6.5 Grendel in a bolt action

[jason miller]

I bought a Howa Mini in 6.5 Grendel back at the end of 2016. It's the 20" heavy-barreled model. It's a handy little rifle that tips the scales at barely over 6 lbs before scope, after a couple hours with an orbital sander to slim and lighten the stock. I haven't gotten out shooting nearly as much over the last year, but I think I finally settled on a load in this rifle.

Hornady brass
CCI 450
123 Hornady A-Max(will have to replace with ELD)
29.0g AR Comp
2.335"

Five shots with this load on my last trip to the range went just over half an inch and did 2609, 2614, 2614, 2614, and 2609 fps.


I've posted this load over on the Grendel forum. Most of those guys seem to have an AR background, though, and seem to think that running a Grendel over the SAAMI 50,000 psi or 52,000 psi or whatever it is will blow brass and rifles up. I believe there was a big problem with people breaking bolts in their AR rifles when the cartridge was first developed, which has lead to what I think is an over-cautious outlook. There isn't hardly any info out there in trying to run a Grendel up to 60,000 psi(or more?) for a bolt rifle. Those guys also put no faith in Quickload because they assume that since powder charges don't matc with their experience, the program must be useless. Personally, I'm more of the mindset that velocity=pressure and if I can get a reasonably reliable idea of what my max velocity should be, I put more faith in that than what my exact powder charge happens to be when I get there.

I'm thinking that my load is probably very near or slightly over 60,000 psi. Does anyone happen to know, or know how to figure out, exactly what velocities should be achievable when going from 50,000 to 60,000 psi? Anyone have any idea what my max velocity potential for a 129 ABLR or a 140 Berger should be at 60,000 psi in a 20" barrel? I think this little round has great potential and I really dig this little rifle. But I don't want to handicap it at 50,000 psi.

 

[jason miller]

This little cartridge isn't too popular in a bolt action.... yet. But I think it's on the way. My best guess is that a 140 at 2400 fps and a 129/130 at a shade over 2500 would correlate closely to my 123 at 2600 and change.

 

[SJB358]

I can check QL and see what it says.

 

[SJB358]

Your speeds look completely good to me.

Cartridge : 6.5 Grendel (CIP)
Bullet : .264, 123, Hornady A-Max 26171
Useable Case Capaci: 31.135 grain H2O = 2.022 cm³
Cartridge O.A.L. L6: 2.260 inch = 57.40 mm
Barrel Length : 22.0 inch = 558.8 mm
Powder : Alliant AR-Comp

Predicted data by increasing and decreasing the given charge,
incremented in steps of 0.911% of nominal charge.
CAUTION: Figures exceed maximum and minimum recommended loads !

Step Fill. Charge Vel. Energy Pmax Pmuz Prop.Burnt B_Time
% % Grains fps ft.lbs psi psi % ms

-09.1 92 25.45 2416 1594 42488 6120 100.0 1.266
-08.2 93 25.70 2436 1621 43757 6149 100.0 1.250
-07.3 93 25.96 2456 1647 45066 6178 100.0 1.235
-06.4 94 26.21 2476 1674 46418 6207 100.0 1.219
-05.5 95 26.47 2496 1701 47810 6235 100.0 1.204
-04.6 96 26.72 2516 1728 49248 6263 100.0 1.189
-03.6 97 26.98 2535 1755 50731 6290 100.0 1.174 ! Near Maximum !
-02.7 98 27.23 2555 1783 52261 6317 100.0 1.160 ! Near Maximum !
-01.8 99 27.49 2574 1810 53842 6344 100.0 1.146 ! Near Maximum !
-00.9 100 27.74 2594 1838 55474 6370 100.0 1.132 ! Near Maximum !
+00.0 101 28.00 2613 1865 57157 6396 100.0 1.118 ! Near Maximum !
+00.9 102 28.26 2633 1893 58899 6422 100.0 1.105 !DANGEROUS LOAD-DO NOT USE!
+01.8 103 28.51 2652 1921 60696 6447 100.0 1.092 !DANGEROUS LOAD-DO NOT USE!
+02.7 104 28.77 2671 1949 62555 6471 100.0 1.079 !DANGEROUS LOAD-DO NOT USE!
+03.6 104 29.02 2690 1977 64474 6495 100.0 1.066 !DANGEROUS LOAD-DO NOT USE!
+04.6 105 29.28 2709 2005 66449 6519 100.0 1.053 !DANGEROUS LOAD-DO NOT USE!

