flashole reaming, what size???? Help!

[Depreacher]

Finally reamed my first 8x57 flashole today. Could'nt find a .098 drill locally so bought a 7/64" which is supposed to be .1093. It was'nt. It miked out at .1043. See where Brownells has a #40J (.098) for 96 cents. Can't remember where I got the .098 figure, maybe here. I only reamed (ruined?) one case. With CCI 250 mags. and 4759 behind a Lee .324-175, I tried 15 to 21 grains, in one grain increments. At 20, and 21, the primer started to flatten a little, seemingly moreso than with a standard flashole using the same components. Will try to do some group, and velocity testing tomorrow, MAYBE. Some of you guys have some (much) experience with flashole reaming and the results thereof. If you could drop me a few pointers about what works and what doesn't, it would sure save me some time testing different hole sizes vs different powders in diferrrent calibers. I don't care if you did it in your Mongolian Mannlicher, any info or help would be greatly appreciated. Sure don't want to end up with a bolt face for an eyeball!

[45 2.1]

If it were me, I WOULD NOT BE REAMING FLASHOLES for the cartridge and load you are useing. You found out why with the premature pressure signs. You might uniform them with a proper uniformer from RCBS or others, but it probably won't help.

[Willbird]

The most benefit I think is from uniforming flashhole LENGTH not dia, and you do that with a uniformer that uses a long #2 center drill, it lightly machines away the burr from the flash hole being punched from the primer pocket into the inside of the case. It does not typically change the dia of the flash hole at all. If you grab a copy of Precision Shooting magazine you will no doubt see them advertised. They can be a handheld tool.

Bill

[sc03a3]

hi preacher, i enlarge the flash holes on the brass i use for fast powder cast boolit loads[30/06] with excellent results. i use a .098 dia drill bit [ it's either a number or letter bit]. i use these cases with powders like sr-4756, red dot, 2400, sr-4759, with powder charges up to 23 or 24 grains. i have done this flash hole enlargeing for years with no problems, i neck size only and have never had any shoulder set-back on any brass with the over-size flash holes. hope this info helps. sc03a3

[Frank46]

Castboolitpreacher, 45 2.1 is right, there should be no reason to ream out flash holes. Your drill bit is was too big allowing the primer to see more pressure than would be normal if the flash holes were not reamed. Supposedly the sellier and bellot czech cases in 8mm and there may be others by that mfg tend to be on the small side and cause problems with the decapping pin sticking. I shoot 45acp and have a pile of s&b cases and can always count on getting a case stuck on the decapping pin. When using those cases Iuse a wilson punch and base set so's I can screw em off. Not sure but flash holes are supposed to be around .080 Frank

[Junior1942]

I see trying to uniform flash holes as a recipe for disaster. However, de-burring flash holes with one of the several tools available is a worthwhile reloading step, a step you have to take only once. I use a Lyman tool.

First, the cases must be the same length, so de-burr after trimming and chamfering. I adjust the tool's cutting depth so that it cuts a barely-visible funnel in the flash hole exit. In other words, adjust it so it just begins to enlarge the flash hole.

Turn the cases over and tap them in the same spot on your loading bench, and you'll soon have a little pile of gold-dust-looking brass shavings. I de-burr the flash holes of all new cases. As you'll discover, about every other case will have a decided lip on one side of the flash hole exit.

[Bass Ackward]

If you could drop me a few pointers about what works and what doesn't, it would sure save me some time testing different hole sizes vs different powders in diferrrent calibers.

Preacher,

I have played this game and it does give you flexibility to use cooler primers which are always more consistent from shot to shot than a hotter primer. But you MUST MARK YOUR CASES!!!!!! It can allow you to go down in burn rate. But fillers that compress perform the same task.

The drawback is really that it has to be done right. That means you need a primer pocket guide for the drill bit so that it aligns the case and the drill bit and opens the hole directly in the center without walking or angling. Otherwise case positioning will drive you nuts!!!!! And how can you know which ones walked off center? So what you really end up with are cases not uniform in any sence of the word.

My advise would be to stay close to what size you have and just use a bit as a .... uniformer to clean up what's there with your fingers if you feel it is necessary. But from the wording of your post, I get the feeling your mind is pretty well made up. So I would only go one drill size up at a time until you get to the promised land. Use 5 cases for testing so you can always go back or start again.

[Larry Gibson]

Castboolitpreacher

For those who don't know; the reason to drill out flash holes to a larger size is to prevent the explosian of the primefrom driving a rimless case foreward and readucing headspace on the cartridge. I use specially marked cases with the flash holes enlarge with a #29 drill bit. I use a drill press and a vice with a V cut in it to consistantly align the cases. It goes real quick and there is no problem with wandering or off center flash holes. I have also held the case in a padded vise and used a small hand held variable drill. If one goes slow and easy and pays attention itis easy to do.

