PB vs. BB

[sw1115]

Could someone explain the +'s or -'s of plain base boolits verses bevel base boolits. At this point I am casting and loading for .38 .44 .45 and I'll be going to .35 Rem, 7.5x55 and 8x57. Thanks

Skip

[imashooter2]

The largest issue with bevel based boolits is that conventional lubrisizers like to put lube around the bevel. There are several work arounds... modifying the bottom punch, using a gas check or a foam disk on top of the bottom punch, etc., but none are truly satisfactory. Nose first sizing as on a Star or commercial machine or film lube eliminates the problem completely.

Some will claim that plain base boolits are more accurate than bevel base. I'll let them make their case. I haven't seen it though.

[blikseme300]

There are opinions and then there are experiences.

Some will state that BB will always lead. I ask this: Is a ball BB? I have launched many a ball without any leading.

The pressure in the cartridge is equal all over no matter the shape of the base. That the hot gas somehow seeks out the bevel base to cut it is BS. The typical problem is a boolit that is under size. This is when hot gas leaks and cuts the boolit. People need to learn about gas pressure distribution before they voice their wrong opinions.

(My flame suit is on and I don't give a hoot. I have no leading in any of my boom-sticks.)

Bliksem

[RobS]

Yep.....lube on the base of the boolits when using a RCBS, Lyman, Saeco, or even pan lubing. All ready stated there are work arounds but in the end a Star lube sizer is the clear winner. I simply prefer plain base boolits as to a bevel design. Regards to accuracy, I would say with the lower pressure rounds i.e. 45 ACP, 38 special not a noted difference.

[H.Callahan]

Bevel base bullets are, theoretically, easier to start into a case for seating. They also tend to be a bit heavier than the same design in a plain base. This is because the bevel is usually added on to the PB design, using a little bit more lead.

The big down side to BBs, at least to me, are that unless you tumble lube, no matter how you try to lube them, you are forever cleaning lube out of the bevel portion. Given that I, at least, don't find starting a PB bullet in a properly expanded and belled case to be that big of a deal, I generally use PB bullets unless there is no other choice than a BB.

As always, your mileage may vary.

/edit: WOW, 4 responses from the time I started typing this and the time I posted it. Gotta start typing faster!

[sw1115]

I know. I went outside to put some stuff away before the storm and was surprised at the response. Thanks. I'm tumbling everything at this point so the lube isn't a problem but I'll keep this in mind for future mould purchases.

Skip

[Larry Gibson]

Not being critical but informative; "PB'd" includes FB'd, HB'd and BB'd and "healed" cast bullets. It also can include a GC'd design used sans the GC.

Thus there is no difference between a PB'd abd BB'd because it are one.

There are, however, differences not only in design but in performance between BB'd, FB'd, HB'd and healed bullets......if that is the question?

Larry Gibson

[sw1115]

Nope, was just looking for opinions on plain base and bevel base. Being new I wanted to know if the consensus went one way or the other. Thanks for the info.

Skip

[MikeS]

If you're using a Lyman/RCBS/Saeco in/out style lubrisizer BB boolits can be a pain as lube gets in the bevel, and can work it's way below the boolit making for a mess. If you're either using a Star sizer, or tumble lubing, or even pan lubing then there's really no problem with BB boolits. IMHO it's not the small ring of lube in the bevel portion that causes a problem, but rather when the lube gets below the boolit that causes the mess / headaches, that's why it's not a problem with pan lubing. I have a few BB design boolits, and before getting a Star I hated lubing them, not they're the same as any other boolit design. Of course the Star has it's own problems to deal with, but they're mostly a steep learning curve, and so once learned it's no longer a problem.

[leadman]

Many commercial casters buy the Magma BB dies I was told because they release from the mold better than a PB.
Some of Lee's molds are BB but usually smaller than the BB on the Magma molds and I have no accuracy or leading issues with the Lee's.
The commercial boolits are normally way too hard with a very hard lube. Seldom do they fit the gun and they usually do lead.
The Lee 45acp 200gr SWC has a larger BB so I just plugged some holes in the sizer die with lead shot and put pressure to the lube when the boolit was down in the die. This was with a RCBS sizer and it worked fairly well. Also the foam from an egg carton works fairly well but does have to be changed frequently.
If I can get a PB instead of a BB I will.

[fcvan]

I'm not a fan of the little bevel on some of my Lee molds because of the lube-sizer thing. My work-around was to keep the pressure low on the lube reservoir. I lower the handle, apply a little pressure to the lever and then raise the boolit. It took getting a feel for the right pressure but now I do it instinctively. It has even worked when lubing checked boolit deigns without checks. I'm waiting to take these molds to a friend's shop to remove the bevels on some and to plain base a couple gas check molds. Frank

[Bret4207]

My biggest beef with BB is that it's tough to see incomplete fill out on the BB portion. I think this is why a flat base generally shoots better for me than a BB. I prefer PB to BB, but it's not a deal breaker either way.

[44man]

Not being critical but informative; "PB'd" includes FB'd, HB'd and BB'd and "healed" cast bullets. It also can include a GC'd design used sans the GC.

Thus there is no difference between a PB'd abd BB'd because it are one.

There are, however, differences not only in design but in performance between BB'd, FB'd, HB'd and healed bullets......if that is the question?

