My love for this round is fading

[pinzgauer]

Can anyone explain this craziness? I am starting to think its me and I have some sort of crazy mental block that wont allow me to successfully shoot the first round. I will post pictures of the groups when I get home from work this evening.

Coming in late, but the one thing I noted in your last post is you are not using the "sweet spot" powder & bullet. Not bad, but not what most of us have found to be ideal in our Grendels.

I found the Sierra's a bit finicky, especially the VLSD'ish one. (123g?) 120g was OK. Once 123g AMAX's & SST's became available I found they worked much better in pretty much every load I tried. No surprise also that my best groups came from factory 123g AMAX ammo.

Likewise, many of us have found AA 2520, 8208, CFE, etc to work best for us. I don't have much experience with TAC in Grendel. But it seems not as popular here. (Though there may be others getting great results)

I guess my point is there may be more to it than cleaning regimen, cold bore, etc. If I saw the same exact results with factory AMAX I'd be more concerned about the rifle/bore/whatever.

My approach is to try to isolate and exclude different factors. same with factory as reloads? Check, not my reloads. Same on bags vs not? not a foreend issue, etc

I did have a cheap optic once do what you are describing. move the rifle it would be way off. 2nd and later shots solid, until I moved the rifle and it would start again.

[tackdriver]

I think that the first shot being loaded by dropping the bolt vs following shots having a different point is an issue that has been talked about before. I have the same issue and due a similar excesses when I shoot groups

I have a seperate bullseye that I shoot my first shot at and another for the next 5. I can do this 5 times and end up w/6 good groups. I don't compete so it doesn't bother me but I would like to know the mystery?

[1911man]

Here are the pictures. The pic with the two black circle targets shows my initial shots where the first shot was wide of the group then the following 4 were really tight. The next two pictures show a couple groups where I fired 6 shots but with the first shot being intentionally off the target and then 5 shots after that. On the second pic those groups look like 4 shots but there are definitely 5.

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[1911man]

I think that the first shot being loaded by dropping the bolt vs following shots having a different point is an issue that has been talked about before. I have the same issue and due a similar excesses when I shoot groups

I have a seperate bullseye that I shoot my first shot at and another for the next 5. I can do this 5 times and end up w/6 good groups. I don't compete so it doesn't bother me but I would like to know the mystery?

Yeah, I also have been loading each round one at a time to see if there was a difference it the rounds cycling through the magazine and the one being loaded first. Nothing changed. I dont have much of problem with getting groups this way, but it just doesn't seem right. Also, the first round is the most important as it is the round that will be shot at an animal. I am going to try to chart all of my cold bore shots to see if they are predictable. One thing I was really happy about is the consistency of where my XBR load is landing. If you look at the second pic where the orange target is above the black circle target. Those two groups would be right on top of each other which shows my point of impact is consistent. Its just that dang first shot. I am still going to take everything apart and square the receiver and add the adjustable gas block as well.

[lamrith]

I think that the first shot being loaded by dropping the bolt vs following shots having a different point is an issue that has been talked about before. I have the same issue and due a similar excesses when I shoot groups

I have a seperate bullseye that I shoot my first shot at and another for the next 5. I can do this 5 times and end up w/6 good groups. I don't compete so it doesn't bother me but I would like to know the mystery?

Maybe (if your range allows it ) load up a 20rnd mag with 16 rnds. Drop the bolt like normal for 1st round. Aim 1st shot off to side like have been for that flier, then shoot 5 shot group, put gun on safe let it sit for a while, shoot another 5, let sit and final 5? That will tell you if it is in fact the drop off BHO versus literally the 1st "cool" shot that is causing an issue, or if it is a something else.

[pinzgauer]

Coming in late, but the one thing I noted in your last post is you are not using the "sweet spot" powder & bullet. Not bad, but not what most of us have found to be ideal in our Grendels.

Rereading your initial posts, I realize you've been trying all the right things. Did not mean to insult your intelligence!

