The Kaboom That Wasn’t

Yesterday I had a bullet in the bore in front of another complete cartridge that was fully chambered.  The bolt was in battery, the hammer cocked, and the safety was in the Total Devastation position.  But I thought better of dropping the hammer.  Well I didn’t think so much as feel that for some non-specific reason it might be a good idea to get out of my ready-to-shoot position and open the action.

I had fired hundreds of these cast bullet loads for a Win ’94 carbine and was having quite a good time shooting, using the new tang aperture sight after getting the sights dialed in.  The 311291 mold puts out a “bore rider” bullet, meaning the shank of the bullet ahead of the drive bands kisses the rifling as it’s chambered.  It’s supposed to make for better accuracy, and so far these have been pretty good in that department.  But my mold produces bullets that more than kiss the rifling– they have to be jammed in with just a tad bit more force than optimum.  I’ve chambered and un-chambered lots of them before without observing any sort of problem.

Yesterday, I don’t remember why, I decided to check the status of the rifle before taking a shot.  It was harder than usual to extract, so when it came loose, the bolt came back rapidly, expelling an empty case.  “Odd” I thought, “I’m pretty sure there was a loaded round in there.  Oh well.” (first red flag).  So I rammed the lever home to chamber another round.  It took more than the usual amount of force to chamber (second red flag).  But it chambered.

I actually had the rifle up to fire, and then…”Naw…I’ll be needin’ to see that cartridge.”  Again it was harder than usual to extract, and this time I could see fine ball powder all over the action and my hand.  “OK then, I’m done with the Winchester for the day.”

That first hard extraction had pulled the bullet from the case, but I didn’t notice the spilled powder because I had my long-range shades on (can’t see close-up very well) and the low, direct sun made for so much contrast that anything in shadow was much harder to see.  I didn’t notice the little detail of the still un-dented primer.  The next round was harder to chamber because I was forcing the first bullet deeper into the bore in front of the fresh cartridge.  The new brass was maybe a little soft, and maybe that bullet was on the large side of the size variation range, and maybe the case was on the short side of the narrow length range I had allowed, the crimp design is very good at preventing bullet set-back (which is the concern with tubular magazines) but poor at preventing bullet pull-out, so anyway the bullet pulled free and stayed behind when I extracted the case.  Never heard of such a thing, which is why I bring it up here.  Maybe I should get another bullet mold.

You know they say that for a single shot action, you don’t need any crimp at all.  After yesterday, with any bore rider design I would recommend a crimp no matter what.

Shooting alone is a real pleasure for me.  I love taking other people along and having a good time that way, sure.  Some of my best shooting memories come from having other people along.  I have to get out alone once in a while though, especially with rifles, and I highly recommend it for everyone.  It allows focus, and the contrast between the fire and the total silence during breaks does the heart good somehow.  On the issue of focus; I believe that the chances of my pulling that trigger on that double bullet load were fairly high, had there been company along.

Edited to add; Below is the bullet in question.  You can just see the engraving from the rifling.  That individual bullet fit pretty well, but others are a bit tighter (random variations in casting).  I should have posted this photo earlier to avoid some of the confusion.  “Regular” bullets begin to taper off right in front of the case mouth, but this one is designed to enter the bore in front of the throat, touching the lands.  The design helps align the bullet right from the get go.  For actual use, the front drive band at the case mouth (and those behind it) is sized to .309″ to tightly engage the .308″ barrel groove diameter and produce a good seal.  Also notice the ring around the back of the short ogive, from the seating plug that was designed for longer ogive bullets.  This photo was taken over a year ago, before I fired any of these rounds, and you’ll see that the case is either crimped very lightly or not at all.  This was a test seating.  You also see that the chamber throat is super short (the rifling comes very close to the case mouth, but it’s a largely non-issue here).  That’s not a problem with most modern full-copper-patched bullets either, but it does limit the styles I can use.  This #2 alloy cast 170 grain gas checked bullet load reaches 2,000 fps from a 16″ barrel, using White Label Carnauba Red lube and 33.5 gr of Win 748 with a WRLM primer.  The powder charge and primer are from the Speer manual as a jacketed load.  After 50 shots, the bore looks like a polished mirror (the powder burns clean and the bullets don’t leave lead behind).

14 thoughts on “The Kaboom That Wasn’t

  1. I use a sizing die, but that only touches the drive bands– the bands (the major bullet diameter) need to be about a thou over the groove diameter, so I size to .309″. You’d need a custom die that only sized the smaller bit in front– that needs to be about the same size as the bore, or land, diameter, see. So you’d need to push the bullet nose into this custom die thingy that no one makes, then back it out, so the drive bands don’t end up way too small. That’d make for two sizing operations– once to size the bands and seat the gas check, and again, in and back out, to size the nose portion. I’d rather get a new mold and not have to futz with it so much.

