Erratic OAL

[StanDahl]

Am I being unrealistic in expecting my seating dies to give a consistant OAL? I have never been able to get a repeatable exact OAL no matter what brand of dies or press I use without going to extremes. For example, with cast bullets I'll seat a bunch of them partially, wipe any extruded lube off of each bullet/case, clean the die, then finish seating. Still one will be spot on and the next will be .001 to .005 to even .010 off of the last one. Most will be within .0015 or so either way, and I've come to accept that. This is with a Lee turret press with the jumpy turret as well as a solid top RCBS press. I figured the problem was caused by the softer cast bullets slipping into the seating stem, which does happen with some designs. (The Lee 312185 bullets even get a ring on the ogive using Lee dies.) It makes me wonder if air is trapped at the top of the die and is pushing on the bullet. I figured it was a cast bullet problem, as that's all I load these days, but last night loading some jacketed bullets (.221 Rem & Sierra 50gr spitzers) I had the same problem, but with a much wider variation. This may have been due to a very tight neck because I couldn't change OAL much after the fact, the bullets refused to be nudged. Am I too picky, or will I be investing $40 per caliber in Redding Competition Seating Dies? Thanks, Stan

[D.Mack]

Standahl- since you mention a ring on the ogave, your problem may be a slight variation in bullet diameter (actually nose diameter) alowing the seating stem to contact the nose in a slightly different location, resulting in a slight variation in length. DM

[shooter2]

Well, there may be a couple things to try.

First, Lee tolerances are pretty darned close. The bullet may actually be catching in the die body before it hits the seating plug. Hard to measure without the right tools, but try contacting Lee and asking what the measurement is. I had to have one replaced for bullets that measured .310" or .311" and the die was cut just under .309". Just a tad too tight for cast, but great alignment for jacketed.

Second, with cast I always seat and crimp in two separate steps. You can buy a separate crimping die from Lee (I have a couple dozen of them) or you can reset the bullet seating die and crimp with it. Redding sells a set of 7/8" spacers that allow you to crimp/not crimp as well as .38/.357 or .44sp/.44mag. I forget what they measure offhand, but worth the few dollars they charge.

[cbrick]

Bullet noses, cast or jacketed, will vary at least this much. Are you sure the variation your getting isn't the depth of the seated bullet but rather the shape of the bullet tip??

As for the Redding Comp Seater dies, I highly recommend them. I have one for each caliber that I shoot that they make. I wish they would make them for more calibers. This die also doesn't use the the bullet tip for seating.

Rick

[NVcurmudgeon]

Re cast boolits another thing to check is buildup of boolit lube in the seating die, causing variable seating depth. The tipoff is often a constantly decreasing OAL.

[swheeler]

Stan; what you are seeing is variation in ogive position (and shape)on the bullet If you want to get real "fussy" use a bullet comparator, and seat all to the same overall length measured off the ogive at bore diameter ,and not the tip of the bullet. Use jacketed bullets from the same lot, and cast bullets from the same cavity, they will be closer. Not all bullets are created equal, of the few thousand I have run thru a comparator, the Nosler Competitions were #1, Sierra MK #2, HORN HPBT #3--- REM CL way out in left field! When you seat bullets by measuring off the ogive, you will get the same jump to rifling every time, not so if you measure OAL off the bullet tips. A good reason to check when you empty a box of bullets before you are done with loading, and have to open a new box(Lot#)
Scooter

[drinks]

Give up on oal, get a Stoney Point gage set that actually measures the ogive diameter, which is what really matters, where the bullet is seated in relation to the rifling, which governs the jump and pressure on start.

[beagle]

There are a couple of other variable that haven't been aired also.

#1 is that bullets that are base first sized will vary a bit in length due to some nose bumping brought on by bullet size, swaging down the GC, etc.

#2 is that bullets will sometimes swage down a bit in size and also bump a bit during seating.

Both of these factors will affect your OAL...among other factors. Actually, the OAL shouldn't vary much. Th eposition of the case mouth on the bullet will vary quite a bit./beagle

[swheeler]

"but last night loading some jacketed bullets (.221 Rem & Sierra 50gr spitzers) I had the same problem, but with a much wider variation. "

What beagle says does apply to cast and can happen, but you are not bumping up jacketed bullets while seating them

[StanDahl]

Thank you for all of the input...let’s see if I can put it to use...first, Lee tolerances. While seating 311359’s today with the same Lee 30-30 seater (a “dead-length” seater), some lube oozed out laterally but didn’t touch the die body, so that die, at least isn’t too narrow.

