Primers can make a difference.

[RichCoyle]

You increased the powder weight for each shot. And then you changed the distance, the primer, as well as the powder charge for each shot on the second group.

Of course. That was part of the test.

The distance is explained in another post.

Both the first and the second group used the same amount of increase per shot.

I have fried this rifle enough to know it is going to fire about the same MOA whether it is 200 or 100 yards.

The 10* of temperature change is irrelevant to most folks; and certainly to this test.

What I learned from it is I will use the large rifle primer instead of the magnum primer.

 

[JustMe2]

This rifle has fired multiple sub 1" groups at 300 yards. I was concerned the bullet holes would be too close together to make any since of if I fired them at 100 yards. When I saw the shotgun like pattern on the 200 yard group I was not concerned about firing the next load at 100 yards. I'm old and excel at lazy, so I didn't walk out to the 200 yard targets.

Next time, take a bicycle with fat tires.

 

[JustMe2]

This one time at reloading camp I stuffed LPP In my 300rum with 92gr H1000, lowest ES ever.

Try it out you might like the results.

I'll bet your velocity decreased with your decreased ES because you weren't burning all your powder before the bullet exited the barrel. The non-mag primer caused a more gentle ignition of the powder, but also probably did not burn all the powder. Next time, try reducing your powder charge with the smaller primer until you reach the velocity change of the non-mag primer rounds. That would be a fun test of ignition efficiency.

 

[RichCoyle]

I just thought of something. The bolt action doesn't know if I was shooting at 100 yards or 200 yards. The bolt action did demonstrate the Magnum primer produced stiff bolt lift and the non-magnum primer did NOT produce stiff bolt lift.

 

[KNOTFERSAIL]

I'll bet your velocity decreased with your decreased ES because you weren't burning all your powder before the bullet exited the barrel. The non-mag primer caused a more gentle ignition of the powder, but also probably did not burn all the powder. Next time, try reducing your powder charge with the smaller primer until you reach the velocity change of the non-mag primer rounds. That would be a fun test of ignition efficiency.

Just to clarify..I'm fibbing and adding no substance to this thread.

 

[slv hunter]

My GS told me years ago, the only time a magnum primer is needed is when your using ball powders in a magnum case.

 

[bluedog69]

Just to clarify..I'm fibbing and adding no substance to this thread.

There are guys out there trying their best to decode what you said.

 

[Echo Charlie]

Just taking care of velocities looks like you have a velocity node on the first 2 charges with both primers

3693 fps
3699 fps
with one
and
3647 fps
3659 fps
with another

if you are happy with this velocities test them more.

Good luck

 

[Lee Goodwin]

I just thought of something. The bolt action doesn't know if I was shooting at 100 yards or 200 yards. The bolt action did demonstrate the Magnum primer produced stiff bolt lift and the non-magnum primer did NOT produce stiff bolt lift.

Maybe the non mag primer wasn't burning all the powder.?

 

[Pureblood]

Mt friend Dave says there is little to no difference between small rifle and large rifle primers in 6.5 creedmore.

 

[RichCoyle]

Just taking care of velocities looks like you have a velocity node on the first 2 charges with both primers

3693 fps
3699 fps
with one
and
3647 fps
3659 fps
with another

if you are happy with this velocities test them more.

Good luck

Thank you. I did not notice that.

 

[MagnumManiac]

I'd like to agree with you as I find using BR2 CCI (non-magnum) primers for my 300 win-mag yields better (lower) MV ES without any issues.

However, using same (BR2...) on my 338 LM causes over 30% misfires. When I open up misfired cartridges, the powder looks singed, but intact.

The powder is the same in both cases: VN565. The loads are: 75.2 gr for 300 win-mag and 84.2 gr for 338 LM, and the only other difference is the case size/shape. The 300 win-mag bullet is a 168gr TTSX and the 338 LM bullet is a 250gr scenar.

Care to comment ?

A primer provides 2 distinct parameters, pressurising the case prior to full ignition and a progressive ignition, if either of those things aren't there due to case capacity and load density, it fails to ignite the powder.
The other thing is, really slow powders in large cases are harder to ignite. In my 338-416 Rigby Improved 45° case, most standard primers do the same as you describe, yet a WLR works just fine.

Cheers.

 

[MW204]

Yes it's the same shoulder but I was shooting in a little over a week . I heal quickly and it wasn't a full replacement. I'm getting a itchy trigger finger

A perfect time to practice with the opposite shoulder.

 

[Bullwhacker]

Not aligning with this test procedure but primers can be a big variable in tuning a load and should be tested if you have them available.