What's the best 7mm cartridge?

[Rich Coyle]

Longer necks seem to allow for longer throat life. You can borrow my unused reamer. It is a .338 Rum with a .100" longer than standard neck. Pac-Nor sent me a 6.5mm barrel instead of the 7mm like I wanted. So I rebarreled my six lug Weatherby and chambered it to 6.5 Coyle.

 

[Sniper97]

So the 7 lrm would arguably have the longest throat life?

 

[MudRunner2005]

In my personal opinion, it's all old wives tales thanks to modern slower-burning magnum powders. If neck length really mattered these days, we would still be using cartridges like the .577/450 Martini-Henry...But we don't.

 

[WildRose]

I do not have any 7s right now, but it will be my next build. I have done a lot of research and just need some help. First off, I do not want to mess around with a belt. I have just had bad experiences with belted magnums. Secondly, I would like something somewhat unique, while at the same time being able to find components. I want something with a little more horsepower than the 7 rem mag that can shoot the 180-195 grainers at or above 3000 fps. I have thought about the 7lrm, 28 nosler, 7mm dakota, and 7-300 win mag (I now it has the belt). I would rather not burn my throat out quickly, which scares me with the 28 nosler. Any help is greatly appreciated. Thanks!

Skip the LRM and just go with a 7mm-375 Ruger. You'll pick up a few more grains of case capacity and not be married to the crappy overpriced brass from Gunwerks if you want something "unique".

You'll need custom dies made but I'm sure that PT&G, Redding, and Hornady have the spec's as quite a few people have built them over the last ten years.

Go with a minimum of a 1:9 tw preferably 1:8.5 or 1:8tw so you can stabilize the heavy for caliber bullets.

 

[WildRose]

So the 7 lrm would arguably have the longest throat life?

No reason to believe that, there's no science supporting it.

 

[Rich Coyle]

In my personal opinion, it's all old wives tales thanks to modern slower-burning magnum powders. If neck length really mattered these days, we would still be using cartridges like the .577/450 Martini-Henry...But we don't.

I used ignorant prejudice at time. This is one time when I'm not. Loney at Hornady used a .22-243 and a .22-6 Rem for a season of benchrest matches. The .22-6, with its longer throat, lasted twice as long as the shorter throat counterpart.

 

[MudRunner2005]

One may have lasted better than another (that could also come down to alloy fluctuations in the metallurgical properties of each barrel, powder, bullet, how hot he shot it, etc...), but I'm not buying that it lasted 2x longer. I'm sure shoulder angle and case shape had a bit to do with it, as well, since the 6mm Rem case has a sharper and shorter neck angle.

If that little bit of a throat length makes that big of a difference, when why does the 7mm LRM and the 7mm Weatherby only get the same barrel life as the 7mm RemMag?

 

[just country]

morning, 6.5x7mmwbee justme gbot tum

 

[highdrum]

morning, 6.5x7mmwbee justme gbot tum

@Longtooth32 had built a 6.5wby as well, necked up 257, necked down 270 don't matter. He's getting 3400+ fps from 150 matching on 28" tube accuracy is there. He's gonna jump up to 160 matrix and see what happens there. I'm curious as to barrel life. Thing would be a hammer. However McWhorter also made a run at the 6.5bee a few years back, 264wm was pretty close in speed.

 

[Sniper97]

How about a 7-300 prc? That seems interesting!

 

[Rhino Hunter]

I'm considering a 7mm for LRH. This is a great thread to learn from! Thanx to all.

 

[Sniper97]

How about a 7-300 prc? That seems interesting!

Any thoughts?

 

[Clark]

I have (3) 7x57, (3) 280AI, (11) 7mmRM, and (1) 7mmSTW

Those are all good, but for bullets I have been using 140 gr Nos Bal Tip, until 2018, when I killed (5) animals with 140 gr Nos Accubond.

They both work.

 

[Sniper97]

Is it possible to break 3000 fps in a 26 inch barrel with a 7rm and a 180 grain bullet?