7MM Creedmoor

[wapiti16b]

I know it's been covered before but I can't find the posts .
Please , anyone with information and preferably those that load this round share your findings/loads .
Thanks !

 

[wapiti16b]

I'm thinking now that LAPUA is making 6.5 CM brass this might garner further investigation !
Anybody ?

 

[dryfire]

I plan to build one for my next rifle.


Sent from my iPad using Tapatalk

 

[davere]

Just FWIW... there are several 7mm calibers that are going to get you into basically the same ballpark. 7 SAW might be exactly what you're looking for, actually... Instead of necking up 6.5CM brass, you neck down Lapua's .308 Palma brass - just run it through the die once and you're done, no neck turning, etc. The Palma brass is small primer, and cheaper than Lapua's 6.5CM brass. There's a couple threads on the forum that go into it a bit, but ... https://westtexordnance.com/7mm-saw/

 

[spife7980]

^^ that's interesting

Necking up might lend itself to donuts with creedmoor brass, no? Not sure of the shoulder or neck thicknesses.

Why not just a 7-08 or AI it if you want steep shoulders. Sure it would be slightly more recoil with the higher capacity but with a brake it wouldn't be too bad. You'll be able to push them faster.

 

[davere]

Well, with the 7-08 AI, you have to fireform... but not dramatically different in terms of performance, either way. Here's one of the other threads... https://www.snipershide.com/shootin...-unit/sniper-s-hide-reloading/6509648-7mm-saw

 

[spife7980]

Yeah, your saw beats it with no fireformjng but 7-08 is adequate in and of itself. What I'm not sure of is ease to fit long bullets in a mag? The creed may beat it there in oal. Never looked that closely at how long the 160 and 180s are for 7mm.

 

[davere]

With the heavier bullets, mag length does become an issue, apparently - like, you need to be running AICS mags w/ the spacer removed, or AW / Accurate / Alpha mags.

I don't really have a dog in the hunt, actually. I keep running numbers (because I'm a dork) and I just don't seen an advantage in the 7mm short action calibers over my 6.5CM load w/ 140s. For hunting, it'd be a different story, because the 7s deliver a good bit more energy downrange, but for PRS style matches that extra energy turns into recoil. The ballistics differ so little that it's almost negligible. But, there's something cool about a short action 7mm, so I keep coming back to it for giggles I keep coming back to SAW because of the performance vs. ease of use thing it has over the others, but in the end, it's not a dramatic performance gain over 7-08 (unless you can really load long), and brass prep is what makes it better (in my mind) than 7-08 AI.

Some quick research (ie - not exhaustive) suggests similar performance between 7CM and 7SAW (and 7-08AI). They all get about 100fps more than a straight 7-08 w/ a 162. Out of those three, the SAW has the least amount of brass prep involved, and - if we're talking Lapua brass - has the cheapest brass (and a small rifle primer, vs Lapua 7-08 brass). So, if all else is equal, I'm lazy... LOL

 

[wapiti16b]

The Rifle will be a fun gun and sometime hunter for the most part as I do not compete . The SAW is the most logical option but would require me to change bottom metal and magazines . If I can avoid that and stick with my factory FN SPR BM and mags with the 7CM so much the better . I plan on shooting 162&168 bullets and if possible the 180's and do not want to single feed so the 7CM looks promising but like everyone else I want as much FPS as possible both for ballistics and KE on animals .
I'd like to see some data on the SAW & CM and load information for a 26" barreled rifle .
Thanks !

 

[davere]

I found some 7CM data via Google. WTO also has this up on the SAW: https://westtexordnance.com/7mm-saw-barrel-length-and-power-tests/

 

[WarbirdWeaponry]

I experimented with case capacity using 6mm Creed brass necked up and it was only 0.5 gr less water than 7mm-08 WW brass.

Edit: I should clarify, I entered the weighed case data into QL and the 0.5gr difference is in useable capacity after seating a 162 Amax to 2.9".

 

[wapiti16b]

So it looks like new bottom metal would be a wise choice for me and my particular application ! , next question , neck up or neck down ?
Either way it will be LAPUA brass 6.5 CM or 308 PALMA , I like the ease of case prep with the SAW but have a question , doughnuts occur when necking up or down ?
Please excuse my ignorance , I've always reloaded factory cases .
I know I want to go double stack on the magazines and the Alphas and ARCs have my attention so far , I guess it will come down to what CDI has to offer for bottom metal .

 

[spife7980]

It can occur both ways but I think necking up is more prominent. The top of the shoulder gets folded out into the bottom of the neck when you neck up where as necking down takes some of the neck and bends it down to become the top of the shoulder. If the shoulder is thicker than the neck when that shoulder becomes neck it will be thicker there and thus you have a donut of fat material you have to turn off or keep your bullet above. And eventually in many sizings it will flow forward enough to have the same phenomenon.

 

[Jedi]

I have given some thought to this, my requirements

1. Neck down preferred, minimize doughnut thing

2. Push shoulder vs fireform, ala SLR etc. Already have this step down. remove 20-25 thou off bottom of AI die .. TA da

3. Lapua brass

4. Small primer

Notes
Modified 7-08 AI die not only push shoulder in a single step, also perform initial necking op

Advantage over 7cm
COST 82 vs 110
Doughnut issue

Now the WTF
Lapua already does 260 and 7-08 brass
both 260/7-08 cost 96 vs 82 for 308p

how important is that small primer?

So for very little work you can save 30c a case and end with basically a 7cm

biggest ass ache in process, machining the 7-08AI die

The shoulder push and neck down op are painless and pert much warrant same fuss as necking fired brass

NO i do not run one

Info here for those that maybe considering it

Almost forgot
6.5 creedmoor: 52-53 gr case capacity
6.5 SLR: 55-56 gr

You pickup some case cap, more important push also yields longer neck ala SLR
to sum up
7-08 done right
longer neck
sharper should
small primer

no fuss solution

Surprised this option has not become all the rage, think once folk fig out how simple it is plus cost savings

 

[steve123]

Or scratch 7Creed and go straight to 7x47l AI. So many good 6.5 bullets now with high BC, 147ELDM, 150SMK, 155B, that only 7mm with heavies has the appeal.

7x47L AI has room for mag fed heavies. Handles pressures well, slower (or try longer barrel) but high BC makes up in the wind, high energy on target due to bullet weight. Makes a lot of sense. JBR1000 did a straight neck up and had better results as far as speed than thought would be. AI should add another 50 fps.

http://www.accurateshooter.com/guns-of-week/7x47-lapua-wildcat-cartridge/