It's very interesting to me that you saw the same excellent factory hornady accuracy initially. Others may have beaten the AMAX loading, but in my bull barrel grendel it was fairly consistent 1/2 MOA at 100-200 yards. And that was with modest glass and trigger. I have not been able to beat the factory loading, but will be starting with Lapua Brass/CFE/123g AMAX. Mine also shoots the 123g Nosler Custom Competitiion blems ok, but not as good as the AMAX. (But I've not tried to dial them in yet)

Curious what you are torquing to? Early on people were torquing on the high side, but later input from Bill Alexander and other serious accuracy types suggested lower ranges. (minimum plus whatever required to line up)

Another thing to try would be to single feed your shots and look for a behavior change. (IE: drop the bolt each time) Should not have to do these things, just things I would try to isolate.

Wish you luck! And don't give up in Grendel, it's the most fun I've had with AR's lately.

[1911man]

Rereading your initial posts, I realize you've been trying all the right things. Did not mean to insult your intelligence!

It's very interesting to me that you saw the same excellent factory hornady accuracy initially. Others may have beaten the AMAX loading, but in my bull barrel grendel it was fairly consistent 1/2 MOA at 100-200 yards. And that was with modest glass and trigger. I have not been able to beat the factory loading, but will be starting with Lapua Brass/CFE/123g AMAX. Mine also shoots the 123g Nosler Custom Competitiion blems ok, but not as good as the AMAX. (But I've not tried to dial them in yet)

Curious what you are torquing to? Early on people were torquing on the high side, but later input from Bill Alexander and other serious accuracy types suggested lower ranges. (minimum plus whatever required to line up)

Another thing to try would be to single feed your shots and look for a behavior change. (IE: drop the bolt each time) Should not have to do these things, just things I would try to isolate.

Wish you luck! And don't give up in Grendel, it's the most fun I've had with AR's lately.

As mentioned in my previous post I have been loading them one round at a time and dropping the bolt as you suggested. As far as my torquing of the barrel I put moly grease on the threads and torqued to 30 lbs. Then I back off and tightened to 30 lbs again. Then I torqued the bolt until the hole for the gas block lined up. I believe it was 70 lbs but I am not sure as i had to back it off just slightly to get the hole to line up. The barrel looks super clean to my naked eye, it looks perfect in fact shiny as it gets. I have 300 rounds through it right now and I cleaned it thoroughly before my last outing. I plan on letting it run dirty for a while to see how that goes. I really like the loads I worked up with TAC so I am going to play with that powder and little more to see what kind of groups I can get. I also have all of the parts/tools I previously mentioned now so I am going to use them. When I go out next time I will have a square receiver face,bedded barrel, and an adjustable gas block. Thank you for your input.

[pinzgauer]

70 seems high after an initial 30-35lb torque, and I'm not a fan of backing off once peaked. (But others may have different approaches)

I've done it multiple ways, but I've typically increased the torque 5-10 lbs after initial torque and retorque. And keep increasing until you are lined up. I don't recall it taking more than one or two increases.

There is also the nuance of torque wrench in line with tool or at 90 degrees. Some will tell you to use it at 90 degrees, but the GI manual and spec is for it in line with the a GI tool. So the torque value already adjusts for the additional leverage from the wrench.

If you are going to the trouble to re-do the barrel torque it's worth checking flange and nut squareness. Does not make sense to "face" the receiver and not check the other items as well.

There are others with far more experience, maybe they'll also weigh in with suggestions.

Good luck!

[1911man]

I considered the squareness of the barrel nut as well, I am wondering if I can used the Brownells tool for that. I am not sure what part your referring to when you say flange?

[pinzgauer]

I considered the squareness of the barrel nut as well, I am wondering if I can used the Brownells tool for that. I am not sure what part your referring to when you say flange?

Just confirming the barrel extension is square and the flange on the barrel. Personally, I believe these are diminishing returns because you have a decent barrel and they way the extension and barrel are mfg'd it's unlikely they are not square.

Just keep in mind the brownell tool only squares the receiver nose, and there are other components which also "squareness". Personally, I don't believe it makes a difference if you have a properly made receiver. Yes, I know some receiver noses are not square. But the majority of high accuracy players I know don't find this a big deal. And two major vendors who do nothing but high accuracy stuff don't even offer this a a service, etc.

