Bullet diameter - How big is too big? 30 BR

J

jimsplce

Member
I'm trying to get started in 30BR, VFS.

I have a new Krieger 1-17 barrel that was marked 300 / 308. What meaning does that have?

AND
My concern is that I have some Lapua 100 grain 30 cal bullets. I have measured them and they measure .3089 - .3090 Is that OK? What do most 30 Cal bullets used for Benchrest measure?

Does anyone have any experience with these bullets and would they be competitive? Their ads claim they are BR bullets.
 
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jimsplce said:
I'm trying to get started in 30BR, VFS.

I have a new Krieger 1-17 barrel that was marked 300 = land diameter / 308= groove diameter. What meaning does that have?

AND
My concern is that I have some Lapua 100 grain 30 cal bullets. I have measured them and they measure .3089 - .3900. Is that OK? YES, that is OK What do most 30 Cal bullets used for Benchrest measure?

Does anyone have any experience with these bullets and would they be competitive? Their ads claim they are BR bullets.
Click to expand...

I have no experience with these bullets but the sizing is correct
 
CIP 30br spec

.300 & .308 refer to the nominal bore size (lands) and the rifling groove diameter respectively.

Interestingly, CIP specification lists a 7.82mm (.3079) projectile max diameter for a 30br whereas for .308 win it is 7.85 (.3085)
 
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I have no experience but the sizing is correct?????
There is a huge difference between .3089 and .3900
Is that a typo Alinwa missed?
 
FBecigneul said:
I have no experience but the sizing is correct?????
There is a huge difference between .3089 and .3900
Is that a typo Alinwa missed?
Click to expand...

It's a fair question but should be directed to me.
It should be .3089 - .3090.

I will change that in my original question.

Whether Alinwa missed it or felt sure what I meant I don't know, but sure appreciated the reply.
 
Yes, I am aware of neck size consideration. My chamber neck size is .330 and I will target .228 for neck diameter.
 
Ok, another novice question.

I'm using Lapua 6BR brass and expanding the neck using a Harrel's expanding die to 30 Cal.

I also have a 7mm mandrel along with the 30 mandrel. Is it beneficial to expand in two steps as opposed to one or is there a down side to doing that?
Also, When I expand the case, I get a slight ridge or doughnut inside the case at the neck shoulder junction. It doesn't interfere with the neck turning, but there is a small ridge. Is it recommended to use a separate reamer. or in my case, a pilot with a cutter to remove it?
I'm aware of the doughnut on the outside, but this is inside.
 
jimsplce said:
Ok, another novice question.

I'm using Lapua 6BR brass and expanding the neck using a Harrel's expanding die to 30 Cal.I would like to propose an entirely different method

I also have a 7mm mandrel along with the 30 mandrel. Is it beneficial to expand in two steps as opposed to one or is there a down side to doing that?There is a downside. Every time you stretch brass and stop it work-hardens. It is generally best to move brass in one motion. When I neck cases up or down so much that it requires multiple operations I find it best to anneal between moves.
Also, When I expand the case, I get a slight ridge or doughnut inside the case at the neck shoulder junction. It doesn't interfere with the neck turning, but there is a small ridge. Is it recommended to use a separate reamer. or in my case, a pilot with a cutter to remove it?I own three different brands of piloted inside neck reamers designed to do exactly what you propose and have never gotten sasisfaction from any of the three.
I'm aware of the doughnut on the outside, but this is inside. Donuts are formed on the inside and need to be ironed to the outside
Click to expand...


OR... to try something completely different;

I find best results via blowing the necks out with an appropriate gunpowder charge instead of mandrelling up...... and then onto a mandrel for turning, a mandrel which pushes the donut from inside to outside and you turn it off the OUTSIDE instead of trying to ream it.


Here's how I would go about making cases for 30BR (having never done it)

#1-load a primed case up to the base of the shoulder with Clays shotgun powder, roll a little wad of paper towel to plug the neck and fire it into the air...NO BULLET!!!

check your results. Add/reduce powder charge.

You might find that you run out of powder room before achieving satisfaction in which case you have two choices, a heavier plug than the paper towel (wax, play-dough, modeling clay) or a faster powder (Win WAALite or Norma R-1)

report back






Meantime, maybe this will spur some of the actual 30BR shooters to respond to your question

We can hope! :)
 
Wayne Shaw said:
The only thing you need to worry about is your loaded round size versus the chamber neck size.
Click to expand...

