Best LR .30 caliber on .473 bolt face

[Arkansasdad]

My cousin is looking to rebarrel a Rem 721 long action and is wanting the best .30 caliber he can put on this action. Not looking to change the bolt face. He is looking to match or exceed 300 Win Mag if possible. Just share facts and your experiences please. Please don't make this a ,,,,,, contest.

Tell your cousin to save a bunch of money and heartache and go buy an Mark V® Accumark. Cartridges are easy to find and more hump than a 300 WM, plus a lot cheaper than a rebuild. When your done you will actually have something to trade or sell if you want. I have safes full of proprietary calibers and if you don't reload and reshape brass your going to spend a lot of money now and down the road. It used to stroke my ego a little years ago to have the newest trendy caliber but now after thousands of dollars and lots of consideration I advise folks to go with the older, tried and true calibers in a proven rifle. Put the money you save in a better scope than you would have gotten to begin with. Just something to throw against the wall, maybe something will stick, ha... Good shooting.

 

[FEENIX]

This is why I never ask what rifle to build or buy.

 

[TRexF16]

Regarding using the Wby RPM case as the basis for a wildcat 30, I don't think you'd have a problem going form .264 to .308, particularly using the Cream of Wheat filler fireforming method. As a reference, a friend and I designed an built a couple wildcats about 25 years ago that could be considered about like a 338 Gibbs, that we called the .338 Express. We used .280 Rem cases as the basis for it and don't recall ever losing any. It was a huge PITA but I had the wildcat bug and it was fun for a while. We had to neck up to .358, then back down to form a false shoulder, then Cream of Wheat fire form to get the final case. In contrast, forming a "7.62 WBY RPM" would be a one step fireform with a small charge of Bullseye and a case full of COW.

Who knows how well it would feed in the OP's rifle, but I just wanted to address the case creation.

I'm with Feenix that either the basic -06 or one of the wildcats on it that plays with the shoulder is the best bet. Jud96's numbers above with the -06AI and the 205 Berger look real nice and perfectly reasonable. I can't imagine any safe way to achieve the OP's desire of besting the 300WM with a .473 rim except some pretty significantly rebated-case option.

Funny, I just saw the press release about those new rounds adopted by SAAMI three days ago and wrote to my buddy, "Better stand back before the wildcatters trample you running for that 6.5 Wby RPM!"

Cheers,
Rex

 

[Huntz]

As @FEENIX showed above, the Gibbs has nearly 9% more capacity over the standard 30-06. Even if it only gained 4% velocity, if a standard 30-06 does 2800fps with a 180Gr the Gibbs will do 2926fps. In reality the Gibbs is a 150-200fps gain in velocity.

Actually if you load to the pressure the cartridge was intended to be used at you use the 1 in 4 factor which come out to 2.25% increase in velocity and 65FPS more velocity then the standard velocity.Very few improved cartridges if loaded to equal pressures are much of an improvement.How ever most folks who load improved cartridge load until they can barely open the bolt,back off a grain and call it good to go with out having any idea of the actually pressure as they have no access to the strain gauges needed for this.Look a PO Ackleys books and some of the loads he used ,velocities claimed with no access to a chrono.SCARY!!!!!

 

[xsn10s]

This is why I never ask what rifle to build or buy.

Yeah it's to the point I don't even ask for "actual use" anymore lol.

 

[Overkill338]

I'm late to this post, and ita probably already been said, but what about nicking up the 6.5 RPM?

 

[JMW67]

the easiest way to get performance gains will be with the 30-280 ackley neck up some peterson 280 ackley brass and get to shooting it will not be very far behind the Gibbs or sherman this is unless rich has the brass for the sherman ready to go

 

[ntsqd]

So a .30-03AI?

 

[Overkill338]

Actually if you load to the pressure the cartridge was intended to be used at you use the 1 in 4 factor which come out to 2.25% increase in velocity and 65FPS more velocity then the standard velocity.Very few improved cartridges if loaded to equal pressures are much of an improvement.How ever most folks who load improved cartridge load until they can barely open the bolt,back off a grain and call it good to go with out having any idea of the actually pressure as they have no access to the strain gauges needed for this.Look a PO Ackleys books and some of the loads he used ,velocities claimed with no access to a chrono.SCARY!!!!!

Experimenting can get dangerous. I had a load in a 24" Ruger .338 Win Mag that scared me. My cousin brought his chrono over, and the three shot average for a 250gr Partition was 2840. The third shot, the bolt was a little tough, but the velocity told me I was in dangerous waters.

 

[nksmfamjp]

The longer neck for accuracy claim can be very subjective ...

View attachment 227191

(SOURCE: http://bulletin.accurateshooter.com...de-the-box-stan-wares-wicked-no-neck-wolfpup/)

I have only loaded the Berger 190 VLD with powders already opened but I am currently propelling it 2806 FPS with 57 RL-17 out of 24" barrel, 3.34", ES=15, SD=6, and .75 MOA with still plenty of room. Brass was fireformed .35 Whelen just to get me started. I will be trying the .270/.280 soon and see if the additional .046" makes the difference.

Thanks for the education.

 

[Rich Coyle]

Actually if you load to the pressure the cartridge was intended to be used at you use the 1 in 4 factor which come out to 2.25% increase in velocity and 65FPS more velocity then the standard velocity.Very few improved cartridges if loaded to equal pressures are much of an improvement.How ever most folks who load improved cartridge load until they can barely open the bolt,back off a grain and call it good to go with out having any idea of the actually pressure as they have no access to the strain gauges needed for this.Look a PO Ackleys books and some of the loads he used ,velocities claimed with no access to a chrono.SCARY!!!!!

The weakest link in the rifle / cartridge is the cartridge case. If the case is fine then what's so scary?

 

[FEENIX]

Thanks for the education.

As a continuous learner, I enjoy the learning process too.

 

[FEENIX]

The weakest link in the rifle / cartridge is the cartridge case. If the case is fine then what's so scary?

Agreed! The "NUT" behind the trigger remains the biggest factor.

 

[Rich Coyle]

FEENIX,

I will go a step further and say ignorance is a factor, also. When I was a new loader I read about cream of wheat for forming. I weighed out the powder charge and then weighed out the cream of wheat to fill the case as though it were a bullet, but with no bullet. The brass swelled on the belt .170". That is not .017". Of course the bolt had to be beat open with a rubber hammer. The chamber was bulged a few thousands. What I learned was one doesn't load the cream of wheat and wait a week before one fires it.