What is/ and how do I achieve "nose riding"?

[Dthunter]

I have been thinking about that "nose riding" thing.

I am using a Lyman #311291, 170 gr. Gas checked bullet.
Cast hard. Almost pure Linotype.

Getting a bullets nose to snugly align itself before the rifling fully engauges the bearing bands makes sense.
*I will tell you what I have done so far.
Let me know any ideas or misconceptions I have about this.

First, I tried seating my bullets further and further into the rifling.
I was hoping that I could seat the bullet far enough forward to get the gas check to stay contained the case neck, away from the powder chamber and the combustion gasses.
Seating my bullets about* 0.150" further than I had before, I noticed that as I locked the bolt closed, I could feel the bullet slide/engrave into the rifling.
I lifted the bolt, and had to pound very firmly back on the bolt to open the action.
*
This time the front major bullet bearing band had a clearly defined rifling grooves, AND the bullets nose had clear indication of tapered rifling marks. Is this what we are looking for?
By the way, the noses on my bullets vary between 0.301 & 0.03027" in diameter.
*
I have seated bullets into the rifling before when using jacketed bullets,* and that always made me feel a little nervous about spiking pressure potential.
*
Is this much bullet engraving with the cast bullets "normal" for Cast Bullet precision shooting?
If so, I will go after it, and continue to experiment, and load develop.
*
At this point, the gas check is probably just entering the bottom of the neck. I suspect that* the combustion gases will still get to the side of the bullet base, before, the neck completly encompases the bullets base. But MUCH better than before.
*
Do you experienced cast bullet*target shooters have your rifling machined to allow for this style of bullets, or a custom mould made?
Let me know what you think.

[W.R.Buchanan]

Dt" The nose rider style of Boolit generally has a long nose section that is slightly smaller than the bore diameter. One of the classic styles is Lyman 311299 Which when poured from Linotype comes out with a nose section at .299 and driving bands at .311. Lee also makes a variety of bore rider designs that work well and I have .308-190GC that is a good example which has always provided good accuracy. They also have made 150 and 170 gr versions of that mould.

On most .30-06's and .308's the bore dia is .300 and the groove dia is .308-.310.

I also have Lyman .314-299 which is a slightly larger version of .311-299 and it drops at .302 on the nose end and .312 for the driving bands.

This boolit will not chamber in any of my rifles!As the nose section is .002 bigger than the .300 bore.

And you probably shouldn't do your's that way either. :idea:

You are essentially Plugging the barrel. And the accuracy will probably be abismal if you don't get blown up. The boolit you are using is designed to have a running start at the rifling, It is NOT a bore riding design.

The whole idea of the bore rider style of boolit is that you have a section of the boolit that is being held true to the centerline of the bore and actually in the bore when chambered, while the driving bands seal the barrel and provide both thrust and rotation to the Boolit. The front porton of the boolit is not being engraved,, it is "riding on the bore". This is how it is supposed to work. The idea is there is no wobble imparted to the boolit while traveling down the barrel, thus it should fly strait when it leaves the barrel. Results do vary.

I would contact Al Nelson of NOE moulds and buy a .311-299 mould from his recent run. This is the most perfect iteration of Lyman 311299 anyone has made and is a bunch more better made than any Lyman mould.

I got one coming, and it will drop WW material at .2998 for the bore riding section, which is about as close to a perfect fit you can achieve without actually engraving the Boolit. I am expecting great things from this mould.

In the pics below you can see the difference between the 2 bore rider designs on the right and the non-bore rider boolit on the left. Note the long strait sections of the noses of those boolits as opposed to the non existant strait section on the boolit on the left.. Center is 311299 right is Lee.308-190 and the one on the left is Lyman 311041 which is actually meant for the .30-30. I believe your boolit was originally designed for the .30-40 Krag, hence the long driving band section.

Also note on the loaded cartridge how far the boolit sticks out and yet the driving bands are covered in the case and the gas check is not below the case neck.. The boolit is crimped in the top groove and there is a driving band forward of the case but it is well back from the rifling. When this cartridge is chambered the nose section will be well into the bore of the gun but there is no resistance encountered when closing the bolt as the boolit is NOT being engraved. The only part that will be engraved is the driving bands, and obviously that will not occur until firing. Also note the driving bands will have to jump to get to the rifling which allows for pressure to build gradually as as the boolit moves forward, as opposed to spiking with the plugged bore of a boolit stuck in the bore. The bore rider portion of the boolit maintains alignment with the bore until the driving bands are fully into the rifling.

Hope this helps with your understanding of the bore rider concept. :cbpour:

Randy

[Dthunter]

THIS is the reason I joined up with cast boolits!
I can get the info I need, from the experienced guys!
Thankyou!

Now all I have to do is find another mould ( of bore rider design)
I am going to have a little more trouble finding a mould that is not a Lyman design here.
I live in Canada.
Cast bullet shooting is very rare!
Take care and straight shootin!

[Norbrat]

Surely bullet moulds are not a restricted item in Canada! :???:

You should be able to mail order any mould available.

Another thought is to ask members here for some samples of boolits you may be interested in before you commit yourself to a particular mould

[waksupi]

Check With our member, RedRiverRick. He is a mold maker in Canada. I'm pretty sure he is one of our vendor sponsors here. Check that section.

[Dthunter]

Moulds are not restricted, just very uncommon.
I have never even seen a custom mould.
But would love to get one!

[W.R.Buchanan]

It came today. I'm thrilled.

Randy

[405]

Dthunter,
Since you already have an impression of the leade and first part of you bore (chambered then retrieved round) you can measure that to get the bore diameter of that portion of your bore and some idea about your throat. Then you need to slug your bore to get a better picture of your overall bore and groove diameters. Then when shopping for a proper bore riding bullet/mold you have some numbers to go by.

BTW, in two of my 30-06s, the Lyman 311299 bore rider mold won't drop a nose large enough to be a bore rider. So, I use a 314299 sized to .310 which provides the correct fit for these two rifles. The .310 diameter is perfect for my .309 groove diameter bores and the nose at .301-2 is a perfect fit for my .301 bores.

[Calamity Jake]

There's nothing wrong with the fit of your 311291 boolit.

In a 308 and up size case load 16 of 2400 with the boolit seated to be slighty engraved by the rifling and shoot it, I think you will be supprised by the way it will shoot.

[Dthunter]

There's nothing wrong with the fit of your 311291 boolit.

In a 308 and up size case load 16 of 2400 with the boolit seated to be slighty engraved by the rifling and shoot it, I think you will be supprised by the way it will shoot.

I will get a chance to do some shooting tommorrow and sunday!
Finally! After waiting two weeks to shoot!

I will start with a few loads, testing with IMR SR4756, Trail Boss,IMR4198,Reloader7.

Hopefully one of these combinations will shoot close to an inch-1.25"
I am trying the reccommended starting loads and 2 grains more for each powder.