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What's your opinion regarding using Large Rifle Magnum primers to ignite the powder in the 6.5mm Creedmoor case? I have no standard-power LR primers and I'd bet the farm that Scheels doesn't have any, either...
 
What's your opinion regarding using Large Rifle Magnum primers to ignite the powder in the 6.5mm Creedmoor case? I have no standard-power LR primers and I'd bet the farm that Scheels doesn't have any, either...
LRMs can certainly have an effect on a load compared to normal Large Rifle primers.
On other forums, folks have posted their results from testing 6.5CM with magnum primers. A few use magnum primers by choice.
1) The extreme spread of the velocity seems larger with magnum primers.
2) Ball powders displayed more sensitivity. H4350 is extruded.

If the load is worked up from a safe margin, it can work. Might not be recommended (because it hasn't been tested) but that is what you will be doing.
Note that the difference in velocity isn't always obvious. With 6.5CM small primer brass, I tested normal small rifle primers compared to magnum small rifle primers I noticed a 25 fps speed increase using the normal BR4 primer versus the 450 magnum primer. I guessed it was the BR4 allowed the pressure to build a smidge (technical term) slower and resulted in more speed compared to a faster pressure wave and a little slower velocity. Like I said it was a guess.
I measured 50 rounds with 25 of each and that was the average speed delta.

On a side note, Temperature can have a larger impact on velocity/pressure depending on the powder.
With older N160 before it was formulated to be more temp stable, I measured 75 fps increase over a 40 degree temperature rise (50 degrees vs 90 degrees)
6SLR (243 clone) with 105gr Hybrid, Fed 210M and Lapua brass sized, turned
 
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LRMs can certainly have an effect on a load compared to normal Large Rifle primers. If the load is worked-up from a safe margin, it can work.
I'm guessing the LRM primer throws a larger flash through the powder column. I doubt the temperature of the flash is a lot higher than the flash from a standard-power primer-- just that the flash is larger. A "bigger bomb," if you will. Part of my case prep is to chamfer the inside of the primer hole. I'm telling myself the chamfered hole will allow for the flash to spread itself into a wider funnel. The chamfering tool also enlarges the primer hole a bit, making it identical from case to case. All my cases are trimmed to the length the Lee Precision case trimmer provides. All the mouths of all the cases are chamfered inside and outside. Just waiting on what our members have to say about the possible use of Magnum versus Standard primers before we take the next step...
 
Mag primers don't have a larger flash or more power. They work on magnum loads of slow burning powders by providing a longer burn. instead of a quick flash they provide a longer extended burn. compressed loads of slow burning powders are the hardest to ignite. And the longer burn does a good job of that.
Other than the higher cost I would not avoid using them in standard loads. DR
 
Mag primers don't have a larger flash or more power. They work on magnum loads of slow-burning powders by providing a longer burn. ... Other than the higher cost, I would not avoid using them in standard loads.
Alrighty, then! I'll use the Large Rifle Magnum primers I have. I'm not concerned about their high cost: I guessing I paid fifteen to twenty dollars for the 1000-count box I've had since January of 2007.
 
More background on primers...

CCI spokesman comments on Magnum Primers:
Magnum Primers
There are two ways to make a Magnum primer — either use more of the standard chemical mix to provide a longer-burning flame or change the mix to one with more aggressive burn characteristics. Prior to 1989, CCI used the first option in Magnum Rifle primers. After that, we switched to a mix optimized for spherical propellants that produced a 24% increase in flame temperature and a 16% boost in gas volume.

As Forest might say...
That is all I have to say about that...
 
Prior to 1989, CCI used the first option in Magnum Rifle primers. After that, we switched to a mix optimized for spherical propellants that produced a 24% increase in flame temperature and a 16% boost in gas volume.

As Forrest might say...
"That is all I have to say about that..."
My box is from January of 2007, so mine are of the optimized type. Now I must concern myself with using a spherical powder. I discovered a nearly-full bottle of Alliant 4000-MR, which some source I do not recall at this moment said was a good one for the 6.5mm Creedmoor. Seems the only problem the source had with it is that it didn't flow throw the powder measure or powder funnel like Shih-Tzu through a goose. I always tap the rim of my powder funnel to make sure that the entire charge goes into the case. I learned to do that when I was dropping sixty-some grains of stick-type powders into my 358-caliber mildcat. One charge of that all over the bench certainly elicited some language that a novice nun shouldn't hear...
 