BTW, I do usually seat and crimp in separate steps. This die, I discovered, doesn't crimp at all, which was kind of annoying as I was counting on it to straighten out the slight bell I put on the brass. I ended up having to use the gutted f.l. size die to taper the bell out.

As for the bullet noses varying in size, some loaded 311359 samples I measured were very consistant. But the Lee 312185’s I had a problem with were not as consistant, some being about .001 larger than the rest. Hmmm. And this from a single cavity mould! I’ve got to get better casting skills.

I do clean lube out of the dies regularly, and the extra step I take in seating takes care of most of the lube that gets in the way. My OAL jumps up and down, not just gradually down.

The Stoney Point gauge sounds interesting, and another chunk of money too. I should get a few anyway, I could learn something. I looked around while cleaning up today and figure I’ve spent about 20 times more on reloading and casting equipment than I ever would have if I just bought factory ammo. But...I can make a box of 50 32-20 cartridges for about $1.10 instead of the $18 barrel fouling, slow moving crap that comes pre-assembled, so it’s worth it right? Of course if I factored in the cost of the 9 32-20 moulds, the various loading tools and 500 Starline cases, they would be about $23 per box. Luckily, none of that counts.

Anyway, I don’t size base-first, just lube. Sizing and gc application is done on Lee push-through dies. That makes it possible for me to spend the most money per bullet. I’m thinking of buying a Star sizer to do it all at once and base-first too, that way I can sell the other sizers/lube dies for pennies on the dollar.

Looking at some jacketed loads made a few years ago, the OAL was fairly consistant, varying by about .001” either way. I can make it happen with cast loads, but it's such an annoying process. Seems like I should just be able to pull a lever and make it happen. Stan

[Bass Ackward]

Anyway, I don’t size base-first, just lube. Sizing and gc application is done on Lee push-through dies. That makes it possible for me to spend the most money per bullet. I’m thinking of buying a Star sizer to do it all at once and base-first too, that way I can sell the other sizers/lube dies for pennies on the dollar.


Stan,

Just realize that no matter what sizing method used that no metal is removed. The bullet is simply elongated. If you nose through size and your bullets varried in diameter before sizing, they will varry in length afterwards too. Just so you know.

[NVcurmudgeon]

Drinks, does Stoney Point now make their modified cases in diameters suitable for use with oversize cast boolits?

[StanDahl]

Stan,

Just realize that no matter what sizing method used that no metal is removed. The bullet is simply elongated. If you nose through size and your bullets varried in diameter before sizing, they will varry in length afterwards too. Just so you know.

Okay, I can understand that, but that shouldn't have an effect on OAL, should it? The bullet would simply be shoved in deeper or shallower than others, right? I suppose I should just concentrate on casting the most consistant bullets possible and I won't have to deal with many of these side issues. Gotta go practice...

Do any of you really pay much attention to the OAL in a batch, or do just check a few and crank out the rest and shoot them?

[SharpsShooter]

For match ammo, I check each one. Perhaps I am being too picky, but MOA accuracy in my BPCR indicates that it works for me. I'm seating .010 short of engraving, so a variation couild cause chambering problems in my application.

BTW...once the die is set, I see very little variation on OAL.

[slughammer]

The Lee turret is not helping the issue, it really brings case tension into the equation and that will throw in variation.

I just got a set of Lee 32 H&R mag dies. The seater die only measured .313 and was leaving a ring on my boolits. I lapped it out with sand paper on a drill rod to .315 and now my .3145 boolits are loaded unharmed.

[Blackwater]

NVcurmudgeon, dang good question there! Just sittin' at the 'puter, would it be possible to use the expander die from my .303 or 7.62x54 to expand a std. '06 case, for instance, to fit larger dia. cast bullets? Or maybe use the std. expander ball for .30 cal. and wrap with aluminum tape to get the neck bigger? I think your question was a darned good one. Any comments on my speculations? Anyone done this?

[StarMetal]

blackwater,

Some dies for certain calibers, such as the 7.62x39 come with two expander balls. That's because some rifles have a groove of .310 and other, like SKS, AK's, etc. are larger and there are a few different diameter bullets out there for that caliber, in jackets. So it does make sense if you're using a fat bullet to expand to the proper size. Say your expander expands a 30-06 neck out to .306 (inside diameter) and your rifle has a really fat groove and you're using say a .313 cast bullet or larger, that's too tight. Probably that tight of a neck would size your bullet down some just seating it.