Results caused by ± 10% powder lot-to-lot burning rate variation using nominal charge
Data for burning rate increased by 10% relative to nominal value:
+Ba 101 28.00 2684 1967 69971 6148 100.0 1.047 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 101 28.00 2504 1712 45639 6768 100.0 1.216


Here are the others... Not too shabby at all.

Cartridge : 6.5 Grendel (CIP)
Bullet : .264, 140, Berger VLD #26401
Useable Case Capaci: 29.203 grain H2O = 1.896 cm³
Cartridge O.A.L. L6: 2.260 inch = 57.40 mm
Barrel Length : 22.0 inch = 558.8 mm
Powder : Alliant AR-Comp

Predicted data by increasing and decreasing the given charge,
incremented in steps of 0.981% of nominal charge.
CAUTION: Figures exceed maximum and minimum recommended loads !

Step Fill. Charge Vel. Energy Pmax Pmuz Prop.Burnt B_Time
% % Grains fps ft.lbs psi psi % ms

-09.8 90 23.45 2228 1544 42472 5595 100.0 1.357
-08.8 91 23.70 2248 1571 43827 5626 100.0 1.339
-07.8 92 23.96 2267 1598 45230 5657 100.0 1.321
-06.9 93 24.21 2287 1625 46679 5687 100.0 1.303
-05.9 94 24.47 2306 1653 48175 5717 100.0 1.286
-04.9 95 24.72 2325 1680 49723 5747 100.0 1.270
-03.9 96 24.98 2344 1708 51322 5776 100.0 1.253 ! Near Maximum !
-02.9 97 25.23 2363 1736 52975 5805 100.0 1.237 ! Near Maximum !
-02.0 98 25.49 2382 1763 54684 5834 100.0 1.222 ! Near Maximum !
-01.0 99 25.74 2401 1791 56453 5862 100.0 1.206 ! Near Maximum !
+00.0 100 26.00 2419 1820 58282 5889 100.0 1.191 !DANGEROUS LOAD-DO NOT USE!
+01.0 101 26.26 2438 1848 60165 5916 100.0 1.176 !DANGEROUS LOAD-DO NOT USE!
+02.0 102 26.51 2457 1876 62105 5943 100.0 1.162 !DANGEROUS LOAD-DO NOT USE!
+02.9 103 26.77 2475 1905 64105 5969 100.0 1.147 !DANGEROUS LOAD-DO NOT USE!
+03.9 104 27.02 2494 1933 66172 5995 100.0 1.133 !DANGEROUS LOAD-DO NOT USE!
+04.9 105 27.28 2512 1962 68306 6020 100.0 1.119 !DANGEROUS LOAD-DO NOT USE!

Results caused by ± 10% powder lot-to-lot burning rate variation using nominal charge
Data for burning rate increased by 10% relative to nominal value:
+Ba 100 26.00 2479 1910 71028 5671 100.0 1.119 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 100 26.00 2328 1685 46446 6214 100.0 1.291










Cartridge : 6.5 Grendel (CIP)
Bullet : .264, 129, Nosler AccuBond LR 58943
Useable Case Capaci: 29.690 grain H2O = 1.928 cm³
Cartridge O.A.L. L6: 2.260 inch = 57.40 mm
Barrel Length : 22.0 inch = 558.8 mm
Powder : Alliant AR-Comp

Predicted data by increasing and decreasing the given charge,
incremented in steps of 0.963% of nominal charge.
CAUTION: Figures exceed maximum and minimum recommended loads !

