6.5 Grendel Preferred Loads

[stokesrj]

I think the 6.5 Grendel is a fantastic cartridge, mild but yet effective over a wide range of conditions, and of course the fact it fits into the AR platform is just icing on the cake.

One of the things that seems to elude us, is a bullet and a powder that just works in everyones gun. Since I am a High Power competitor, I come at it from this perspective. The .223 or 5.56 service rifle just simply hammers with the Sierra 77 SMK or Hornady 75 BTHP match bullet with several powder charges of commonly available powders loaded to magazine length of 2.250". It is no secret, load development has already been done, almost any barrel buttoned or cut of high quality, Douglas, Wilson, PacNor, Green Mountain, Krieger, Bartelien, Schnieder, Satern and others chambered with a Wyld Chamber and set with a 6.5-8 twist per inch simply works. It is expected to produce .5 MOA groups in 98 out of 100 barrels. And it does with 24.5 grains of Varget, 24.0 grains of Reloader 15, or 23.2 grains of IMR8208XBR. With these loads if you do not shoot clean (perfect scores) it is you, all you.

But I continue to find finicky results with the Grendel, by this I mean that loads which shoot clover leaf groups in one barrel shoot playing card sized groups at 100 yards in another. I think it would be of great benefit to the 6.5 Grendel if we were to find a handful of loads that work in everyones gun. Okay, that is overly optimistic, so lets confine it to everyones gun providing they have a Grendel SAAMI chamber.

Today, at the range I was testing my 14.5" ultralight with some loads that have shot really well in it previously and some loads that shoot really well in others rifles.

To illustrate this, I fired several five shot groups with one of my favorite loads, the 123 Hornady A-Max over 28.5 grains of IMR8208XBR, Lapua cases, Wolf small rifle magnum primer seated to 2.250". This is from the bench, using sand bags and the Nightforce 2.5-10 NXS scope set at 10X. All groups were one hole and well under .5MOA.

I then used one of the loads that BWild had developed using the 100 grain A-Max over 34.0 grains of Hodgdon CFE223 with the same results, clover leaf one hole groups.

I then switched to the 129 Hornady SST, a bullet that has performed really well for me in several rifles with several powder charges. This time I used another of BWild's loads that performed really well in his rifle, 30.8 grains of CFE223, expecting similar results, only to find an improved cylinder pattern of about 5 MOA. My rifle categorically rejects this load.

Experiences like this leave me scratching my head, I know I could successfully develop a load for this bullet the 129SST in this rifle. The real reason is why should I have to? Why have we as a community not honed in on three or four loads that shoot in all rifles. It isn't that hard, what is preventing us from achieving this goal?

LR1955 continually points to the 120 SMK as the go to bullet, I continually point to the 123 A-Max as the go to bullet. Yet, we fail to converge on a single load that shoots from everyones guns. We also fail to find a series of charges that shoot from everyones guns.

Hornady has achieved this goal, or at least come the closest to developing a single load that shoots in most everyone's rifle with the 123 A-Max factory loading. I do know some who claim it doesn't shoot in their rifle, but I'm not clear if their rifle is a Grendel or variant. My rifles shoot this load to less than MOA but my handloads do better, perhaps because of the Lapua cases or perhaps due to the precision exercised in assembling the loads.

I think it would be a worthwhile exercise to focus on finding a few loads that shoot universally well from the 6.5 Grendel rifles out there. Since the Horandy 123 A-max is readily available to most of us I would like to propose using it as a test standard to compare results to. For me this would mean any load I can develop, restricted to magazine length loads that will outperform the Hornady factory load should be considered as a candidate.

My proposal would be the load I listed above, 123 A-Max, 2.250", 28.5 grains of IMR8208XBR, any case, any primer.

If your load can outperform the Hornady factory load, and my load listed above in your rifle, please document it and propose it as a candidate.

I'm looking forward to what you, the Grendel Aficionados, might come up with.

Bob

[bobke]

Quite the challenge, Bob. I'm in. Will post up, as able.

