Haven't even handled SP15 but have shot other similar sidecharger. The problem with (un)chambering is that you're fighting against the buffer spring and also the rotating bolt creates extra "resistance" in the process (compared to regular turnbolt). So doing it all quietly is kind of PITA (with non-sidecharger it requires even more dexterity since you have to manipulate charging handle and forward assist at the same time to gradually move the BCG forward). Of course this is not an issue if you're satisfied with letting the BCG slam forward and not care about the noise.
Other problem is the pistol grip and trigger, AR is just more difficult to shoot accurately than decent turnbolt. Your hand position is a compromise, lock time is slow and it's very difficult to get a trigger comparable to something like Tikka T3 (that Rob-E had as the other option).
I have 12.5" and 20" ARs set up for vermin, but if I expect longer range shot I prefer bolt action. If I had to compare distances, let's say I'm confortable shooting bolt action at 1.5x the distance compared to the 20" AR, with similar accuracy expectation. And it's all about ergonomics, not the mechanical gun/ammo accuracy. The 12.5" is still more challenging since it has short forend, but it's very nice to carry (on the chest).
Tikka's are great rifles and you will always have more control with a bolt action than an AR with a side cocking handle.
However, I don't see an issue with noise when removing a round from the chamber as I am finished shooting for the day when that happens. When I leave my vehicle to start shooting, a round goes into the chamber and the safety is applied, no worries about noise from that point onwards. The weapon is re-cocked as soon as a shot is fired and the safety applied, no worries about noise again.
Good quality, well maintained AR's do not suffer with resistance from the rotating bolt.
My SP 15 has great accuracy (German 14.5" barrel & Federal Premium ammo).
All my weapons are pistol grip or thumbhole as I have a shoulder injury and being able to lock the weapon into the body due to its design. I doubt you will find an issue sniper rifle anywhere in the world that does not have a thumbhole stock or pistol grip, what does that say about hand position and accuracy?
I changed the trigger on my Schmeisser not because it was poor, but due to my preference for single stage triggers. I like Timney triggers, but there are many on the market for the AR platform if you are not happy with the factory one.
As the AR is designed to be semi-auto/auto and has a lock time of 10ms, I wonder how you think this is slow?
AR's are not for everyone and what works for you is the important factor when hunting.
The AR's & AK's I have used around the world, have never let me down, but they have all been good quality weapons that were well maintained which equalled accuracy and reliability. If you find you can't be accurate with an AR platform, I would suggest that design is not for you. If you like the AR platform but still struggle with accuracy, it is either lack of practice, lack of confidence, a poor weapon, wrong ammo or training in the weapons system is needed.
If you are anywhere near me I am more than happy to help you sort your AR's out.
…not really….it shoots sub moa every time out.
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