, but the load I have will certainly be accurate out to the ranges I am comfortable with (400 yards or so).  I also worked up a very hot load with 100 gr bullets for longer range antelope hunting, but now that I'm settled on two good loads, I'm pretty set.  I do mess around with loads with my .243 and .25-06 (both heavy barreled rifles), but I find the most accurate loads are not near the max powder charges.

I also use 140gr Partitions out of my 7RM, 4831sc

[Bill W]

If you want to see how recommended maximum loads are all over the place, find some of the old books from the 60's and 70's and see what those maximum loads were.

You'll find out maximum load recommendations are way more cautious these days.

[Reidus]

Bobcat,
I realize the chronograph will tell you the velocity, but how does it indicate the max load?  Do the velocities from shot to shot become inconsistent as you go beyond the "max" load?
Just curious, I never heard of using the chrono to determine max load.

You could graph velocity vs. powder charge and it should look like a fairly linear increase.  Then as you reach max powder, you will see the graph flatten out.    There does come a point where more powder does not result in much of a velocity increase.  (There may even be a point where increasing powder results in less velocity.)

This doesn't make sense to me. With certain powder/bullet combos it may work but in some cases I think you will see flattened primers and a sticky bolt before you see a decrease in velocity gain.

[bobcat]

Bobcat,
I realize the chronograph will tell you the velocity, but how does it indicate the max load?  Do the velocities from shot to shot become inconsistent as you go beyond the "max" load?
Just curious, I never heard of using the chrono to determine max load.

You could graph velocity vs. powder charge and it should look like a fairly linear increase.  Then as you reach max powder, you will see the graph flatten out.    There does come a point where more powder does not result in much of a velocity increase.  (There may even be a point where increasing powder results in less velocity.)

This doesn't make sense to me. With certain powder/bullet combos it may work but in some cases I think you will see flattened primers and a sticky bolt before you see a decrease in velocity gain.

You should stop increasing your powder charge once you reach the maximum expected velocity. If you're getting more velocity than the book shows you're most likely also over pressure. If you're seeing over pressure signs with your brass and/or your bolt being hard to open, then you're probably WAY over pressure. Better to stop before you reach that point. This is why a chronograph is very useful.