[Dogue]

I like it! Unfortunately I just did some load tests today with 123 Amax's and XBR...but I didn't load any higher than 28.0g . I wanted to test the same loads in Hornady brass and some fireformed Fiocchi X39 brass I bought (and have almost identical capacity). Both ran around 2510 fps on avg. out of my 18" barrel. I wasn't trying hard for tiny groups at this stage but did manage to get sub-moa with this load...4 of 5 were 1/3".

It'll be a couple weeks before I can get back to the range so hopefully others will help us nail down a couple loads.

[bwaites]

I'm in, and I know the 28.5 load shoots in both my rifles, a 20" and 28".

I've shot sub .5 MOA at 275 yards with that load and CCI 450 primers. I need to get out the Wolf and load some back to back with CCI's, though.

My 28", because of the rifle characteristics, was a bit hard on that brass until I went to a Tubbs carrier weight and heavier spring. I think an adjustable gas block would solve the problem, but I'm still working on that because no one makes one that fits without modification.

[davidj]

Slightly off-topic.
Bob,
You didn't mention the 123 gr nosler cc hpbt. Have you come up with a load for all those Cabella's pills you bought a while back? are they as good as the A-Max?
I haven't been very successful using CFE with them. I was going to go to IMR8208XBR next.

Dave

[stokesrj]

I haven't yet tried the 123 Noslers out of my Grendel, I did try them out of my 6.5 Creedmoor with the same load I use behind the 123 Hornady A-max in it, 39.0 grains of Varget. They didn't group as well as the A-max with that powder charge, still sub MOA but the A-Max groups .3-.5 MOA. I wouldn't put too much credence on that since it is quite common for bullets to prefer different loads to shoot their best.
Bob

[Grimmy]

Stokes I agree with you on how finicky the Grendel can be alot of the loading you guys post don't shoot well in my rifle. I have been using Hogdon LVR and it's been giving me some great results. That load has been 30.5 to 30.7 with a 123 Amax and it's been showing .5moa out of my 20". Hornady factory is at .75 to 1.25 moa at a hundred out of my rifle. So I understand the subject of this post.

[Drifter]

For the 123gr A-max, your load using 28.5gr of 8208 is somewhat hot in my Grendel chamber (using CC #41 primers). 28.0gr or slightly less does reasonably well. Same charge using AR-Comp has been more accurate for me.

As for the 129gr SST, I get good results with 27.0gr of AR-Comp, and decent results with the same charge using 8208.

While a barrel might perform well with a variety of powders, I see less temperament with accuracy when switching bullets if the same powder is used for both (assuming the powder's burn rate is appropriate for bullet weights being used).

[LRRPF52]

Stokes,

I think the measurement stick of finding good loads for service rifle AR's with cut-rifled 20" barrels is clearly more uniform, mainly because of the common barrel length.

Since we have a lot of 16", 18", 20", 22", 24", and 28" Grendels amongst us, longitudinal shock wave theory says that we'll all have different accuracy nodes with the same load. Your 14.5" barrel is pretty exceptional, compared to the barrel lengths of others, which makes sense as to why Bwild97's 24" sweet spot doesn't work in your 9.5" shorter pipe, even if he handed you the same loads from his press.

I'm a huge believer in velocity as being the determining factor in accuracy nodes for a particular barrel, and see it regularly when doing load development. Velocity always shrinks or opens my groups as I work up through a series of increasing charge weights. We would have to find a load that hit the velocity accuracy nodes of all the different barrel lengths, which would be a very narrow margin if even possible, with a powder that would need to be absolutely temp-stable. Maybe it can be done for 16", 20", and 24", but it gets harder when throwing in 14.5", 18", 22", and 28". Add in the variant chambers, and it gets very dodgy.

[seatleroadwr]

I tried the recipe you recommended Bob. 4 of 5 went into a nickle sized area. The last shot opened the group to about an inch. A few weeks ago I moved my rifle's throat forward by .060". When I set an Amax with a COL of 2.28, the groups become more consistent and tighter. Still, 4 of 5 in a nickle is nothing to sneeze at.

