6.5 Grendel Preferred Loads

[Bwild97]

GregP42, Thank you!

I mainly use Hornady brass. I do have some Lapua brass, and when adding load info to the Chrony slips I note the loads using Lapua brass with "Lapua" or "L". The loads using Hornady brass usually get no note unless it is new brass and you may see "H" or "New H"

The program I used is Called OnTarget PC, it costs about $15 and I just recently discovered a free version "1.10" The TDS version is about $75 and has a few more features. I also use PointBlank Ballistics. Both programs do roughly the same thing But OnTarget is much easier to use quickly. PointBlank Ballistics is free with an option to donate.



And I also just realized that I didn't note these slips as the brass used was all new Hornady brass.

[rickOshay]

BWild - can we get you to post results for commercial 123 AMAX as a way to calibrate the preferred loads?

GregP42 - if you haven't found it already, there is a link to On Target in my post on page 10.

[Bwild97]

Factory 123g Amax

[GregP42]

I have been thinking about this all night, you use factory brass and 28gr of powder. I have been using IMI only and I have not went over 25.5 grains yet, I have not wanted to go much higher because the IMI brass has less volume that factory brass. Those of you using IMI brass what loads are you using so far?

Rick, I went back and saw your post and downloaded the program, now to just get to the range before the cold weather sets in and when the wind is low.

Greg

[LRRPF52]

Using the IMI 7.62x39 brass, run a ladder test for pressure sensitivity in conjunction with a chonograph. Look for your first indication of pressure signs with erratic shifts in velocity, as you inspect your fired brass for bulge signs at the case web just above the extractor groove.

With the Grendel, I've seen a consistent relationship between velocity and charge weights across everyone's published data. A .2gr increase in the charge weight can be as much as 37fps. A .3gr increase can be 50-75fps, with a 75fps increase letting me know we're in a max load area.

Since your brass has less volume, you will build pressure faster. I think you really need to try CFE 223 from Hodgdon's. Do the math to get your charge weight relationship data for percentages to figure out a start load, and go from there. The CFE 223 is a high density, fine grain powder that might be just what you're looking for.

[GregP42]

OK, so I made it out today, light rain, but no real wind, 3 - 4 MPH at the most.

Lets see if they come out ok on here.

All loads are in IMI brass with CCI 34 primers, one is a 10 shot group that I did just for giggles. Two of the targets are 2" diameter, the others are all 1".
This is all from my 18" barrel, no chronograph data because it was too overcast with the rain for it to work.

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[Bwild97]

Good Job GregP42!

How do you like that Software? Did you buy the TDS version?

[GregP42]

BWild,

I like it just fine, so far I am using the free version until I figure it out more. I think I am going to buy a copy of it as it seems like something I can use. I wish it hadn't been raining when I shot those, I wanted to shoot a group at both 200 and 300, but with the rain and the high humidity with low temps the air was a little too thick for good long range work, the vapor trails were interesting to watch through the scope when I tried a couple of long shots. Now I just need a bright day to get chrony data for those loads.

Greg

[BjornF16]

Went to the range today...had good results with 120 SMK and AA2520 (30.0 grains). I used AA Lapua brass (once fired), CCI 450 primers, Redding .288 bushing. This was my best grouping of the day. My chrony printer ran out of paper by this time.

Downloaded the OnTarget Shooting software...trying to figure it out.

100 yds, 25 shots: .916 MOA avg; 2465 fps avg; ES 50 fps avg; SD 17 fps avg

18" Satern barrel


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[sititunga]

I've been up as high as 31 grains of TAC behind the 108 Lapua, which I thought was excessively hot, but it was recommended to me by someone in the industry, albeit 1.3 grains over Bill's listed maximum. I had a hard time breaking the 2710 fps mark with this load from my 22 inch tube. I have successfully tried Ramshot X-Term and have been using 29.6 grains of this behind the 108 Lapua and getting in the 2730 - 40 fps range. I've used this load for 1000 yds shooting. 29.1 grains of TAC behind the 120 gr Berger has also been accurate and achieves 2530 fps out of my gun.

[BjornF16]

Had decent results with 120 SMK and IMR 8208XBR (28.0 grains). These were my first shots after initial sighting in shots (not recorded). I ended up adjusting windage after these shots for the AA2520 string (previous post). Conditions were a little gusty for this string (quartering tail).

20 shots: .92 MOA avg; 2452 fps avg; ES 87 fps avg; SD 25 fps avg


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[Grendel-Gene]

Bob,
I would suggest the following.
Lapua or Hornady Brass and Rem 7.5 primers. Velocitiy listed for 20" LW barrel.

120 gr. Nosler Ballistic Tip – Overall Cartridge length = 2.225”

XBR 8208
28.0 gr – 2515fps,

100 gr. Nosler Ballistic Tip – Overall Cartridge length = 2.225”

XBR 8208
30.0 gr – 2760 fps, SD 12.2, ES. 30.6

Or if you like ball powder

H335
30.0 gr – 2775 fps

These have worked great for me, but I have less range time with the 120 gr load. I saw you suggested 28.5 gr of 8208 for the 123 Amax, and that load would like do well with the 120 NBT as well. I settled on 28 gr to try to lower the operating stress a little.

