Month: November 2011

Converting berdan cases to boxer

Posted by on November 29, 2011

My last posting was about priming with berdan primers.    Willie Barnard posted a reply that explains a simple method of hydraulic decapping that he devised, which avoids the need for a lathe turned punch.    The only downside, if it can be called that, is that the pistol case must fit the rifle case within fairly close limits, so it might not work with all calibres.    But then, there are not many berdan primed calibres these days, only the 7.62 NATO and possibly some 5.56NATO.    It is a simple and clever method, and shows what can be improvised when the mind is applied.

Converting berdan cases to accept boxer primers is something done by very few reloaders.    Some of us, including Willie Barnard and I, do it for the hell of it, and because we don’t want to throw away good cases.    But generally, it is a survival measure that you do when you can’t get boxer brass.    In the nineteen seventies, when economic sanctions were imposed on South Africa, we had the strange situation in which boxer primers were imported sporadically despite the sanctions, but boxer cases were all but impossible to get.    It was therefore quite common practice to convert military 9mm brass to boxer.

At first sight, it is simple – you drill a central flash hole, at the same time taking off the berdan anvil.    It is easiest on a lathe, but works well (and faster) on a small drill press with a simple fixture to centre the case under the drill bit.   What about the existing berdan flash holes ?    Doesn’t matter, they are so small that they can be ignored.    A 2mm drill is suitable.    But the drill bit will wander when it contacts the anvil.    I found that a 2mm end mill works better – it machines off the anvil very neatly and drills the hole as well.

Somebody marketed a die that did the job a lot faster.    It looks very like a sizing die, for use in a loading press,  complete with what looks like a decapping pin.    But it isn’t a decapping pin, it is a hardened punch with a perfectly flat end.    In use, it is screwed into the press, and the case inserted into the shellholder,  just as for normal resizing.    The ram is brought up very smartly, and the “die” punches a 2mm hole through the web of the case, and removes the berdan anvil at the same time.    I have one of these – I have no idea who made them – Keith Dyer of Magnum magazine found two of them in a shop in Durban.    Apparently they had been lying around for years – nobody wanted them, so the shop gave them to Keith, who sent one to me because he knew I’d be interested.   I tested it – it works well – the hole it leaves is often a good bit off centre, but that doesn’t matter.   The hole is also ragged, but is easily cleaned up.       

Small berdan primers are 4.50mm (.177 inch) diameter, small boxer are .175, so the boxer primer is a loose fit in the berdan pocket.    In the 1970s the boys filled the gap with nail varnish.    I don’t think that’s too safe with a high pressure cartridge like the 9mmP, but a lot of it was done without trouble as far as I know.     What’s worse, though, is that boxer primers are thicker than berdan.   I measured a few of each, and the average was berdan 2.76mm, boxer 3.22.    Therefore, a boxer primer in a berdan pocket stands proud quite a lot.    It could prevent the slide of a 9mm pistol from closing fully, and I suspect that it was tolerated in a pinch, and that 9mm pistols are all military, with chambers that are generous enough for it to be gotten away with.    But I’m horrified at the idea of a slide closing on a primer standing proud of the case.    I have never heard reports of a problem in that respect, but, all things considered, I consider it a risky conversion to be done only when there is no choice.    

It is an even bigger risk with rifle because of the higher chamber pressures.    Large primers are even looser in the pocket than small primers.    It occurred to me that the berdan pocket could be machined deeper with an end mill ground to the right diameter, but the metal is already quite thin at that point, and would be dangerously thin if reduced by half a millimetre.

I know of at least one individual (a toolmaker) who made up some tooling for pressing something like a ring crimp around the primer pockets of rifle brass.    But it is not a crimp – it reduces pocket diameter for about one third of the depth.   It over-reduces it slightly, then it can be brought to the correct diameter for a boxer primer with a pocket uniforming punch.    That’s a neat way of doing it, but it doesn’t take care of the pocket being too shallow.   Maybe the guy has solved that problem too, maybe I should try to find him and ask.  

But until I get a satisfactory answer, I wouldn’t try the conversion – rather get some berdan primers.

Berdan Priming

Posted by on November 15, 2011

Berdan priming is really an unneccesary chore, but some of us do it for various reasons.   In my case, I couldn’t bear to throw out 300 good once fired cases, so, as berdan primers are still available (occasionally) in South Africa, I accept the chore of loading them.    

Once primed, the rest of the loading process is no different from boxer.    The chore is in the decapping.   There are two methods of decapping, a hook tool and hydraulics.    The only tool I know of is the RCBS.   It hooks into the rim or extractor groove, and a hardened tooth penetrates the primer and lifts it out of the pocket.   I have found it unreliable.  It works only some of the time, and breaks teeth often.    To be fair to the tool, military primers are crimped into their pockets and are very resistant to removal.  

Hydraulic removal is a bigger chore but works better.   At its simplest, the case is filled with water, and a close fitting steel or brass punch inserted into the neck and struck a smart hammer blow.    The hydraulic pressure is  often, but not always, enough to force out the primer.    It depends on the crimp.    On one occasion, half the primers came out easily enough, but the other half were so tight that the pressure bulged the cases enough to reduce them to scrap.    But that was extreme, and usually they come out without damage to the case.

It is a bit messy, but it is only water.   I do it inside one of those plastic cat litter trays.   It also works better with a base for the case.    I use a decapping base from a Lee Loader.    It is nothing more than a steel cylinder with a through hole and a counterbore for the case head.    The punch must be a tight fit, ie tight enough to need a couple of light taps to get it into the case neck.    If it is not tight, the water will squirt out the neck and the hydraulic pressure will be insufficient.

