Time to make the donuts....

[D Coots]

They measured in the .2438-9 area. 68 gr? Lot 22 for example made on the old die, back in the 70's? Looking back I may have needed more freebore diameter to shoot them. I couldn't make them agg.

 

[brcman]

Dave- I pretty much only shoot flat base bullets (not always) and most 6MM bullets with a flat base generally measure .2433 to .2434, and my reamer was .2434- so really no clearance with regards to freebore diameter. About 2 years ago I went to lunch with Geotge U and discussed this with him and he recommended I get a reamer with .2440 freebore diameter. I had a new reamer made a few months ago with that .2440 diameter.

 

[jcarpen]

Ok. A bullet spinner checks the finished bullet? How does that differ from checking concentricity?

Confused....

Dave-I had a little trouble with this too. Had to go back and re-read Randy’s post on this.

Roundness (TIR) is measured on the outside diameter of the bullet. A BULLET spinner will check roundness.

Concentricity as commonly used in bullet making jargon is a measure of the difference in thickness of the walls of the jacket itself. This can be measured with a JACKET spinner or a good tenth ball mic.(visualize two perfectly round circles having a slightly different axis. They are round but not concentric.

 

[WIB3]

All jacket spinner does is recognize variations in the wall thickness of a jacket. This number is expressed in .0001 of an inch.
the trick is to get an accurate measurement in spite of the inside of a jacket being tapered.

You want jackets with a minimum wall thickness variation so the bullets will be balanced in rotation.
Picture the lead core not being exactly in the center of the bullets OD as the bullet rotates.

There are a few other reasons to strive for jackets with no wall thickness variation, but this is the most important.

It’s like a truck tire being unbalanced. They put weights on the rim to balance it out, but with a bullet spinning way faster, well everyone knows.

 

[Mulligan]

Ok. A bullet spinner checks the finished bullet? How does that differ from checking concentricity?

Confused....

Dave,
Yes in my post I referred to a bullet spinner checking the outside of a finished bullet for concentricity.
What I found was my core-seating process was wonky.

When I make long 6's, I pre-form the jackets in a separate step using different punches with a different adjustment on my core-seat die. After I pre-form a bunch, I readjust the core-seat die and swap punches.

I was using two lockrings and shims to help "keep my place" to where the die should be set for each operation. In the end, I was making crooked bullets because my core-seating die was on a bind in the press due to "redneck engineering".

Not all lock rings are flat!

Clay

 

[WIB3]

Everyone today knows how fast their velocity is at the muzzle, and rate of twist of their barrel. Simple math. Bullets that fall a sleep faster, shoot better. Kind of like a football.

 

[WIB3]

Everyone today knows how fast their velocity is at the muzzle, and rate of twist of their barrel. Simple math. Bullets that fall a sleep faster, shoot better. Kind of like a football.

A 6mm bullet leaving the muzzle at 3000fps in an 1-8 twist barrel is rotating over 100 revolutions per second. Argue with me that an unbalanced bullet doesn’t matter. Testing is quite difficult, mother nature has the ultimate say. And it is quite rare to find uniform conditions for testing. If a jacket is larger on one side it obviously weighs heavier on one side. The cores are all uniform if weighed. There is no discrepancies in weight from side to side. I have gotten out of the process of making bullets, just some insight to what I have learned. Keep in mind I was making BT match bullets, completely different than FB Bullets.

 

[gunsandgunsmithing]

A 6mm bullet leaving the muzzle at 3000fps in an 1-8 twist barrel is rotating over 100 revolutions per second. Argue with me that an unbalanced bullet doesn’t matter. Testing is quite difficult, mother nature has the ultimate say. And it is quite rare to find uniform conditions for testing. If a jacket is larger on one side it obviously weighs heavier on one side. The cores are all uniform if weighed. There is no discrepancies in weight from side to side. I have gotten out of the process of making bullets, just some insight to what I have learned. Keep in mind I was making BT match bullets, completely different than FB Bullets.

Ok....and not arguing, but a serious question....So, what is better, a say 14 twist or say a 12 twist...all else equal?
Lets not forget that the bc may be increased by a bullet that is NOT marginally stable. It's perfectly ok to say that you have NOT tested both ways, but I have. My conclusion is that a little too fast is GOOD...not bad. Too slow is always bad. Again, from testing as well as a national championship...fwiw Which stabilizes faster? One that may never be stable or one that is stable when it leaves the muzzle? Serious question...

 

[WIB3]

and that says it all right there, the bullet that stabilizes the quickest will be less affected by the wind

Thank you George. It’s not an easy path to follow. My advice is to let those who have quality dies and have figured out the process make them for you. SOO much cheaper in the long run.