PA

I wonder what the muzzle velocity difference might be between using 28.5 grains versus 28 of 8202... I am also contemplating trying to stay at the lower stress levels. Does anybody know? I have an 18 inch Satern barrel.... Thanks

[Deezil]

28gr 120gr nosler out of a 16" gets me 2488fps

[Rambozo]

My go to Grendel load has been, and remains, 27.7gr of IMR4895 behind a 120smk or 123amax, in Wolf brass, and Tula(Wolf) LR primers, crimped. That same load however, does not shoot nearly aswell in Lapua brass. I am pretty confident in this load. I would love to hear how it shoots out of other rifles.

[Drifter]

My go to Grendel load has been, and remains, 27.7gr of IMR4895 behind a 120smk or 123amax, in Wolf brass, and Tula(Wolf) LR primers, crimped. That same load however, does not shoot nearly aswell in Lapua brass. I am pretty confident in this load. I would love to hear how it shoots out of other rifles.

I've used 27.7gr of H4895 with the 123gr A-max, SMK, and Scenar in Hornady and Lapua brass. Velocity isn't impressive, but accuracy has been outstanding. Burn rate will often cycle actions that short-stroke with other powders.

[stokesrj]

Okay guys, I think it's time we get a little more organized. Most of us seem to focus on what shoots best out of our rifle. That is not what we are after here. I would like as many people as possible to load and shoot the four loads picked as candidates and provide all the data in the spreadsheet provided by Rickoshay.
I know that is a lot to ask, but I think if we put in a team effort to shoot all four loads and provide the data requested in the spreadsheet posted by Rickoshay we will gain more knowledge about the Grendel in general. That is my goal, to identify one or two loads that any new shooter can start with and be reasonably confident in achieveing good results.
It may be getting too cold in some parts of the country, but southern states are just comming into the best time of the year to do development. Let's see if we can't have 25 complete sets of data, including comparison to the Hornady 123 A-Max factory load by late spring.
Bob

[PA_Allen]

I wonder what the muzzle velocity difference might be between using 28.5 grains versus 28 of 8202... I am also contemplating trying to stay at the lower stress levels. Does anybody know? I have an 18 inch Satern barrel.... Thanks

Grendel-Gene,
The extra 0.5 gr of 8208 gave me about at 30 fps increase with the 120 NBT. You should be close to 2500 fps with 28gr and your 18" barrel

Best,
PA

[Rambozo]

Okay guys, I think it's time we get a little more organized...

I think you're absolutely right. The problem though, is that people like me are late to the thread, and so it requires backtracking. confining the project to a single thread, I think, is inherently unorganized. I propose dedicating new threads to the individual proposed loads. Each thread will simply be titled the specific load details. Each reply should be a succinct and standardized results report including things like, elevation, temp, weather conditions, average velocity, extreme spread, group size, barrel make with length and twist rate. It should probably include a photo of the group as well. That way you can see if there is any kind of consistent group characteristics.

I think it should be held to strict standards, as was previously suggested, no variation in components, but everything as specified in the thread title. Then people can casually chime in as they test the load. Testing should be confined to a specified chamber, as was previously suggested. Perhaps load testing can branch off in new threads with new variations, but I think consistency is important.

With that, it would be easier to compile all that data into a spreadsheet later. I think we can stand to learn a lot by doing this. Not only will it define how reliable specific loads are, but also barrels, powder temperature sensitivity, lot variation, and so on.

Beyond that, there can be a master thread, for the purpose of compiling a master spreadsheet to compare the various load results.

I think doing it this way might make it a little more straight forward.

[pinzgauer]

While I know it's not the intent of the test, I'd love to hear of any IMI brass based loads that align to the benchmark loads. IE: IMI 7.62x29 loadings with same powder & bullet that duplicate the benchmark loads. I'm assuming it would be 1-2 grains lower based on my experiences.

I'm still working through my initial IMI 7.62x39 stash. I'll replace it with H or L at some point, but for now would rather spend my shooting money on bullets, powder, and primers!

Also wondering about H's comment about starting with 2520 if trying to duplicate the factory loading. Several mentioned temperature sensitivity, yet it's about all I shoot and I've not seen a trend. Are you guys just more observant or measuring better? I don't chrono often, so if that's the main way you tell that could be my ignorance.

For a bit it souned like like AR-Comp was becoming the "go-to" grendel powder, but based on the recent comments sounds like 8208 XBR is a better fit. Any consensus?

[BjornF16]

Okay guys, I think it's time we get a little more organized. Most of us seem to focus on what shoots best out of our rifle. That is not what we are after here. I would like as many people as possible to load and shoot the four loads picked as candidates and provide all the data in the spreadsheet provided by Rickoshay.
I know that is a lot to ask, but I think if we put in a team effort to shoot all four loads and provide the data requested in the spreadsheet posted by Rickoshay we will gain more knowledge about the Grendel in general. That is my goal, to identify one or two loads that any new shooter can start with and be reasonably confident in achieveing good results.
It may be getting too cold in some parts of the country, but southern states are just comming into the best time of the year to do development. Let's see if we can't have 25 complete sets of data, including comparison to the Hornady 123 A-Max factory load by late spring.
Bob

Sorry...with my MB Pro, I couldn't download and populate my data into the spreadsheet. I did take 25 shots of one 120 SMK load, and 20 shots of the second 120 SMK load and posted those results (even though I didn't post all my pictures).

I would appreciate it if someone could populate the spreadsheet for me.