I have lived and die by a bolt action rifle. But I finally bought a windham weaponry HBC AR. With Hornady 55gr. SP W/C it groups 3/4" at 100 yards. Not as good as my bolt rifles but pretty impressive for a semi auto. Any one else had this experience?

Yep. Parts gun with a Montana Rifleman HBAR 1 in 8 barrel. 50gr HP's or 77SMK's

Colt Competition---.350 from the factory with target-shot by humans and over a sand bag-no mechanical rest=great

Another reason why a quality AR makes a better choice as a varmint rifle than a bolt action:)

If a AR won't do this then all it needs is a better barrel

My Barnes Precision rifle will shoot 69gr Nosler CC, 75gr Hornady BTHP, or 77gr Nosler CC with RL15 or H4895 into ragged holes at 100yds and will hold .6-.75MOA to 600yds. I've been shooting the 75gr and 77gr bullets in DMR matches lately. I've only owned 4 black rifles: 3 Barnes and 1 LWRC. The LWRC is the only one that wouldn't shoot like that.

I never kept a barrel that would not put 10 shot groups at 600 yards into at least 3-4 inches max. Very much so had many barrels that would do 2.5-3.5 inches normally.

Best group was a 5 shot group in a really good Krieger at 600 that we roughly put a ruler on for grins, around 1.25 inches

Good ones will generally shoot .5 moa at 100 easily. Further out it takes some tweaking.

Jeff

Mine does this day in and day out with 25 gr TAC and a 50 NBT, no matter the round count down the barrel. So far I would think its at about 150-200 with out being seriously cleaned (I have mopped it for powder but thats it).

Cleaning is for the 500 round interval if that... I know competitors that were still winning matches that didn't clean all year... we are talking around 3-5000 rounds or so depending.. just wiped the BCG group down now and then and re lubed..

I was out this morning working up a 6.5 Grendel load. 100gr TTSX, looking for best jump to the lands. Shot a 3-shot group of 0.6" at .030 off the lands. I'm getting 3/4" with 100gr Nosler BT also with this upper. It's an Alexander Arms 20" upper
with a lower a buddy and I put together with parts he had. I'm sure it would do better with a better trigger and a better nut behind the trigger.

The 6.5 grendel will shoot even better than that with a better tube that Bill sells with the uppers. A Krieger or similar and I've shot some really snug groups at 600 with one many years ago.

Working on loads with the powders available I shot a 3 shot at 300M plus a bit on a day when the wind didn't blow and the sun was behind clouds , that measured 0.61. This with a Fulton Armory FAR308/ AR10 type. Stays under 1/2 minute with most loads at 300M. Other people and rifles do even better.

Fulton must still be selling guns from the look of this post. under 1.5 inches or so at 300 ain't really bad.

Mine puts 3 in 0.6" @ 100, using 60gr Hornady SPs and H335 or AA2230. Just a tad larger using 55gr MSS Varmint Extremes. That's with a 4x scope and milspec junk trigger.

My son and I have 3 FAs between us, the 2 AR15s are Preditor models and are target accurate. My 308/762 is the "Liberator" model, its hybrid target and military capable, Criterion barrel, side mount bolt handle. Ive become fond of all of them(except for the weight).