One word of caution with these cases that others have mentioned; you are using a "slow" fast powder and are approaching some pressure problems. I use flash hole drilled 8 mm cases only with very light loads of fast burning powder with 150-160 gr bullets. Mostly with Bullseye and Unique covering velocities of 850 fps and 1400 fps.

Larry Gibson

[45 2.1]

For those who don't know; the reason to drill out flash holes to a larger size is to prevent the explosian of the primefrom driving a rimless case foreward and readucing headspace on the cartridge. Larry Gibson

I don't guess the whack from the firing pin has anything to do with driving that case forward, just from the primer.

[woody1]

Castboolitpreacher

For those who don't know; the reason to drill out flash holes to a larger size is to prevent the explosian of the primefrom driving a rimless case foreward and readucing headspace on the cartridge. I use specially marked cases with the flash holes enlarge with a #29 drill bit. I use a drill press and a vice with a V cut in it to consistantly align the cases. It goes real quick and there is no problem with wandering or off center flash holes. I have also held the case in a padded vise and used a small hand held variable drill. If one goes slow and easy and pays attention itis easy to do.

One word of caution with these cases that others have mentioned; you are using a "slow" fast powder and are approaching some pressure problems. I use flash hole drilled 8 mm cases only with very light loads of fast burning powder with 150-160 gr bullets. Mostly with Bullseye and Unique covering velocities of 850 fps and 1400 fps.

Larry Gibson

IMO and experience, Larry has it right. The primer constantly pushing the case forward upon firing will eventually cause head separation. Enlarging the flashholes (only in low pressure fast powder loads) seems to reduce the primer pressure, thus the case doesn't move forward so much. Yes it prob'ly does increase pressure. I've proved this to myself even with rimmed (30-30) cartridges. I routinely drill out flashholes on my 30-30 cases, mark them, and reserve them for low velocity/pressure loads. They last most forever. Without enlarged flashholes, I was getting head separation.

I've also tried reaming flashholes to speed ignition using MilSurp 7383 in the 223 with cast boolits. That still requires more testing although I did get cleaner burning. FWIW, Regards, Woody

[swheeler]

Woody: that seems kinda suspect on your 30/30 as it should headspace on the rim, thus the primer force shouldn't be changing headspace-UNLESS headspace is excessive on the rifle, and you are infact headspacing off the SHOULDER? Scooter

[felix]

Always assume that headspacing off of a rim or belt is joke on you and me. Very few guns are chambered properly is the motto we have to live by. So, always assume headspace is off of the neck ramp if indeed there is one to be absolutely safe. You always know the minimum headspace would be measured off of the rim or belt, however. ... felix

[Depreacher]

Men, I must have made the primer flattening sound worse than it was. On the 21gr. and 22gr. loads for the 8x57 ( mistakenly said 20 and 21 originally), the primer was flat on maybe 75% of diameter its face (CCI250). Nothing like 53gr. H380/150 J-boolit would do. I've loaded many a 30-30 j-load that looked much flatter than the 22gr. load I shot. All rounds were fired straight up, so as the get max vel, (and pressure???). Don't worry, I live in the middle of nowhere. I twelve gauged 3 'dillers in the yard last night. Wife never woke up!! sc03A3 seemed to have good results with a .098 drill. I have a 1/2 hp drill press and drill vise, like someone else suggested to use. Looks like you could take a short piece of drill rod that was almost (and I mean almost) primer pocket diameter, chuck it up and adjust the vise to where it was centered, then raise the spindle and chuck up a .098 drill and carefully drill. When you live in the middle of nowhere, and exist on limited funds, you learn to improvise, improvise. That's what makes this hobby fun. Has anyone done a test of standard diameter vs. reamed out, as to changes in vel., SD, ES, powder position, and so on. Sounds like too much w-o-r-k, but would be interesting.

[Depreacher]

Back Assward, It has just now hit me about the primer pocket guide you suggested. Excellent advise!!! If I can make it, then harden it, it could be held with fingers in the primer pocket as The spindle is lowered thus running the drill through the center. This would be pretty precise. Still need to take the burr off the inside somehow. Think I'll also order a 8mm pilot for my Forster outside neck trimmer. Hey, precision match ammo for a slave made K98. Neat, huh?

