SUB2000 Accuracy


Howdy All
I would like to know what kind of accuracy you are getting at 25 and 50 yards ?

I’m having a problem with group size, It seems more like a pattern than a group.

My rifle is not consistent in that I will put 4 shots inside of the 2.00" bulls eye at 50 yds then I get two flyer’s that are 3.50" from the rest of the group low and left . I went to a fresh target and my shots are all over the place. one will go high right, the next low left off of the target then the third shot will be six inches high centered over the bulls eye, then the next 5 shots are grouped nice and neat inside the 2.00" bulls eye. I’ve repeated this several times with the same results. Had my hunting buddy try it and got the same results. If I was shooting a consistent 4.00" group I would be happy.

It does not matter if I use my hand loads or factory ammo (124 gr. Blazer Brass ) . I’ve used 122 GR. lead and 124 GR. jacketed bullets for hand loads. Powder used is Power Pistol and HS-6 both of which have worked well in my handgun . I have Winchester 231 and Accurate # 5 powder that I can try also.

It could be the bullets. I have some 115 GR. Hornady HAP bullets that are supposed to be a quality accurate bullet and will try them.

I’ve put just about every M*CARBO upgrade on my rifle and the trigger kit improved the trigger a lot, also installed the flip up peep sight . I’ve gone over the rifle to make sure everything has been installed correctly and it is, the rifle function is good no problems with that.

A little about my background, I’ve been an aircraft mechanic and inspector for 40 years. My reason for telling you this is so that you understand that I pay very close attention to detail when reloading or installing parts.

Maybe I’m expecting more than the rifle is capable of.




This right here. I just think people expect every gun to be match grade precision accurate. I think there’s levels to this firearm game and some manufacturers are going to be head and shoulders above others when it comes to precision accuracy. My expectations for the sub have always been tempered. I use it to compete and plink and for that inside 30 yards it’s dead on. But then again I’ve never been a “sit on the bench with a rest and shoot all day” kind of guy. I want to run and gun and as long as the sub can hit center mass on the target I’m gtg.


Thanks for the reply Kona.

I don’t expect tack driving accuracy out of this rifle, I just want it to be consistent in grouping. I can live with a 4 or even 5 inch group just as long as it remains consistent. Flyers are to be expected for whatever reason but to shoot one group where all the rounds are in the same general location and then the next mag shoots a pattern is not acceptable to me.

When sighting a rifle in I always bench it to get it on target and prove accuracy so when I’m shooting off hand or other position I know that any inaccuracy is me and not the gun or ammo. Speaking of ammo I have some Federal 124 GR. FMJ that I will use and see if is any better.

When shooting I was careful not to put any upward pressure on the barrel thinking that this could / might affect accuracy due to the way the rifle is designed to fold open and closed, just trying to eliminate things one at a time.

Have you shot your rifle for accuracy ? What were your group size at 25 & 50 yds ? Again thank you for your reply.



@MontanaCowboy. Nope. Benched it for red dot zero and as long it’s close to center on a 9 inch paper target at 25 yards I’m good w it. Hopefully MCARBO has a match grade barrel in the works. Fingers crossed.


How are you holding the Sub? Holding so that there is no stress at the chamber (because this is the point of fold) will get your best results. I don’t sling the Sub for this reason.


@Kona Exactly!! The purpose of my S2K is for gunning on the move for ranges 20-50 yds.


We have a sub 2000 in 40 sw glock. All upgrades except for the performance trigger bar, on backorder. I just ordered thier muzzel break has not arrived yet. Vortex strikefire green/red dot. Tack hammer at 25 yards. Inside half dollar. Load 40 sw hornady HAP. If you can hold it steady it should hit where you aim it.


I am not much of an expert reloader but over the past few years I have come to learn that some firearms prefer one ammo over another or handload over another. While your buddy’s same exact rifle prefers the opposite. So I agree that the Sub is not a 2 shot one hole rifle but experimenting with different powder and bullet combos along with OAL’s can really take a rifle from a shotgun pattern to inside your tolerance with some trial and error. There’s a small thread here of reloaders that maybe someone can help guide you for what works good for them.

Mine personally likes Xtreme 124gr RNCB with 5gr of CFE Pistol. OAL I am not sure off hand at the moment.

What Reload Works For Your S2K?

Thank you all for replying to this post. Have the grand daughter this weekend so had to tend to her for awhile.

To answer one of your guestions I’ve been reloading for almost 40 years so I feel I have a good understanding of the process . I’ve had only one problem during that time and that was with a military 30.06 round I reloaded, it failed to fire due to the primer pocket was deeper than normal and the firing pin could not set it off.

When shooting I’m holding the S2K so that it is only the weight of the barrel resting on the shooting rest forward of the action mid point between the forward end of the barrel and the action.

