Bullet question

[Billco]

I'm still fairly new to reloading, and am curious if there is any appreciatable difference in HBRN and FBRN loading. Both plated and 230 gr 45 ACP.

[gregintenn]

Hollow base bullets are designed for the pressure caused by the burning powder to swell the bullet base, causing it to obturate and fit into whatever size bore it goes down, within reason of course. This creats a seal where gas can't pass the bullet in the bore, causing accuracy problems. I don't think the flat base is designed to do this, and is less forgiving as it pertains to bullet size verses bore size.

[glockster157]

Hollow base bullets are designed for the pressure caused by the burning powder to swell the bullet base, causing it to obturate and fit into whatever size bore it goes down, within reason of course. This creats a seal where gas can't pass the bullet in the bore, causing accuracy problems. I don't think the flat base is designed to do this, and is less forgiving as it pertains to bullet size verses bore size.

What greg said is right, however, hollow based bullets are designed to be shot at lower pressures to achieve that obturation(filling out) of the bore. If you push hollow based bullets to hard it can damage that skirt and increase leading, they are designed more for target shootingl. One the other hand, flat based bullets will also fill out the bore under pressure but they need more pressure to do it, so they are more suited for service load/power loads.

[Dolomite_supafly]

Anther thing to consider is the HB will increase the internal case capacity so you may have to up the powder charge a bit to achieve the same velocity as a FB. Always work up and never assume anything when it comes to reloading. People use the HB bullets all the time in 1911's. They seem to say the 185's shoot more accurately than the 230's though.

I am having leading issues with my 1911. I use a cast FB bullet that doesn't seal well even though I am in +P territory. I may have to try some HB bullets to see if I can get a load that doesn't lead the bore. I never noticed they made a HB bullet that would work in a 1911 until you asked, thanks.

Dolomite

[LngRngShtr]

how hollow is the hollow ?

I had some once that claimed to be hollow based,.. but was more of a slight dishing/depression maybe a few thousandths deeper in the center of the base

I wouldn't consider that a hollow base ie: the 148 HBWC for a .38 goes in better than half the bullets length.. if it is a dish base I would treat it like a flat base could you post up a pic or two ?

Be careful when pushing true hollow base bullets fast as you can "blow the skirt" on some designs where the bullet separates leaving the skirt behind,or more accurately blows the nose of the bullet out ... have seen a 148 HBWC do that it wasn't pretty.....pretty much a midrange design but a stout .45 HB would act more like a Minie' ball

Minié ball - Wikipedia, the free encyclopedia

as you can see from the drawing to thew right the hollow goes up into the bullet pretty deep...

John