Joe

[C1PNR]

Drinks, does Stoney Point now make their modified cases in diameters suitable for use with oversize cast boolits?
Who cares? Fire a round in your rifle, knock out the primer, and drill the base to accept the Stony Point tool. That's how I got mine for the 7.62x54R & 7.5 Swiss. Actually, I think my 6.5 Swede and 8 Mauser were also done that way.

You make the hole in the base is just large enough to slip fit over the threads on the Stony Point tool. It it's a little too big, a wrap or two with teflon tape makes for a press fit.

You may lose a case or two getting everything just so, but you get one in the size and caliber you need.

[Bass Ackward]

Okay, I can understand that, but that shouldn't have an effect on OAL, should it? The bullet would simply be shoved in deeper or shallower than others, right? I suppose I should just concentrate on casting the most consistant bullets possible and I won't have to deal with many of these side issues. Gotta go practice...

Do any of you really pay much attention to the OAL in a batch, or do just check a few and crank out the rest and shoot them?


Stan,

Sorry. Missed the question.

Technically, it does make a difference, because it does alter pressure. Just understand the logic that the greater difference would be felt the faster powder you chose to burn. Try it for yourself to see if it is something "you" should be concerned with.

Me I don't care really.

[44man]

Why not buy a tap to thread the back of the case to fit the Stony Point tool? Makes no sense to make a slip fit over the threads when taps are so cheap!

Sharpshooter, where are you located in WV? Where do you shoot BPCR matches?

[StanDahl]

I posed the question to my shooting mentor 'xxgrampa', whom some of you may know. He suggested that the bullet is compressing air as it's being seated, and the air is shoving the bullet back out. I had a suspicion that might be happening, although I pictured it in happening in the boogered-up seating die. He says try seating once, then let them sit and try again later after the air pressure equalizes. That may account for some instances, but not all IMO. The jacketed loads that were all over the place I still can't explain, unless there are loose die or press fittings or something sloppy somewhere else along the way.

As far as seeing if sloppy OAL makes a difference to me, I'll have to look into that. My problem is that I keep buying new guns before I get the old ones figured out, so I'm constantly working up loads and not wringing out old ones. I'll need to go back to a load that I know works, then set up a workable experiment with OAL. Unfortunately, my mediocre casting skills may throw too many variables into the study, and I may have to try this with some of those funny orange boolits. Stan

[Ricochet]

Dunno about air pressure, but I've sure had some bullets sitting on compressed powder charges that crept back out to various overall lengths. When I'm doing that stuff I like to crimp 'em in place right after seating.

[C1PNR]

Why not buy a tap to thread the back of the case to fit the Stony Point tool? Makes no sense to make a slip fit over the threads when taps are so cheap!
Tell me the right tap to use and I'll look at that idea. My understanding is that it's non-standard, and therefore a bit pricy!

The slip fit works pretty well, as long as you keep some pressure on the base.

[sailinon]

Thank you for posting this StanDahl. I've been reloading entirely cast boolits, mostly .45ACP since 1994 (not long to some of you, I realize).

Recently I began reloading 158 gr LRNFP over 3.5gr WIN 231 out of an RCBS Rock Chucker.

My concern, and maybe yours too StanDahl, is pressure. OAL info:

Goal 1.425
0.002065867 standard deviation
1.424962963 average
1.425 Mode
1.421 Minimum OAL
1.431 Maximum

As measured with a Dillon Dial Caliper.

So maybe I have too much time on my hands, but I do this type of statistical $h!t for work every week and as sick as it sounds, it comes naturally to me.

What do you all think? Is my very expensive S&W 340PD gonna go boom (in a very bad way) on me?

Thanks in advance,
Sailinon

[gefiltephish]

I'm guessing you didn't realize you posted to a 6 year old thread? It's easy to do after using the search utility, though I'm quite certain I've never done such a thing myself :oops:

[popper]

If it is F/N bullets, turn the Lee seater plug around so you are using the flat instead of cupped part.

[fredj338]

Yes you are being reloader anal. A diff even 0.01" isn't a big deal pressure wise or accuracy wise IME. Bullet noses vary almost that much in commercial bullets. If you load mixed brass you add more variation.