bevel base

[41cal]

Is there any benefits to using a bevel base bullet vs a plain base other than easier loading into the case mouth. If sizing in a star sizer would you size base first or nose first?Does it matter?

[44man]

All of the bevel base molds I have played with did not group. Removing the BB from the mold cut groups in half.

[cbrick]

All of the BB I've used were in a 45 ACP and fairly low pressure and velocity, they worked fine for me.

I size them nose first in a Star but then I size everything nose first in a Star. Only one punch per caliber is needed that way and bullet noses aren't even touched much less deformed.

Rick

[dardascastbullets]

Is there any benefits to using a bevel base bullet vs a plain base other than easier loading into the case mouth. If sizing in a star sizer would you size base first or nose first?Does it matter?

It is much preferred to size [nose down] in a Star sizer. The punch is flat anyway and it is detrimental to the nose if you were to obterate it with the punch.

Matt

[Echo]

On the other hand, I always size base-first on my Star. A good nose punch, plus reasonably hard alloy, means no harm to the nose, and NO TAILS on the boolits! The base is the rudder for the boolit (part of the reason BB boolits don't group as well as PB boolits) and I dont want any tails that might not be thumb-nailed off completely. Yes, I know Star suggests nose-first.
Only one nose-punch per caliber is nice, but accuracy is most important.

[cbrick]

On the other hand, I always size base-first on my Star. A good nose punch, plus reasonably hard alloy, means no harm to the nose, and NO TAILS on the boolits! The base is the rudder for the boolit (part of the reason BB boolits don't group as well as PB boolits) and I dont want any tails that might not be thumb-nailed off completely. Yes, I know Star suggests nose-first.
Only one nose-punch per caliber is nice, but accuracy is most important.

???

Tails on the boolits???

Many, many, many thousands of boolits through a Star nose first and I've yet to see "a tail".

100% of my shooting is for accuracy first, anything and everything else second.

Reasonably hard alloy? I also match alloy BHN to pressure, velocity, firearm and action type, not to a nose punch.

Rick

[Larry Gibson]

Concur with 44man; "Removing the BB from the mold cut groups in half".

At one time a commercial casting outfit called Greer (no longer in business) had identical .357, .41, .44 and 45 bullets with and without BBs. I did side by side accuracy comparisons and the PB without the BB always shot at least 1/2 better groups. The BB bullets shoot ok but for best accuracy a flat based bullet is best.

Larry Gibson

[Bass Ackward]

Concur with 44man; "Removing the BB from the mold cut groups in half".

At one time a commercial casting outfit called Greer (no longer in business) had identical .357, .41, .44 and 45 bullets with and without BBs. I did side by side accuracy comparisons and the PB without the BB always shot at least 1/2 better groups. The BB bullets shoot ok but for best accuracy a flat based bullet is best.

Larry Gibson



Interesting. Sometimes it pays to put things into context.

Removing the bevel puts weight back on the rear of the bullet where it is easier to stabilize so it will stabilize at a lower RPM. It also strengthens the base of the bullet for a clean exit without stripping. Or you can say that a PB can be shot softer than a bevel.

By moving the balance point forward, you increase the amount of RPMs required for stabilization unless you counter it by hollowpointing. Same as shooting a GC design without the check. If you find a combination of load and hardness that allows a clean exit where the lower band can hold, then the slug will stabilize, but it will have a lower top end potential because of it. This is why Elmer said Lyman ruined his design when they cut down his front band. IT shifted the balance point back losing flexibility above the barrier.

This also applies to rifles. The bore ride (semi wadcutter for rifles) is the easiest to stabilize, but it has the lowest velocity ceiling for stabilized flight at the top end. A bullet with a central balance will be the most flexible, but balance, when lube is involved, is often very tricky. Use a short, light, nose heavy (forward balanced) design, like an LBT and you have much more flexibility for higher velocity flight that is stable. This is assuming proper fit for all slug designs.

Same logic with jacketed applies. BT spitzer designs generally have to be pushed harder than the same design in a flat base to stabilize and work if you can reach a harmonic node. But hollow point it, and it becomes much more flexible.

[Shiloh]

I prefer flat base. No lube in the bevel. The bevel is supposes to make them easier to load, but on a Dillon press, the cases are belled when they are primed so it's not necessary. Flat or plain base bullets are best for accuracy, bevel base load a fraction easier.

Shiloh

[Larry Gibson]

Bass

Just a note; The AOL of the FB bullets was slightly shorter than the BB bullets. Weight was the same. At normal velocities (standard and magnum where applicable) with the same load velocities were almost identical with any variance being within SD variance. Velocities were within the norm for the twist of the barrels and the bullets used. Alloy and lube was identical as was the sizing. I used the same powders and loading dies for each caliber. Loading was done on the same press with the same dies at the same time. Testing was done with a Ransom Rest. The only variable was the difference in bases. Fact is, without over thinking it, the FB bullets are more accurate than BB bullets. The BB was made to facilitate easier loading, especially with automatic loading machines. As Shlioh notes; most of us don't really have any problem loading FB bullets so the BB'd bullets provide no advantage for us.

Larry Gibson

[Bass Ackward]

Bass

Just a note; The AOL of the FB bullets was slightly shorter than the BB bullets. Weight was the same. At normal velocities (standard and magnum where applicable) with the same load velocities were almost identical with any variance being within SD variance. Velocities were within the norm for the twist of the barrels and the bullets used. Alloy and lube was identical as was the sizing. I used the same powders and loading dies for each caliber. Loading was done on the same press with the same dies at the same time. Testing was done with a Ransom Rest. The only variable was the difference in bases. Fact is, without over thinking it, the FB bullets are more accurate than BB bullets. The BB was made to facilitate easier loading, especially with automatic loading machines. As Shlioh notes; most of us don't really have any problem loading FB bullets so the BB'd bullets provide no advantage for us.

Larry Gibson


Larry,

I figured that you would be fairly thorough. I have been getting some questions on design lately. And what logic I use to get around existing designs, etc.

This was a good opportunity to make folks think with one post instead of humteen emails. Saves on my fingers.

I have never did a one to one comparrison to see for myself as I just don't have the interest. The only time I have any trouble getting a BB to shoot is when they are too light and soft for the caliber and the band strength is affecting my ability to reach stabilization levels.

All things considered, I'd rather have back heavy handgun bullets and a PB beats hollow pointing for speed and effort.

[Larry Gibson]

Bass

Oh, BB bullets shoot alright if they are a reasonable fit as you indicate. The difference was mostly between 2-3" groups for the BB and 1-2" groups for the FB bullets with 12 shots for revolvers and 14 shots for the semi. Many find the accuracy of BB bullets to be just fine for their type of shooting. Others prefer to get the most accuarcy. Just a matter of ones needs. I don't turn down BB'd bullets if the price is right. I actually shoot quite a few of them, mostly in .45 ACP amd 9mm. However, fact remains that FB'd bullets are demonstratably more accurate. I do abhore the hard wax lube most of them come with as leading is common. I most often wash it off and relube with Javelina or just tumble the bullets as is with LLA for lighter loads. I then get no leading at all.

Larry Gibson