Home Forums Hunting & Shooting Long Range Hunting Help me choose a 7mm Chambering......

You make it sound, Oh, so simple! The 7WSM shoulder is considerably further forward than the 270 or 300. Making it out of 300 brass requires forming a false shoulder and then fireforming. Once this is done, you can just load them up with your standard dies.

Also, why do you run your brass through a sizer die when it is new? New brass does not need to be resized unless you are loading a wildcat. This is a good way to bump a shoulder back and create head separations. Having made my share of 7WSM brass, I have found the best way form the false shoulder, load the case with 18 grains of Unique, top with Cream of Wheat (COW), press a bar of ivory soap into the neck to seal it. This makes reasonably sharp necks and has an danger range of about 8'. If you live where you can make noise, you can fire-form at home.

If you are simply loading this up with your preferred bullet and shooting it, you are wasting expensive bullets and, to some degree, barrel life. I have found that doing this does not result in great accuracy and not the same velocities either. Once it all fired, you work up a new load and start over??


Of the choices he gave, to clean up his chamber, the 7WSM is the best choice. If a 7RSAUM will clean it up, this would be good too. The worst choice is the 7RUM. In a barrel that short, you would not get velocities any where near what is expected for that over-bore cartridge.

I really like the SAUM. Too bad they are DOA.

i went the 7/300wsm route. ordered a 7/300wsm sizing die from rcbs (already had a match seating die) and use 300wsm cases. i do turn the necks but thats only due to having a tight neck chamber (.315)
my accuracy load uses the berger 180's, RL25 and fed match primers at about 3050fps great round and wouldnt hesitate to recommend.

Hey Pat, what bullet do you and your friends/clients like in the 7mm-08 and WSM? Flinch

That's because it is. I have found that many pieces of WW 7WSM brass have dinged or out of round case mouths, hence the reason why I run them through the sizer before loading them. How is neck-sizing 7WSM brass different from creating a false shoulder in .300WSM brass? It's the same process. My "fire-forming loads" are every bit as accurate as my main loads, and I'm getting 3050fps from a 140gr bullet, aka .280Rem performance. Even my fire-forming loads kill stuff dead, and ring the gong with impressive accuracy. I was out shooting at a dinner plate-sized rock a month or two back at 1120 yards with my fire-forming loads. Didn't seem to have a problem smacking it. My full-house loads get that 140gr bullet to 3295fps, and those are what I typically use for hunting.

Works just fine for me, and all my loads turn in MOA or better accuracy. Brass forms just fine like this, and I'm on 4x firing one particular batch of FF brass, and it's still going strong (could use another annealing, perhaps).

I'm a bit slow here today so forgive me but that 3295 is with your WSM right Jordan?

Thx
Dober

Hey Jordan, question for ya' - are you saying the 300WSM's existing neck size (approx. 0.338") is large enough to use as a false shoulder for the 7mm WSM? So just sizing the neck, since the 7mm WSM has a shorter neck, leaves a false shoulder? Are you seating the bullet into the lands for fire forming?

7 WSM!

Yessir

Yes, and yes.

Jordan-if you don't mind, how much and what are you burning with this?

Thx
Dober

I use a die that has no body in it- I just bump the neck maybe a 1/16" of an inch. I use no lube and it takes just a second. Forming the false shoulder requires setting the die up just perfect to make the brass snug on chambering.

If you are running your brass through your full length dies first then you are having to lube and clean them. That is a lot of time and work for accomplishing nothing. Try just bumping them with a tapered expander ball. Hornady makes the best one for that. Generally the only dents are on the very edge of the mouth- the neck itself is fine.

I just don't see the point going into the field with those half- power loads. If your fire-forming loads are as accurate as your real loads then you have some work cut out for you to find the better load. The fired brass should be perfectly straight- not something that can be said for the new brass.

Well, look....the good thing today is you have lots of choices and what you want is based more on the action/rifle you are drawn to, or have as a donor.

Clearly, what you have today is an embarassment of riches, and a 7mm to fill every tiny niche.

I'm a M70 guy,like long actions and hate bullets peeking bashfully from the confines of cases...I like 'em seated long and hate pushing cartridges.If I want 3200 from a 160, I want it "easy", so I like a case with capacity.Years of handloading have taught me, if you want velocity, get a larger case.Balance plays a role.

Others like the shorties and the WSM,Saum,7/08 fits the bill.Or if a guy is lucky enough to have an Oberndorf, properly dimensioned, hanging around,the 7x57 is really the only choice

Others have actions hangin around,want to stay within the confines of what they have available...seems there is a 7mm to suit needs.Today you can have what you want.

Hey Dober,

It's 63.5gr of RL17 and CCI250.

Both the FF load and my regular loads produce sub-0.5MOA, and even my worst loads will do MOA. I won't use anything that doesn't produce at least this level of accuracy in my serious rifles.

I mostly use the FF loads for practice. But then again, I like practising on steel, paper, and other things when I'm not killing stuff.

This is the thing I find interesting about this loading stuff (just a comment here nothing else) but the Alliant site lists a 145 along with the same load going @ 3166.

Gotta be a fun rig to work with!

Dober

I've always heard they were efficient. Time to throw the 7mm rem mag in the trash can and get me one of those wizzums........

Yeah, I seem to get higher velocity out of this barrel than what some of the load data suggests. I get nearly 140fps more velocity out of the 162gr A-Max with IMR7828 than what IMR reports (I'm using 0.5gr more than their max load, and they use the 162gr BTSP, rather than the A-Max). As you've pointed out, I'm also getting about 130fps more with the RL17 140gr load.

My drop data out to 1120 yards suggests that these chrony-measured velocities are accurate, too.

I don't doubt their accuracy, I'm a believer in fast and slow barrels. I've seen it often enough to make me firm in my beliefs on it.

Merry Christmas my friend.

Dober

Side note Jordan, I might be in Calgary March 21st for a Chris Tomlin concert maybe we can grab some lunch?

Dober