Burnside Conical Diameter Question.

[rcbloom2]

What should conical bullets be sized to? Also, to fit in the cases, don't the bullets have to be a certain diameter in order not to shave them in brass cases? If I have a mold made what diameter should I have the mold made to? .556 like the Rapine mold? Do the brass cases expand upon firing to a larger size? I measured my new cases .550 diameter, would not .556 bullets not fit or lead be shaved off? Thanks in advance.

[ms3635v]

The original Burnside is .562" in diameter. The Rapine bullet is not the correct diameter and is shorter than an original (the bullets cast from the Rapine mould drop from the mould at about .556"). The Rapine bullet also will tumble in flight because of its diameter. You can use a .560" round ball also.

[rcbloom2]

The original Burnside is .562" in diameter. The Rapine bullet is not the correct diameter and is shorter than an original. The Rapine bullet also will tumble in flight because of its diameter. You can use a .560" round ball also.

Accurate Molds will make me a .562 mold. Now is there an issue with seating them in the cases since mine seem to measure at .550?

[Hal]

I'll have to say .550 seems quite small to me. Mine are more like .556 or maybe a little bigger. Been a while since I measured them but I bought a .556 mould based on my case ID. It's hard to measure a slug or chamber cast with an odd number of grooves, but I believe my .556 bullets to be undersized for my barrel and also feel that is the reason I can't get it to shoot very well. After having gotten the mould I discovered that chambering the brass will crimp the cartridge lip somewhat, so I believe my cases are actually a bit larger than .556 on the ID and that the .556 was being measured on a crimped lip. But I digress....In my opinion, .550 ID cases sound way undersized to me.

[rcbloom2]

I'll have to say .550 seems quite small to me. Mine are more like .556 or maybe a little bigger. Been a while since I measured them but I bought a .556 mould based on my case ID. It's hard to measure a slug or chamber cast with an odd number of grooves, but I believe my .556 bullets to be undersized for my barrel and also feel that is the reason I can't get it to shoot very well. After having gotten the mould I discovered that chambering the brass will crimp the cartridge lip somewhat, so I believe my cases are actually a bit larger than .556 on the ID and that the .556 was being measured on a crimped lip. But I digress....In my opinion, .550 ID cases sound way undersized to me.

My problem is going to have to fit .562 conicals and round balls in brass cases that are .556 in diameter without shaving. I wonder if the nylon cases are more forgiving. Not surprised if the cases are crimped to create a seal when chambered. I can get a .562 mold from Accurate Molds, the 540390A is for the Burnside and you can request the diameter you wish.

[John Holland]

If you are willing to have a custom mould made, have it made with a rebated base with a diameter that will fit your case mouth.

[rcbloom2]

If you are willing to have a custom mould made, have it made with a rebated base with a diameter that will fit your case mouth.

Good idea. Thank you.

[Hal]

I'm going from memory here, but as I recall, most, if not all of the bearing surface of a Burnside bullet goes down inside the case.

[John Holland]

Hal - You are correct in regards to an original Burnside cartridge. The problem today is that the cases are machine turned from solid bar stock, which necessarily leaves heavier case walls which in turn causes the inside diameter to be too small. The original deep drawn very thin brass case walls provide enough clearance for the correct diameter projectiles.

[rcbloom2]

I was thinking that the case mouths expanded upon firing like modern cartridge cases, thus allowing bullets of greater diameter to be seated. I was also thinking I could anneal them before firing so expansion of the case will be easier. The nylon cases do stretch a bit.

[Carolina Reb]

The case mouths will expand if you anneal them. Depending on your chamber dimensions the fire-cold water quench method may leave them too soft and cause problems. The lead dip method is safer. It isn't as extreme, so takes two or three shots to expand the necks fully.

[noonanda]

another option is to use the plastic cases sold by lodgewood, then all you need is to just use a little bit of leverage and .562/.563 bullets will fit in

[toot]

I get mine from TOTW, .562 RB, they work fine.

[Hal]

I see a lot of people on here who seem to have good results with the plastic Burnside cases. When I first got my Burnside, probably 5-6 years ago, I bought 10 each of the plastic and brass ones. The plastic ones lasted exactly one shot. The thin rim at the mouth of the case melted. Now I suppose I could TRY to reuse them like that, but....................

I now have 100 brass ones.

[noonanda]

I see a lot of people on here who seem to have good results with the plastic Burnside cases. When I first got my Burnside, probably 5-6 years ago, I bought 10 each of the plastic and brass ones. The plastic ones lasted exactly one shot. The thin rim at the mouth of the case melted. Now I suppose I could TRY to reuse them like that, but....................

I now have 100 brass ones.

I had one plastic case melt, all the others have held up