"And here, you have it" - Wayne is correct. :D
Adding to Wayne's statement, with proper loaded-round/chamber clearance & judicious load development, bullets, up to, at least, .310" diameter work pretty well . . . don't ask me how I know . . .:p Of course, with longer bullets, requiring some free-bore, a wider free-bore may also be desirable.;) RG
 
I agree the ideal way to fire form the case in 30BR would be to have a fire forming barrel and use a fast powder. However, I don't.

I'm guessing that not too many 30BR shooters have fire forming barrels because there aren't that many "shot out" 30BR barrels like in the PPC world.

Right now I'm at the stage of working on getting cases fire formed that have been fired 3 times to send off to get a sizing die made.

For a novice this is a challenge trying to get a custom sizing die without having a die to use for reloading the cases I'm trying to make.

It isn't the first firing that I'm unsure of, it's what to expect for the next two firings.

My concern is having bullet tension for the next two firings without having a die to size the neck to hold the bullet. I'm planning on placing a neck sizing bushing on the case and using an arbor press to create enough tension to at hold the bullet. Is there a better way? The bushing I plan to use is a .328, does that sound reasonable for this operation?
 
If your chamber is 0.330" at the neck and you're aiming for a loaded round of 0.328", you need a smaller bushing. Try 0.324" or 0.325" and seat the bullet long. It'll get pushed back and jam into the lands. This'll hold the case head firm against the bolt face. Just be sure to lube your bolt lugs well.

-Lee
www.singelactions.com
 
jimsplce said:
I agree the ideal way to fire form the case in 30BR would be to have a fire forming barrel and use a fast powder. However, I don't.
Click to expand...

For all reading this who didn't understand my explanation, this IS NOT ABOUT FIREFORMING IN AN OLD BARREL WITH FAST POWDER!

My intent is/was to propose fireforming with SHOTGUN or PISTOL powder and no bullet right in your own barrel. No special preparations necessary.

I'll back out now because this scares me..... I do it all the time but I absolutely know for a fact that pistol powder and a bullet will make you dead. Because I know two brothers of a man DEAD from this.

I'll


STOP
 
For a sizing die just order a harrels br #3 die and have them open it up to a 30 cal for you. In the long run that's what you will end up with so save some time and money and just get the #3 and be done with it
 
alinwa said:
For all reading this who didn't understand my explanation, this IS NOT ABOUT FIREFORMING IN AN OLD BARREL WITH FAST POWDER!

My intent is/was to propose fireforming with SHOTGUN or PISTOL powder and no bullet right in your own barrel. No special preparations necessary.

I'll back out now because this scares me..... I do it all the time but I absolutely know for a fact that pistol powder and a bullet will make you dead. Because I know two brothers of a man DEAD from this.

I'll


STOP
Click to expand...

I obviously wasn't clear in what I said or meant.
I know what you are talking about when using a fast powder and paper towel or wax to fire form. (No bullet)

I do have a reservation about using that method with a new match grade barrel. I'm not comfortable doing that with a new barrel, and since I'm just starting with the 30BR, I don't have old barrels.

From what I've read, I don't anticipate having worn out barrels anytime soon.
I have a fire forming barrel for my PPC, that it is used only for fire forming.
 
I'm pioneering a couple new rounds on my youtube channel, BIG rounds based on the 404 Jeffery case and I've blown a few out in the last few mo just to make cases in brandie new barrels. I clean them immediately (I clean E V E R Y T H I N G while it's still warm. I don't get carbon rings) and can discern not a mark int the bores whereas after only 8-10 normal firings I can see cracking

I've been told all my fireforming life that "fireforming with pistol powder promotes as much wear on the bore as conventionally firing a bullet"

But I no longer believe that.
 
Unless

steve stanley said:
For a sizing die just order a harrels br #3 die and have them open it up to a 30 cal for you. In the long run that's what you will end up with so save some time and money and just get the #3 and be done with it
Click to expand...

You spec a reamer with a FAT back end. I did just that. No matter how much lube I used on the case I got that god awful chatter of the press trying to size the cases. I called Harrels and asked them to send me 2 more dies. A #2 and a #2.5

I should have just went with the 2. That is what I use now. Cases size fine, like they should.

Initially I thought it was maybe my small Harrel press was not stiff enough to size the cases. So I set the die up in my big ole RCBS press. Nope still the same. The die change made all the difference.

Just the experience I had.

Calvin
 
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