why dosnt anyone make boat taled CBs?

[rufracer]

Im thinking that with a bt a heavier boolit could be seated into a bottle neck case below the sholder, and since that section wouldnt touch the bore, it wouldnt cause excesive leading as do many cbs that get seated below the sholder.

What do you guys think?

PS

Im new to this so tell me if Im missing something.

[KCSO]

Take a g/c bullet and shoot it w/o a check and see how it does, samo samo as a boat tail. I personaly have never gotten it to work really well. In addition the difference between a boat tail and a p/b bullet really doesn't show up till you get past 300 yards and i just don't shoot that far with mst of my guns.

[Bret4207]

You need a really consistent, round and square base with lead. A BT would allow all sorts of bad things to happen, in theory anyway.

[rufracer]

i know, im going to try loading some CBs backward, and see what happens. Reduced charge of corse.

[oso]

There are plenty of Boattail boolits but it seems most casters put gas checks on 'em as KCSO pointed out. I seat heavier boolits out to fill the throat (and touch the rifling), good fit helps avoid leading. I haven't noticed leading with my loads if the boolit base is below the case shoulder. By the way, a boattail design does not necessarily make the base or the final part of the last driving band out of round or off square.

[oso]

i know, im going to try loading some CBs backward, and see what happens. Reduced charge of corse.

Some boolit designs lend themselves to this and I've tried it myself (looking for better fit in the throat and/or larger meplat) but i wouldn't recommend a bore rider.

[waksupi]

A cast boat tail boolit, will most likely only shoot as fast, and as accurate, as a plain base, non-GC boolit. If that.

[rufracer]

I must have missunderstood something I read in the past on this subject.

How would you guys go about loading a boolit about .3" past the shoulder? Does a gc really help since so much of the boolit is exposed. It will be fired from a 300 whisper at aprox 900-1100 fps w/aprox 8-13 gr case cap.

Would a really long base shank help. .3" long or so.

btw. I wasnt really looking for a better BC, just trying to solve a leading issue involving seating way past the shoulder, but I think now (with your input) that this prob. isnt the solution.

[truckjohn]

The historical main advantage of a Bevel Base was to add effective range for "Volley Fire" and machine guns. If you could get an extra 200 - 400 yards of effective range out of a machine gun for "Suppression fire" -- that is a big advantage against a massed enemy. Think of this... if you could keep an Enemy in a hole out at 1300 yards vs at 700 yards... that gives you a lot more room... and hand to hand is where things get really messy.

For cast boolits, on the other hand.... Mostly, we shoot them in Pistols... and Black Powder rifles operating at much lower velocities. Suppression is not particularly important.

Remember, there are *Zillions* of "Boat Tail" cast boolits....
We just call them "Bevel Base" designs.
Mostly, they are made to make loading easier -- reduce shaving off corners of the boolit base on loading into cartridge. Don't need to put such an agressive flare on case mouths, etc.

Many competition guys use the BB design -- as they are way easier in progressives.

Generally, pistol folks want a smaller BB rather than a larger one.... they are slightly more accurate.

Now, the discussion is different on high power rifles -- where a GC is mandatory.
Most GC's already have a slightly rounded base, but a long tapered design would require a longer Gas Check -- adding more expense.

On the BPCR stuff -- If they could get a BB/boat tail design to give them even a slight advantage.... they would all be using the boat tail designs in competition. Instead, they are fooling mostly with long, elliptical noses and reduced grease grooves.

Good luck

John

[Echo]

It's my understanding that the boattail doesn't do any good until the round slows down to transonic speed. Then it reduces turbulence and drag during the transonic phase of the flight, typically giving more accuracy at long ranges.

[shooter93]

Rufracer...I don't know if your gun is going to be suppressed or not but mine are so I can tell you this much...gas checks are pretty much a no no with supressors. Using lead bullets through one it's handy if the suppressor can be taken apart to clean. Shooting them a lot you will get lube and small lead deosits in them that eventually won't soak out, it does take a lot of shooting though, mine come apart easily so it's never been a concern to me. Smaller rounds like the 300 whisper, I have one of those are a bit tougher with cast bullets I think, Definately harder than the 45/520 we have. Seating the bullet that deep hasn't worked out as well as i had hoped, this depends on the accuracy level you want, so what I decide to do after talking to Veral Smith was to have him make me a mold to cast a 250 gr soft lead bullet. like 30-1 with a small rear driving band and one grease groove that will keep the base of the bullet right at the shoulder junction. There is enough lube for the sub sonic velociteis and I'll re-throat the chamber to take that bullet combo. Makes it a bit of a specialized rifle but suppressed rifles are a speciality gun anyway.

[BOOM BOOM]

HI,
NEI make a mold for a true boatail bullet. IIRC it was a 500gr. 45 cal.
I am not talking a stepped base (as a GC design W/O the GC), or a Bevel base, or even a tug base.
Do not know how it works though.

[Bret4207]

I must have missunderstood something I read in the past on this subject.

How would you guys go about loading a boolit about .3" past the shoulder? Does a gc really help since so much of the boolit is exposed. It will be fired from a 300 whisper at aprox 900-1100 fps w/aprox 8-13 gr case cap.

Would a really long base shank help. .3" long or so.

btw. I wasnt really looking for a better BC, just trying to solve a leading issue involving seating way past the shoulder, but I think now (with your input) that this prob. isnt the solution.

I'm not sure what you're asking, but if I had to load one deep to fit the chamber then I'd just do it. I've loaded some where the GC is way down past he shoulder with no problems at all. And yes, a GC does help- it helps protect the base and gives you a "square" base which is so important on exiting the muzzle and it may act as a scraper to get rid of some accumulated fouling in the bore. Of course if you're shooting a good clean load in the first place thats a moot point.

What is the leading problem you're having? Boolit fit is the very first place to look with leading problems.

[Just Duke]

It's my understanding that the boattail doesn't do any good until the round slows down to transonic speed. Then it reduces turbulence and drag during the transonic phase of the flight, typically giving more accuracy at long ranges.

Corrrect. The boat-tail stabilizes the bullet after it has gone transsonic. This orignally was for 762.59 M-60 round so the guys could theoretically shoot further. But, But!.... 168 grain SMK's out of my M-14's would key hole at the 1000 yard marks so.......;)
That's why guys switched to the 173 in the high power matches. It beat the heck out of a M-14 though.

[rufracer]

Ive heard that gcs are bad w/suppressors. I will be using a coastal supp. so I can disasimble it.

This is for an AR-15 so seating the boolit way out is not an option.

I found out that a lot of my leading broblem was due to the fact that my cases were not expanded enough and were scraping off most of my TL, plus, I realized I was using some lead I had molded 4-5 time, and had removed a lot of antimony in the process.

I may also fire lap my barrel as it is a little rough.

[dakotashooter2]

Keep in mind that in a boat tailed cast bullet, the balance of hardness and velocity will be more critical as you will have more surface area for hot gasses to act upon. You definatly would want to have them reasonably hard and push them hard. I have tried a couple BB bullets in my 41 mag and have little luck in finding a load that didn't lead terribly.