BTW, velocity averaged 2535 with your recipe from a 22" Lothar Walther barrel and a CSS chamber. An Amax touches the lands with a COL of 2.3810"

31.5 grains of LVR with an AMAX 123 set at 2.2815" averages 2593 fps and gives a .5" 5 shot group. I've found that the LVR powder behaves almost identically to the CFE 223 powder and I have the better part of an 8lb keg of the LVR.

[stokesrj]

I understand where you are coming from but the observations I have with the 77 brain Sierra Match King from the .223 covers both cut and buttoned service rifle barrels, which you point out are relatively consistent velocity, I see about 200 FPS variance even with consecutive runs of barrel blanks chambered with the same reamer. But even more telling is that we see the same results with match rifles (space guns) with 24, 26, 28" barrels which can be 300 fps faster still. They all shoot those loads well.
Bob

[LRRPF52]

Maybe it's the process that goes into bedding, loc-titing, lapping the lugs, trueing the bolt face, etc. that goes into competition guns versus rack-grade Grendels?

I also think the Grendel shoots better on average with a more rigid upper receiver, and the bare bones .222 Remington upper receiver geometry that was built to cut weight to a minimum for military use is not ideal for an X chaser, especially when you increase the powder capacity, double the bullet weight, and increase the cartridge diameter.

Thanks for the mentioning of those 77gr SMK and 75gr Hornady .223 loads. I'll try them in a few of my 5.56 guns, as I have some of the new Lapua Scenar-L 77gr, a bunch of 75gr Hornady BTHP, and 77gr SMK's. They make a good bullet weight for my part of the Country, being that we have a lot of wide open spaces, & high altitude.

[Bennybone]

stokesrj -

First off, I enjoyed the original opening post, and while I do not sense frustration I do understand being anxious to nail this down as it would make for a great baseline method to establishing accuracy potential in a Grendel/Variant AR.

I too tried BWilds 30.8gr CFE223 load and was disappointed to see 1-3 MOA results.

Unfortunately it looks as though I will have to develop a load for my specific rifle using the 129gr SSTs being that I just bought into 100 of them for this Winter's hunting trips.

I am tagging this post for after the Fall hunts to see if you had any other members post their 123gr Amax results and to see if your goal is closer at hand or still a mystery of the Grendel.

Thx,

BB

[stokesrj]

I don't think it is the process of building the match rifles, in fact I was surprised to see how simply they are put together. no lapping, truing or anything like that, just a high quality barrel, and freefloat tube is all that is required.
I won a few hundred 69 and 77 Scenars this year. They shoot really well but no better than the 77 SMK's or 75 Hornady BTHP, even at 600 yards. The AMU used the 77 Scenars at 600 in 2010 and 2011 for 600 yards after running into a bad lot of 80 SMKs but then moved to the Berger 73 grain VLD this year. Didn't seem to matter, they posted pretty much the same results. Six of the AMU members made it to the Presidents shoot off but five of them along with the All Guard team were disqualified for refusing to shoot in the shoot off in honor of two first time ever perfect scores shot. So we will never know for sure how the shoot off at 600 would have turned out. As it was a guy from California won shooting Sierra 80 SMKs against the Ty Cooper of the AMU using the 73 Bergers. I suspect that any of the bullets could have won, depending on the skill of the shooter.
I can't help but wonder if the real reason we get such different results with the 6.5 Grendel, is that we have such a wide variety of barrels. By far the most popular barrel in the national matches is the Wilson 1:7 followed by the Kreiger 1:7.7 and the Douglass 1:8 a far distant third. There are Satern, Pacnor, and Green mountain. But you never see a Shaw or Shilen, at the national matches. And everyone knows not to bring a chrome lined barrel.
Bob

[Drifter]

I can't help but wonder if the real reason we get such different results with the 6.5 Grendel, is that we have such a wide variety of barrels.

