Anyone own a 7mm 300 Win Mag?

[Kiwi Nate]

Hi Weaselthis. Ok, you should always use lube for sizing bottle neck cases, whether it be graphite or wax based. Furthermore, if you are reforming such as necking down, lube is even more important. The only situations where lube is considered unnecessary is for resizing pistol brass using tungsten carbide dies.

The second problem you are most likely experiencing is that you are running the .300 case too far into the die, pushing back the shoulder and also increasing the body dimensions. Annealing will actually cause more bulging as the brass is more maleable. Nevertheless, by not using sizing lube, the brass will be work hardening quickly anyway, necessitating annealing.

You are really going to have to re-address your reloading practices regardless of your past 25 years experience, not just to be able to form a wild cat, but also for the sake of accuracy. There is no point having a potent cartridge that will only group 1.5 MOA because you have been rough on the brass. Slow down a bit and take so try to study what is going on, you will work it all out just fine. If you can get your head around the fact that you may have to lift your game a bit for this project, you will find any obstacles a lot easier to overcome and the results will be very rewarding.

I use a basic Hornady 7m Mag neck die for my 7mm Practical: The 7mm Practical. A Practical Magnum.

I own very expensive bench rest dies but they make no difference, the Hornady neck die is fine. The reamer for my cartridge as well as other reamer options can be obtained from Pacific tool and Gauge. Please bare in mind that they are under a heavy work load at present/ this year so gather what information you need prior to contacting them via these posts and contacts so they can process your order without fuss. Throwing a heap of questions at them is currently too much too ask of them when the work load is so high.

Yes, fireforming will remedy your cases but you probably won't be able to chamber them due to the body dimensions they have been pushed too. If you try and force them, you'll risk snapping an extractor.

Hope that all helps and I hope I haven't been offensive in answering your questions.
Nathan.

 

[Weaselthis]

Thanks, Nate, thanks for taking the time to reply and no offense taken at all. I appreciate the insight & constructive criticism. If you can't learn anything new, then you're DONE and ya might as well eat the end of your shotgun and see what's next in store! LOL

btw, I read your article on the 7mm Practical front to back. Your comments
and those of Broz were wholly instrumental in my decision to do this project.
You guys offered up great stuff there. Thanks. I won't be making a 7mm Practical, but am getting a 7/300, so I ASSUME the shoulder angle w/ still be 25 degrees of the parent 300WM.

Yeah, it was dumb not to use lube on the first 6. I normally neck size w/ graphite INSIDE the necks to ease it over the expander ball. Going down from .308 to .284 is a bit of a push. AND, if I'd been thinking right, I wouldn't have annealed first. So, that lesson is learned.

Your comment about running the case too far in the die seemed to make sense to me, BUT I didn't do it at the time cuz I thought I would need to make **** sure the neck was 7mm all the way to the shoulder and not leave any .308 neck diameter unsized. DOhhh.....Another lesson done. Thanks.

In your article, you mention using regular 7RM neck & seating dies. What die would you use IF the need arose for a FLS, or is that never done w/ this round?

Like you say, I need to get edumecated some more. 25 yrs. of sizin' 'em, stuffin' 'em, & shootin' 'em ain't gonna make when the wildcats are involved. It's a learning curve and a journey I look forward to taking. Made up my mind to get stubborn and get knowed up some.

I appreciate any and comments and help you and others on this forum have to offer. Take care.

 

[Weaselthis]

Nate, one more thing. I get really good vel. & accuracy w/ Retumbo and am really looking forward to trying H1000. Do you have any comparison figures on case capacity between your 7MMP and the 7/300? Thanks.

 

[Kiwi Nate]

Good stuff, glad you are enjoying the process.

