3.7 in AA Drill round

[hangarman]

I have a (potentially) nice 3.7 in AA drill round. The unfortunate bit is the neck of the case is badly flared and I wondered if anyone has any ideas on how to shrink it down to its original size. The projectile is painted a lovely gloss red and blue . What colours would it have been painted originally?
Thanks in anticipation,
Hangarman

 

[Gspragge]

sizing

I have used a Swiss brass cowbell to resize the top 1/8 inch of 37mm casings successfully. Something of that shape but rather immense and a sledge might work. It is the braas of the bell and smooth inside that dosen't cause damage, the slight incline reshape the neck, you need something wider and slowly deeper. A 12 inch bell 18 inches deep might work.

 

[2pounder]

3.7 in or any flared case

The problem with dents or flaring of cases is that if the metal has stretched and so you have to loose the extra material somewhere, dents you cant, with necks then the only real place is forwards and make the case longer and trim back. If you can get a bit of metal turned and bored to make a sizing die this is worth trying but very hard to get to go down the neck squarely if hammering it. Small cases can be got under a press which makes life easier. A skilled sheet metal worker can dress the flare out using a tool called a flipper and manipulating the metal forwards. I've not tried using any sort of big circular clamp like a huge tough Jubilee clip but in theory this should work. Gentle bending with pliers around the rim might reduce a small amount of flaring. Remeber if you anneal the brass it is easier to work but will be easier to stretch and make things worse like increasing the diameter of the neck if striking the brass. Each case needs to be considered as to the extent of damage to be able to pick a method of repair and how much itime and effort and possibley is reasonable. Good Luck.

 

[Falcon]

Interesting post, I can frequently be found in the workshop where I work removing dents from cases with a rubber mallet and a mandrel. I know they never come out perfect, but often the deep dents can be made much less apparent.

 

[2pounder]

dents

I'd always try and improve a dent by pushing it out as far as possible using mandrels or on bigger cases car body type dollies if you can get your arm down the case. Its worth practicing on less interesting ones first. It is a skill you may have a gift for.

 

[Chris 42 RQ]

Case neck flared !

One way of reducing flaring to a case neck is to heat the affected part of a BRASS case to a dull cherry red then allow it to cool off (if you are confident in handling it hot then this is better and quicker) but for most people this can be a risky business, so allow to cool, then you will need a sturdy vice to hold a large bar or tube horizontally and with a small plastic or hide mallet tap the neck back towards the centre of the case, it is important that you hold the case very slightly angled so that the "flared" end is unsupported, so when hit it can be beaten towards the centre of the case.
This process will take a long time and will require re-heating on several occasions to soften the brass case neck.
Even the most severely damaged case can usually be salvaged using this method.

Most importantly visually check the entire case and primer for any traces of explosive matter before proceeding-you never know !

Chris :tinysmile_shy_t:

 

[Falcon]

The technique I have used is heating the case mouth until a blue-grey ring starts to travel down the case, then quenching the case in cold water.

I had a really badly damaged 1893 47mm Hotchkiss case that I annealed with this process then tapped back into shape around a mandrel in a vice, it came out really well. Brass age hardens, so old cases can br brittle.

To give some idea of the damage, at one point in the neck it was dented so badly that what should have been the very top of the case mouth was folded down inside the case neck.