Bolt Action Grendel

[Mutt]

Give me one ...... I'll take it to the range and tell you how it went ...... LOL. I'll even video running it on the chrono.

[eljefe]

That it does, but I would estimate the pressures needed to throw a 123gn at those speeds from the Grendel case will be closer to 80k PSI. Only guessing mind you, someone with Quickload could help on this theory. My 6.5x47 Lap will achieve those speeds at the 65k PSI limit of that cartridge, just.

At pressures above 75k PSI brass flows like liquid and would probably lock the action up on both the CZ and the Mini Zastava when it flowed into the ejector slot.

Oddly the actions are probably able to contain pressures towards 90k PSI, although I'm not sure how it would look afterwards or how useable it would be.

Adam-
Cartridge : 6.5 mm Grendel
Bullet : .264, 123, Lapua Scenar GB489 6032
Useable Case Capaci: 31.925 grain H2O = 2.073 cm³
Cartridge O.A.L. L6: 2.554 inch = 64.87 mm
Barrel Length : 24.0 inch = 609.6 mm
Powder : Vihtavuori N550

Predicted data by increasing and decreasing the given charge,
incremented in steps of 1.0% 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

-10.0 89 26.88 2145 1256 27783 5783 85.9 1.588
-09.0 90 27.18 2170 1286 28634 5872 86.5 1.568
-08.0 91 27.48 2195 1316 29509 5960 87.2 1.548
-07.0 92 27.78 2220 1346 30420 6047 87.8 1.528
-06.0 93 28.08 2245 1376 31359 6133 88.4 1.509
-05.0 94 28.38 2270 1407 32329 6219 89.0 1.490
-04.0 95 28.68 2295 1439 33333 6303 89.5 1.471
-03.0 96 28.97 2321 1471 34372 6385 90.1 1.453
-02.0 97 29.27 2346 1503 35446 6467 90.7 1.434
-01.0 98 29.57 2371 1536 36542 6547 91.2 1.416
+00.0 99 29.87 2397 1569 37706 6626 91.7 1.398
+01.0 100 30.17 2422 1602 38898 6703 92.2 1.378
+02.0 101 30.47 2448 1636 40130 6779 92.7 1.359
+03.0 102 30.77 2473 1671 41408 6853 93.2 1.340
+04.0 103 31.06 2499 1706 42731 6926 93.7 1.321
+05.0 104 31.36 2525 1741 44103 6996 94.1 1.302

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 99 29.87 2549 1775 46023 6834 97.6 1.285 ! Near Maximum !
Data for burning rate decreased by 10% relative to nominal value:
-Ba 99 29.87 2210 1334 30633 6090 82.2 1.523

[adamjp]

Thanks for that.

It is interesting to note that there it appears impossible to load enough N550 in the case to acheive the stated velocity.

[eljefe]

Guys, I was reminded of the COAL I used being 2.5 inch as compared to 2.260. So I ran a fresh set and here's where we stand:

Cartridge : 6.5 mm Grendel
Bullet : .264, 123, Lapua Scenar GB489 6032
Useable Case Capaci: 27.837 grain H2O = 1.807 cm³
Cartridge O.A.L. L6: 2.260 inch = 57.40 mm
Barrel Length : 24.0 inch = 609.6 mm
Powder : Vihtavuori N550

Predicted data by increasing and decreasing the given charge,
incremented in steps of 1.0% 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

+00.0 114 29.88 2560 1790 51340 6454 94.4 1.232 ! Near Maximum !

[JASmith]

QuickLoad seems to have a temperature knob to twist.

I assume the loads were run at the default temperature.

I wonder what the calculated velocities would be if 0 deg F and 130 deg F were used?

[LRRPF52]

I just confirmed that it was in fact a Grendel bolt gun, and it was an extreme pressure test to certify whether or not the Grendel could be used in EU hunting where they have certain velocity, bullet weight, and caliber minimums required for moose, and related competitions.

The load is considered dangerous in a bolt gun, and brass is toast after 1 firing. While discussing this today with one of the head R&D guys at Lapua, he said to think about the maximum pressure capacity of .300 Win Mag, then add about 20%. That is what it took to push the 123gr Scenar at 940 m/s from a bolt gun Grendel. I think .330 Win Mag is 64ksi SAAMI, so 20% on top of that is about 78,000psi-not recommended to try at home folks.

I am quite familiar with the 6.5x47 Lapua, and know several competitors who use it. I almost chambered my AR10 in it, but chose .260 Rem for brass availability. A buddy of mine pushes the 140gr VLD's from a 25" RPA at over 2980fps, and I know some Norwegian Snipers who push the 123gr Scenar well over 3200fps with the x47. Primer pockets will loosen quickly with those loads, to say the least, but the trajectory is awesome!

[adamjp]

The load is considered dangerous in a bolt gun, and brass is toast after 1 firing.

Gee, I can't imagine why?

The CIP Specification for the 300 Win is 62k psi. So yes, nearly 75k psi.

[JWP58]

Does savage make a .223 specific sized action? Or would you just use a regular short action (.308)?

[JASmith]

Does savage make a .223 specific sized action? Or would you just use a regular short action (.308)?

The discussions I've seen suggest that it is a .308 length action.

A good way to confirm is to do a search on the the Savage Forum. Join up and post a query if the answer doesn't pop up!

[adamjp]

I think the Savage 25 is a 223 sized action, but it has little in common with the standard Savage rifles. It is also quite a long action for what it is - unfortunately quite typical of Savage rimfires too.