Case capacity between the 7/300 and my Practical is identical. People do seem to get carried away with the idea of shifting a shoulder angle forwards to increase capacity but it really means squat. There is plenty of powder space in there, 77 grains of H1000 or Retumbo fits easily with room to spare and I have just put 85 grains US 869 into a case as a start load for experimenting and again, plenty of room. My fireform loads have the standard 25 degree shoulder. I only opted for 30 degrees as a means of aiding positive headspace. That and I also noticed that cartridges with 30 degree shoulders tend to grow the necks rapidly which was desirable as the Practical is a long neck design for optimum bullet to bore concentricity.

If you need to FL size, you will have two options. The first is to have PTG send a drawing to Hornady and they can make a die, they really do a very good job of this. The second option is that you neck down as per usual with the neck die, then use a .300 FL die for the shoulder and body, being sure to remove the expander spindle.

In the Practical, I would have to use a Hornady custom made die. Its no big deal, not really any different to ordering a standard die set. That said, I try to avoid having to FL size altogether. I guess the main thing is to not push the brass beyond its pressure limits. I believe this is how I am able to neck size year in year out without having to FL size brass in our rifles.

 

[Slopeshunter]

Nathan, great read on the 7 Practical. Thanks for linking. Great shooting too!

Cheers.

 

[Weaselthis]

Good stuff here......thanks. I'm gonna try an get my smith to make me a FLS die w/ the reamer he uses, just in case. He says he's never done that but shouldn't be a problem. If not, I'll get a 300WM die and have at it! I have neck sized everything I shoot until there is resistance to chambering a round and then I only "partially" FLS. That's worked well all this time.

I took your advice and ash canned the remaining brass I'd botched. Cost of learning......lol

 

[Kiwi Nate]

You won't be able to use the reamer to make a FL die. The reamer is shaped for the chamber, not the brass. If you FL sized using the reamer, it would not be any different to chambering a neck sized round in the rifle. In other words, a seperate reamer of slightly smaller dimensions is used to create an FL die. This sizes the brass to dimensions smaller then the chamber (chamber reamer).

 

[Weaselthis]

Now why didn't I see it that way? Makes perfect sense now but that never entered my mind. NOW, I'm wondering about a smith who didn't tell me that........LOL.
Sounds like I'll be neckin em or fls em w/ a 300WM die if need be.
Thanks, Nate.

And good shootin in the video there, pard!

You won't be able to use the reamer to make a FL die. The reamer is shaped for the chamber, not the brass. If you FL sized using the reamer, it would not be any different to chambering a neck sized round in the rifle. In other words, a seperate reamer of slightly smaller dimensions is used to create an FL die. This sizes the brass to dimensions smaller then the chamber (chamber reamer).

 

[Kiwi Nate]

I was chuckling when I posted that, now I have read your reply and I am giggling again- I knew it would make perfect sense and seem obvious to you once it was described- ain't that often the way. I felt like a right ***** posting that. Ah well. You will never be able to top the mistakes I have made over the years, got a nice 30 cal bullet hole hole through and through my arm from my early days, experimenting with gong materials at 25 yards- back when I was young and bullet proof- oops, no I wasn't, I mean young and stupid.

Sometimes a smith won't be able to work these things out simply because he has so much on his plate already, that other prototype/ odd jobs are just too much to have to deal with so they get shelved in the -OK, I will give it a go, deal with that when the job turns up department. In other cases, the smith might just be hopeless, a guy who did a machine shop apprenticeship because thats what he was told to do. You would be surprised how many machinists don't even like talking about steels, have no passion for metals, alloys, heat treatment, its all about a pay check and that is all. Some guys just like to pontificate (like I am doing right now LOL), show how much they know, get all the attention, something to do with their mothers not loving them or something like that.

Its a tough call, you don't need someone who is exceptionally intellectually gifted to do your smithing, all that is really required is someone who is passionate about what they do, honest and enjoys the learning process that each job brings. You can get a feel for this kind of thing over the phone or by email, good attitude, a willingness to help get the job done properly- and help rectify any problems that might occur down the line.

