Here are some relatively randomly structured, shotgun blasted thoughts I have on jamming.
I’m not averse to jamming, but I am averse to the consequences of jamming, just enough to avoid it in most circumstances. If I were shooting benchrest or even F-class where my life hung on raw or aggregate groups, I would probably be jamming, but I wouldn’t love it.
I’m not willing to “shoot into a stump” and add unnecessary pressure on the game every day and add complexity to unloading my rifle just for a hunting load. When coyote hunting, I might make a dozen sets in a day - should I really blast a round at every one of these spots just to feel confident in the safety for travel? And do the same the next day? And the same the next weekend? A mis-fire condition is another opportunity where, when hunting, I’d prefer to not have a bullet lodged in my lands, requiring careful ejection with the barrel pointed upwards to avoid spilling powder in the chamber and action, and subsequently tapping the bullet from the leade with a rod... I’d much prefer to cycle the round out as God intended, and deliver the next round on target. Meat in the freezer or fur on the rack... It’s simply not worth any complication, when great shooting loads are easily developed without such consideration.
Equally, I preferred to NOT jam when shooting benchrest, as some ranges I used required the rifle to be cleared at the line, and wouldn’t allow the muzzle pointed upwards to eject... so if I timed out and needed to eject a round (didn’t happen, but “if”), I was stuck dumping powder in my action and tapping out a bullet. Equally, ejecting live rounds can and does happen just often enough in PRS, I wouldn’t jam my match ammo either. A solid bottom single shot action is easier to clear of powder than a repeater, but I simply don’t see enough advantage to jam, or enough disadvantage in not jamming.
That said, I’ve jammed a lot of bullets. Some for the precision, some for fireforming. Load development has to be done with jamming in mind, and the juice really has to be worth the squeeze for me. I’ve never had luck “kissing,” I tend to do better >= 5 thou off or >= 10 thou in.
For solids or partition type bullets, I’ve had my best luck at >= 50 out, and I’d really, really have to have a strong motivation I don’t currently experience to convince me to jam either of these.
I’ll also note - there are enough guys jumping secant bullets a LONG ways for me to acknowledge no rule should be considered gospel. I’ve jumped A-Max’s and ELD’s as far as 70 thou, VLD’s as far as 50, and have commonly found one or more of the following truths: the sweet spot isn’t always close to the lands, there might not be a sweet spot at all (aka, the bullet isn’t very jump sensitive), and/or the sensitivity isn’t as big as my inherent inaccuracy.
And that’s probably the biggest driver in my consideration. I’m not a world class shooter, but I’m capable of regularly sustaining groups under 1/2moa. Regardless of what combinations I have tried - neck or full length sizing, jamming/jumping, this press or that, this powder/bullet/brass/primer/cartridge/barrel/trigger/stock/scope or that... I can’t say I have found anything which can make me shoot smaller. I know a few combinations do make me shoot larger, but I know I can’t reliably say jamming has been consistently more precise than jumping when I’m behind the trigger.
I do however fully trust the science behind it, and also fully trust the experience of BR shooters which jam because they’ve demonstrated for themselves that jamming delivers the smallest potential.
Ultimately, I think most folks can safely manage development of a jammed bullet load. The folks who can’t understand jamming influences development shouldn’t be jamming, and they’re often self-aware enough to blindly follow “jamming isn’t safe”. An example of the difference in handloaders vs. reloaders, and the world needs both kinds. And I also think most folks talking about jamming vs. jumping, like myself, really wouldn’t be able to tell the difference.
For the group on the left, the first shot at 12 o'clock opened it up from around 0.3 moa to 0.6 moa but that was the cold bore shot.
