Finally got some groups!

[bigbear_98]

I finally got everything tuned like I like it on my grendel. I went through all of the accurizing steps. Bedded the barrel to the receiver. I actually put a shim in as well so it isn't just loctite. I lapped the face of the receiver. I've shimmed the upper and lower receivers to keep them completely tight. Krieger 20" with a suppressor.

I installed a 20moa base and a tubb's level a few days ago. I took it out and shot it today. Adjusted the gas block till it worked well without too much soot on my brass and shot some groups.

Group 1,2,3 were sighting in groups. On group 3,4,5 I was really trying for a good groups. 4 and 5 were to check if my scope and bubble were level. The flyer in group 5 was my second shot of the group, and the scope was canted to the left. I never had any idea that scope level could change a group so much. Scope tracks well. 16moa=16.75"

This was all with factory hornady 123 sst. I have great hopes for this rifle.

The other groups were some 308 loads I had. Just dumping the bullets so I could use the brass for my usual load.

Let me know what you guys think.

[BluntForceTrauma]

Looks like you're gonna kill what you aim at!

John

[montana]

What range did you shoot your groups, I 'm guessing 100 yds? It appears you did a good job on your build and you have a good shooting rifle. I'm interested how your groups would do at two hundred, three hundred yards ,etc. I bet you will be pleasantly surprised shooting at further distance. Great story and pictures ,thanks for sharing.

[bigbear_98]

yes at 100. I will do some more testing later at 200 and hopefully beyond.

[LRRPF52]

Nice groups and consistency. That 123gr SST load seems to love your rifle.

[frittsk]

What did your groups look like before you did the work? I just finished bedding the barrel and truing the receiver because I couldn't get anything tighter that 2". Can't wait to shoot it tomorrow and see if I made any progress.

[bigbear_98]

What did your groups look like before you did the work? I just finished bedding the barrel and truing the receiver because I couldn't get anything tighter that 2". Can't wait to shoot it tomorrow and see if I made any progress.

I had done the barrel to receiver work when I first built the rifle. I only had gotten 45 rounds through it and the bolt broke. During that time I was getting ok groups, but not consistently. See the three pictures below. I don't know that just the receiver work was the only factor as my receiver was pretty square.
I finally got a couple of bolts from Maxim. About 2 weeks ago had a chance to put some time behind the rifle at 500 yards. I was hitting a 4" target but wasn't super consistent.
First I had to adjust the cheek riser a few times to get comfortable behind the scope. Then I noticed I couldn't hold the reticle truly level with the world. When I would dial the knobs, being unlevel would throw the round out of the group.
I then decided to put a little dryfire on the rifle to get used to it during which I noticed a tiny bit of play between the upper and lower receiver. I know everyone says it won't matter, but I saw this with my own eyes. I could no more than twitch my hand, and the sights were off by inches left to right. I believe when the rifle would fire, it would tweak a little and my eyes to sight to target line was getting tweaked. I took a small shim and fit it between the receivers on the sides of the front lug. I also put an accuwedge at the rear lug. The two are solid like a bolt gun now. No lateral movement.

I have also learned a few ways to make my shooting more consistent.
1. Don't use orange dots. For some reason optics and mirage make it hard to focus on them
2. let the rifle be completely supported by something other than your body. Whether it be your bipod and a sand bag, or a benchrest. Whatever. You can make the rifle shoot poorly by trying to fight it.
3. When you are shooting at circles, put the reticle at the edges of the circle. makes it easier to hold on a constant spot.
4. Turn your knobs a 1/2 moa or so off of your aiming point so you don't shoot out your aiming point.

I'm sure I don't need to tell you these things, but when I find something I want to do, I try to learn all I can about it and share the info when I can. Maybe I have OCD? :-)

[frittsk]

Bigbear,

No worries! You shared some great ideas that I have never thought about. Thanks for the input. I have been shooting at orange dots and will try your idea. I've been frustrated with my Grendel as I've been consistently shooting 1/2" groups with my 223 under the same conditions. I've read many posts where bedding the barrel really pays off. When I lapped the receiver, it was pretty square but the barrel was loose in the receiver. I'm hoping the bedding gets me a tighter group.

[bigbear_98]

I was looking to get the most accuracy from my Grendel when I started building it. I lapped it and bedded it with loctite first thing. I decided the loctite wasn't going to make the extension perfectly centered in the receiver so I put a .002 (after measuring of course) feeler gauge blade on the extension then put loctite all over it. It was a snug fit.

[frittsk]

Bigbear,

I shot the Grendel today and there was improvement in the groups after lapping and bedding the barrel. Shot one group at .5" and several around an inch. Now I need to work up some loads. Very encouraging and definitely good enough for hunting.

[bigbear_98]

Bigbear,

I shot the Grendel today and there was improvement in the groups after lapping and bedding the barrel. Shot one group at .5" and several around an inch. Now I need to work up some loads. Very encouraging and definitely good enough for hunting.

That is great news! Which barrel did you have? Glad to hear you're getting good results.

[frittsk]

I have an SSK production 20" with 1:8 twist. It is not a match barrel, but if I can shoot the groups I did not Saturday, I will be happy. Love working on my ARs and have learned a great deal on this forum. I am probably getting knowledgeable enough to be dangerous at this point. I'm thinking about building a 204 - my 3rd AR. Thanks again for helping out!

[bigbear_98]

I have an SSK production 20" with 1:8 twist. It is not a match barrel, but if I can shoot the groups I did not Saturday, I will be happy. Love working on my ARs and have learned a great deal on this forum. I am probably getting knowledgeable enough to be dangerous at this point. I'm thinking about building a 204 - my 3rd AR. Thanks again for helping out!

Awesome! Yes, the black rifle is an addiction. I have built a number for myself and my family. It only gets worse and if you are like me you only want to learn more.

Did you use any of the shooting tips I gave you?

[frittsk]

Yes, I tried shooting at the edge of the circle and it is easier to hold on the same spot. I shoot off a lead sled and usually a heavy shooting bench. Last weekend I had to shoot of the tailgate of my pickup and it still worked pretty well. The bench is much better though. Also loaded up some different loads using TAC and CFE and Hornady 120gr A-Max and 120 gr Nosler BT. Won't be able to shoot for a couple weeks, but anxious to check out the different loads. I have determined that 305 gr of CFE is where I need to be and will need to determine the optimal charge for the TAC. I want the try some 2495 BR but can't find any anywhere. Do you have any advise with these bullets?

[bigbear_98]

I haven't made any of my own grendel rounds yet so I have no load advice for this caliber. I have been shooting factory hornady 123 sst.