Just got my 7mm-300 win mag reamer

[FURMAN]

Ya its called a 7MM Practical. Thats what Nathen Calls his round. Not used to calling it a 300-7mm or 7mm 300 what ever. To me its a 7mm Practical!!

Yes his round is a great round ironically it is not near as practical as necking down stuffing a bullet and shooting.

 

[louis f]

Yes his round is a great round ironically it is not near as practical as necking down stuffing a bullet and shooting.

Terminal Ballistics Research is his web site, might be a good site for you to look at and see why he calls it a Practical.

 

[FURMAN]

Terminal Ballistics Research is his web site, might be a good site for you to look at and see why he calls it a Practical.

I have read pretty much everything he has written. Like I said above it is a great cartridge but not near as "practical" as a simple neck down and go using readily available dies.

 

[louis f]

I have read pretty much everything he has written. Like I said above it is a great cartridge but not near as "practical" as a simple neck down and go using readily available dies.

I sent a copy of the reamer print along with two fired cases to Hornady they made me custom dies for around a couple hundred bucks. Never tried using a random size die with a bushing, so I can't say if the work or not ,as far a acceptable accuracy. Just went with the custom dies.

 

[FURMAN]

I sent a copy of the reamer print along with two fired cases to Hornady they made me custom dies for around a couple hundred bucks. Never tried using a random size die with a bushing, so I can't say if the work or not ,as far a acceptable accuracy. Just went with the custom dies.

Once again, I am well aware but still not as easy as a 7-300 period. Here we are again derailing the OP. Back on topic. If you desire start a 7mm practical thread.

 

[louis f]

Once again, I am well aware but still not as easy as a 7-300 period. Here we are again derailing the OP. Back on topic. If you desire start a 7mm practical thread.

Steady my friend steady.

 

[Azrael]

I would assume you mean 7-300? A 300-7mm would indicate a 308 bullet in a 7mm case.

Depends where you're from.

 

[nmbarta]

As far as on topic goes.
The 7x300 win is as overbore as I personally care to take the 7mm/.284 bullets. (just my opinion, I don't care if you neck down a cheytac to 7mm as long as it's safe)
It offers a clear advantage over the 7rm, without adding any steps for the novice/experienced reloaders.

You just put a .284 bushing in a 300 win mag die and size it. No need to for more than on step in my experience. You'll have to play with the bushings a little bit to get your neck tension where you prefer it.

Then you just use a 7mm seater die to seat the bullets. Pretty easy.

You can run long bullets in a standard mag and still run with the 7mm stw.

It's one of the easiest "wildcats" that you can own if that's what your into.

Readily available high quality brass.

No factory ammo, a touch of recoil, and little loss in barrel life are the only downfalls I see compared to the 7rm.

Mine is broke in now, and speeding up a bit. 175 eldx at 3197, I'd guess I'll have to back it off a bit to get back to that 3150 node, not a bad problem to have.

175 eldx at 3150 that shoot's 1/2 moa, is just what I was looking for. There's few other great options that'll get you right in there, but the 7x300 is right there with the best them.

Looks like your barking up the right tree.

Good luck with yours.

 

[Badgerclaw]

Well a little update. Im going to order a 300 win bushing die, like everyone sugests, but I started off using what I have on hand to form brass. It was new brass so I didn't run it through the FL 300 die, just ran it through a FL 7mm rem mag die until the neck was sized all the way down to the shoulder.

Then I did a ladder test with H1000 looking for pressure. Started at 72.5 gr and it actually made a decent plunger mark and slightly flattend primer. I'm using winchester brass for now. Went up to 73 and started seeing less pressure. 73.5, almost no pressure signs. Worked up to 75gr and started to see the primer flatten out just a little again, no plunger mark. I threw the magneto speed on and 75gr shot 3104. So I have a starting point anyway. This is with 180gr Eld-m out of a 26" 1-8.75 twist barrel.