The first job after decapping is to chamfer the pocket with a chamfer tool.    I do that with my boxer cases because it eases priming, but it also removes the crimp from the berdan cases.    Future hydraulic decapping is then much easier.

I prime with a Lee hand priming tool.   As berdan primers are slightly bigger than boxer, they won’t fit into the shell holder.   I polished out the hole of a shell holder to take the berdan primers, and made a new punch to fit the hole.    Fortunately, it is for the 308 Win, which makes that shell holder fit a whole lot of other calibres. 

I haven’t checked whether press mounted primer arms, or ram prime tools, have enough dimensional tolerance to work with berdan primers, but if not, they shouldn’t be difficult to modify.

Small berdan primers are 4.50mm (0.177″) diameter, boxer are 0.175″(4.445mm).    Large berdan 5.50mm (0.2165″), boxer 0.210″ (5.334mm).    Note also different thickness.    Large rifle berdan 2.76mm (0.109″), boxer 3.22mm (0.127″).    As boxer primers are made to imperial dimensions, nominal thickness is 0.125″ so the measured 0.127 is because of tolerance.    Small boxer primers are 0.302 – 0.304mm thick (0.119 – 0.120″).    I have no small berdan to measure, but it can be assumed that they are thinner than boxer.

Sophisticated tools are available for hydraulic decapping.    They work on the principle of equalising pressure by having water inside and outside the case.    The idea is to avoid losing the cases by bulging them.    A buddy of mine made one – it worked very well.

All this is for bottle necked rifle cases.  It doesn’t work too well for short pistol cases like the 9mm or 45ACP, because the case tapers inside, and there is not enough depth for the punch to exert enough pressure.   It will probably work quite well for longer straight cases like 38 Spl and 357 Mag, but I haven’t tried it.

Alox/beeswax bullet lube – what is it ?

Posted by on November 1, 2011

50/50 Alox/beeswax has been the standard bullet lube since the nineteen sixties.    Except, that is, for the increasing use by commercial casters in the last few years of hard wax because it is cleaner and less messy in packaging.

It was developed by Col E H Harrison and his team at the NRA.    Before that, all sorts of concoctions had been used, some more effective than others.   Col Harrison decided that it was high time that something better was developed, that would work well even with cast rifle bullets.    It was a long and thorough search, well documented in his book “Cast Bullets” published by the NRA in 1979.

Success did not come easily.   It was not difficult to find products which prevented or minimised leading, but there was wide variance in accuracy.   It may seem strange that the type of lube should affect accuracy, but it does.   So the quest was for a lube that would prevent leading and also permit fine accuracy with rifle bullets.   Eventually, a particular type of grease made by Alox Corporation showed promise.   But the NRA, not satified with “almost good enough” pressed for further development.   The result was Alox 2138F, which is a thick grease.   

It was found to work best, across the board, when mixed 50/50 with commercial yellow beeswax.   The beeswax is the carrier, and the alox the lubricant.    It quickly became the standard, and is still the best lube for individual use, in my opinion.    But a few years ago, I forget exactly when, Alox Corp was bought out by Lubrizol Corp, and 2138F was discontinued.

It can be duplicated.   97% Alox 350 mixed with 3% Petrolite C-700 microcrystalline wax = Alox 2138F.    Alox 350 is still made, and Petrolite C-700 is made by Baker Hughes Corp.   It is not mixed by simply adding 3% C-700 to 97% Alox.   First mix 7% Alox with the 3% C-700, ie mix 10% of the total as a 70/30 mix.    Then mix that with the other 90% Alox.

There is some difference  of opinion about the exact mix.    One formula recommends 5% C-700.    It is not critical. 

Presumably that is how Lee and others mix their lube.   If not, I don’t what it is that they market as Alox/beeswax. 

When I bought 2138F, the smallest quantity was a 16kg drum.   That’s over one million bullets, so it’s a lot for one man to buy.   But it’s a very practical proposition for four or five guys to share.   A lifetime supply, and very cheap lubing.

Alox bullet lube – why I can’t supply it

Posted by on November 1, 2011

I have had a few requests for bullet lube on this blog and by e mail.  I can’t supply it.  Let me explain why.

In the early days of my commercial bullet casting, hollow lube sticks at retail price were much too expensive, so I imported a 16kg drum of Alox 2138F and mixed it with local commercial beeswax.   It was identical to the commercial product sold be Lee and others at one tenth the cost.  I am not aware of any bullet lube better than 50/50 Alox/ beeswax, even today.  I stopped using it in favour of modern hard wax only because it is too messy for packaging for sale. 

But I had a lot of it left, so I offered it for sale, either in its pure state or mixed with beeswax in big blocks or hollow sticks, for which I made a simple mould.   I didn’t advertise it in Magnum because the cost of such adverts is disproportionately high for the likely sales volume.   I offered it through SATalkGuns, my local club, and what other channels I could think of that wouldn’t cost much.   Two guys bought 1 kg each of bulk lube.   One of my own club members bought a few sticks.   Not one dealer in the greater Cape Town area would buy it.   So I couldn’t sell the 100% genuine product at half the price of normal retail.   I concluded that only branded goods will sell, and the price doesn’t matter.   When I moved to smaller premises recently, I gave it to a friend who likes to experiment.   There was about 10kg, which would make 500 hollow sticks.

Just for interest, I ran two tests to see how far a kg would go.  It averaged 40 000.   90% of my production was single groove 9mm and 38Spl, the remaining 10% being mostly 40S&W and 45ACP.    At the time (a long time ago) the alox cost R320 for 16kg, and local beeswax R25 per kg.    It worked out at 56 cents per 1000 bullets, or 90 cents per hollow stick.   At the time, hollow stick retailed at R11.

Alox 2138F is no longer available as a standard product.  It can be duplicated, but I will explain that in a separate post.