>>Wonder if a low tech bolt action is more reliable than a semiauto. Especially, in adverse environments. When accuracy and reliability are important, I’d choose a bolt action. Or a revolver, too. Same idea.
It’s the 21st century. Modern design and manufacturing processes have made semi-autos statistically as reliable as revolvers and bolt-actions. If you shoot 1000 rounds you might see a difference, but if you need to shoot 1000 rounds, then the semi-auto will make that a lot more practical.
Also, as you mention an auto is designed to shoot multiple rounds quickly and in succession. If a person cannot hit the target the first time while hunting and they have to pull the trigger several times to hit the target then maybe they are not that good of a shot.
Bottom line: a firearm is a tool and the more complicated the tool, the more problems it will have over the lifetime or under adverse conditions.
“Wonder if a low tech bolt action is more reliable than a semiauto. ... Or a revolver, too. Same idea.” [dhs12345, Post 7]
semi-autos statistically as reliable as revolvers and bolt-actions. ....” [Bryanw92, Post 57]
In handguns, revolvers are still more reliable than semi-autos: feed-failure rate of a revolver is only 1 percent that of a semi-auto (unchanged since early 1990s). Standard definition of reliability is the probability that the second shot will feed & fire successfully. Before 1980, the ratio was worse: 1/5000.
Similar rates for semi-auto rifles vs bolt actions.
These numbers are very approximate: much depends on gun design, cartridge design, choice of bullet & load, state of cleanliness of the arm, mud/dust contamination, rate of fire, etc.
Manufacturers keep figures as quiet as they possibly can. So does the military: Dept of the Army is executive agent for small arms development. Prying test results out of them is near impossible, even when other military departments seek the data.
I spent over half my active-duty career performing operational tests for DoD (13 years of it) so I was able to poke about in dark corners few others knew about. After leaving active duty, I spent over a dozen years working in gun repair for a small dealership, which helped shed additional light on the problems.
No rifle can be as accurate as a bolt action, for a given weight, cartridge, and cost. Semi-auto rifles have to be made to looser tolerances merely to function; all those moving parts slamming about at high speed also degrades accuracy. Some semi-autos can be tuned to deliver very good accuracy; only then can they challenge the average bolt action. US military marksmanship unit technicians spent decades ironing out the problems of the M1 Garand; then it was able to fire groups almost as small as issue M1903 rifles did, right off the rack.
Apart from reliability and accuracy, manually cycled arms like revolvers and bolt actions will function with any bullet shape and any load; semi-autos are limited to a narrow range of bullet shapes, propelling powders, and load density.
Revolvers and bolt actions are also far more forgiving of poor reloading practices. They will fire a round that will tie up an autoloader. And semi-autos can be reduced to junk if the reloaded round has a high primer.
Autoloaders toss brass all over the place, which matters more to reloaders than shooters who do not bother with reloading.