Strange bumps on cast boolit from Lyman 311291 on fleabay.

[marvelshooter]

Can somebody take a look at http://www.ebay.com/itm/Lyman-311291-2-cavity-30-Cal-309-170gr-Round-Nose-Gas-Check-Bullet-Mold-/261301149505?pt=LH_DefaultDomain_0&hash=item3cd6c31f41 this mold and tell me what I am seeing. There looks to be about a 1/32" diameter hole in each cavity near the nose and it shows up on the boolits also.

[skeettx]

Those are indexing bumps
Not from the factory, but put on by an owner.
They allow the placement of the bullet at the 12 o'clock position
each time to insure consistency.
Work? Each gun is a different animal
Mike

[Le Loup Solitaire]

A gentleman named Marshall wrote an article that was published in one of the Lyman casting or bullet manuals some years ago. He was shooting 311284 in what looked like a WinM70 and getting good results. He had marked the mold to cast a small bump for indexing purposes and oriented his cartridges always to the same position in the chamber. Strangely enough there was a small insert placed in the article that was written by Lyman which stated that they (Lyman) did not endorse the alteration of their molds in any way. That seemed kind of unscientific to me at the time and still is. LLS

[rintinglen]

Frank Marshall was a nationally recognized cast bullet shooter who won a lot of CB matches and was a proponent of marking his boolits by banging a dent in the nose of the mold. He did so to allow him to precisely orient the boolit to the case, and then the cartridge to the rifle's chamber to minimize the variables in group shooting. He wrote extensively about cast boolit shooting and was very active in the Cast Bullet Association. Many people followed his advice in the quest for extreme accuracy. I suspect that is what we see here in the link to the E-bay auction.

[geargnasher]

I have a .22 mould marked with a file on one cavity half so it leaves pointed flags on the noses. I never understood why there were two marks on one cavity and one on the other, seems one mark on one cavity would suffice for cavity ID, but I guess orientation was the reason for marking both. I tend to reason that if your system needs to be clocked like that, it's time to find the runout culprit, either in the loading process or the rifle's chamber/bore relationship.

Gear

[skeettx]

The reason for the double and single marks:
After casting the bullets are sorted into one mark and two mark piles.
They are then processed separately and loaded in lots.
Mike

[Frozone]

I know the reasons, but the term "bolts snugged down too tight" comes to mind.

[graphic914]

Never saw this before

[bhn22]

I've had a number of molds like this. As long as it wasn't overdone, it hurts nothing. I probably have at least two like that right now.