Arne Brennan of Competition Shooting Sports posted about his tactical Grendel in my forum, and I thought I'd give an update here. His tactical model has a Lothar Walther 16.1" barrel, and I'll quote him below for the rest of the information.



Here are Arne's results in his own words:

"Lapua 144 (.636 BC) - AA2520 powder - CCI 450 = 2275 fps
Lapua 139 (.615 BC) - AA2520 powder - CCI 450 = 2305 fps
130 Norma (.590 BC) - AA2520 powder - CCI 450 = 2425 fps
130 Swift (.571 BC) - AA 2520 powder - CCI 450 = 2425 fps

"Starting Load for all of you to work with is 29.0 grain and OAL was kept at 2.255".

"In shooting everything from the Lapua 108 up through the Lapua 144, the Lapua 108 was 200 fps faster in the 28 inch long range model. As we stepped up to the heavier bullets, that velocity shift was reduced to 175 fps. The 108 Load being run was a mild one, but velocity still was 2525 fps in the 16.1 inch barrel.

"The 130 Norma and 130 Swift loads clearly had some room to play with and I believe 2475 fps is achievable without getting crazy on pressure. Any of the 130's, the 139 and 144 will make major power factor for you 3 gun shooters wanting to take your AR15 into the land the AR10 and the .308. The Lapua 139 and Lapua 144 are already making the 320 PF level required for major power factor. Quite an achievement for a 16.1 inch barrel.

"Again, we were conservative on loads wanting to keep pressures in the area of 50,000 PSI. Accuracy wise, at 300 yards, we were able to maintain MOA with all the loads and take some into the .5 moa range."

John

Very nice.  

Do you know if AA 2520 is optimized for this round?  I can't believe it would be optimum for all weights spanning 108 to 144 grains, I just don't have a feel for if it is a tad too quick for the heavy stuff or a tad too slow for the light stuff.

Any word on the AA 14"/16" CM/CL models? Or am I going to have to call up Bill again and harass the hell out of him again

Those are some dang high BCs!

Quoted: Any word on the AA 14"/16" CM/CL models? Or am I going to have to call up Bill again and harass the hell out of him again

Formal announcements are coming at Shot Show, per Bill in a recent post over at www.65grendel.com.  

Damn double tap...  

Quoted: Very nice.   Do you know if AA 2520 is optimized for this round?  I can't believe it would be optimum for all weights spanning 108 to 144 grains, I just don't have a feel for if it is a tad too quick for the heavy stuff or a tad too slow for the light stuff.

I was out shooting this weekend with Arne, so I can answer the question.  

The 108 load was using N133.  The 2520 was used for the 130s, 139s and 144s.

I have been finding best accuracy with the 107s and 108s with powders in the N133 burn rate area, Benchmark, H322, etc.  Get up the 130s and between 4895 and 2520 seems to be the ticket...

Arne's post is a bit confusing, with the 108 out of an AR w/a 28" barrel - velocity was 2725, and out of the 16.1" barrel it was 2525.  

FWIW - I have been loading the 108s for my bolt gun much hotter and getting upwards of 2950 with the same powders.        

Quoted: Quoted: Very nice.   Do you know if AA 2520 is optimized for this round?  I can't believe it would be optimum for all weights spanning 108 to 144 grains, I just don't have a feel for if it is a tad too quick for the heavy stuff or a tad too slow for the light stuff. I was out shooting this weekend with Arne, so I can answer the question.   The 108 load was using N133.  The 2520 was used for the 130s, 139s and 144s. I have been finding best accuracy with the 107s and 108s with powders in the N133 burn rate area, Benchmark, H322, etc.  Get up the 130s and between 4895 and 2520 seems to be the ticket... Arne's post is a bit confusing, with the 108 out of a 28" barrel - velocity was just about 2725, and out of the 16.1" barrel it was 2525.   FWIW - I have been loading the 108s for my bolt gun much hotter and getting upwards of 2950 with the same powders.

Thanks, that makes a bunch of sense.  Any idea what pressures your BA loads are running?

Quoted:  Thanks, that makes a bunch of sense.  Any idea what pressures your BA loads are running?

Not quite sure, but they are about 1.3-1.5 grains over AAs max load (approx 50k psi).  However, I don't have any bolt lift problems and no pressure signs in the primers.  The bolt action I am using is a Panda, so it is pretty stout...  

If you kept it under 50K psi in the "conservative range" what is the maximum the 6.5 can handle?  I thought 50K psi was the max?

Devl, I believe the 50k psi figure is for the sake of working within the limitations of the AR platform. The cartridge case itself can handle much more pressure, but I don't know the absolute max.

John

Neat stuff, thanks for posting the data.

Are the lapua's 144s and 139s mag length or are they set up for single shot loading?

The 6.5 seems so awesome.  I'd love to have one.  One day I suppose.

Quoted: Are the lapua's 144s and 139s mag length or are they set up for single shot loading?

All loads tested were mag length.    

Walker,

What kind of groupings were you getting out of the 28" long range last weekend?  And with what loads?  

