Energy Calculations - Grendel Hunting?

[Flyby]

There are a variety of stopping power formulas and calculations to see if a bullet or cartridge is "big enough" for certain game. I've found six, there are probably more. I thought it was interesting to compare them all. I don't particularly subscribe to a particular method, I just find it interesting.

I'll attach my spreadsheet, you can add your favorite loads.

[JASmith]

Thanks for sharing that work with us! It looks like you sorted by the HITS score, which was what I would have done until discovering a better measure.

There are indications that momentum, energy, and sectional density mean diddly squat when a bullet hits an animal.

A lot of testing and plain physical phenomena suggest that, when most bullets hit between 2,000 ft/sec and 3,000 ft/sec, only two things matter for penetration: bullet construction and weight. True the bullet won't go as far when hitting bone and will go deeper when going through the lungs, but the relative penetration for the same path remains weight and construction.

Read the discussion on Ideal Bullet Weight for more details. While not mentioned specifically, you will see the Grendel is arguably an all-around medium game cartridge.

[Flyby]

Thanks for the article, I'll give it a read tomorrow.

[sneaky one]

Switch to the mono pills in a lighter wt. They are the rockstars for this round. They lose no wt.

[joker31]

Its funny to see how flawed the Taylor and Thorniley are. It must be weighted for either solids or towards bullet diameter. Thanks Hornady for fixing the seriously flawed numbers. Funny how a 300 AAC is lower than a 5.56 with 75's, I have taken a lot of Boar up to 280lbs with my 10.5" 300AAC, with 165gr Noslers. even took a 290lber with my AK (Use for seriously overan areas for real fast followups on the whole pack instead of 1 or 2. I also hadn't planned on going in woods that day (went to check traps for a friend and was charged. I usually carry the AK behind the seat of my truck and only had my CCW 9mm on me that day. I ended up shooting him from my back after a bunch of smaller ones knocked me down....he got 7 rounds as fast as I could pull the trigger, 1 would have done it but fired all 7 in a 1-2" hole in his chest cavity. the result was a hole we put a tennis ball in. I had 123 ZMax Zombie bullets in it (Were given to me as a joke from DHS friend of mine.) he's on my wall now so all was good.

[JASmith]

sneaky one may be right -- the all-copper expanding bullets in the lighter (100 gr class) have the potential to become "rockstars" in the Grendel.

The Hornady HITS score is indeed very high on the list of credible indicators of performance of standard bullets.

I started looking for alternatives mostly because I couldn't find a method that relates the performance of all-copper, partition, and bonded bullets. I knew from the start of the search that a 45 gr TTSX was probably not as good a game anchoring bullet as, say, a 225 gr Core-Lokt .338 Win Mag , but there's a lot of water between those two points.

It turns out that a few other folks have been doing relevant research, although I will admit that it almost seems to be a stretch to use the insights of hunters from the mesolithic period (10,000 years ago), but that is the starting point for the ideal bullet weight method. Combining those insights with the results of extensive terminal ballistics testing by 3 - 4 other people builds a basis for comparing the bullet types.

The Ideal Bullet Weight discussion shows the relationships in a single chart and gives a top-level view of how 10,000 year-old insights were combined with modern testing to develop the relative performance metrics.

And, yes, the 100 gr TTSX is a pretty good choice for all game one might sensibly go after. While it is close to being OK for elk, one might consider the 120 gr all-copper bullets or the 140 gr Lapua Naturalis for the larger ones.

[skeeter355]

I loaded up 120 gr TTSX bullets for my daughter's 18" Grendel last year and kept her to 200 yds for her cow elk. She had three great hits in the lungs before the cow went down. All were complete pass through penetration but not sure if there was much hydrostatic shock at 2000 fps. The 100 gr TTSX would have provided that shock a little better though the energy numbers were the same at 200 yds for both bullets. I almost think the 123 gr SST would have been a better performer. Nosler's new 129 gr Long Range Accubond looks interesting with a min velocity of 1300 fps. Being bonded it should perform better than the SST but that bullet is even longer than the 120 gr TTSX. The Grendel can be a elk cartridge though a bit on the light side.

[JASmith]

Her bullets may have been acting more like solids when they hit at 2,000 ft/sec.

The minimum impact velocity for reliable expansion is an elusive animal.

I double-checked Barnes' website and found this page: http://www.barnesbullets.com/resources/n...-bullet-n/ and it indicates a minimum of 2,000 ft/sect for 'most TTSX' and 1600 ft/sec for ALL LRX.

We probably should use the higher figure of 1600 ft/sec for the LRX until independent test data surfaces.

[skeeter355]

Yeah that was why I was limiting her to 200 yards. The Barnes rep was saying 1800 fps as min and I bumped that a little to 2000 fps but do think they acted more like solids. Would be nice if we could convince Barnes to develop a Grendel bullet like they have for the 300 Blackout (110 gr TAC-TX). That bullet is supposed to expand at much lower velocities than any of their other bullets.

[cory]

Yeah that was why I was limiting her to 200 yards. The Barnes rep was saying 1800 fps as min and I bumped that a little to 2000 fps but do think they acted more like solids. Would be nice if we could convince Barnes to develop a Grendel bullet like they have for the 300 Blackout (110 gr TAC-TX). That bullet is supposed to expand at much lower velocities than any of their other bullets.

Back before the craziness happened LRRPF52 was in contact with them about it. There's a thread if you do a search.

I was really hoping to see that happen.

[JASmith]

Ha anyone tried the 127 gr LRX or the Nosler 129 gr Accubond LR?

[LRRPF52]

Back before the craziness happened LRRPF52 was in contact with them about it. There's a thread if you do a search.

I was really hoping to see that happen.

I just talked with some of the Barnes employees F2F at the Utah State Sniper Shoot-Out, and one of them was their Ballistics R&D guy. They're making 2 new 6.5mm target bullets in the Match Burner line, and I floated the idea of making a specific pill for the Grendel in the 100-110gr weight class, with VOR-TX expansion threshold and a high BC using a compound hybrid ogive and long boat tail.

[KentuckyBuddha]

Did they sound receptive to your pitch? How big were the Match Burner pills they were thinking of making?