I’m a experienced shooter better than some folks but not as good as other folks. My hunting shots are limited to max of 75 yds with my hand gun but prefer closer. I do not shoot unless I know that I have a killing shot. The farthest shot has been 35 yds.

I’m looking to buy a red dot for the rifle, I’ve been looking at them for the last 6 weeks and this weekend a couple of places have a sale going on. Right now I’m looking at the SIG ROMEO5 , SIG ROMEO5 XDR and the SIG ROMEO5 COMPACT. Reason is my eyes are getting worse the older I get. Need to make my mind up soon.



I have had pretty good luck with consistant groups using 115 grain bullets. My 9mm pistols like 124 grain best, but my S2K likes the 115 grain best. My pistols like Power Pistol powder, but the S2K seems to like slightly slower burning Bluedot powder. I just picked up a Sierra reloading manual and it has a section of data for pistol caliber carbines. I am beginning to test some of those loads now. So far what I’ve experienced is I am getting better results with slower powders. To me, this makes sense since there is 12 more inche’s of barrel for the powder to slow burn in and thus having a more consistant pressure curve.


Morning Texprep
I’ve been using Power Pistol too. Been using HS-6 which is still faster burning than Blue Dot. I do have some True Blue which I have not yet tried and it is close to Blue Dot on the burn rate chart. I see that the Lyman 50th Edition has load data for True Blue which is slower burning than HS-6.

What is your average accuracy out of your S2K ?


Here is a photo of a target with 116 rounds (3-33 round and 1-17 round mag) shot at 25 yards. The ammo here is S&B 124 grain FMJ factory ammo. The orange circle is about 4-1/2". As you can see, the majority of the shots grouped fairly well. There was some flyers, but I think most were me. One thing I don’t like about this rifle is the ability to get a good cheek weld to the stock. I’m a pretty tall guy, 6’5" and really need about 1 to 2 more inche’s of stock length. I’m constantly catching myself holding this carbine off my shoulder to get the cheek weld I want. This was the day I was sighting in with all new internal Mcarbo parts and the new Mcarbo notch flip sight. I was having a problem with the flip sight drifting down (forward) on me with the recoil of the gun. I corrected that by tightening the screw more. With the same sight in, my groups on the 50 yard range are to the high side of the bullseye

This was my shooting setup on the day this target was shot.


I’m a tall guy too, 6’3 and longer arms than legs! Hoping for the definitive MCARBO solution in a new buttstock that would address stock length. I don’t really dig the ATI butt pad.

I attached a pic of @Dred’s S2k and his awesome integration of an AR Minimalist buttstock. Looks like a couple more inches there! I want one. I know that I ain’t alone! :money_mouth_face:


I shot mine for the first time today. I was shooting at rifle targets at 25 yards. I was shooting with my arms resting on the bench. The gun wasn’t touching it. I was punching out most of the large bullseye area which is rare for me since I shake. Ammo was 124 grain Federal American Eagle. It’s way more accurate than I expected and way more accurate than me.

I was holding the grip about middle to in on the handguard.


@GL9CK I think most people who shoot the S2K find it more accurate than they thought it would be. :smiley:


Have you checked if there is any play between the barrel and the stock? This target was from a 22rd mag. The flyers kept getting worse until i tightened the barrel nut.


Texprep I am 5’ 8" so I am a good bit shorter than you. I do agree about the length of the stock needing to be a couple inches longer for a proper cheek weld.

I have the flip up peep sight on my rifle from M*CARBO and mine came loose so I tightened it up at the range. tomorrow I will remove the screw, re-clean and use a little more blue Loctite . When I first installed it I cleaned the threads with alcohol then applied Loctite and it sat for two days before I fired the rifle.

I have fired 4.500" groups at 50 yds and that was 14 shots, if you include the flyers it would open the group up to 6.750 inches. I will probably hear that I should not be complaining about that but It does not do it consistently. As I have said I shoot one target put in a new mag and the next group has all kind of flyers more like a pattern than a group.


Gilligan I did check to see if there was any play but I did not detect any. Did you use a torque wrench to torque the barrel nut ? If so what torque did you set the wrench at ? Just out of curiosity I’m going to check it again.

GL9CK I do have some Federal 124 gr. and I will be trying that next time at the range.


Just curious, is it a particular mag or brand of mags that gives you the flyers or is it a random thing where the mag shoots good once and then all over the next time?


I keep a fistsized group at 100m, that was before the upgrades im getting ready to do, only change i made when i got the rifle used was to have the barrel crown’ed. I do that to all my long guns, im a creature of habit sometimes. I will get some pics after my upgrades, . have 1 more piece to buy before tearing down…

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