 

[Weaselthis]

Apologies to Broz, not trying to get off topic here or highjack his thread so here's my contribution: I'll post work up methods, mistakes, successes, thoughts from an old timer that recognizes "he ain't in Kansas no more, Toto" when it comes to wildcats and knows enought to be dangerous BUT knows he dangerous, when I get the gun back. Perhaps a perspective from a novice viewpoint might help someone here in my shoes.

I went back a read Bob's (smith) reply and my bad.....he said "getting dies shouldn't be a problem". He emailed me Sat. w/ the exact explanation you gave. I'm gettin it from all sides here! LOL
He has built my 280AI and it is scary accurate w/ 168g VLD at 2950fps & RE22. He knows what he's doing and he's fast and he's cheap! He's a retired engineer w/ more money than God and just does this stuff for relaxation just for friends and referrals. I used to work w/ him 30 years ago. Was good to strike up an old friendship again.

We should start a thread about "mistakes I've made" relating to guns/reloading etc. I won't bore you w/ how I have been shot twice, once in the head and once in the leg, both times by the same guy but 17 years apart. I still see him everyday! I love the guy! He's married to my wife and is the father of my daughter. LOL
Take care, Nate. Thanks again for all the GREAT info. I hope you and everyone on this thread will be as willing in the future to share your knowledge should other questons arise. Gotta go. Going to So. Dak. for a few days pheasant killin!

 

[tresmon]

Hey getting in on this late in the game. A few questions:

I'm heavily invested in .300WM- neck bushing dies bump dies etc etc. But now that the barrel of my 300wm is shot out I really wanted to drop down to 7mm for the better BC and a little less recoil. I had decided to just stick with the 300wm untill I found this thread...

Can I use my 300WM bushing dies for the 7-300 and just use a smaller neck bushing?
Thanks all,
Tres

 

[Broz]

Can I use my 300WM bushing dies for the 7-300 and just use a smaller neck bushing?
Thanks all,
Tres

Yes, that is what I do. As long as the reamer you use to chamber the rifle retains the origional 300 win shoulder angle. But for necking down bass the first time you will need several bushings to step it down. Or run it through a seperate special die the first trip. After that and they have been fired in your rifle simply use the 300 win die with the correct 7mm neck bushing.

jeff

 

[Weaselthis]

Now you've got me thinking and that's dangerous for me anyway.....
I took my 7mm Mag die, adjusted it up some and ran some 300WM brass thru it. Some failed and some did ok, I THINK (I think they are ALL too short). Learning curve. Is using the 7mm neck die the right way to go or should I just buy a 300bushing die and go w/ several size bushings as you suggest?
Any suggestions are greatly appreciated.
ps.....the reamer is a standard 300WM shoulder w/ 7mm neck, I HOPE! LOL
It's not here yet so I'm won't say 110%.
Thanks guys!

Yes, that is what I do. As long as the reamer you use to chamber the rifle retains the origional 300 win shoulder angle. But for necking down bass the first time you will need several bushings to step it down. Or run it through a seperate special die the first trip. After that and they have been fired in your rifle simply use the 300 win die with the correct 7mm neck bushing.

jeff

 

[Broz]

In my opinion the Redding "S" type competition neck bushing die is the only way to go. Then have a 300 win body die if you need to slightly set the shoulder back a bit. The problem with using the bushing neck die to neck the brass from 300 to 7mm is, the redding bushings have only a very slight taper on the bottom and are designed to accept brass that is only slightly larger. So you need to do it with several bushings and small steps. I have always wanted to take a 7mm bushing to a lathe and cut a larger dia slow taper on one side. I think that would do the trick for first time sizing down. Then flip the bushing over or use a second bushing for the final size after fireforming. I have pretty much completely converted to the Redding comp bushing dies. I like to size my necks and body in seperate steps as the body seldom needs sized. I get concentricity of less that .001" T.I.R. as an average and I like that.

Jeff gun)gun)