[woody1]

Woody: that seems kinda suspect on your 30/30 as it should headspace on the rim, thus the primer force shouldn't be changing headspace-UNLESS headspace is excessive on the rifle, and you are infact headspacing off the SHOULDER? Scooter

There are many, many 30-30's out there that will show you a protruding primer when fired with a low pressure load. I have to assume (1)that even though they may be headspaced properly, they may be at maximum. Or (2) they have some excessive headspace. In either case, the case is driven forward some amount by the primer and the chamber pressure is not enough to drive it back, reseat the primer, and fully re-expand the case. At least that's my take on it. Regards, Woody

[swheeler]

seems if they are too low pressure to stetch the case enough to re-seat the primer, they should't be causing case head seperation

[Depreacher]

Larry, Brownells shows the #29 drill to be .1306". If you are having good results with this, then I may have the nerve to drill out 10 cases with the 7/64" (.1043) and start a few tests. Many variables here, powder type (burn rate), boolit weight, primer, etc.. Sure want to go slow and careful. May copy sc03A3s work in this area as a start. Says hes done it for years. No problems. He uses 4759 too, and neck sizes only just as I am now that The Lee collet sizer came in. Midways package was in my mailbox 47 hours after I ordered on their website. They just made a customer.

[Larry Gibson]

Castboolitpreacher

Yes the #29 drill makes for a pretty big hole. There seems to be just enough room for the legs of the anvil to rest securely on small lip that is left. I had thought the little lip would blow out but it has not proven to be. A side benifit is small charges of fast powder are not "case sensitive hardly at all. the flash from the primer gets into the case right now. If you've any doubts start with a #31. Just need to make sure the cases are well marked so you don't use them with full charges.

Larry Gibson

[Bass Ackward]

Back Assward, It has just now hit me about the primer pocket guide you suggested. Excellent advise!!! If I can make it, then harden it, it could be held with fingers in the primer pocket as The spindle is lowered thus running the drill through the center. This would be pretty precise. Still need to take the burr off the inside somehow. Think I'll also order a 8mm pilot for my Forster outside neck trimmer. Hey, precision match ammo for a slave made K98. Neat, huh?


CBP,

It is the ONLY way to garantee concentrisity. And RCBS has a hand powdered uniformer for the inside. But then it depends on what you expect or want from loads too. Everyone should be encouraged to experiemnt as long as it can be done safely. That's what we have to consider when offering advice.

I guess people have to do what they have to do to make something work, but when I want more pressure or better ignition, I use other methods now. My loading of cast, no matter the caliber or the use, is always approached from the standpoint of starting a cast bullet off as gently as possible. So I go the exact opposite and use pistol primers for cast. The last thing I want using that technique is to upset that approach by drilling flashholes.

[giz189]

Fired straight up? What goes up must come down, spinning wheel got to go round...still i am glad i live way way over in the next county.

[Depreacher]

Hey giz189, I can't believe it!!!!!!!!!!! Figured no one else within 150 miles or so cast their own rifle boolits, and you just 25 miles away. A wonder we haven't met at Olsons or somewhere. My gun trading goes all the way back to Olives when he was in the hardware business on the square. Bob, Bismark, Charlie Yates, you name 'em, I traded with all of them. If you're the guy that casts some of Billy Dons handgun slugs rest assured I have shot many of your .38s.44s, and .45s. Also duck hunted with Butch Wilke for years. Too old now. Is the Magnolia range, near the airport, still open?? I always wanted to come over and shoot. Let me hear from you. Mack Lester

[Depreacher]

Hey giz 189, Glad to hear from you. Really surprised to hear of someone this close. Who knows, we may have met at Olsons, Charlie Yates, Bismarcs, Bobs. If you are the handgun boolit supplier to Billy Don, rest assured I have sent many of your slugs downrange. Is anyone else from there abouts shooting cast rifle slugs. Figured I had it all to myself. Mack Lester ps. Billy Don knows me well.

[Depreacher]

OOPS, sorry, I thought the first reply didn't take.

[BOOM BOOM]

HI,
I have a small letter gauge drill bit in a small hand drill that I've used to make all my brass have the same flash hole size. Now I'm not really drilling w/ it, just push the bit in & pull it out, so it may be what some call uniforming. I've done this w/ light & medium Pb bullet loads & w/ hot j-bullet loads. I've not had any problems so far.
If I remember right ,this was a tech. developed by the benchrest shooters over 30+ yrs. ago and accually shrank group size.

[Depreacher]

THANKS Boom Boom. Good advice. Just uniforming flash holes as to hole dia. would have to make ignition more consistant round to round fired. Then uniform the flash hole exit with a small reamer like RCBS sells. Had a $60 order from Midway come in last thursday, and emailed them another $40 order yesterday. If I keep on I'll save enough money by shooting cast bullets that I can retire in the Bahamas. cbp

[drinks]

For normal loads, I sometimes CLEAN the flash hole after dirty powders, but I use a tip cleaner set from the welding supply, just push in and pull back, then try the next bigger size and see if it will go in easily, if not , quit.
Tip cleaner sets are about $2.
I do drill the flash hole out to 1/8" for shotshells, the recoil on firing is not enough to reseat the primer when firing and the protruding primers soon lock up the cylinder if this is not done.