I'm interested in a grendel for reaching out and touching something.

tag

Quoted: Walker, What kind of groupings were you getting out of the 28" long range last weekend?  And with what loads?   I'm interested in a grendel for reaching out and touching something.

If you look at those BCs, you can reach out and touch something from a 16" barrel.  Those bullets just keep going and going and going.....

Just when I thought I was getting ready to buy an AR10.  Hmmmmmmmm

Quoted: Walker, What kind of groupings were you getting out of the 28" long range last weekend?  And with what loads?   I'm interested in a grendel for reaching out and touching something.

The real purpose of the shooting was only get get some chrono numbers.  It was very foggy when we started, and you could just barely see the targets at 200 yards.  The 28" upper was the first we tested, so we really paid no attention to groups at all.  

With my 24" Overwatch upper, I was averaging about 1/2"-3/4" groups at 200 yards.  

With my Grendel bolt gun, they are much better.  Here is the last 5 shots from 600 yards:  

I had a chance to shoot this rifle with Arne and WalkerTexasRanger at the 300 yard line in Houston this past weekend. From someone that owned a 6.8 SPC, I can say theya re both very similar in recoil. With the choice of bullets out there for the 6.5mm(Higher BC), this rifle is going to rock for long ranges and a semi hunting rifle.

Quoted: Arne Brennan of Competition Shooting Sports posted about his tactical Grendel in my forum, and I thought I'd give an update here. His tactical model has a Lothar Walther 16.1" barrel, and I'll quote him below for the rest of the information. www.65grendel.com/GCS16.jpg Here are Arne's results in his own words: "Lapua 144 (.636 BC) - AA2520 powder - CCI 450 = 2275 fps Lapua 139 (.615 BC) - AA2520 powder - CCI 450 = 2305 fps 130 Norma (.590 BC) - AA2520 powder - CCI 450 = 2425 fps 130 Swift (.571 BC) - AA 2520 powder - CCI 450 = 2425 fps "Starting Load for all of you to work with is 29.0 grain and OAL was kept at 2.255". "In shooting everything from the Lapua 108 up through the Lapua 144, the Lapua 108 was 200 fps faster in the 28 inch long range model. As we stepped up to the heavier bullets, that velocity shift was reduced to 175 fps. The 108 Load being run was a mild one, but velocity still was 2525 fps in the 16.1 inch barrel. "The 130 Norma and 130 Swift loads clearly had some room to play with and I believe 2475 fps is achievable without getting crazy on pressure. Any of the 130's, the 139 and 144 will make major power factor for you 3 gun shooters wanting to take your AR15 into the land the AR10 and the .308. The Lapua 139 and Lapua 144 are already making the 320 PF level required for major power factor. Quite an achievement for a 16.1 inch barrel. "Again, we were conservative on loads wanting to keep pressures in the area of 50,000 PSI. Accuracy wise, at 300 yards, we were able to maintain MOA with all the loads and take some into the .5 moa range." John

Has this configuration (16.1") been provide to Dr Roberts (have asked before with no real response) for testing yet? Also are 25rnd mags avaliable for testing also?

Quoted: Has this configuration (16.1") been provide to Dr Roberts (have asked before with no real response) for testing yet? Also are 25rnd mags avaliable for testing also?

That is a Bill or Arne answer on Dr. Roberts.  Concerning the 25+ round mags, last I heard was Creative Products would have some at Shot.  

Quoted: Quoted: Has this configuration (16.1") been provide to Dr Roberts (have asked before with no real response) for testing yet? Also are 25rnd mags avaliable for testing also? That is a Bill or Arne answer on Dr. Roberts.  Concerning the 25+ round mags, last I heard was Creative Products would have some at Shot.

Replyed in the other thread. Understand on the mags.

Tag.

Quoted: ... (snip) With the choice of bullets out there for the 6.5mm(Higher BC), this rifle is going to rock for long ranges and a semi hunting rifle.

The 130gr Swift (Scirocco) will have enough energy at 500yards (~900 ft pounds) to cleanly take a deer out of a 16 inch barrel AR!! The "deer PBR" with this bullet/rifle is ~250 yards to boot (aim at the heart from 0 to 250 yards) and with a high SD bullet!!

(Based on an assumed 2500fps muzzle velocity with a tweaked, but safe, loading of the bullet. I also use 900ft/lb as my energy threshold for deer... YMMV)

A statement of the obvious - yes - and possibly of no significance to zombie slayers. I just personaly find it neat to have such hunting capability in an AR15

Tagged for all things Grendel

I have a can of N135. I never see this powder mentioned with the Grendel. Is it not a good burn rate for that cartridge? Has anyone done any testing with it? I thought maybe it would be good for the 130-144 weight bullets.

Quoted: I have a can of N135. I never see this powder mentioned with the Grendel. Is it not a good burn rate for that cartridge? Has anyone done any testing with it? I thought maybe it would be good for the 130-144 weight bullets.

I have done a bit of develoment with it, but not much.  You are right, it should be a good burn rate for those weight bullets, at least the 130s for sure.  I have been using H4895 with the 123s and 130s with good success.  Last group at 600 yards with a Norma 130 and 4895 was 2.25"  (This is out of a bolt gun.)  

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Tag.