My love for this round is fading

[1911man]

So I have been trying to come up with a "pet load" for my 18" BHW 264 lbc/6.5 and have yet to have any real success. I thought I had come across two loads with promise which were 28.3 grains of XBR 8208 and 28.5 grains of XBR over a 120 smk. I loaded up 30 rounds of each to do some more extensive testing. I decided to play with the OALs a little bit in 10 round batches to see if it would make a difference.

The results are killing me. If anyone read my last thread you will see that I had a couple of promising groups with one round that was opening them up. Well today was the exact same result. The groups were so consistent that I gave up out of frustration. 4 rounds in a group that I find acceptable (3/4 MOA or better) and then one round that opens the group up to about an inch. Does anyone have any experience with something like this? It seems too consistent to be me. I regularly shoot 1/2 MOA 5 shot groups at the same range, in the same position with two other rifles that I own. I also decided to load each round into the chamber individually just in case the action was messing with the seating of the round while pulling it out of the mag and into the chamber. I felt very solid about each shot. One thing that I wish I had was my chronograph so I could have recorded the velocities of each shot. Do you think it could be my loading process? Maybe my scale is off and that round is getting an extra tenth or two of a grain? I weigh and sort all of my brass and bullets, I also trim them all to between 1.515 and 1.519. This is driving me crazy. What i keep thinking is why am I wasting my time, money, and resources on this round when I could be loading for my .308 which I know exactly where its going to hit and I have a great load that will shoot out to 1000? At this point its just because the Grendel is "cool". Also, one thing I would like to point out is that when I first bought this barrel it would shoot factory SSTs and Amaxes to the tune of 1/2 MOA or better and now they are grouping around an inch as well with the occasional good group. Maybe I have a barrel problem? PPU boxed ammo seems to shoot exactly as good as my handloads maybe I shoot just stick to shooting that every now and then.
I shot 3 5 shot groups of each but here are the only two pics I took of my targets before I threw them in the trash. Ignore the high shot above the bulls eye on the second target. That was the cold bore shot from my brothers rifle.
0724152315a-1.jpg0724152315.jpg

[GarandThumb]

What did your 28.3 and 28.5 groups look like?

Where they impacting in the same area of the target?


It's possible 28.3 and 28.5 are not in an accuracy node but I would have to see photos of the targets. As you mentioned, the chronograph could help explain things too.

This thread over on accurate shooter is pretty long, but it's a good read. The first post by Erik has everything you need if you don't want to go through the whole thread. Before I came across that threat my reloading methodology was essentially chasing after loads that produced the tiniest group, when in reality you have to look at all the groups and how they relate to each other to find the node.

http://forum.accurateshooter.com/index.php?topic=3814361.0

If you can't find a similar pattern with your current bullet/powder combination then its time to move on to a different setup. See my results with the berger 130 hybrids and RL-17, no point in trying to develop that combo further.


If your other rifles are shooting good than its probably not your reloading equipment. I also think extra steps like sorting bullets is overkill at this point, you can do that later after you found your node.


Hope this helps.

[Ott]

After extensive testing I too was having so-so results. I tried all the "hot" loads and never hit on a magic load. Then someone posted that when they wanted to shoot short range bragging groups, they loaded 26.6 grains of 8208XBR. The result was a 5/8" one hole group at 150 yards. I'm happy again!

[Hoser1]

I too am having the same issue, built a load of 30.7gr of 8208 and 100gr nosler BT. Which shoots .605 @100yds, took it to 200 yds and the group went to crap, opened way up like 4". So I believe that I'm going to pull all that I have left and start over with 10x. I have a load of 26.6gr with 95gr vmax that shot a 600 yd group of about 6". Which isn't fantastic but isn't bad either. The link that garandthumb posted was an eye opener, I believe I have been doing it wrong all along. Going to research that a lot more. just wanting a load that performs across the board, deer, dogs, hogs, whistle pigs, and anything else that I hunt.

[jurassic]

1911man, its been the experience of many on the forum your rifle should shoot really well with factory Hornady ammo. If it won't, something is probably not right at least that has been my experience. Have you tried that yet?

[wfa17332]

Is it the "last round" that's out of the group? If so, I'd suspect "heat" as the cause. I have a "slim" profile barrel, and I'm finding a similar trend - four "friends", one "outsider". Just a thought.