Larry Gibson
This is the direction I lean. There is a difference in accuracy.
I do not blame the BB for funny stuff, what I look at is bearing length of the boolit to twist and velocity. BB is a boolit that can shoot great from one gun but not from another. Same as leaving a GC off one boolit but you dare not with another.
It only comes down to your gun and the boolit design.

[popper]

incomplete fill out on the BB portion Totally agree, plus flash if the sprue plate is loose or not flush.

[MikeS]

My biggest beef with BB is that it's tough to see incomplete fill out on the BB portion. I think this is why a flat base generally shoots better for me than a BB. I prefer PB to BB, but it's not a deal breaker either way.

I've heard this argument before, and I don't really understand it. When casting BB boolits it's real easy to see if the base is filled out properly by just looking at the base of the boolit while it's still in the mould right after opening the sprue plate. If the base is properly filled it will no gaps, if there are any gaps then the base isn't filled out.

[376Steyr]

+1 on the hard to see if there is partial fill out on a BB when inspecting them cold. Culling them as them come out of the mould is good, but that doesn't always happen when I cast.

[Bret4207]

Mike, that shows that particular section, but it doesn't let you see the whole thing. And that part you are looking at isn't the whole "steering end" of the boolit, it's the part inboard from the actual steering gear, so to speak.

Look at any boolit with lube grooves and find some that aren't filed out completely. It might be a smidgen of a dip here, and slight divot there and a crease over the other way. Same thing with a BB. On a FB you have a right angle, more or less, that's real easy to see. With a BB you have at least 3 angles in play an for the life of me, I have a hard time seeing a ripple here and there. It shows up on the target though. Another plus for the FB is that when you size it and apply some pressure you can help square the base. I don't see that happening with a BB. Either way, it's a judgement call. They can shoot fine or they can be a disaster, same with a FB. I just have a lot easier time seeing the issues on the tail end with a FB.

[williamwaco]

The only disadvantage I am aware of is the lube ring around the bevel. Since I now use LLA, that problem is gone.

I have done some extensive testing of the BB vs FB accuracy issue. This consisted of firing 80 five shot groups, 40 BB and 40FB.

If you are interested in this issue, you can see the results here:

http://reloadingtips.com/pages/exp_bb-vs-pb-accuracy.htm


You might be surprised by the results.

.

[ShooterAZ]

The lube ring around the base of the bevel is simple to wipe off on a paper towel. Just have plenty of them on hand. I have a S&W 625 that absolutely LOVES the RCBS 45cal 185 SWC BB. That boolit shoots so well in that gun that I have no problem (I didn't say I enjoy it) wiping off a little bit of lube.

[45-70 Chevroner]

The lube ring around the base of the bevel is simple to wipe off on a paper towel. Just have plenty of them on hand. I have a S&W 625 that absolutely LOVES the RCBS 45cal 185 SWC BB. That boolit shoots so well in that gun that I have no problem (I didn't say I enjoy it) wiping off a little bit of lube.

The paper towel thing works ok, but I found a better way IMHO. I went down to the carpet store and got a bunch of remnents no charge. I get the lowest nap carpet they have. I cut them up into 4"X5" squares, I use my staple gun to attach them to my work bench right next to the reloading press. I wipe the base of the bullet on the carpet and change it as needed. I can wipe about 500 boolits before I need to change it, and it wipes cleaner than paper towels.

[imashooter2]

The paper towel thing works ok, but I found a better way IMHO. I went down to the carpet store and got a bunch of remnents no charge. I get the lowest nap carpet they have. I cut them up into 4"X5" squares, I use my staple gun to attach them to my work bench right next to the reloading press. I wipe the base of the bullet on the carpet and change it as needed. I can wipe about 500 boolits before I need to change it, and it wipes cleaner than paper towels.

Pure genius. Thanks!

[ShooterAZ]

Agreed, I will have to give the carpet trick a try. Thanks as well.

[Fishman]

The only disadvantage I am aware of is the lube ring around the bevel. Since I now use LLA, that problem is gone.

I have done some extensive testing of the BB vs FB accuracy issue. This consisted of firing 80 five shot groups, 40 BB and 40FB.

If you are interested in this issue, you can see the results here:

http://reloadingtips.com/pages/exp_bb-vs-pb-accuracy.htm


You might be surprised by the results.

.

A very interesting and thorough test.

[Larry Gibson]

Fishman

That was a very well conducted test. It shows with the very minimal BB on the Lee bullet there is little difference in accuracy compared to the same bullet with a true FB. However, we should note that the Lees have a very, very small bevel. The BB on my own soft cast TL358-158-SWC, 356-120-TC, TL41-175-SWC, TL41-210-SWC and TL44-240-SWCs all but disappear if I size the bullets .002 from as cast.

In the past I have rand tests with match revolvers in .38 SPL and .45 ACP comparing FB'd bullets to heavily (as in most other designs and most all commercial BB'd cast bullets). I used a Ransom rest and tested 3 ten shot groups at 50 yards. I've also tested numerous of the same in my Contenders with a conventional rest. The results were always the same; the FB'd bullets were always the more accurate. Sometimes not by much but other times by a lot.

Again, a very good and well conducted test but the caveat should be added that the test is a comparison of the very small Lee BB'd bullets to the same as FB'd bullets.

Larry Gibson

[1Shirt]

Have no problem with BB for handgun, and do like the way they load. On the other hand, the only way I have been able to get acceptable accuracy with BB rifle boolits is at vols in the 1200 fps level or below. Am not particularly enamored with BB rifle boolits.
1Shirt!