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Posted: 12/8/2016 2:51:16 PM EST
I built a Mega upper/lower with a 16"Noveske Barrel. BCM bolt with Gemtech carrier. On the end is a Saker 762. Vortex Razor1-6, SAA trigger
I was expecting a little better groups then what I received. All shots where with the rifle in a lead sled with no weight & I had to re-adjust after every shot.
100yards, very little wind.

Ammo: IMI Razor core 77gr, Barnes 5.56 69gr, Federal 77gr 223 & Hornady 75gr 223




Link Posted: 12/8/2016 3:08:28 PM EST
Assuming those are 1" squares, it looks like it's shooting right around 1 MOA. What were you expecting?
Link Posted: 12/8/2016 3:11:24 PM EST
I kind'a agree....
Link Posted: 12/8/2016 3:21:44 PM EST
[Last Edit: 12/8/2016 3:24:38 PM EST by Banjo51]
1" squares
I don't know if I measured MOA right. I went from center to center of the farthest apart shots.

Barnes was 1.02
Federal was .744
Hornady was 1.11
IMI was 1.49

Expected a .5-.75 MOA , Is that unrealistic? I don't know, still learning.
Link Posted: 12/8/2016 3:32:13 PM EST
1 - how many rounds through the barrel total? your groups should settle down a bit after it's broken in.
2 - ~1moa is a realistic goal, consistent 1/2moa isn't common on factory ammo. Every gun is different and you just need to find the load that your rifle / barrel likes.
3 - 3 shot groups will tell you that you are on paper and hitting where you want it, but you need more rounds to judge consistency.
4 - gas guns can be finicky on a lead sled. Have you shot it off of bags?
Link Posted: 12/8/2016 3:43:12 PM EST
Not sure on total round count. 350-500 rounds I would have to guess.

Never really on bags. What causes the issue with the Leadsleds and DI?
Link Posted: 12/8/2016 3:54:50 PM EST
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By Banjo51:
Not sure on total round count. 350-500 rounds I would have to guess.
Never really on bags. What causes the issue with the Leadsleds and DI?
View Quote


Incorrect use of a lead sled can affect the groups on any rifle, but consistency is the most important aspect, especially with an auto.
Are you strapping it in, and how? Are you fully seating the stock the same way for each shot? Remember, the gun starts traveling to the rear before the bullet exits the bore, and any interaction with the sled, the bag, or your shoulder must be consistent.

I'd say pick up some shot / sand bags, including a rear bag, and try it out. Your POI will likely change, and if you do your part, your groups may shrink as well.
Link Posted: 12/8/2016 4:30:26 PM EST
No straps on the Leadsled DFT. Pretty sure I made sure it was seated the same way every time, well the best I could anyway.

I am going to try some weight in the lead sled and just sitting on sandbags as well.
Link Posted: 12/8/2016 4:36:04 PM EST
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By Banjo51:
No straps on the Leadsled DFT. Pretty sure I made sure it was seated the same way every time, well the best I could anyway.

I am going to try some weight in the lead sled and just sitting on sandbags as well.
View Quote


May be relevant to your interests:
http://www.ar15.com/forums/t_3_18/569429_Lead_Sled_DFT_Issues.html
Link Posted: 12/8/2016 4:41:49 PM EST
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By RDTCU:


May be relevant to your interests:
http://www.ar15.com/forums/t_3_18/569429_Lead_Sled_DFT_Issues.html
View Quote


Interesting. Yes getting the right cheek weld is a issue. The rifle sits higher off the bench then what I am used to and had to sit on the bench with a foot under my butt to be at the right height.
Link Posted: 12/8/2016 7:19:04 PM EST
Try five shot groups to get a better assessment of the accuracy of the rifle and individual loads. There is too much element of random chance affecting a single shot when you only shoot three.

I use three shot groups to confirm that the rifle has not changed its zero, but that is all. I use five shot groups for evaluating accuracy of factory ammo, and for load development of my handloads. To determine whether you are MOA or under, the groups need to be larger, IMHO. Some would say ten shot groups. That's expensive, but does give you more valuable data points.
Link Posted: 12/10/2016 9:21:02 AM EST
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By Banjo51:


Interesting. Yes getting the right cheek weld is a issue. The rifle sits higher off the bench then what I am used to and had to sit on the bench with a foot under my butt to be at the right height.
View Quote

Banjo: Yes, you should expect better accuracy from the Noveske barrel. What is its twist rate? Sounds like you are confined to factory ammo. That means you will have to spend some moola until your find the load your rifle likes. I suggest you try some factory match ammo with bullets in the 52 to 55 grain range, from name brand makers like Black Hills. In my experience with 1in8 twist barrels, these shorter pills do better at 100 yards.

