7 mm Rem Mag, CCI BR2 vs Federal 215 primers and PPU vs Peterson brass

[menhadenman]

I started loading for my second 7 RM in early 2021, this one with a 8" twist for heavier bullets. Couldn't find large magnum rifle primers to save my life so wound up shooting with BR2s (maybe 300 rounds) behind IMR4350, H4831sc, H1000, and Retumbo. Retumbo gives me crazy speed (close to 3200 fps with a 168 VLD), but IMR4350 is pretty solid too. Going with Retumbo on the temp stability factor.

Also started with a bag of Prvi Partizan (PPU) brass that looked a little shoddy at first but it's shot well for me. I have quite a few mixed headstamps from 20 years ago when I only slung factory ammo. Scored a few boxes of Peterson brass afterwards, and after a year of looking, a case of magnum primers (215s). Wanted to sort out what it means for this rifle that I really enjoy and will probably take out west this fall (a H. Canyon Speed, X-bolt).

I've got a solid node between 71 and 72 grains of Retumbo using 168 VLDs. Compressed load but I'm loading long (71.7 gr is max according to Berger). Loaded up a pile of combinations to shoot up this morning with the Magnetospeed. The brass is probably 4-5x shot, once annealed, so maybe not the best.

Summary of comparisons between two brasses, two primers, and three charges of Retumbo (3-5 shots of each):

• PPU is faster than Peterson with the same charge. 56 fps on average, ranging from 24 to 93 fps more zip. Haven't measured it but guessing it's less case capacity/higher pressure.
• Magnum primers are about 40 fps faster than BR2s and I didn't notice any pressure signs. One oddity with with PPU where the BR2 primer was 14 fps faster.
• Peterson was slower, but SDs were much better compared to PPU brass. Normally an SD around 10 fps with Peterson (down to 3) and close to double that for PPU.
• Magnum primers had more consistent velocities (lower SDs). I'm guessing a better burn with that much crammed into the case.
• I wasn't necessarily shooting for groups but most were 1 MOA with a few < 0.5 MOA.

In the end, I think I'm going to roll with the Peterson brass and magnum primers. And as much as I hate to say it, I may push it a just little more (maybe 72 gr). The 3,175 fps load with PPU is crazy fast and stupid accurate. A little more consistency in speed would be great at distance.

Here's what it looks like on paper if you want to be confused.

 

[bullgator]

The Peterson brass is usually match quality and therefore more consistent, which is why you’re getting better SD and ES numbers. In theory…….that should translate to better and more consistent accuracy.
Definitely try to stay with magnum primers for the slow burning stick powders, and especially if you’ll be hunting real cold climates.

 

[Darkhorse]

Not my way of keeping notes for sure, but whatever floats your boat. At least you are keeping a record.
I've been shooting a 7mm mag. since around 1981 and I've settled on my loads and components if I can get them. WW western cases bought 100 at a time.
WW large rifle primers. IMR 4350 powder. Performs well at least on elk to 400 yards.
I'm satisfied. But if I take it on another hunt I might just check out some of the newer powders.

 

[Darkhorse]

I meant WW large magnum rifle primers.

 

[menhadenman]

The Peterson brass is usually match quality and therefore more consistent, which is why you’re getting better SD and ES numbers. In theory…….that should translate to better and more consistent accuracy.
Definitely try to stay with magnum primers for the slow burning stick powders, and especially if you’ll be hunting real cold climates.

I’ve got two more unopened boxes of Peterson. Nice stuff and they’re a solid US company. Spent a lot of time monkeying around with other components and know it matters… but didn’t know how much.

 

[sleepr71]

That’s a solid performance from the old 7RM. With those 168’s I bet it thumps on both ends?! I stick with 140-150gr for Whitetails & have never had a reason to complain. I bought a Sako 75 Finnlight(in 7RM) when they first came out with that model & love the gun + caliber. Hope nothing ever happens to it?

