Old Soldat Wrote:I have 2 24" barrel A/A Grendel A3 Overwatch and after 2 years using multiple types of powders and 5 different type bullets, I still can not get 1MOA at 100 yards.
The scope is mounted correctly and not loose. I have 6 other rifles will shoot 1MOA at 100 yards. All ammunition is hand loaded. I am an old soldier so I believe in having a clean barrel.
Suggestions are invited.
OS:
Those Overwatch barrels are probably Shaws. Not the best but good enough for hunting purposes. If you are focused on precision, get a top end barrel.
Also, you may be cleaning too much. Shoot it and leave it dirty for a while and see what happens. Or just run a bore snake through it and a chamber brush after blasting.
Oh yes, if you haven't done so yet, try some 120 Sierra Match Kings. Very forgiving bullet. If it won't shoot well with a 120 Match King, get a new barrel.
04-15-2018, 11:07 AM (This post was last modified: 04-15-2018, 11:41 AM by bj139.)
Here is a tracking test I posted last year shot with a standard 24" Overwatch which I assume is a Shaw.
I think these were 85gr Sierra HP over 25gr H335. Mild loads.
bj139 Wrote:I thought there would be more comments about 1 shot every 10 minutes. Is this best?
Kudos to you for the patience. I'd take a temp gun and get temp readings from the very first shot, and subsequent shots to see if you are getting back to ambient temps (betting you are).
Sticks Wrote:Kudos to you for the patience. I'd take a temp gun and get temp readings from the very first shot, and subsequent shots to see if you are getting back to ambient temps (betting you are).
I don't do this but someone on this thread posted they do. I just wanted opinions about this.
All my shots are cold bore shots for shooting tight groups, if I don't the accuracy falls off, I bring other guns to the bench to shoot while I'm letting it cool off
outdoorsmanjimjo Wrote:All my shots are cold bore shots for shooting tight groups, if I don't the accuracy falls off, I bring other guns to the bench to shoot while I'm letting it cool off
I will try this. You never get a second chance to make a first impression.
bj139 Wrote:Here is a tracking test I posted last year shot with a standard 24" Overwatch which I assume is a Shaw.
I think these were 85gr Sierra HP over 25gr H335. Mild loads.
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bj:
Looks pretty much as I would expect from a Shaw. Nothing spectacular but more than adequate for hunting.
100 yards is not a real good distance to determine accuracy potential. 3 shot 'groups' is probably worse.
At least shoot five shot groups and if possible, at 200 or even 300 depending on the purpose you have for the rifle.
I used to buy shot out high power barrels chambered in 6.5-284's and the like. They were 30" long and pretty crusty on the chamber end but made excellent and extremely accurate AR barrels when turned down and 6" of chamber end cut off. Got the barrels for $50-$75 each and the bores scoped like new from the new chamber forward. They were well broken in too and I don't remember one of them that didn't shoot 1/2 MOA...of course these were Krieger, Barlein, and other top quality barrels. Lately due to time constraints I've just bought ARP barrels and they have shot extremely well, certainly less than MOA.
Two suggestions.
1. Examine barrel with a borescope. There is a $50.00 one on amazon that so far is working fine for many. (I like mine.)
2. measure and record the bullet to lands seating length and select a bullet that will do three things.
A. be within 30 thousandth of the lands, B. Fit in the magazine, C. go at least one caliber (.264) into the neck.
For me there were three bullets that I have that do this: Sierra 120MK, Sierra 120 Pro hunter and Speer 140 Hot core, all three give excellent accuracy in my firearms.
I bought an Overwatch as my first Grendel, one with the Shaw barrel back in 2007, or so. With the AA Lapua 123 Scenar factory loads it is a 1 MOA upper, sometimes a 1.25 MOA. The uppers I assembled myself outshoot it consistently, even the AR Stoner Liberty 24" 5r. I gave up chasing handloads on it, as I had better success with my other Grendels. I didn't shortchange it with the lower, either, PRS, JP captured, Geissle trigger, Baer BCG, AA lower, the Overwatch I bought came with it's own bolt.
It is a heavy beast, thick barrel, so I really don't use it much anymore for anything other than nostalgic trips to the range.
Old Soldat Wrote:2 years later I finally replaced the barrel with a ODIN WORKS 20" stainless steel DRM. Accuracy is outstanding.
Any groupings pictures? Im on my 4th BBL now
First 2 were PSA stainless. Nominally 1.5-2 MOA.
3rd was a Team Monster 20". It grouped about the same, maybe slightly better.
4th is an AA 1/9 20", and it is grouping about 1-1.5 MOA. Depending on the load.
My goal is to use this a NRA Tactival AR 600 yard Midrange rifle, while still practical as a general usage rifle.
As to the 1/4 MOA pics, I too have been unable to tr replicate that. If I can get a solid 1 MOA performer in a 600 HD appropriate load, I'll be happy. I think im close with my AA BBL.
1/4 MOA from an AR over multiple KDs would be truly awesome. I can get that from a bolt action, but never from an AR, I have 8 "precision" ARs, in 3 calibers, combinations of my assembly and factory that individually cost more than 1/4 MOA bolt guns and none of them have ever demonstrated repeatable 1/4 MOA results like the bolt guns can.