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My box is from January of 2007, so mine are of the optimized type. Now I must concern myself with using a spherical powder. I discovered a nearly-full bottle of Alliant 4000-MR, which some source I do not recall at this moment said was a good one for the 6.5mm Creedmoor. Seems the only problem the source had with it is that it didn't flow throw the powder measure or powder funnel like shih-tzu through a goose. I always tap the rim of my powder funnel to make sure that the entire charge goes into the case. I learned to do that when I was dropping sixty-some grains of stick-type powders into my 358-caliber mildcat. One charge of that all over the bench certainly elicited some language that a novice nun shouldn't hear...
You can use dryer sheets to help minimize static cling. Ball powder loves to stick to everything so you won't make it perfect but somewhat better.
 
Seated my first-ever Hornady 143-grain ELD-X bullet into one of my 6.5mm Creedmoor Starline Brass cases. I didn't charge it with powder because I was testing and tweaking as to how deep to seat the bullet. Once I'd determined that, I tried to use my kinetic bullet-puller to recover the bullet. I couldn't get it out without hitting so hard that I feared I'd break it. I don't remember using red Loc-Tite when I was testing for bullet depth, but it sure feels like I did. I don't have a puller for 6.5mm bullets, so I may have to bend the neck a bit to loosen the bullet or... grab the bullet with a Vise-Grip and ruin it. The bullet is not crimped, but it's sure in there dam-ned tight...
 
Seated my first-ever Hornady 143-grain ELD-X bullet into one of my 6.5mm Creedmoor Starline Brass cases. I didn't charge it with powder because I was testing and tweaking as to how deep to seat the bullet. Once I'd determined that, I tried to use my kinetic bullet-puller to recover the bullet. I couldn't get it out without hitting so hard that I feared I'd break it. I don't remember using red Loc-Tite when I was testing for bullet depth, but it sure feels like I did. I don't have a puller for 6.5mm bullets, so I may have to bend the neck a bit to loosen the bullet or... grab the bullet with a Vise-Grip and ruin it. The bullet is not crimped, but it's sure in there dam-ned tight...
For bullets under lots of neck tension, a collet style bullet puller is what works best. I like Forster but others work as well.
This style has a nut for a wrench compared to a handle that can be hard to get tight.
Cheapest price was $22 but with higher shipping charges than Midway

neck tension is one of those variables that affect accuracy. When it's high, it is challenging to get consistency.
I use gauge pins or mandrels to adjust my necks to a less grippy diameter. Not required but it's a step that helps long range groups.

When I'm using pins or mandrels, I pull the expander included with the die and put it back in the box.
 
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For bullets under lots of neck tension, a collet-style bullet puller is what works best.

Neck tension is one of those variables that affect accuracy. When it's high, it is challenging to get consistency. I use gauge pins or mandrels to adjust my necks to a less grippy diameter.
Earlier today I ordered a 6.5mm collet-style thang to use in my RCBS puller. Customer reviews indicated that it pulled the bullets without buggering-up the exteriors. Total was $21-something-- about the same as the gas to go to Scheels and buy it right then. At least two hours of high sun and 87-degree weather avoided. Puller will be here in a few days.

The OD of the necks on my brass is 0.289 inches with no bullet seated; that's what the resizing die gives me. I am in no position to argue with it...
 
Now I can screw-up to extents never before seen by man nor beast...
100 cases prepped and primed. Found I did not have to trim them; they were about 0.01" short right out of the box. Now to decide which of the dozen-some powders I have on-hand to load the first ones. Still haven't found my cleaning rod; don't have a 6.5mm borebrush, either. Have only fifty of the 143-grain ELD-X Hornady bullets. Must "choose wisely," to quote a Star Wars character...

Would my Ruger American be of sufficient character to make hits on a Hawaiin Punch jug from 600 yards? It's just a production gun with a production stock and a production barrel. 600 yards is 21,600 inches. A Hawaiian Punch jug is about 5.5 inches wide. 5.5 divided by 21,600 = 0.0002546. One minute of angle is 1/3600th of 100 yards = 0.0002777. Looks like my jug is just slightly less than one MOA at 600 yards. To hit that would be a dam-ned good shot. Six inches at 600 yards is also 0.0002777, so a hit on a one-gallon Hawaiian Punch jug at 600 yards is essentially a one-MOA shot. Good to know because I have several dozen HP jugs that I've saved over the past few years. I pour the HP into one-liter bottles and drink from them while I'm going down the road on my FedEx Ground trips. I refill the jugs with filtered tap water because the water in my little Nevada town is so loaded with hardness and odor that it's dam-ned difficult to drink it. I run it through my on-faucet PUR filter and it comes out just fine. Still hard as a Saturday night trouser snake, but the chlorine smell is gone. I use the filtered tap water ("FTW" in Sharpie pen on the jugs) for cooking and other forms of consumption.
 

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