But this is a separate debate that will not be resolved anytime soon, no need to rehash.

[tackdriver]

I have been head scratching for months about the change of poi from that first round to the rest of the mag. I am just an average Joe shooter and handloader and am all ears to info or just opinion from others. What are your thoughts on the bullet possibly sliding out of the case on bolt release ( changing OAL)? I imagine this could be just enough to change poi a little. This is assuming you don't put a crimp on your loads and I realize the bullet could slip on all the following rounds but maybe to a different amount of movement? I realize it's the same bcg but it seems a bolt closing from the locked open position and the bolt closing from the cycling motion could be different. Just a thought!

[LRRPF52]

Dry-firing until you're in your zone will eliminate the 1st-round flier in my experience. I have seen a lot of people say their rifle does this or that with shot placement, especially AR10's, but I think it's just that 1st shot after being rusty. Then the gun settles the position with the initial recoil impulse, and the remaining shots can be really tight.

I'm not seeing any accuracy issues with your groups 1911man.

[1911man]

Dry-firing until you're in your zone will eliminate the 1st-round flier in my experience. I have seen a lot of people say their rifle does this or that with shot placement, especially AR10's, but I think it's just that 1st shot after being rusty. Then the gun settles the position with the initial recoil impulse, and the remaining shots can be really tight.

I'm not seeing any accuracy issues with your groups 1911man.

Yeah, I will second this sentiment. I practice dry firing over and over again before I shoot to try to make sure that first round is true, especially when I am hunting because obviously your only going to fire one round. Either way some times I just dont get in a groove until I have put a few shots down range. That is why before shooting for groups I send a couple down range. 1. To foul the barrel and 2. To get a feel for the shot. I am shooting about once every two weeks right now so I feel very comfortable behind this rifle. If I go 2 months or more without shooting I dont feel well at all about my shots. I am really liking the two loads I came up with using TAC. I am going to play with that powder a little more to see how much my rifle likes it.

[Jakal]

Take a black sharpie and color the whole bullet from case mouth to the tip on 6 rounds. Measure the COAL or Ogive of all 6 & write down and load mag from 6 to 1 order. With the bolt locked back, insert mag and (muzzle down range etc.) release the bolt. Does the bolt fully engage into battery? Now eject that first round and lock back the bolt, any land-marks on the bullet? Drop your mag and remove the top (#2) round. Did the COAL change due to setback? Any marks on the bullet?

If no change to the second round, reinsert into mag and load, (muzzle down range etc.) release the bolt. Fire this one off and safe the weapon and drop the mag. hand eject the #3 round and visually verify and re-measure. Any changes? Take the #4 round out of mag and measure, any changes.

Any deformed bullet tips? any maligned bullet seating?

Looking for change between intial load COAL and cycling and firing.

If no changes you should have 5 rounds, light'em off and tell us how this worked out, if you choose to go thru it. Back to the basics.

[1911man]

I want to kind of wrap a bow around this thread by sharing my experience since I started this thread frustrated over that one " flier". In the end I completely stripped my gun down, I trued the face of my receiver, bedded the barrel, added an adjustable gas block, swapped scopes for higher magnification, and swapped in a new bolt carrier. I saw my groups tighten up but I believe it has more to do with these three things.

1. I found a load that shoots better. My TAC loads are shooting much tighter than the XBR loads I started this thread with. My XBR loads still produce sub MOA groups but my TAC loads have just been more consistent.
2. Higher magnification scope. My original scope was a fixed 10x scope and with my eyes not being so great I think it was effecting my point of aim. With vortex scope I have on their now I am setting it to 16x and its helping me with focusing on that same aiming point for each shot.
3. Im just more familiar with the weapon now. after getting a ton of practice in I am very comfortable behind this weapon and am just shooting more consistently.

In the end I went through and rebuilt this rifle but I think it was the three things listed above that really made the difference. Since writing this thread I have been to the range three times and my average groups with my preferred loads have been .729" out of 12 groups and that is included the 1" plus groups. So in the end I think this rifle is performing well, now if i could just find a load that works with the 123 AMAX.