30BR, 4198, 112's and Other Stuff

[longrange223]

start at about 31.3 grs of the tubal & work your way up,i use 31.85 with a 115 gr bullet,wouldn't go above 33grs,some are but it's awful hot & hard on brass

 

[Al Nyhus]

'Morning, Charles.

The accuracy 'peaks' (I didn't say 'nodes'....) seem to occur at 60-75 fps. intervals with the 30BR and Hunter capacity (45.0 >) cases. The exact velocity level where these happen will change a bit with each barrel but the interval 'stairstep' remains pretty constant. I shoot my HV 30BR around 3020, my LV 30BR at 2980 and my 30 WolfPup around 3180 with a 1.00" jacket non-coated 117's.

When going from one step to the next, all three of my .30's show the same trait....first I notice about half a bullet of vertical, add another .3gr. of powder and I get a full bullet of vertical, tip the can another .3 gr. and the vertical comes back down a half bullet, then another sprinkle of powder and it's back to one hole. Add more powder and repeat. My approach is a lot of neck tension (.004-.005), a good amount of jam (.025-.030) and keep tipping the can. I use a bit more neck clearance than most and consider this the biggest single area that gets people into trouble....people can connect those dots as they see fit.

I've yet to have a single .30 cal. barrel that doesn't follow the same pattern, whether they're Hunter or LV taper.

Good shootin'. -Al

 

[Al Nyhus]

Aren't the groove diameters larger on the Rock than the typical 308 barrel?
Butch

Butch, the dimensions for my 17 twist Rock are .3080/.3000 as suggested by Paul Tolvstad at Rock. He and James Lederer are pretty accomodating guys over there and have these .30 barrels well sorted out.

Whether there is a 'standard' groove dimension or not, I can't say. -Al

 

[Butch Lambert]

Al,
That sounds like a standard dimension to me. My Kreiger and Shilen measure 308 and 300. I just heard a rumor.
Butch

 

[Charles E]

Thanks for the replies Al & Randy -- 'bout what I thought. We all need to remember that "such & such a velocity" is insider shorthand, otherwise there'll be a host of shooters trying to use a chronograph to tune their factory & hybrid rifles.

BTW, my barrel blocked .30 BR likes different numbers . . .

 

[Joe Duke]

neck tension

Al, when you say " My approach is a lot of neck tension (.004-.005), ", do you mean for instance that in a .330 chamber, you are using a .325 to .326 bushing or do you mean with a .328 neck, you would use a .324 to .325 bushing?

Thanks,
Joe

 

[mike in co]

jackie,

is your reamer a 6br necked up to 30...with std 6br sides(case taper)..? or ??

mike in co

 

[jackie schmidt]

Mike

Yes it is.In fact, it is nothing more than Randy R's Reamer Grind with the only change being a overall trim to length being 1.550.......jackie

 

[Al Nyhus]

Al, when you say " My approach is a lot of neck tension (.004-.005), ", do you mean for instance that in a .330 chamber, you are using a .325 to .326 bushing or do you mean with a .328 neck, you would use a .324 to .325 bushing?
Thanks,
Joe

Joe, I size the necks .004-.005 under what a loaded round measures. In other words, if a loaded round case neck measures .328, I'd be using a .324 or .323 bushing.

I run .004 neck clearance in both my 30BR's (.326 loaded neck dia/.330 chamber). My bushing sizes are .322 & .321.

Good shootin'. -Al

 

[Jeffreytooker]

Proper Way To Make 30 BR Brass

Since I didn't get to make the trip to Denton, I decided to spend today working with my new 30BR effort.

This is the one that I had Dave Kiff to grind me a reamer that utilizes the full length BR Case. As many know, since we blow our caes out rather than neck them up with a mandrel, they retain much of the originol length.

I just had Dave Kiff grind me a reamer that is a direct copy of the Robinett zero freebore, but with a trim to length of 1.550.


Jackie and All:

The quote above talks of making brass by "blowing it out". I will be making my brass from 7 BR Rem untill I can get some Lapua. For 6 BR I have been told to open it to 7 with a .284 M die, then to 308 with a 308 M die then FF. You seem to be talking of a different method.

Jeffrey Tooker

 

[David Halblom]

Jeff,

Since I didn't get to make the trip to Denton, I decided to spend today working with my new 30BR effort.

This is the one that I had Dave Kiff to grind me a reamer that utilizes the full length BR Case. As many know, since we blow our caes out rather than neck them up with a mandrel, they retain much of the originol length.

I just had Dave Kiff grind me a reamer that is a direct copy of the Robinett zero freebore, but with a trim to length of 1.550.


Jackie and All:

The quote above talks of making brass by "blowing it out". I will be making my brass from 7 BR Rem untill I can get some Lapua. For 6 BR I have been told to open it to 7 with a .284 M die, then to 308 with a 308 M die then FF. You seem to be talking of a different method.

