Accurate PC 350 Yds part 1

[Bama]

Depends on barrel. One measures .3000 thousands, another just shy of .3001. If you go up into the higher velocities ie. more pressure you will probably find that all but the very tip will be expanded out to the full bore diameter with full rifling engagement. In all test so far groups suddenly get a lot smaller when expansion occurs.

[ibgp3]

Sounds like it is basically a question of getting a PC'd nose sized to fit into the bore,
...and then pushing the bullet hard enough to get the expansion.
I'm in the process of putting together the tools to try to do a comparable 6.8 SPC.
I'll see how I do at trying to adopt and adapt your method and all of the info you have shared.
Thanks
GP

[Bama]

Everything I have tested so far indicates that up to the point that the bore rider expands to full bore diameter the same parameters apply as a conventionally lubed bullet apply. Bullet fit is the main requirement for accuracy. Powder coating allows us to use the pressure to fully form the bullet to the full bore similar to the old black powder slug guns where a hammer was used to form the bullet to rifling. Fit is still an issue but from what we have seen alignment with bore also is a strong factor. We have started taking the old C&H sliding sleeve bore seaters with the same shoulder angle and boring out to just over the bore rider diameter and short lead to case diameter. If the necks are slightly chamfered you don't have to flare the necks and get almost no run out.

[ibgp3]

Driving bands are .278
Nose is sized to .251 (cause that is what I have).
A die to nose size to .270 is on order.
I think some like these can be PC'd and sent downrange while I wait.
...a crimp type groove to end the nose sizing makes it a lot easier to release.

[Bama]

Looks good. If you tumble lube, PC may add too much to diameter without resizing front section to go full depth in rifling. Good check is to see if it will fit at muzzle--figured that out the hard way!

[ibgp3]

Am I the only one who has found the NOE push through sizers, or have they been tried and found wanting?
http://noebulletmolds.com/NV/index.php?cPath=104
...a wide range of nose and body sizers.
... I ordered 2 calibers for about $75
...off the shelf and due Monday!!
My opinion should be posted here next week.


OOPS - Make that $100 (I forgot the push rods)

[ibgp3]

I was rereading the thread and when I got to Bama's last post I realized that the NOE sizing package will allow a quick adaptation when the PC is thicker or thinner than expected.
I can see nose-sizing one size before PC and another size after.
$17 and a 3 day wait for a new die!!

[Dragonheart]

Am I the only one who has found the NOE push through sizers, or have they been tried and found wanting?
http://noebulletmolds.com/NV/index.php?cPath=104
...a wide range of nose and body sizers.
... I ordered 2 calibers for about $75
...off the shelf and due Monday!!
My opinion should be posted here next week.


OOPS - Make that $100 (I forgot the push rods)

If you need a number of different sizing dies the the NOE system becomes economical. If you only need a few, using sizing dies you may already own from a lube sizer or the Lee push through work quite well.

The NOE sizer system works well and if is says .308 it is .308 not .3085 like the variation one may see with Lee, if that makes a difference. Since the NOE sizing die body stands an inch proud inside the press's work area you have that much less working space in the press; that may or may not pose a problem.

My problem is with the NOE nose sizing. You can size a bullet's bands and get a perfectly round circle. Then you can size the bullet's nose and get another perfectly round circle. As you can imagine, you can lay a nickel on a quarter, which are two perfectly round circles, but that doesn't mean they are concentric to each other. Here in lies the problem, as there is no provision for keeping the bullet's nose or body in alignment with the bands when the nose is sized. So, what you have with this two step process is a non-concentric (lopsided) bullet. A lopsided bullet is not going to be accurate at distance and velocity. If you check the concentricity a quality jacketed match bullet you will find it as about as perfect as it gets.

This subject has been talked about many times and swagging, however it is accomplished, is the only answer I can see as to achieve a concentric bullet.

[ibgp3]

Sounds like "tried and found wanting".
I'll have an opinion soon.
If I test concentricity to the case for the nose and again for the body, will that give me an idea?
Seems like too many variables.

[popper]

If using the NOE nose sizer, got the proper nose punch too. Even after beveling the entrance on mine I get stuck boolits. Lube didn't help any.

[ibgp3]

If using the NOE nose sizer, get the proper nose punch too.

Tell me more,
If I am nose sizing a .270 bullet at .268 do I need a .264 push rod for the pushing the bullet back out?