 

[BJH]

I am currently running a 7mm-300 Win. on a Defiance Action and a 28" Bartlein 1:8" twist. The load mine likes best is the 195 Berger on top of 68 grains of Retumbo in Winchester brass and a Federal 215M primer. Seated 0.020" off the lands. It produces 1 hole groups consistently at 100 and the best group I have shot is 2.5" at 1,000 yards. The velocity is a on the slower end at 2862 fps. But it works so well I don't see the need to change anything.
The one thing that I had to learn the hard way was the brass my rifle likes. My gunsmith told me to use Winchester, but it is pretty ugly when unpackaged. I'm sure any of you that have used it know what I mean. Anyhow, I tried Norma and Nosler brass because it seemed to be cleaner and more consistent. The accuracy was good (under 1/2 moa consistently), but the S-D was all over the place (anywhere from 15 to 30 fps). After burning up a lot of lead and powder I got some Winchester brass and my S-D is now 3 fps and the gun performs flawlessly.
I use the 300 Win Mag Redding Competition bushing die set and step down in 3 steps. I use the 300 Win Mag Seating die with a 7mm VLD stem.

 

[nmbarta]

BJH,

Which bushings do you use to step down?

I'm curious as to why you step down in three steps, I could be doing something wrong, but my smith told me one step was all I need and have not had any problems.

Have you run into problems using one step?

Badgerclaw,

Is it possible that you had the head space messed up on that case? Maybe when you were setting up the die, you bumped the shoulder back too far on one case? You shouldn't be seeing pressure there, and obviously your not if you could go 2.5 gr higher without problems. Excessive head space can look like high pressure.

 

[Badgerclaw]

BJH,

Which bushings do you use to step down?

I'm curious as to why you step down in three steps, I could be doing something wrong, but my smith told me one step was all I need and have not had any problems.

Have you run into problems using one step?

Badgerclaw,

Is it possible that you had the head space messed up on that case? Maybe when you were setting up the die, you bumped the shoulder back too far on one case? You shouldn't be seeing pressure there, and obviously your not if you could go 2.5 gr higher without problems. Excessive head space can look like high pressure.

I could have bumped the shoulder just a smidge. But I believe it was only .0001 or .0002 if I did. I have seen flattened primers before in loads that I knew were well below a max load. One thing I learned from reading this forum a few years back is that some people are of the opinion that brass signs are of little use at best. I don't know where to quote this from but I know people have said that the best way to tell if you have pressure, is by velocity, because pressure and velocity are directly related. So if most people can get around 3200 fps (most people with 180 begers) in the same chamber, with the same powder, then I believe I can safely get to 3150 which is my goal with the 180 eldms. I belive it should only take another .6 -.8 gr of powder. I was going up about 30fps with every half gr of powder through my ladder test pretty consistantly. And my primers were just barely starting to flatten out at 75gr.... almost an Un-noticeable amount.

 

[FURMAN]

I could have bumped the shoulder just a smidge. But I believe it was only .0001 or .0002 if I did. I have seen flattened primers before in loads that I knew were well below a max load. One thing I learned from reading this forum a few years back is that some people are of the opinion that brass signs are of little use at best. I don't know where to quote this from but I know people have said that the best way to tell if you have pressure, is by velocity, because pressure and velocity are directly related. So if most people can get around 3200 fps (most people with 180 begers) in the same chamber, with the same powder, then I believe I can safely get to 3150 which is my goal with the 180 eldms. I belive it should only take another .6 -.8 gr of powder. I was going up about 30fps with every half gr of powder through my ladder test pretty consistantly. And my primers were just barely starting to flatten out at 75gr.... almost an Un-noticeable amount.

I agree with some of what you typed but you need to be careful. All bullets of the same weight are not the same. 180 hybrids have a short bearing surface the ELDMs are long. You are not going to reach the same velocities with the ELDM as the hybrid all else being the same.

 

[Badgerclaw]

I agree with some of what you typed but you need to be careful. All bullets of the same weight are not the same. 180 hybrids have a short bearing surface the ELDMs are long. You are not going to reach the same velocities with the ELDM as the hybrid all else being the sane.

I hear ya. I know I won't get to the same velocity, but from what I've seen in my other calibers that I've tried both eldm and bergers, it seams like I usually hit pressure about 50-70 fps sooner with the eldm's pretty consistantly. So I guess I figured 3150 was a safe bet. Just shot 3 rounds at 75.5 gr and had slightly stuff case extraction. When I get home I tried to stuff an eldm down a fired case, it was way too tight! So I think part of my problem is a tight neck chamber. I measured the necks at .016. I just turned them down to .013. I figure I could try three more at 75.5gr and see if the neck was the problem. I also double checked my sizing, now that I have fired cases. Turns out I was bumping the shoulder about .010 like BJH mentioned I might be doing. I reset my 7mm sizing die and the shoulders are only being bumped about .003 now..... we'll see what happens now that the brass is just like I want it