Bore riding and coatings

[nighthunter]

Bore riding bullets are used by most of us to get the most accuracy from our rifles. I'm wondering how the various coatings effect the fit of our bullets nose to our rifling. With most of the coatings we are adding .004 to .005 diameter to what is a critical section of our bullets. Do any of you have any thoughts on this topic?

Nighthunter

[Beagle333]

My .30-30 boolit noses already drop at .301 and engage the rifling as cast, so they will not fit with the coating. I will have to size in two steps. I size the body to .310 and will size the nose back to a .300
Otherwise, you have to get tricky about shielding the nose during spraying/coating, and I have not been successful at that yet, since I am already shielding the GC shank. That makes it more complex than simply "Just stand em nose down in a hole" kinda thing.

[KYShooter73]

My PC ads more like .002 or .003 tops to the total diameter. The nose is coated also, so the boolit would be seated .001 or .0015 deeper. Divide that by 2 because when you measure diameter, you are measuring the coating twice, you are talking about .00075? I can't come close to that kind of seating precision. That's all just my WAG theory. Testing will tell.


Edited....guess beagle know better than my WAG.

[farmerjim]

I cast the Lee c457-500-f for my 45-70 Handi rifle. They are 19 BHN and coated them with green Hi-Tek and GC and sized to .459. Even without the coating the nose is too big, but the coating makes it even bigger. I like this boolit for my gun. It is the only one that will shoot a less than 6 inch group. It shoots almost an all in the bullseye group. All outside of it are my fault not the Boolit or the gun.
I am seating the boolit way too deep to be able to get it to chamber. I want to size the nose only in my old Herters sizer (uses Lyman dies) and then run the entire boolit through the Lee sizer.
If this doesn't work I will continue to load with the boolit too deep because it works.
Attachment 87744Attachment 87745Attachment 87746
Note where chambering has taken the coating off the Boolit.

[Beagle333]

Another option that I have considered, is saving up and ordering an Accurate mold with a .298 nose to begin with.

I have also heard some rumblings about coating the inside of the mold on the nose section with various things to reduce cast nose size... but nothing definite or practical.

[nighthunter]

KYshooter ... you have to add the coating twice as that is the actual diameter of the bullet you are trying to put in the tube. If you add .002 to each side of the bullet you now have a bullet that is .004 larger in diameter.

Nighthunter

[popper]

Farmerjim - I've had a few like that, 308/30-30. Didn't cause any leading or accuracy change. 40SW was a different story. Seems nicks aren't a problem but scraping the PC off the bore rider is.

[farmerjim]

The boolit is shooting excellent in my gun. No leading. It would be nice to recover one of the boolits to see how they take the trip down the barrel. This is the only accurate load that I have found for MY Handi rifle.
My neighbor has a bunch that work fine in his, but they don't work in mine. I am using this load for hunting, but I sure would like to find a lighter load that is accurate in this gun. I sure do like all of these coatings much better than the lubes for me.

[Beagle333]

I may have this figgered out. Right = a .3015 nose boolit.(before)
Left = a .300 nose boolit. (after)


The trick.... a nose sizer in my lubesizer. It holds captive, a .300 (or whatever size you want) Redding nitride-bushing, inside the die. The top punch shoves the boolit down to whatever depth you like (just set the bottom punch to stop somewhere short of the .310 driving bands, I stopped a little short of the crimp groove) and the upstroke pushes the boolit back out with a nice shiny .300-exactly nose! Now, I'm thinking I can coat some boolits and size the bands with the Lee push-thru sizer, and resize the nose with this die. I used lubed boolits for the first pics because that's what I found first when I started rummaging for test boolits.


A closer pic of the die/bushing....


Shove 'er home....


And up pops a nose sized boolit. Now to PC a few (the next chance I get) and see how this works. There is no lube involved here.... there are no holes in the side of the die... I just don't tighten the pressure screw when I use this die, even though the tube is full of CR.


Before.... nose is .3015


After.... nose is .300 exactly. I'm lovin' it!


I could have sized it all the way through the crimp groove, but I don't think it matters. It is well past cleared of where the rifling starts. It should just touch the rifling now.

[Freightman]

Another fix! if you don't have a nose sizer I got some high-temp. 1200 deg. paint and painted the nose section of the mold and let it cure. Now no problem with too large nose. Simple but effective.

[HiVelocity]

Beagle333 (Chuck),

Re: shielding the nose during coating/spraying.

I'm working on developing a baking tray with holes strategically placed to PC and bake rifle bullets upside down, no powder on the bullet from the 1st driving band forward. I'm thinking I can probably do this with a 1 x 8 and simply let the pc dry before baking. Thoughts? Suggestions?

HV

[Beagle333]

HV, see post #1669 on this page. I haven't tried it, but Smoke4320 had a suggestion when mine failed.
http://castboolits.gunloads.com/show...Boolits/page84