[1911man]

What did your 28.3 and 28.5 groups look like?

Where they impacting in the same area of the target?


It's possible 28.3 and 28.5 are not in an accuracy node but I would have to see photos of the targets. As you mentioned, the chronograph could help explain things too.

This thread over on accurate shooter is pretty long, but it's a good read. The first post by Erik has everything you need if you don't want to go through the whole thread. Before I came across that threat my reloading methodology was essentially chasing after loads that produced the tiniest group, when in reality you have to look at all the groups and how they relate to each other to find the node.

http://forum.accurateshooter.com/index.php?topic=3814361.0

If you can't find a similar pattern with your current bullet/powder combination then its time to move on to a different setup. See my results with the berger 130 hybrids and RL-17, no point in trying to develop that combo further.


If your other rifles are shooting good than its probably not your reloading equipment. I also think extra steps like sorting bullets is overkill at this point, you can do that later after you found your node.


Hope this helps.

Thanks for the resource and the response. The two pictures are of my 28.5 XBR groups. Basically all of my groups looked like this. I didn't save the targets; which I almost always do. I spent a fair amount of time developing this load. Started with a ladder test to find the accuracy node. Then I loaded up 5 round groups of each load to find which ones grouped the best. The 28.3 and 28.5 grouped almost identical. I also did a velocity test on each of them and found consistent velocities for both. My last time out to the range with these two loads I was getting really tight 4 round groups with that one 5th flier. I thought maybe there were a variety of factors and that if I loaded up more rounds and shot more groups they would tell me whats going on. That is where I am at today, I went out and shot those loads and repeated the results exactly. I really regret not bringing my Chrony but cant go back now.

In response to others yes I have shot factory hornady ammo and had mixed but good results. When I first purchased the barrel it would shoot 1/2 minute quite often. Now it still mostly shoots sub MOA but I havent had any really exceptional groups out of the factory SSTs or Amaxes in a while. I have also tried several loads with different bullets and powders like CFE 223 with terrible results. I just picked up 2lbs of TAC to try out as well. I hate that I am addicted to making this rifle work. I should just sell it and enjoy shooting my other rifles. I really want a semi auto with the versatility that others are getting out this cartridge.

[1911man]

Is it the "last round" that's out of the group? If so, I'd suspect "heat" as the cause. I have a "slim" profile barrel, and I'm finding a similar trend - four "friends", one "outsider". Just a thought.

I also thought about heat. The problem I have is with my fixed 10x scope I cant see all of my hits so I dont know if its the last round or not. I am going to put a higher magnification scope on it to help with this. I have a Vortex that was on another AR sitting in my safe that will do the trick.

[bwaites]

10 years ago if someone had complained that the BEST they could do was 1" groups with an AR the world would have jeered them into oblivion. 1" groups are great out of what is acknowledged to be a good barrel, but not necessarily a GREAT barrel. BHW barrels aren't out there winning competitions left and right, and there is a reason for that. They will shoot great groups, and some of them shoot them consistently, but they aren't famous for tiny groups, like Bartlein, Shilen, and some others. If this barrel shot much better when it was new, then start looking at your barrel cleaning technique, possible gas issues, loose gas block or loose gas key, bad gas rings, loose barrel, loose scope mounts, scope issues, etc. If they are all good, I would consider having the barrel scoped.

I had a 7mm barrel that shot lights out for about 100 rounds, then fell off the face of the earth. I cleaned and cleaned, but no luck. Then a member here suggested I might have a carbon ring in the throat and told me how to fix that. I did, and that rifle is back to 1 hole groups.

LOTS of things can mess with accuracy, but I'm betting your rifle just needs a thorough going over! Good luck.

[1911man]

Thank you for the suggestions Bwaites. To be honest I agree with everything you said in the first two sentences about the barrel not being high end and your average AR not shooting this well. The problem is that it was getting killer groups for the first 100 rounds or so. Also, the nature of my groups with the 4 shots being tight and 1 flier. It is just different than anything I have experienced with any of my other rifles. I will look into the items you listed.

Can you elaborate on how gas issues can cause problems with accuracy? I would think it would just cause problems with function but maybe it effects chamber pressure?

[37L1]

Try shooting out to 200 yards.





Maybe then you will have more than one flyer, LOL! Problem solved!

I do this to aggravate myself when I think I have a great load. I call it the antacid test.

