Small flash holes in 223

[RDavies]

With the benefits of small primers and flash holes in such cartridges as 6BR, 6 Dasher and 6.5x47, I would have thought we would be seeing small flash hole 223 brass maybe. Have any manufacturers tried small flash holes in 223 before?

 

[1raggedhole]

223 already uses small primers and has probably been developed beyond compare. I have a buddy who reloads a bunch for pdogging and uses Fiocchi brass. We noticed a while back that the flash holes are almost never centered, which we thought was crazy and hard to believe that the decapper always seems to hit the hole, and wondered how it could be accurate. His rifles shoot consistently under a half inch with that crap brass, so I guess it doesn’t matter much.

 

[SmokinJoe]

The old subcontracted Lapua from maybe 20 years ago had the small flash hole, but that brass was softer than old Norma.

 

[RDavies]

I wonder how it would go then if they made some of the newer, lighter, tougher brass with small flash holes, whether the ES/SD would come down while still allowing high pressures and velocities as with other small flash hole brass. Getting the ES/SD down with 223s seems to be one of the main problems with getting them to work well at 1000yds

 

[DMC]

I wonder how it would go then if they made some of the newer, lighter, tougher brass with small flash holes, whether the ES/SD would come down while still allowing high pressures and velocities as with other small flash hole brass. Getting the ES/SD down with 223s seems to be one of the main problems with getting them to work well at 1000yds

Hey Rod
The first bags ADI brass I had bought, used the have the small flash hole, latest versions seem to have the normal sized flash hole. Difference also being the first bags were marked “ADI and them a number eg 09 , now there marked ADI 223

 

[RDavies]

Hey Rod
The first bags ADI brass I had bought, used the have the small flash hole, latest versions seem to have the normal sized flash hole. Difference also being the first bags were marked “ADI and them a number eg 09 , now there marked ADI 223

Ok, I just read the ADI brass had .070” flash holes which was an improvement on the standard .080” flash holes, but it looks they they have been changed as you say.
How can we talk Lapua into making some 223 Palma brass?

 

[Laurie]

How can we talk Lapua into making some 223 Palma brass?

That depends on how Lapua and its customers see the role of the 223. As long as it is overwhelmingly used as a sporting and military cartridge, reliable ignition in all temperatures is more important than reduced ES values. Outside of the USA and Canada (maybe Australia too?), 223 is not a primary competition cartridge and is in fact a real novelty in Europe for say serious F/TR shooting. Even in the US, I'd imagine for every 223 round fired in F/TR or similar, there will be hundreds if not thousands fired in informal target shooting on ranges, plinking and vermin / small game. These users (and even XTC shooters) wouldn't thank Lapua for getting decapper pins stuck in undersize flash-holes. Many high-volume 223 users prefer ball powders too for mechanical metering on progressive presses, and the existing set-up just about has trouble setting some of these grades off reliably.

The other potential downside factor is whether 223 would follow 308 in needing a charge weight increase to obtain 'normal' MVs - with some powders I've seen a 1-1.5gn discrepancy between the two types and thnis is apparently due as much to flash-hole size as the change in primer energy. the 308 case has enough capacity to avoid this being a major inconvenience, but the 223 needs every bit of potential energy it can get from the powder charge. The equivalent of a 0.5gn charge reduction could see the MV drop out of the key 2,825-2,850 fps accuracy node with 90gn bullets in F/TR.

 

[RDavies]

That depends on how Lapua and its customers see the role of the 223. As long as it is overwhelmingly used as a sporting and military cartridge, reliable ignition in all temperatures is more important than reduced ES values. Outside of the USA and Canada (maybe Australia too?), 223 is not a primary competition cartridge and is in fact a real novelty in Europe for say serious F/TR shooting. Even in the US, I'd imagine for every 223 round fired in F/TR or similar, there will be hundreds if not thousands fired in informal target shooting on ranges, plinking and vermin / small game. These users (and even XTC shooters) wouldn't thank Lapua for getting decapper pins stuck in undersize flash-holes. Many high-volume 223 users prefer ball powders too for mechanical metering on progressive presses, and the existing set-up just about has trouble setting some of these grades off reliably.

The other potential downside factor is whether 223 would follow 308 in needing a charge weight increase to obtain 'normal' MVs - with some powders I've seen a 1-1.5gn discrepancy between the two types and thnis is apparently due as much to flash-hole size as the change in primer energy. the 308 case has enough capacity to avoid this being a major inconvenience, but the 223 needs every bit of potential energy it can get from the powder charge. The equivalent of a 0.5gn charge reduction could see the MV drop out of the key 2,825-2,850 fps accuracy node with 90gn bullets in F/TR.

Come on now Laurie, don't go bringing facts and reason to this argument.
Yes, the 223 is not normally a competitive cartridge, but then they did bring out 308 Palma brass just for competition and they did change the Lapua 223 bras a few years ago to increase the internal volume.
I don't suppose anyone knows for sure yet whether going to a smaller flash hole will increase primer energy in relation to powder energy, but if it did increase it, then maybe they could switch to milder primers??? If it is a case of the velocity and pressure decreasing, then reloaders could switch to slightly faster and more dense powders such as 8208 XBR? Either way it is a moot point if no one brings out the brass.

 

[Ned Ludd]

If I'm not mistaken, one of the following manufacturers (Alpha Munitions or Peterson, can't remember which; I couldn't relocate the original e-mail info) .308 Win Palma brass uses standard flash holes rather than the smaller flash hole, even though it does use a small rifle primer like other vendors' Palma brass. According to the information I received from them, their testing did not reveal a huge difference between the two flash hole sizes in .308 Win Palma brass.

By analogy, it is possible that the use of a smaller flash hole in .223 Rem cases might make little noticeable difference in terms of ES/SD, or might even even go in the wrong direction. My guess is that for the small .223 Rem case, if you change the size of the flash hole, you must be willing to rigorously test primers over a wide range of brisance to find the specific primer best suited to the flash hole size you're using, regardless of whether it is large or small diameter. I strongly doubt it is simply a matter of making the flash hole smaller and the ES/SD will suddenly magically shrink to similar values across a wide range of different .223 Rem loads and/or bullet weights, such as can routinely be obtained with .308 Win in Palma brass. The fact is, the same primer-based approach can already be used to help minimize ES/SD with the standard .223 Rem case flash hole. It's just that not everyone has the motivation or wherewithal to carry out rigorous testing using a wide enough range of different primers with their current .223 Rem loads.

The size of the flash hole is likely not the sole reason it is more difficult to routinely obtain low ES/SD with .223 Rem cases. Variance in charge weight will have almost twice the effect on velocity as in the larger .308 Win case, and it is likely there are also velocity effects due to neck tension consistency. Large cases generally make it easier to obtain low and consistent ES/SD values, regardless of the size of the flash hole. I'm not saying a smaller flash hole wouldn't have an effect in .223 Rem cases; I'm simply saying that it might not be large enough to make a significant difference. Until such time as someone produces some and actually tests them, it is almost impossible to predict what the magnitude of the effect will be. In somewhat of a catch-22, small flash hole .223 Rem cases also seem unlikely to be on the near horizon unless there is a proven advantage (i.e. - someone can make enough money selling it).