Berdan Martini shell conversion to Boxer?

[fiatmom]

I have a box of Kynoch 577-450 M.H. rounds that I will shoot ( some go bang others do not) I was going to try to drill out the primer hole insert a bushing and then install a shotgun primer. Has any tried this? A friend did this with old Lebel shells and lg rifle primers and it seemed to work.

[Reg]

Not too sure about using a shotgun primer, might be a bit much. Have made tiny bushings and set berdan primed cases up for regular LR primers and have had good luck. Also some sizes of berdan primers can be reworked to make their own bushings by removing only the center of the berdan primer itself. Seems like there was a thread on here not that long ago that described the process very well. It's a very do able process to convert berdan cases but still not comfortable with that shotgun primer .

[I'll Make Mine]

I'm not sure why a shotgun primer would be too much; lots of folks have converted Berdan smokeless rounds to shotgun primers, and it's also fairly regularly done with brass shotshells (which come pocketed for large pistol). A black powder load in the .577/.450 shouldn't be enough pressure to cause trouble with a 209 -- but if your pockets or Berdan primers are of a size to readily convert to accept Boxer primers in one of the standard sizes, there's no good reason to use shotgun primers which, at the very least, will be less well retained in the brass and may, because they protrude inside the case head, be more prone to leaving a "ring" of unignited powder behind the tip of the battery cup that will burn late, compared to the normal ignition sequence. I don't know what trouble that might cause, but why risk it if you don't have to.

[Lead pot]

Why not just use a berdan primer again?

[Reg]

R.E. , the support of the body of the shotgun primer. Just guessing here but knowing what pressure does, might it be possible that the unsupported part of the primer ( that portion that would protrude beyond the inside base of the shell ) be capable of expanding and in effect "rivet" itself to the head of the shell ????
There would be no possibility of this happening if one stayed with the correct berdan primer or one converted to a LR size.

[fiatmom]

I would have to use a larger bushing than the Berdan primer as Knyoch used a very large primer. The shot gun primer would work . I would just have to ream out the old primer a bit. If I do bush for a lg rifle boxer what would be the best metal ( brass tube?)to use, and would it be a good idea to solder it in place?

[Boz330]

Take a look at the British Militaria board there were guys converting to 209s back before brass was available for boxer primers in the 577-450.

Bob

[I'll Make Mine]

R.E. , the support of the body of the shotgun primer. Just guessing here but knowing what pressure does, might it be possible that the unsupported part of the primer ( that portion that would protrude beyond the inside base of the shell ) be capable of expanding and in effect "rivet" itself to the head of the shell ????

If that doesn't happen firing a primer in an empty case, it won't happen when the case is loaded; the highest pressure inside the battery cup relative to outside (which is what would "rivet" the primer in place) is when the primer charge is fired, before any main propelling charge comes up to pressure; this will happen the same with a loaded or empty case (but for what it's worth, I've converted a few 7.62x54R cases to 209, and fired a smaller number with only an 8 mm airsoft BB projectile, no powder; haven't observed this despite a good 3/32" or 1/8" protrusion inside the case head). If it does happen, you just lose a case; nothing worse there than recycling the Berdan primed brass in the first place (in fact, you got one more use out of the cases).

[Ed in North Texas]

I guess if you just wanted to do it as a project, it is certainly doable. Before Magtech shotshells switched to Boxer priming, some used to convert them to shotshell primers and convert to .577 and .577-450.

But that kind of begs the question of why not just convert the current 24 gauge Magtech shotshells? At $23/25 plus shipping (Graf's), they aren't exactly expensive. I think the conversion to .577-450 is easier (and certainly simpler) than the conversion of the Berdan cases to shotshell primers. But then there is the issue of the challenge involved in the project. So whatever floats your boat - so to speak.

Ed

[Ragnarok]

Yeh....I've been making my Martini brass from 24ga shotshells....not very hard to do.

[C Sharps]

I reload my Kynoch 577-450 with Berdan primers. Not very difficult to do.
C Sharps

[Ed in North Texas]

I reload my Kynoch 577-450 with Berdan primers. Not very difficult to do.
C Sharps

Over the years the difficulty has been in obtaining the proper size Berdan primers, or at least a stable supply of them. As you note, once you have those, the rest isn't much more trouble than reloading Boxer brass.

Ed