[bwaites]

Thank you for the suggestions Bwaites. To be honest I agree with everything you said in the first two sentences about the barrel not being high end and your average AR not shooting this well. The problem is that it was getting killer groups for the first 100 rounds or so. Also, the nature of my groups with the 4 shots being tight and 1 flier. It is just different than anything I have experienced with any of my other rifles. I will look into the items you listed.

Can you elaborate on how gas issues can cause problems with accuracy? I would think it would just cause problems with function but maybe it effects chamber pressure?

Anything which affects the cycling of the rifle can cause accuracy issues. We've seen improvements with accuracy from such things as bedding the gas block even.

Because of your early accuracy, I suspect something has changed. My first bet is that there is something that is causing a change of some type within the firing string. I've seen loose gas keys cause that on one of my own rifles, I've seen loose gas blocks do it on others. My second bet would be that you have scope mounts or a scope that is settling between shots causing your issues. Tracking down a scope issue can be as simple as a scope swap and the issue going away, but it can be really frustrating.

I have also seen carbon rings cause strange bullet behavior. My 7 WSM would shoot 2 or 3 into the same hole, then a bullet would simply blow up, causing a puff of smoke at about 50-100 yards. Then the next shot would be back and then another would disappear. You couldn't see it if you were firing, but you could standing next to me. The first time it happened, I was at a match shooting F Class at 1000 yards when I went 10, X,X, 10, and then NOTHING. I called for a rescore, nothing. I called the RO over and he spotted a puff at about 100 yards and we figured out what it was doing.

Since the barrel shot well initially, it probably isn't the barrel itself, but something attached to it that is causing the issue.

[GatewayShepherd]

I feel your pain…and frustration. I’m about 300 total rounds into a Lilja AR740 20” 1:8 twist. Initial load development looked promising..but nothing exceptional. But it hasn’t gotten any better…other then I can tell you that it shoots better dirty then clean. I’ve had groups spread between .25 MOA all the way up to 3 MOA..and as random as can be. Same issues as you…split groups with a single or double flyer depending on the number of shots. I’m taking great pains in the reloading process and my shooting isn’t at fault either. Today after having the same problem again..switched over to one of my other guns and proceeded to put down 3 consecutive .3 MOA groups and one in the Zeros. Switched back to the Grendel…and same problem again. I’m fixing to tear the Grendel down and go over it and check everything…adjust the torque on the barrel nut and remove the JP muzzle brake and shoot it without it on. Even though there is a considerable cost difference between our barrels…I’ve seen countless pics of others group shooting averaging 1 MOA as well. To me this is just not good enough. I have another 223 AR-15 that will consistently shoot .25 MOA all day long with hand loads. With mine it doesn’t seem to matter if it’s the 123 Amax or 107 SMK…which are the two main bullets i’ve used so far. Been looking for some 120 Ballistic Tips…but to no avail.

[LR1955]

Anything which affects the cycling of the rifle can cause accuracy issues. We've seen improvements with accuracy from such things as bedding the gas block even.

Because of your early accuracy, I suspect something has changed. My first bet is that there is something that is causing a change of some type within the firing string. I've seen loose gas keys cause that on one of my own rifles, I've seen loose gas blocks do it on others. My second bet would be that you have scope mounts or a scope that is settling between shots causing your issues. Tracking down a scope issue can be as simple as a scope swap and the issue going away, but it can be really frustrating.

I have also seen carbon rings cause strange bullet behavior. My 7 WSM would shoot 2 or 3 into the same hole, then a bullet would simply blow up, causing a puff of smoke at about 50-100 yards. Then the next shot would be back and then another would disappear. You couldn't see it if you were firing, but you could standing next to me. The first time it happened, I was at a match shooting F Class at 1000 yards when I went 10, X,X, 10, and then NOTHING. I called for a rescore, nothing. I called the RO over and he spotted a puff at about 100 yards and we figured out what it was doing.

Since the barrel shot well initially, it probably isn't the barrel itself, but something attached to it that is causing the issue.

Bill:

Loads are too hot is all. I have seen this numerous times at High Power matches. A couple go right in the middle and the next blows up about 100 yards down range. Couple more go right in the middle and another one blows up. Simply put, the load is too hot for the bullet you are shooting.

LR55

[GatewayShepherd]

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