Oversize Flash Holes

[alamogunr]

I've been using a batch of mixed headstamp brass that I bought as 1X fired for plinking and semi-serious practice. I had a small group of decapped brass sitting on the bench and decided to check the primer pockets to see if they were too gunked up. They were but something else jumped out at me. There was some variation in flash hole size. One was very obvious. Three samples were:

#1 #30 drill approx .1285" WW headstamp
#2 3/32 drill *I* "
#3 5/64 drill RP "

I have to say that all these are approx within the limits of my collection of drills. The cases with 5/64 flash hole were much the majority.

Is this normal? I don't recall seeing any as large as a #30 drill but have to admit I don't check closely.

[retread]

I've never really checked for flash hole variation but I do know that I have enlarged some in the past for shooting wax bullets with primer only. Makes for more umph with wax.
Marked them so they would not be used for anything else.

[Mike W1]

I/ve never checked flash hole size as I only use new brass. Seem to recall that when they used to load wax bullets with just a primer for propellant they drilled out the flash holes to a larger size. Think it had something to do with the primer backing out if they didn't do so.

[Zymurgy50]

an empty case with no powder or boolit, when fired in a revolver, will lock up the cylinder about half of the time in my experience.
got a box of the speer plastic 38 bullets years ago and did not know to drill out the flash holes............ figured it out pretty quick though

[alamogunr]

It sounds like the case with the large flash hole may have been drilled out for shooting wax bullets. I wonder if there is any risk in using such a case for a regular round? I'm not going to find out.

[Scharfschuetze]

I drill out the flash holes for all my squib loads in bottleneck cases. That way the case maintains it's proper headspace without shrinking from the low pressure loads. Sounds counterintuitive I know, but the factory diameter flash hole keeps the pressure from the primer in the primer pocket and that pushes the case forward into the chamber's shoulder. That primer pressure is apparently stronger than the squib load's powder pressure in the main case and thus the shrinking case phenomenon. The enlarged flash hole precludes that by allowing the primer's pressure to escape into the case and cases thussly maintain their HS dimensions.

I mark and keep those cases segregated as a matter of course for the sake of ballistic uniformity.

As noted by other posters, drilled out flash holes for revolvers was quite common at police academies and police departments back in the revolver days. We often used movies film of actors portraying bad guys on a butcher paper screen and then we would shoot when a vignette provided enough info for the use of deadly force. The projector would stop at the report and trainees could see if they hit or not. Just a little more advanced in today's world thinks I.

[billyb]

A lot of the new brass have the larger flash holes. They do not cause any harm with standard loads found in the loading guides. They first started using them in the lead free primed ammo. An article in Handloader had an article about the brass with the larger flash. They stated they cause no harm. I have a lot of CCI brass in 45 auto with the larger flash holes and load them with no problems. Bill

[alamogunr]

I'll have to look up the article in Handloader. Do you remember how recent?

[Cap'n Morgan]

We often used movies film of actors portraying bad guys on a butcher paper screen and then we would shoot when a vignette provided enough info for the use of deadly force. The projector would stop at the report and trainees could see if they hit or not. Just a little more advanced in today's world thinks I.

Over here, virtual shooting cinemas has become very popular for training for running shots. Shooting at driven boars indoors, using your own high power rifle with real ammo is quite fun - and no animals are hurt in the process! ;) The system will project short clips of various real life hunting scenarios from on a 30 feet wide screen. When you shoot, the movie freezes and a large red dot will indicate the point of impact. The real range is 25 meters, but the system compensates for the apparent range and speed of the animal when tracking the shot.

http://img405.imageshack.us/img405/5107/fb95.jpg

[NSP64]

What caliber?
45ACP
or
500S&W?