Been working on a new : HP bullets for target shooting!

[JWFilips]

Hi Folks,
Since I got my 340 Savage 30-30 I have been fortunate to get some nice moulds to try in it from Ben.
He basically sent me his plain based moulds of the Lyman 311291 and the 311467 but the other cavities were drilled for HP's so I retrofitted my "Buckshot" HP pin assembly to fit Ben's moulds!

I did a lot of bench rest shooting in the 1980's with jacketed bullets & i always gravitated to the HP match bullets because of their accuracy potential! Now that I'm only shooting cast bullets in my rifle I decided to try my old 1980's HP concept to cast bullets and Target shooting!
So that became my quest!

Without posting targets ....I have found that the HP versions of Ben's Lyman 311291 and 311467's are far more accurate then the solid versions.

I'm going to to do more testing with photo documentation soon but I wanted to start this thread to get it going.
Mosts folks think of HP'ing a cast bullet is for shooting game! But what I'm saying is that HP'ing cast bullets will improve accuracy on Paper if you are a target shooter!
I will continue this thread!
Jim

 

[freebullet]

Sometimes they require different load configurations to get best accuracy with each. Looking forward to your results.

 

[Ben]

I'm looking forward to this article.

Ben

 

[fiver]

moving the COG will affect flight.
when I design a bullet I try to get the COG to the back so it has the HP balance built in.
HP's are not my idea of a good hunting bullet [if it's something you intend to eat] for the record.

 

[Eutectic]

The majority of my cast bullets are cast 'soft' and are hollow points.....

The majority of my cast bullets are used for hunting.......

I have the ability to hollow point almost any bullet I want to.......

Referring to these statements; I find a hollow point version more accurate at about 80% of tests!
I will use solids (usually) on big game. Varmints and predators get the HP.... Here tissue damage is not a concern; even a good thing for humane dispatch.
Load development is also faster to achieve good results with HP's.

The absolute hardest load development for me is my cast grouse loads. Here, 'minute of grouse eye' (under 1/2 moa) is mandatory as are solids. Add to this the need of that cold fouled barrel putting the first shot exactly in the group.... not even a 1/2" out! I would use HP's for grouse if I could make all 'eye' or even all head shots... But field conditions and longer ranges make me take mostly 'craw' shots! (Above the breast neck shots) We take a lot of abuse in our group if we put a bullet into that luscious breast meat!

Pete

 

[Intheshop]

General ramblings;

I got tired of searching for data on "why" HP JB's were or are the ipso facto on accuracy when dinking sround with my 7-08 EDC CB rig.Yes,I get the swaging process.Reckon the physics of their external ballistics went over this hillbilly's head?

Now,when we got our first metal lathe years ago,one of the first things we started messin with was swaging aluminum arrows to accept "glue on" broadheads.The logic is/was that by eliminating the adapter and insert from the the equation we were in fact establishing a higher alignment potential.Pretty easy once I designed and engineered the tooling.

So,back to....CB's and the notion of no excuses,"perfectly formed" bullets.Swaging or bumping CB's is certainly nothing new.And it does in fact work....the problem is that the process is "static" in a sense.Yes it's dynamic in one(maybe two) plane.But my gut tells me we're leaving right much on the table.With a depth stopped,collet....in a lathe;it would be a simple job to spin swage an existing HP CB.Basically as fast as this is typed.The HP is critical IMO because it allows the tailstock mount swage to move the material around.Abstract;think potters wheel with a hollow "pot" vs a solid lump.

I don't see it a whole lot different from swaging Easton arrows?

 

[Eutectic]

So,back to....CB's and the notion of no excuses,"perfectly formed" bullets.Swaging or bumping CB's is certainly nothing new.And it does in fact work....the problem is that the process is "static" in a sense.Yes it's dynamic in one(maybe two) plane.But my gut tells me we're leaving right much on the table.With a depth stopped,collet....in a lathe;it would be a simple job to spin swage an existing HP CB.Basically as fast as this is typed.The HP is critical IMO because it allows the tailstock mount swage to move the material around.Abstract;think potters wheel with a hollow "pot" vs a solid lump.

Interesting concept you have here Intheshop.... I see it working great too if everything can be held concentric? Would you plan on the collet and 'spin former' having an alignment fit to each other during the spin swaging operation? Or just tailstock to headstock centerline alignment?

Lead is kind of 'sticky' .... so a good lube would be needed. I can see this method being able to apply a short bore ride section to a bullet or even modifying an existing one to size, length... We could increase our repertoire using such a tool. Swaging never hurts a cast bullet either. A lot we don't know about the crystalline structure of lead alloys from casting...

Good thinkin' Intheshop!

Pete

 

[fiver]

sometimes I wonder if it doesn't have something to do with the center of rotation too.
think about if the bullet is slightly off center in it's rotation removing a good portion of the center would lessen the affect.

 

[fiver]

well I know in the inner alloy structure antimony crystals will break down under swaging pressure,
and will let the lead flow over itself a lot easier.
this is why extruded lead [window came/ chemical pipe] has antimony added to it.
it will also move/remove/lessen air pockets if you move enough material to let them flow.

when we fire a cast bullet we are in effect swaging it, only we are doing it from just one end.

 

[Intheshop]

Pete,think potters wheel....it's a feel thing.

The more digital we become....the more we ignore the potential that hands on,manual equipment can provide.So,yes there's definitely skill involved.

Same spin swage idea could be done on our BP(Bridgeport).Now,the swage is spinning and the collet is table mounted.Personal preferences in which works better for the end user?

A shot of dry graphite in the swage and we have a coated nose/bore rider.