Ditch the sled and start shooting off of bags or better yet a quality bipod with a bag at the rear. Pay particular attention to your trigger pull. The key is consistency. Take care to pull the trigger straight back. When you have to readjust your position after each shot, variation in point of impact changes. Once everything is in place, you should expect 10 rounds into less than an inch at 100 yards, maybe more like .75 inch. good luck - CW
Link Posted: 12/11/2016 1:03:25 PM EST
[Last Edit: 12/11/2016 1:08:14 PM EST by Banjo51]
1-7 twist
Trying heavier grains in hopes to be shooting out to 500-600yards. Going to try different Ammo and 10shot groups on sand bags.

How long should I let the barrel cool inbtween groups?
Link Posted: 12/11/2016 2:59:31 PM EST
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By Banjo51:
1-7 twist
Trying heavier grains in hopes to be shooting out to 500-600yards. Going to try different Ammo and 10shot groups on sand bags.

How long should I let the barrel cool inbtween groups?
View Quote


Yes, Try something loaded with 77 grain Sierra Match Kings, (77 SMK around here) with that twist.

I think 5 shot groups are ok for this purpose and would not heat up the barrel as much. If shooting 10 shot groups, I shoot 5 shots and then permit it to cool at least 15 minutes and then shoot the second 5 at the same target. Others will have other suggestions. I don't know if there is a "best practice" on wait time.
Link Posted: 12/12/2016 7:00:48 AM EST
I have to be honest with you, I don't trust the looks of those groups. all but one of those looks like a tighter 2 shot "group" plus a flier. I would want to see either groups with more shots, or more groups of 3 shots.

sometimes a rifle likes what a rifle likes, and the only thing you can do is figure out what it likes. It doesn't matter what you want it to eat. Much like children if you force feed them what you want them to like, you should expect less than desirable results. I have one barrel that, for whatever reason, shoots better with a Spitzer designed Game King series bullet, than any of my SMK pills I have tried to push through it.

Try some other loadings if you want better results, as you never know where you might find it. Different manufacturers will use different powders, neck tension, and seating depth - even though they all load the same projectile into their cartridge. When you're trying to shrink things that are already hovering at and below MOA, those factors all contribute, especially in an auto-loader.
Link Posted: 12/14/2016 7:04:07 PM EST
I've found almost any handload I can whip up will beat factory ammo for accuracy in my ARs.
Link Posted: 12/15/2016 10:51:13 PM EST
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By nvcdl:
I've found almost any handload I can whip up will beat factory ammo for accuracy in my ARs.
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Agreed!
Link Posted: 12/16/2016 7:54:43 AM EST
Originally Posted By Banjo51:
I built a Mega upper/lower with a 16"Noveske Barrel. BCM bolt with Gemtech carrier. On the end is a Saker 762. Vortex Razor1-6, SAA trigger
I was expecting a little better groups then what I received. All shots where with the rifle in a lead sled with no weight & I had to re-adjust after every shot.
100yards, very little wind.

Ammo: IMI Razor core 77gr, Barnes 5.56 69gr, Federal 77gr 223 & Hornady 75gr 223

<img src="https://www.AR15.Com/media/mediaFiles/332844/IMG-3056-100406.JPG " />
<img src="https://www.AR15.Com/media/mediaFiles/332844/IMG-3053-100405.JPG " />
<img src="https://www.AR15.Com/media/mediaFiles/332844/IMG-3055-100403.JPG " />
<img src="https://www.AR15.Com/media/mediaFiles/332844/IMG-3054-100402.JPG " />
View Quote

What is the twist on the barrel? Are you sure you should not be shooting a lighter load??
Link Posted: 12/16/2016 8:21:04 AM EST
In theory with a 1/7 twist the 77gr bullets you have been trying should give great results.
In practice I have seen good results when shot at longer distances but results can be misleading at 100yds

Some of the high end compeditive shooters talk about bullets "settling". They claim it takes time/distance for the bullet to calm down and reach stable flight. In other words the bullet starts with somewhat of a wobble then settles down and flies straight.

Some of the hot shot service rifle guys shoot 52 or 53 grain loads at 100 yard reduced courses and a mix of 69 to 77 or even 80gr at the full length 600 yard courses

I also agree the three shot group is a small sometimes misleading sample of results
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