Best LR .30 caliber on .473 bolt face

[TRexF16]

Yes, but for a given pressure level, a 9% increase in case volume will not gain 4% in velocity, it will only gain about 2.25% in velocity (25% of the increase in volume). This is just the physics of how cartridges behave.
In Feenix's question above, first, we must recognize a 30-06 will easily do 3000 FPS at 60K PSI, not 2900 FPS.
And if the Gibbs achieved 3285 FPS (which I completely believe it did), it did not do so at 60K PSI. More likely it was closer to .270 Win territory of 65K PSI, which again, I contend was probably perfectly safe. But if the 30-06 basic case had been loaded to the same pressure level with the same powder and bullet (not the same powder charge, it would have been a lower charge to get the same pressure in the smaller case), it would have likely produced somewhere north of 3100 FPS. [EDIT - and I should add, probably just as safely as the Gibbs went north of 3200 FPS - that's kind of my point - the gains noted for "improved" cartridges are mostly achieve by increased pressure, and I write this as an improved fan]

Regards,
Rex

 

[Skimbleshanks]

Opening the bolt face and going to the 300 win mag will be the easiest and cheapest way to get 300 win mag performance. Why push things hard to make something what it's not?

 

[xsn10s]

The OP wanted an increase in performance without changing the boltface on his 721. So with the above suggestions a barrel change and ,maybe dies is all that's needed. If he wanted a 300 win mag just buying a new rifle would probably be the cheapest way to do it. But that's not what he's exploring.

 

[FEENIX]

 

[Lee Goodwin]

A straight .30-06 with a 26"+ 1:9" (just my preference) is no slouch. Depending on what your cousin is willing and able to do i.e., wildcatting/fireforming. AI version is another consideration and probably the best improvement with the least amount of work. I have a .30 Gibbs (https://www.longrangehunting.com/threads/30-gibbs-is-finally-ready.242088/) that I am still developing loads.

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Good luck!

Ed

That 30 Gibbs looks interesting

 

[David Emerson]

Alot of good ideas here. I like the Weatherby RPM case idea except I'd be incline to neck up to a 7mm rather than a 30 cal. Only because it seems like a long way to stretch a 6.5mm neck. I've been thinking of a long throated 30-06 with 26-28" barrel. You can get close to a 300 WM, but equal or exceed is a pretty big jump. I'd say to get the best chances to get to your goal do a Sherman or Gibbs with a high quality 28" barrel. I'll probably do a 26" standard 30-06, if I get 2800-2900 fps with a 215 gr Hybrid I'll be satisfied.

I had a 348x450 AI. Neck up a 348 case to 45. No problem and that is a big stretch.

 

[Husky user]

Weatherby has RPM brass,50 for $83 +freight.
Or once fired $1 each+frieght.

 

[xsn10s]

I had a 348x450 AI. Neck up a 348 case to 45. No problem and that is a big stretch.

That is a big stretch, but it's not the same case. It could work and it could be a good fit for the OP. My personal opinionit would be a better fit for a 7mm bullet. I think the capacity would be right inline with a 7mm RM. But the OP wants a 30 cal. For me, maybe not the OP, I'd just go with a standard 06 or an AI. But I like to keep things simple. If the OP wanted to try and get to actual 300 WM speeds a Gibbs or your idea probably are on the top of the list while sticking with the original bolt.

 

[ntsqd]

IF opening the bolt face was an option (I'm fully on-board with it not being for what ever reasons the OP has, those are personal and that is fine) then I'd say that the .308 Norma is the better choice because it was designed to fit and function where a .30-06 was.

Changing the question around a bit, possible to use a mag bolt face 700 bolt in a 721? If that could be made to work then it opens up a LOT of options while preserving the original bolt.

 

[xsn10s]

IF opening the bolt face was an option (I'm fully on-board with it not being for what ever reasons the OP has, those are personal and that is fine) then I'd say that the .308 Norma is the better choice because it was designed to fit and function where a .30-06 was.

Changing the question around a bit, possible to use a mag bolt face 700 bolt in a 721? If that could be made to work then it opens up a LOT of options while preserving the original bolt.

I've heard people have put a 700 bolt in a 721 and it "functioned". I haven't heard of anyone actually firing a 721 with a 700 bolt. I think if I were going to get another bolt I'd just get a new rifle chambered in 300 win mag.

 

[pacowboy]

Just for a little more clarity the gun in question has a 6.5-284 barrel on it now. He would like the option to go back to that if he chose to. He is wanting a better long range option for bear and deer out to 1k.

 

[Jud96]

Just for a little more clarity the gun in question has a 6.5-284 barrel on it now. He would like the option to go back to that if he chose to. He is wanting a better long range option for bear and deer out to 1k.

Tell him to load some 156 Berger's in that 6.5x284 and he will have less recoil than a .30cal and have very good ballistics and similar energy on target compared to an improved 30-06. Just my thoughts.

 

[xsn10s]

Yeah I'd have to agree that for deer and black bear he may want to look at the 156 Berger thread. I'd pay attention to Greyfox's posts on that subject. He's got a lot of experience with the 6.5x284.

 

[Jud96]

.30-06 Improved 205gr Elite Hunter 2750fps

6.5x284 156gr Berger 2900fps