 

[Intheshop]

And Eutectic,that first shot...cold bore precision IS,or should be the holy grail to any load as far as I'm concerned,period.

Fred Bear was quoted as sayin that,one shot every day...was more important than any amount of practice regime could come up with?

I took that to heart.For years the only way I could test "groups" was,one shot every day into the same target.It was only after years of that sort of load development that I fully understood how a rifle and it's stock,truly behaved.A fast 3 shot group is well within the capabilities of anyone reading this.My friend Byron Ferguson (trick bow shot),swears 3 is about all we can produce with 100% concentration.Sort of agree.But if you get your chit together,considering firearms vs bows....and you gotta be fast here,a 5 shot group is doable.

 

[Intheshop]

For lathe guys,google Royal collet closer.

 

[Ian]

I would think the center would have the least possible effect on balance. The HP nose increases the stability factor due to CG shift a was discussed. The ultimate CG shift would occur with a lightweight ballistic tip which also moves the CP forward. The amount of split between CG and CP is what determines stability factor.

 

[Intheshop]

The center is part of the balance equation.

It's back to physics.Gyro effects are obviously more controlled by the radius,but that ain't necessarily "balance".

 

[smokeywolf]

One of the first things JW's comments made me think of, was the reduction of unsupported mass. Something that a hollowpoint and bore-rider would have in common.

 

[fiver]

that's what's messed up here.
the part that has the most bearing and strength is also the part we have a tendency to mess up the most.
the least amount we can mess that up going from the mold to the paper [or animal] the better the projectile will perform.

when I had my 150gr. 30 cal swage die made [.905 jackets] I had it made to 3075, then it slopes down to 307 along the longer parallel side.
if I make shorter 130gr bullets the whole thing comes in at 307, unless I expose some lead at the nose then I get a slight amount of 3075 right at the base.

my 31 cal die has a similar taper to it only from 3115 down to 310 but in a more gentle angle, kind of like a loverign design.
I did that to keep the rifling from cutting deeply into the jacket.

 

[Eutectic]

Well.... we've kicked around CG's and CP's and various balance and rotational influence our bullet sees after exit.... But the last couple of posts go back to the start!

So maybe we think....... "You have to enter a building before you can exit!"

Several years back I ordered a 14" T/C Contender barrel from their custom shop. I liked their 8 groove left hand twist barrels (then) I didn't care for the 10" twist but I ordered it.... It was in .25-20...
It arrived and it was 15" in length.... I mounted it to a frame and it wouldn't close on a case! Measuring showed the headspace .003" under minimum. I machined a lapping tool and lapped the rim recess....
Trying both jacketed and cast, 1 1/2" at 50 yards was its best! I was disappointed! The chamber neck was long and the throat was short. I sized a .250" bore ride on some 86gr Remington soft points and was able to get 1" groups..... Not a grouse gun yet! I pulled off the barrel and stuck it in the dark...

I was reading Mann.... Maybe a 100 years back; but that guy is brilliant! He thinks 'out of the box'... Pope and others did breech seating.... I contemplated breech seating that T/C .25-20 barrel. I couldn't dream up a breech seating tool that I liked. S O O O... I pulled out a .25 caliber throating reamer. I throated the barrel deep! It has a 5/8" length of .2585" free bore! I could now shoot 3/4" at 50 yards! But I was seating the bullet first and then a powdered case with a dacron wad. Rather inconvenient to say the least! I put the barrel in the dark....

On a whim I pulled the barrel out and shrunk a sleeve on the muzzle to give it a 16 1/2" length. I mounted it on a T/C frame with a rifle stock. Boy! What a handy, light little thing! I mounted an old Vari-X II 2 x 7 on it.

I got a 10" twist so I played with 85-90 gr bullets with a lot of bearing surface. Seating only .090" in the case I could get over 80% of the bearing surface encapsulated into a 'throat' that was perfectly centered to the bore. The rounds end up outside lubricated not unlike old .22 Long Rifle match ammo!

That 'thing' shoots!!!!!! It will put an 85gr grouse load into a ragged hole at 70 yards! I've got an 88gr center drilled HP full power gascheck load just in case a wolf stops by while grouse hunting.. A little box for 15 rounds of ammo fits my pocket. The 'wolf' load is exactly 1" high from the grouse load at 70 yards. I can switch them back and forth with no affect to their points of impact.

So perseverance, when many would have quit.... gave me a just reward! Note my focus was always 'entering' the building.....

So I guess the moral of this story could be....

"Don't be thinking about what's for lunch...."

"Think about what's going on for launch!"

Pete

 

[JWFilips]

Well I'm totally amazed and interested with what I'm reading ( I am somewhat also totally lost!)
I will continue to learn from this thread i'm sure
Jim

 

[Brad]

Pete, I have to think you are onto something. Makes perfect sense that if we screw up the bullet on launch it matters not what happens the rest of the way down the bore or at the muzzle.

 

[Ian]

The first half inch of bullet travel is just about everything.

I've done a little informal breech-seating of gas-checked bullets and found as Pete did that they shot almost as well as when assembled into properly fitted fixed ammunition....almost. What's the difference? I'm going to throw neck tension out there as an important factor to improving load consistency, especially with smokeless powder. It matters not how straight the launch if the burn curves are all over the map.

Hollow points, having less mass on the front end, dampen yaw faster than solids. This helps make up for the inevitable yaw upon muzzle exit, and I'd have to say just a little bit for center of mass/center of form mis-matches from a slightly crooked launch, but that last part is mostly speculation, or is dependent upon (don't make me say it.....) the thing that makes groups go to pieces at high speed if you allow a crooked launch.