I agree, and add to that the various chambers.

A safe load in one setup might be excessively hot in another.

I know we're talking handloads, but the Hornady factory load seems to be the best ammo that will shoot reasonably well in a high percentage of rifles.

As I have alluded to previously, I get best accuracy with AR-Comp powder in a variety of barrels (multiple Saterns, a Krieger, a Sabre Defence, and a BHW, including Grendel and 264 LBC chambers). AR-Comp doesn't seem to have such a fine edge between safe and hot, while still providing decent velocity and temp stability. I think AR-Comp is the best general-purpose all-around powder for the Grendel for those not so bent on hot-rodding the cartridge.

[stokesrj]

How about this?

Lets start comparing out favorite handload to the Hornady 123 A-Max factory load. My 6.5 Grendel Ultralight shoots the Hornady factory load to about .7 MOA on average and my favorite handload of 28.5 grains of IMR8208 XBR into about .5 MOA. It also shoots Bwilds load of 34.0 grains of CFE223 behind the 100 A-Max into about .5 MOA. It would be really useful if many of us report out the accuracy of all three of these loads from our guns and any other we find to be a candidate. To keep things consistent lets provide the following information in this order.
Bullet, Powder, Primer, Case, COL, Barrel, Chamber, Velocity, Temperature, accuracy average of five shot groups and distance.
123A-Max, 28.5 gr IMR8208, Wolf SRM, AA, 2.255", Satern 14.5" 1:8"twist, 6.5 Grendel, 2410, 95ºF, .5MOA 100 yds
It's really important to list an average accuracy, for instance I've shot 5 shot groups of .24" with the above load but it won't do that consistently. And to be a great load doesn't require .5 MOA accuracy anything 1MOA down from an AR is good.

If we begin to build the data I'll compile it and share back with the Grendel community. This is one of the ways I saw the High Power National Match Community settle on a few really good shooting loads.

Bob

[bobke]

Bob-
Since you've indicated in the past that the attention to details in the loading process is a contributor to your consistently positive results, do you find runout and/or neck concentricity factors to same or best addressed in die setup? I'm more than occasionally frustrated with wide disparity of one or both, even when trying to pay particular attention when sizing brass. Using Redding FL comp dies with 288 bushing. Some runout .001 or less, the next piece can be out by .005, without any seeming variation in technique. Your comments welcome.

[rasp65]

Bob I think this is a good idea. I have heard that the Federal 308 Win Gold Medal is a load that is consistent in most arms and is widely used in matches. They have found a load that just plain works. So it would be great to have loads that when someone new comes aboard the site we can direct them to loads that have been found to be consistent with a number of members. I think what we need is a sticky with a spread sheet on the 1st page that is updated. They have something like this on arfcom in their reload section.

[LRRPF52]

I'm on-board with this. I have some factory Hornady 123gr AMAX box that I will chrono and shoot for accuracy in my 16", ER Shaw AA button-rifled beater. I have had great results with the 123gr Lapua Scenars from Precision Firearms (Factory loaded moly Scenars) with 7fps Extreme Spread, and a decent .79" 4-round group.

So let's get the initial standardized testing loads out there:

123gr AMAX Hornady box ammo
123gr AMAX 28.5 grains IMR8208 XBR
100gr AMAX 34.0 grains CFE223

[stokesrj]

Yes, that is the concept I'm looking to replicate. The 308 Winchester Gold Medal load using the 168 grain Sierra Match King shoots really well in nearly all .308's out to 600 yards or so. The Black Hills .223 77 SMK load does the same. Both of them will shoot less than one MOA out or almost any decent barrel and if they don't, you really should be looking at what is wrong with the rifle.
In the High Power community there are several know loads that will duplicate or better these loads. That is what I'm looking for, a factory load that shoots well and several handloads that do as well. I'm proposing that the Hornady 123 A-Max factory load is that load. But I want confirmation from many people. Then I want handloads that do as well or better documented.