  2. Ever read the book “the gift of fear?” A major point it that our bodies and brains pick up all SORTS of stuff that mostly gets filtered out as irrelevant, but if you hear something giving you a niggling “somethings not right” feeling, then crank up the critical thinking and awareness to 11, and PAY ATTENTION! This sort of thing may make you seem overly cautions, but it also saves your but from time to time.

    On the “shooting alone,” I think the line “meditation, prayer, and quiet contemplation on the firing line” seems like it has a home in a screenplay somewhere.

  3. Lyle:

    I used to shoot bullseye competition with pistol (before my eyes went bad) in .45 ACP. I had a whole bunch of target ammo made for me by a local reloading house (200 gr. lead semi-wadcutters). A light load of power meant that I used a low-power recoil spring in my target gun.

    I stopped using them after I had a similar incident. The reloaders weren’t setting the bullets deep enough in the case, and the edge on the semi-wadcutter pushed itself into the rifling, but not far enough for the slide to go fully into battery. When I racked the slide, the round came apart with the powder spilling all over, and the bullet still stuck into the rifling.

    I ended up lining up all of the rounds side-to-side, and then started sorting them by height. There was enough of a visible difference between rounds that I ended up with 30 or so cartridges ranging from shortest to tallest. Since I don’t reload myself I don’t know what their problem was in setting the correct overall length (worn out dies?), but I never bought anything from that bunch of clowns again.

    At least with the slide not going into battery there wasn’t the chance of me having it go “bang” with a bullet in the barrel, although I’ve had a semi-squib round that I darned near did that with once.

    @ Rolf…
    One of the main reasons I love to shoot alone is that you can get into that “zone” where, “sight alignment, sight picture, move the trigger back” becomes a mantra, and you can almost think the bullet into where you want it to go. It’s surprisingly peaceful for a pastime that involves minor explosions at the end of your hand.

  4. I see your point about a new mold vs a non-existent-custom-screwball-sizing-die.

    So the problem is new? Any chance something (nick, ding, …) is preventing the existing mold from closing fully? Or are you thinking problem is normal variation, not change, in casting?

  5. Lyle–

    I think that’s one of the more useful shooting/reloading posts I’ve seen lately. With all respect for Jeff Cooper’s Four Rules, there’s an overriding one: Pay attention, even to vague suspicions.


  6. ChrisTE; The mold dropped slightly large-nosed bullets from day one. Lead particles or dings between the mold halves, as you say, will certainly cause bullets to drop large. Then there are the temperatures of your pot and of the mold, which result in minor size & weight variations throughout a casting session. The particular alloy will also determine the bullet size to some degree. Normally these small variations are blown away in a sizing die, but with a bore rider bullet you’re still dealing with them. Interestingly, my bullets are only very slightly effected by the .309″ sizer, meaning that while the bullet nose is on the large side, the major diameter (drive bands) is on the small side. If someone has a Winchester with a slightly larger bore (or land diameter) than mine, but with the same groove diameter, this mold would be a jewel.

    Rolf; I totally agree with you, though I wouldn’t call it “fear” so much as “concern”.

  7. Glad you didn’t trigger that shot Joe.

    IIRC, some 30-30’s were chambered with short throats which may be what you’re running into.
    I think the Speer manuals have a blurb in there about them.

  8. This Winchester does in fact have the shorter throat, but in this case it’s not really the issue. This cast bullet design has a cylindrical shank in front of the drive bands that will enter the rifling of any rifle. That’s the “bore rider” design. The throat length would determine how far the bullet enters the rifling, but not whether it does. The “problem” is that the bore riding portion of the bullet is just a tad large in diameter, meaning that instead of just kissing the lands as it slips in, every bullet is actually engraved slightly as it chambers, meaning that it can stick in the bore some fraction of a percentage of the time, when you try to remove it. If I had just fired that round, without the chamber check, it would have gone off perfectly and I’d never know about this potential problem. As it was, it pulled the bullet, left it behind, and another round was chambered behind it.

    I have to be grateful that this happened. Now I know what to look out for. I said I may have pulled the trigger on that double load with other people around. Worse yet, someone else may have done it. Yes; I am grateful. That 311291 bullet is a very old design, proven over many ganerations and still highly recommended. so I have this bad fit…

  9. What Dia. does the nose of your bullet measure? (check bullets from both cavities, and in line with mould parting line as well as at 90 degrees to parting line… They aren’t usually perfectly round)

    What Dia. does your bore measure when you slug the barrel?

    Did you ever make a cast of chamber/throat? If so, what are the measurements…

    What alloy are you using, how hot are you running the pot?

    It’s possible to tune the as cast Dia. by selecting alloy and casting temperature that cast smaller. It’s also not really too difficult to nose size only, a Lee type die adjusted so bullet only goes in up to the front drive band and knocking it back out rather than pushing completely through is a cheap option for that. If you need a custom die, check with member “Buckshot” on cast boolits forum…

    Realize of course that when you stop it engraving, you may lose some accuracy.

Comments are closed.