 

[rosewood]

I load for 1 Savage 110 7mag 24" heavy barrel. Have only ever used Winchester standard Large rifle primers. Never used magnum and my best load is RL22 with 154 SSTs. Shoots around 1/2 MOA consistently. Never seen any reason to try anything else. I think i have always used R-P brass also. This is one of the few guns that everytime I take it out, it shoots the same. It is just so dog gone heavy.

Rosewood

 

[Dub]

I load for 1 Savage 110 7mag 24" heavy barrel. Have only ever used Winchester standard Large rifle primers. Never used magnum and my best load is RL22 with 154 SSTs. Shoots around 1/2 MOA consistently. Never seen any reason to try anything else. I think i have always used R-P brass also. This is one of the few guns that everytime I take it out, it shoots the same. It is just so dog gone heavy.

Rosewood

Sounds like a wringer.

Is that an aftermarket barrel ?




I've always loved how the Sendero-sized tubes shot.

 

[rosewood]

Sounds like a wringer.

Is that an aftermarket barrel ?




I've always loved how the Sendero-sized tubes shot.

Factory. Police tactical model. Bought on clearance at Walmart in about 1995 for $120. Didn't know what I had until I started comparing to other guns. Bought about the same gun in .308 from pawn shop a few years back and can't get it to shoot nothing like the 7mag.

Rosewood

 

[Darkhorse]

My AVATAR shows how good my old rifle shoots. It didn't always shoot this tight but after I changed my loading process and glass bedded it the rifle started stacking them up.
I have never had a case head separation with my 7mm compare that to my .300 which requires checking all cases before loading.
I do stand corrected on a major point. I do not know how well it kills elk at 400 yards, my longest shot was 291 yards using the old Speer Grand Slam bullet.
It was my 300 Win. Mag. that I made those 400+ yard kills with.
My 7mm was my first true lefthand rifle, a Remington Model 700, I carried it solely for 15 years hunting everything big enough to shoot with it. It remains my favorite caliber still, though not always the best rifle and caliber for the job. Hence the 300.
A lot of people consider the 7mm Remington a dead or dying caliber. But that's only because of the number of new calibers introduced. It was once the hottest thing going and it is just as potent now as it was then.

 

[Dub]

Factory. Police tactical model. Bought on clearance at Walmart in about 1995 for $120. Didn't know what I had until I started comparing to other guns. Bought about the same gun in .308 from pawn shop a few years back and can't get it to shoot nothing like the 7mag.

Rosewood

Deal of the century.

 

[furtaker]

I've always heard that Winchester primers burn a little hotter than most.

I could use a few magnum primers myself but yes they are about impossible to find right now. I'm not out but I'll pick up a few if I run across any. I miss the days when you could find nearly anything you wanted.

 

[Jester896]

I've always heard that Winchester primers burn a little hotter than most.

I think I still have a pack of Winchester Primers that says on the pack it is suitable for regular or Magnum loads. It has been my understanding...at least in the past that they were hotter. I have seen it said that Winchester WLR primers are hotter than CCI 250s.

 

[Dub]

I think I still have a pack of Winchester Primers that says on the pack it is suitable for regular or Magnum loads. It has been my understanding...at least in the past that they were hotter. I have seen it said that Winchester WLR primers are hotter than CCI 250s.

Leading up to the rioting era-covid beginnings.... my local guy was always flush with Winchesters. I distinctly remember opting for Winchester large pistol primers vs his other brands on the shelf. My thought was they'd work with my intended .45acp, 10mm or .44 mag.

I'm sure glad I did...what I did.....when I did.

Woulda shoulda coulda done more before prices skyrocketed.

 

[menhadenman]

I've always heard that Winchester primers burn a little hotter than most.

I could use a few magnum primers myself but yes they are about impossible to find right now. I'm not out but I'll pick up a few if I run across any. I miss the days when you could find nearly anything you wanted.

Let me know if you’re ever up in the mountains, I could spare you a hundred to bridge the gap.