What's with the flash holes?

[Hoot]

I'm processing some 450B brass a fellow gave me. I noticed the flash holes are smaller than .082". Does someone with a better cartridge spec than me look that up and see what they are supposed to be? I'm big on consistency in the interest of predictable and reproducible results. Also, after the depriming/resizing with the Hornady dies, the mouth ID is running .444. My Lee trim cutter pilot is .446 and will not fit inside. A couple of weeks ago, before I was the fortunate recipient of this 450B brass, I bought a bag of .284 Winchester to see whether it could be cut down to make 450B brass. After cutting a few to length, their mouth diameter was the same .444 and since I could not fit the Lee trim cutter pilot in them, I assumed that was a bad decision because their case walls were too thick. I subsequently sold the brass at a loss. Now, with the real McCoy brass, they're still .444 at the mouth. I've reloaded a half dozen different straight walled handgun calibers and about a dozen different bottle neck rifle calibers and have never experienced this, so what am I missing? Lastly, did Hornady ever give a technical reason for using small primers instead of large?

Thanks,
Hoot

[BD1]

I really don't want to be seen as bashing Hornady over thier .450B brass, as I'm really glad they're in the game. However, out of 150 Hornady factory new brass I've bought I've rejected 33 for flash holes way off center, and I've reamed and chamfered the flash holes on the rest to remove the punch "chad". The only place I've seen flash holes this funky before is VN era LC .223 brass. My guess is that they are using some unfamiliar combination of tooling to punch the small primer flash holes in the .284 based case.
BD

[2zero6]

I wonder if Remington will be using the same brass.

[Siringo]

I have always trimmed my cases after expanding. I have just finished prepping 284 cases. After firing the first time, I reamed them to .452. Sizing yielded an ID of .444" -- same as you got. Expanding opening the ID to .448". The pilot on my case trimmer measures .446" -- same as yours.

Guess you could always chuck the pilot in a drill and take it down a little if you want to trim w/o expanding.

[Siringo]

My flash hole uniforming tool measures .080 and slips into the 450B holes with just a little effort. I would say that they are right at .080.

[Hoot]

I wonder if Remington will be using the same brass.

I seem to recall reading somewhere that Remington was using Small Rifle Bench Rest primers in their version.

I have always trimmed my cases after expanding. I have just finished prepping 284 cases. After firing the first time, I reamed them to .452. Sizing yielded an ID of .444" -- same as you got. Expanding opening the ID to .448". The pilot on my case trimmer measures .446" -- same as yours.
Guess you could always chuck the pilot in a drill and take it down a little if you want to trim w/o expanding.

Ah, I didn't expand them yet. Was going to trim them, de-burr and uniform the flash holes, tumble them again and then expand them just before actually dropping my loads. The trim cutter pilot starts in about .25" then seizes as the walls thicken further in.

Update: I measured a dozen random ones and all are actually at or slightly shorter than the trim length in a cool room. I'll caliper the remaining ones but I suspect they will all be too short to need trimming, so the trim cutter pilot sticking was a moot point. I wonder if the lack of growth is a result of the fellow I got them from having a slightly short chamber, or this particular caliber just doesn't grow that much using factory loads.

[quote="Siringo"] My flash hole uniforming tool measures .080 and slips into the 450B holes with just a little effort. I would say that they are right at .080.]/quote]

Mine is .082 and would not go in though it felt and looked like with a small effort, it would. I just didn't want to screw up the formula they use, as I'm sure any deviation has its impact upon results. Looking through the stereo microscope, it appears that in the brass I have, the burred edges on the inside of the flash holes have been smashed back against the web in an expanded pattern like flower petals, so I'm not sure deburring will accomplish anything positive. Nevertheless, I will at least uniform them to .082. The .284 Winchester uses Large Rifle Primers. Now I'd bet a dollar to a donut that affects the formula.

The fellow who gave me the brass promised a box with a hundred of them in it, mixed with some .308s, .300 WUMs and a few 30-378 Weatherby to boot. First time I ever saw 30-378 Weatherby and OMG, they're monsters. I bet they kick you into next week! There wound up being 164) 450B total. Should keep me going for quite some time. Any way, I'll inspect them more closely as I uniform the flash holes and see how many are out of round. In the last bag of 100) new .260 Remington brass I bought, there were 6 that were out of round enough to throw in the scrap bucket.

Thanks to everyone for the reality check.

Hoot

[BD1]

In my experience all of the Hornady brass is under trim to length, and all .450B brass gets shorter with use. Just like .45 acp brass. If you think about how the sizing die works the brass this makes sense. There is no shoulder to blow forward upon firing, and no expander ball dragged through to stretch the neck.
BD

[Siringo]

BD1 -- Originally I trimmed mine after a couple of firings just to "true them up". Wished I hadn't done that for the reasons you have stated - As I have noted them getting shorter. My theory is the faster and harder the action closes, the more the case gets "peened" shorter. I have since slowed the action down and have a softer chambering, so maybe this may minimize the pounding. Some of my cases have been fired 15 times.