[Dragonheart]

The nose punch needs to be smaller that the sizing bushing and match the nose design of the bullet, even so as Popper commented you may end up with stuck bullets and/or deformed bullets. I even tried reducing .001" at a time, but gave up on this two step process. I was never able to make a concentric bullet, therefore I was not able to achieve my goal of a PC rifle bullet capable of accuracy at distance with full power loads. After spending countless hours (days) on this project I finally put it on the back burner to make room for more pressing issues. A non-concentric bullet will give reasonable accuracy at short ranges with full power loads, but at distance you will end up with a pattern rather than a group.

I do wish you more success than I had.

[ibgp3]

I do wish you more success than I had.

Thanks.
If I started out to design one based on your input and Poppers, it would look like this:

The bushing would slip fit into the die and onto the push rod.
The push rod would have a slot for the bullet base to fit into.
The bushing would slip onto the push rod and onto the bullet. (1)
The push rod, bushing, and bullet would be pushed into the die (2)
....with enough force to nose size the bullet, but not enough to swage the base.
The bushing would be inverted, the bullet base slot in the push rod
... would get a nose push rod, (3)
... and the bullet would be pushed out of the bushing.

I would expect that to be more concentric than an eyeball line up of the bullet base and the push rod.
... which is what I was doing yesterday.
Would you expect it to be as concentric as the machined aligned fit of the push rod and the bushing?
Would that be more concentric than what you were getting?
Would that be concentric enough?

[ibgp3]

Aha!
What happens when you hit the base hard enough to swage the nose into the barrel?

Concentricity errors are corrected,
.....and groups get smaller!!

[Dragonheart]

Your swagging tool idea would have to be better than what everyone is presently doing, but I think the best answer would be a one step process instead of two. A big part of the problem is we are using molds designed for lube that cast oversized bullets for powder coating. When a mold is several thousands over our desired size and then we build out three thousands of powder coating from the substrate, that leaves us with a lot of metal to move and it has to go somewhere.

Using the barrel to swage the nose is something "Bama" has pretty well perfected by custom fitting the nose of the bullet to fit the lands. However, Bama's powder coated nose riders are starting out the best cast bullet I have seen as far as concentricity. In addition his gas checks are seated about as perfect as one is going to get with a completely flat and perpendicular base. His GC fit is so good after coating it's hard to tell it's a gas check. Actually, Bama is the the one to emulate as he has taken accuracy at velocity with cast rifle bullets farther than anyone else I am aware of.

[popper]

The 'pusher' for the NOE has a hole for a top punch - it doesn't hit the nose of mine without the punch so I used a rod. Not the best way Lots of pressure on the nose to extract. I use a properly sized washer to do what ibgp3 shows, works best.

[Bama]

You may want to consider the design shown in the first post on this thread. Everyone is right about fit and concentricity. They are required to get consistent accuracy at higher velocities. The clamping or screw in portion on the right in the post is long enough and sized to align the bullet with the bushing. The bushings are ½” OD so if you want to change calibers you only change the clamp, bushing, and punch. Bushings do require longer lead in angles both on the entrance and exit end of the bushings which is not hard to change. The length of bore rider portion is adjusted by screwing in or out on die body. A couple of light taps with a raw hide mallet pushes the bullet back through the die. The punch (far left) is matched to bullet using valve grinding compound and a battery powered drill. The sizing before and after corrects a lot of problems. To date I have not found any molds which cast perfectly round bullets but after initially going through the die they seem to be. I believe this allows the second pass through after PC to be forced to be a uniform coating thickness or at least helps in this regard. All the steps do take a little time but not as much as you think. The accuracy, cost, and satisfaction is worth it in my book.

[ibgp3]

In the fifteenth post you qualify your recommendation for a nose sizer with
..."anyone with access to a lathe or has a machinist friend"
I'm not included in that group, so I'm looking for as close as I can get commercially.
The design in post #133 is thrown out there as a solution to NOE problems mentioned by
Dragonheart and Popper, hoping that somebody might adapt and sell them.
[Since everything is concentric, add a gas check seater to the push rod.]

I think we all appreciate the information that you have so generously provided.
I know I do.

[ibgp3]

Before I screw up, are NOE dies suitable for setting gas checks?

[ibgp3]

What should I pay a machine shop to make for me?
How about this?
(1) & (2) will be caliber specific.
(1) will be a slip fit for a loose gas check, to be seated while nose sizing.
(2) will be a slip fit for the push rod.
Drop this starter on the push rod, Start a gas check on a bullet and drop it into the top (1).
...nose size (Seating the GC).
...Drop the starter off and remove the bullet from the nose sizer.

Start the full length sizer with the same starter,
...Pull the starter off and full length size and lock GC on.

Hard set GC?
Aligned nose and body?