 

[WIB3]

You are talking 14-12 twist barrels. That tells me PPC. I’m not talking FB bullets. I’m referring to 1000yd BR. It’s a completely different game. There are many bullet makers in the 100-300yd game making Bullets.

 

[D Coots]

spun many on a conventional spinner they had horrible run out over .001

Thanks George. .

 

[D Coots]

Dave-I had a little trouble with this too. Had to go back and re-read Randy’s post on this.

Roundness (TIR) is measured on the outside diameter of the bullet. A BULLET spinner will check roundness.

Concentricity as commonly used in bullet making jargon is a measure of the difference in thickness of the walls of the jacket itself. This can be measured with a JACKET spinner or a good tenth ball mic.(visualize two perfectly round circles having a slightly different axis. They are round but not concentric.

Thanks Jimmy...I had my terms between the 2 confused.

Later

Dave

 

[WIB3]

To get started in the hobby of bullet making be prepared to drop $10,000.00 in quality dies and presses. Than you need to buy components. Than you need a space that is environmentally stable, temperature and humidity. Than you need to figure out the process and willing to sacrifice components for experimentation. If you’re lucky enough to figure it all out you might be competitive. There are very few exceptional die makers that will have a conversation with you and support your future die and punch needs moving forward. Take some advice and buy from those who have figured it out..

 

[gunsandgunsmithing]

You are talking 14-12 twist barrels. That tells me PPC. I’m not talking FB bullets. I’m referring to 1000yd BR. It’s a completely different game. There are many bullet makers in the 100-300yd game making Bullets.

No, I'm talking bullet stability vs all out accuracy. The less stable a bullet is....does it become more or less accurate with distance? IME, the more stable the bullet is...sooner...the better it will shoot at all yardages. Problem is...two fold. First, it takes a faster twist to stabilize long bullets AND, they do NOT shoot as small as short bullets at short range. This is not based on what someone told me or what I've heard from a HOF(etc) shooter...but what I've tested to be true, virtually always.

So, to make long bullets outshoot short ones, you have to first overcome their inherent accuracy deficiency. Yes, I said that! And, it's not a guess!

So, at what point does necessary length(bc) become more critical to all out accuracy? Length dictates twist, right?

fwiw, with the testing I have done with short/mid range BR rifles, twist has very little to do with it...as long as the bullet is stable. IOW...it's hard or maybe impossible to twist too fast...as long as the bullet holds up to the increased rpm.

Once more...this is NOT opinion but test results, with a national championship level sr rifle. Yes, as distance increases, the more we rely on bc to cover our own mistakes. No argument there.

 

[WIB3]

Some of the very best die makers were Neimi and George U. They have retired or are in the process. You can’t do anything better. Purchase good bullets from a personal. Best wishes.

 

[gunsandgunsmithing]

Some of the very best die makers were Neimi and George U. They have retired or are in the process. You can’t do anything better. Purchase good bullets from a personal. Best wishes.

I agree but my comment really has nothing to do with who made the bullet or the dies.

 

[jackieschmidt]

Jackie, You are over thinking that whole thing jacket concentricity is nice but not really what makes great jackets. I have had had hall of fame shooters do a blind test with .0007- .0008 tir jackets with .0001 jackets and d the funny part with three different shooters they all said they really close but the "lot B " bullets shoot a little bit better. They were the ones with .0007 tir...next I'm not a big bullet spinner kind of guy BUT its really usefull for setting dies actually I would consider crucial....

George, there seemed to be confusion among several posters about Jacket spinning and Finished Bullet checking.

I am simply trying to explain the difference.

I quit checking jackets years ago. Back when I made that jacket checker that I showed in post #317, I was out to save the whales. I got over that pretty quick.

 

[jackieschmidt]

And what about bullet spinning?

I guess you mean the Vern Jeunke Machine.
About ten years I had access to one of those for some time. It belonged to the late Nick Marino.

Regardless if what it was telling us, it didn’t seem to show up on the target.
We checked some of Jeff Flowler’s bullets, and the darned needle went crazy.

But they all went in the same hole.

 

[D Coots]

Ha, looks familiar George....

 

[JoeDuke]

Dean, the only shank/base checkers I have are my barrels. Randy has multiple checking fixtures that he uses as Q.C. monitors...starting when the jackets hit his door. When I get a different lot number of jackets, I hit the Easy Button and just ask him how they check out!

Most of us dont have any equipment to measure the finished bullets other than a good mike or two. And we truly are at the mercy of the jacket supplier. We get what we get. So, as Al said above , the best checker you have is that barrel on your rifle. Do the bullets shoot to a competitive level or not.