What are the downsides of semi-auto?

Semi-auto seems fun and practical. Why would someone not want one?
A LOT of people on AGN think ALL semiauti suck. I disagree, I own 4 and other than me breaking one they have worked just fine. The AEA .30 Terminator is a beast and I've never had even one issue. Only problem is there are no .30 magazines available. My Hatsan Barrage and Bullmaster worked most of the time. I took time and a lot of experiments to get the balance of moderator, return spring and hammer spring just right and now they just plain work and very rarely have indexing issues. My hatsan Invader I went a little too far in my experiments, it is now a bolt action. I may go back and see if i can make it work but the Bullmaster and it are .25 so not much incentive there.

But to be honest, I don't shoot my semiauto much anymore. More a novelty that have run their course with me. Not much need for one pest wise. Terminator was awesome for Raccoons but have not seen one in over a year. Squirrels are one and done so my more accurate side levers work better.
 
A few downsides:

  1. Fixed-mag semi-autos can jam when using undersized and oversized ammo.
  2. In a hammerless design they are shot from the magazine not the breech.
  3. Not the safest airguns if the magazine can’t be removed (a fixed magazine) and the air gun can’t be de-cocked (hammerless).
  4. Need to learn a different method of cleaning hammerless semi-auto airgun barrels with fixed magazines If you aren’t removing the barrel.
 
A normal PCP can be aggravating enough without adding more moving parts and other inconveniences like mentioned by @Ezana4CE. As an original Leshiy owner, when I heard the L2 was in the works, I couldn’t wait. Scratched it when I found out it was a semi. I would currently be on a Taipan Slash waiting list if it wasn’t a semi. The good ones are just too expensive for me to own as a novelty gun. Because that’s what all my powder burner semis are.
 
I'm new to the air gun world. But I have a fair bit of experience in the firearms world, and I would imagine the differences between bolt-action (or single shot) and semi-auto are the same, since Physics is Physics.

Semi-auto requires that some of the energy (from the air pressure or explosion of powder, as the case may be) is used to cycle the action. That reduces the amount of energy being used to expel the projectile. So projectile velocities are a bit lower with semi-auto.... if that matters.

In the precision (firearm) shooting world, bolt-actions are preferred. Fewer moving parts. Tighter lock-up and chambering.

Semi-autos are more prone to malfunctions / misfeeds than bolt-action.

That's all I've got for now! :cool:
 
personally i think semi auto makes for a lazy shooter , just blast away . If hunting too many wounded shots, yes a kill 2 or 3 shots = suffering on the targets part .
@beerthief We’re just discussing the downsides here. Not whether or not we think semi-auto airguns are a good idea to each individual.
 
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For myself have no need for one. Here are some reasons.
I am a firm believer when hunting any animal, 1 shot 1 kill, make that 1st one count.

1. Air Efficiency & Shot Count

Semi-autos often use more air per shot than bolt-action or single-shot PCPs. That means fewer shots per fill and more frequent trips to the tank or compressor.

2. Complex Cycling Mechanisms

The semi-auto action relies on precise timing and pressure to cycle reliably. If the regulator isn’t tuned just right or the hammer spring is off, you can get:

  • Double feeds
  • Failure to cycle
  • Inconsistent velocity

3. Pellet/Slug Sensitivity

They can be picky eaters. Some semi-autos jam or misfeed with certain slug shapes or skirt designs—especially if the magazine tolerances are tight or the feed ramp isn’t polished.

4. Increased Wear and Tear

More moving parts = more maintenance. The cycling mechanism, especially in blowback-style designs, can wear faster than simpler bolt-action setups. O-rings, springs, and seals take a beating.

5. Trigger Feel

Some semi-autos sacrifice trigger crispness for mechanical simplicity. You might notice a longer or mushier pull compared to a finely tuned single-shot.

6. Regulator Stress

Rapid fire can cause pressure fluctuations if the reg can’t keep up. That leads to velocity swings and inconsistent point of impact—especially noticeable in long-range shooting.

7. Noise

They tend to be louder, both mechanically and in muzzle report. That’s not ideal for stealthy hunting setups unless you’ve got a solid moderator and internal baffling.
 
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personally i think semi auto makes for a lazy shooter , just blast away

That's a shooter issue, not a gun (or semi-auto) issue. "Blast away???" Puhleeze. I have many semi-auto firearms. I don't "blast away" indiscriminately. But I will admit that an occasional mag-dump can be very satisfying, WHEN I hit the target with every round. And I do. :cool:
3D-Torso-Targets-sighted-and-point.jpg



The same is true whether it's air guns or firearms. But I think of bolt-action as the "stick-shift" of guns. I like a stick-shift car, too! There's something satisfying about manually working the action. It's more ritualistic. There's a "zen" quality to it, eh? More "being one with the machine."

They each have their place.
 
The advantage of semi-auto.... Less "work" for the shooter. Also... Easier to stay on target from shot to shot.

That said... as I think about it. Since the semi-auto action is going to use more air (to cycle the action).... probably fewer shots per reservoir fill.

Just like with firearms... everything is a trade-off.
 