Jeffrey Tooker

What Jackie is talking about is using the parent case, in his case a 6BR Lapua, and filling it w/ powder and putting a 6MM bullet on top and shooting it in a 30BR chamber in a 30 caliber FIREFORM barrel, not his competition barrel. This will yield a longer case right off the bat rather than the impact/pressure shorten case that you get when you use an expansion mandrel to neck up the case. This method also yields a case that is chamber straight right off the bat and the cases seem to neck turn a little cleaner and straighter

David

 

[Jeffreytooker]

FF Barrel

What Jackie is talking about is using the parent case, in his case a 6BR Lapua, and filling it w/ powder and putting a 6MM bullet on top and shooting it in a 30BR chamber in a 30 caliber FIREFORM barrel, not his competition barrel. This will yield a longer case right off the bat rather than the impact/pressure shorten case that you get when you use an expansion mandrel to neck up the case. This method also yields a case that is chamber straight right off the bat and the cases seem to neck turn a little cleaner and straighter

David

David thank you for your reply. I can see right now I need to get a 30 Robinett reamer and go nogo gages from PTG. I have an old rough (rusty) barrel blank with an acceptable bore .308 10 twist. I also need to know how well my local gunsmith can chamber a barrel. I can put it in an old 98 action and stock that I have. That would give me a fireforming rifle, and check out my gunsmith. I would think that the reamer would have to have a longer neck. The stock 30 Robinett from PTG LOA for the case is 1.525". IIRC Jackie said he had his reamer neck cut to 1.550". Does this allow for neck length when FFing?

Jeffrey

 

[David Halblom]

in a word

David thank you for your reply. I can see right now I need to get a 30 Robinett reamer and go nogo gages from PTG. I have an old rough (rusty) barrel blank with an acceptable bore .308 10 twist. I also need to know how well my local gunsmith can chamber a barrel. I can put it in an old 98 action and stock that I have. That would give me a fireforming rifle, and check out my gunsmith. I would think that the reamer would have to have a longer neck. The stock 30 Robinett from PTG LOA for the case is 1.525". IIRC Jackie said he had his reamer neck cut to 1.550". Does this allow for neck length when FFing?

Jeffrey

Yes. If you are ordering a new reamer, then ask Kiff for the latest Schmidt reamer. Or maybe Jackie can post the print number here so there is NO CONFUSION.

David

 

[Jeffreytooker]

What Jackie is talking about is using the parent case, in his case a 6BR Lapua, and filling it w/ powder and putting a 6MM bullet on top and shooting it in a 30BR chamber in a 30 caliber FIREFORM barrel, not his competition barrel. This will yield a longer case right off the bat rather than the impact/pressure shorten case that you get when you use an expansion mandrel to neck up the case. This method also yields a case that is chamber straight right off the bat and the cases seem to neck turn a little cleaner and straighter

David

David:

Will 30 BR cases formed by th mandrill method make 1.515" case overall length?

Jeffrey

 

[David Halblom]

I am not

David:

Will 30 BR cases formed by th mandrill method make 1.515" case overall length?

Jeffrey

the best one one on 30BR's. I do NOT know all the dimensions at one end or the other by heart. But.....The mandrel cases will be shorter than the blown out cases. And Jackie says the blown out cases are 1.550. So I suppose the shorter length is reasonably close to what a fireformed mandrel case will be. That is somewhere to start


David

 

[LHSmith]

David:

Will 30 BR cases formed by th mandrill method make 1.515" case overall length?

Jeffrey

Yes, using a K& M one step mandrel ( 6mm to 30 in one pass) on Lapua 6 BR brass I actually get most at 1.522.......but still trim to 1.515 prior to fireforming and am able to maintain 1.515 after F.F.

 

[jackie schmidt]

Jeffery

The way I make my brass is this.

I took a standard worn out 6BR Barrel and ran a .330 reamer into the neck. This, more or less, is a 30BR chamber with a 6mm bore in front of it.

I then simply shoot a fully loaded 6BR case in that barrel. What comes out is a "Factory" 30BR with most of the originol length retained.

I then neck turn, and for all purpose, they are ready to go to the line.

I make cases this way because it is so simple. You can screw that barrel on your Rifle, spend a hour at the range firing forming them, and you have cases that are dead straight.

This is also perfectly safe, as you are shooting a 6mm bullet down a 6mm barrel, as opposed to our shooting the 22 bullet in a 6mm barrel to make a 6PPC from a 220 Russian...........jackie

 

[Jeffreytooker]

Fire Form

Yes, using a K& M one step mandrel ( 6mm to 30 in one pass) on Lapua 6 BR brass I actually get most at 1.522.......but still trim to 1.515 prior to fireforming and am able to maintain 1.515 after F.F.

LH:

You have confirmed the process I am going to use. I have the K&M outside neck turning tool but not the one step mandrel. Thank you for answering the length question.

Jeffrey

 

[Jeffreytooker]

Making Brass

The way I make my brass is this.

I took a standard worn out 6BR Barrel and ran a .330 reamer into the neck. This, more or less, is a 30BR chamber with a 6mm bore in front of it.

I then simply shoot a fully loaded 6BR case in that barrel. What comes out is a "Factory" 30BR with most of the originol length retained.

I then neck turn, and for all purpose, they are ready to go to the line.

I make cases this way because it is so simple. You can screw that barrel on your Rifle, spend a hour at the range firing forming them, and you have cases that are dead straight.

This is also perfectly safe, as you are shooting a 6mm bullet down a 6mm barrel, as opposed to our shooting the 22 bullet in a 6mm barrel to make a 6PPC from a 220 Russian...........jackie

Jackie:

I now understand the process. I have no 6mm barrels. So I think I will try the mandrel method to start. I will probably revisit this issue at some time.

Next problem, bullet weights. For the barrel I am getting 112-125 gr bullets will work. They will all shoot well with proper load development. How does one choose a bullet weight?

Jeffrey

 

[AVanGorder]

... For the barrel I am getting 112-125 gr bullets will work. They will all shoot well with proper load development. How does one choose a bullet weight?

Jeffrey

115GR is probably the more popular in the 30BR.

Adrian