Step Fill. Charge Vel. Energy Pmax Pmuz Prop.Burnt B_Time
% % Grains fps ft.lbs psi psi % ms

-09.6 90 23.93 2305 1521 40432 5767 100.0 1.328
-08.7 91 24.18 2325 1548 41692 5797 100.0 1.310
-07.7 92 24.44 2345 1575 42992 5827 100.0 1.293
-06.7 93 24.69 2365 1603 44336 5856 100.0 1.276
-05.8 94 24.95 2386 1630 45723 5885 100.0 1.259
-04.8 95 25.20 2406 1657 47157 5913 100.0 1.243
-03.9 96 25.46 2425 1685 48638 5941 100.0 1.227
-02.9 97 25.71 2445 1713 50168 5968 100.0 1.212 ! Near Maximum !
-01.9 98 25.97 2465 1740 51750 5996 100.0 1.196 ! Near Maximum !
-01.0 99 26.22 2485 1768 53385 6022 100.0 1.181 ! Near Maximum !
+00.0 100 26.48 2504 1796 55076 6049 100.0 1.166 ! Near Maximum !
+01.0 101 26.74 2524 1824 56824 6075 100.0 1.152 ! Near Maximum !
+01.9 102 26.99 2543 1853 58633 6100 100.0 1.137 !DANGEROUS LOAD-DO NOT USE!
+02.9 103 27.25 2563 1881 60504 6125 100.0 1.123 !DANGEROUS LOAD-DO NOT USE!
+03.9 104 27.50 2582 1910 62440 6150 100.0 1.109 !DANGEROUS LOAD-DO NOT USE!
+04.8 105 27.76 2601 1938 64444 6174 100.0 1.096 !DANGEROUS LOAD-DO NOT USE!

Results caused by ± 10% powder lot-to-lot burning rate variation using nominal charge
Data for burning rate increased by 10% relative to nominal value:
+Ba 100 26.48 2572 1895 67499 5809 100.0 1.092 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 100 26.48 2399 1648 44028 6409 100.0 1.268



It is a 58K cartridge so adding another 2K or even up to 7K won't add too much. I think the AR guys just had a bad time. I think your stuff looks spot on.

 

[jason miller]

Thank you, kind sir. Idk enough about Quickload to understand why people seem to think it isn't accurate with this stubby little cartridge, but it's prediction seems to fall pretty much right in line with factory ammo ballistics at the 52,000 psi limit.

I'm hoping this little cartridge gets more popular in bolt rifles so we can get some more real-world data on it. CZ offers it in their 527 now. Ruger is supposedly dropping it into their American line next year. Barrett has a miniaturized Fieldcraft rifle coming out that they haven't announced cartridges for yet.

My little Howa with its heavy contour barrel tips the scales at just a hair over 6 pounds after I took an orbital sander to the chunky factory stock. My .223 with their standard barrel weighs 5.65 lbs after the same treatment. I'm thinking one could get the standard barrelled 6.5 Grendel close to 5.5 lbs. A 123 at nearly 2700 in such a short and light package would be one dandy little deer rifle- and for a lot less money than anything else comparable. Whittakers has them for around $450 when they're in stock...

Edit to add: I've also proven in milk jugs that the 123 holds together just fine at 2600 fps, while still opening up at 440 yards when started at only 2400 or so fps- which should mean something like 1700 fps impact velocity. And for plinking steel, it stays supersonic past 1,000.

A 147 Hornady or that new 130 RDF just might be supersonic to a mile out in CO where I used to live and shoot, btw. And if one were so inclined, I'm guessing a Sierra 107 TMK should push nearly 2800 fps and still have a .450ish BC. Or even a 100 TTSX or Ballistic Tip that just might nudge close to 2900. That's basically a 250 Savage in a tiny rifle with 30ish grains of powder...

 

[SJB358]

It is a pretty cool little cartridge. I dig the little 6.5's and the Grendel seems like a big performer for so little powder.

QL is as accurate as the data you put in it. Crap in = crap out, if you can work with the program a little, I have found it darned good.