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I think reliability is my primary concern with semi-auto airguns. There's just not a lot of energy to spare for a semi-auto action to operate on an airgun. Everything has to work perfectly in order for that tiny bit of spare energy to do it's job. Firearms generate massive energy and can operate a semi-auto action normally even when conditions are not ideal. The expectation is that a semi-auto airgun would be as reliable as a semi-auto firearm but reports don't bear that out in my opinion.
Anyway, I've always preferred bolt/lever/pump action to semi-auto for most all of my rifle shooting. I did have a nice Ruger 10/22 that I enjoyed hunting with for a lot of years before we parted company. It was a good time, but I don't want another. I work in technology and work is fast paced, sometimes automated because meatbags can't really keep up and there's no time for real skill or craftsmanship anymore.
I guess I prefer to participate in as much of the shot cycle as I can. I can feel if a pellet had a rough time loading when I am doing the work. Little stuff like that matters to me and I would have to give that up and trust an automatic mechanism to do it for me, correctly, every time. Keep going, and you move farther away from what is actually happening... disconnecting. You can probably guess I prefer manual transmissions in my vehicles, too.
Where I really do like semi-auto is on pistols. But the use case (at least for powder burning side arms) is generally different. That said, because my pistols are target oriented, they are single shot jobs and don't even have magazines. If I could find a good, pellet-shooting 1911 replica with blowback, I'd be interested. I might also be interested in a semi-auto marauder pistol, but I have zero interest in the rifle.
 
Semi Auto cons.
AEA/karma= crap triggers, AEA is not reliable and cheap mags.
Huben= mags not removable, very easy to eat pellets fast.
Evanix=slow action, not a great trigger but better than AEA, small count mags.
Leshiy= small mags, trigger has to be punched a bit to not hiss.
Huben and leshiy have good triggers, not great but good, huben with the edge. I have owned all of these,but the Karma( spoke to owners), the only ones i would buy again is a leshiy2 or a gk1. The rest is not worth the time. Then i run into pellet usage and consumption. If you really want semiauto, just get a ruger 22/45 and bulk ammo. Cheap and does it reliably always.
 
I think reliability is my primary concern with semi-auto airguns. There's just not a lot of energy to spare for a semi-auto action to operate on an airgun. Everything has to work perfectly in order for that tiny bit of spare energy to do it's job. Firearms generate massive energy and can operate a semi-auto action normally even when conditions are not ideal. The expectation is that a semi-auto airgun would be as reliable as a semi-auto firearm but reports don't bear that out in my opinion.

That makes sense to me.
 
I brought my semi auto today to give you a more fair opinion. It's fun, but i spent more time loading than aiming or shooting and I drained my buddy bottle about an hour faster than usual 😅 it's a 20 fpe 22 cal with a 330cc bottle on it. Now I'm shooting an old junk crosman 2100 pump that I was given broken and i fixed. Different preferences for everybody.
 
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A few downsides:

  1. Fixed-mag semi-autos can jam when using undersized and oversized ammo.
  2. In a hammerless design they are shot from the magazine not the breech.
  3. Not the safest airguns if the magazine can’t be removed (a fixed magazine) and the air gun can’t be de-cocked (hammerless).
  4. Need to learn a different method of cleaning hammerless semi-auto airgun barrels with fixed magazines If you aren’t removing the barrel.
These are some of the reasons why I'm leaning towards the Mordax but the Mordax is large if used as a pistol. No matter which one I get I've learned there are things I won't like about each because it's that way with every gun I've ever owned.

Concerning my Steyr's I mentioned earlier. They both have nice triggers, have been super reliable, and a pleasure to shoot.
At 10M one ragged hole off a bench for the LP5, and have shot enough groups touching at 50Y with the ProX to be plenty satisfied with it's precision capability.

Both have removable mags too. Just barely enough room to get a pull through patch using tweezers to grab the loop and pull it out but can be done with patience. I haven't ever taken the barrel off of them or seldom need the barrels cleaned.

It was 20-ish years before I finally needed a rebuild for my LP5 which is amazing.

Have never been sorry and have had absolutely no regrets that I acquired them!!!

Now the FX Revolution I owned was the opposite! Not FX's best try.
 
Downside for me is pellet consumption, at least when plinking cans and such. Got my own air so that isn't an issue but would be if I had to rely on a shop for it. My solution for pellets is Crosman's offerings. My L2 and Steyr both shoot them well enough for plinking. If I'm going for a live target I load Hades for better accuracy and effect.

The L2's are more complicated and are more prone to malfunction because of that. I've got 3 of them (.22, .30/.25, .35) and have learned how to treat and maintain them for reasonable reliability.

The Steyr Pro-X is on another level... Or two! Accurate, simple, efficient, and quiet. No air used to cycle the removable mags. 200b fill gives me 80 shots. A nice consistent trigger. Downside is price. I wouldn't own one if I hadn't gotten a crazy good deal on a used rifle.
 
If I'm not mistaken, and I am mistaken a lot, our primary reason for owning an air guns is because we enjoy shooting. I guess one could enjoy staring at their collection of metal, plastic and wood that air guns are made from more than shooting them, but think that would be rare.

I understand the enjoyment of the process i.e. you feel more involved in it when a bolt action is the use case,. But the bottom line is, you still pull the trigger because you enjoy it, regardless of the number of steps that got you to that point. So, I'm a bit confused when you say ammo usage is a con. Isn't shooting the objective? If so, why wouldn't shooting "more" better meet that objective? Speaking for me, shooting more equates to more enjoyment and it would never be a con for owning a semi or full auto air gun.

Is it simply the expense of having to buy the ammo that's the real con?

NOTE: When I say "you" that is not directed toward anyone in particular, it's just a figure speech needed to convey my point.
 
Try a Condor in .25, What do you mean by set up? please tell, just interested. Very high end in $$$

Speaking for myself who has purchased a few Huben K1's and a GK1 fro Kelly at Kraz Cool Airguns.

Kelly asks us how we want our guns setup for preferred pellet/slug, velocity, etc... He'll make recommendations on what works best, and is an excellent listener who takes the time needed to keep his customers happy. He is extremely knowledgeable about Huben's and his after service support is second to none!

No "take off the shelf, put in box and ship" from Kelly. He keeps us informed throughout the 'setup' process, and we know exactly what we are receiving and how it will perform.