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6.5 Grendel

10 Oct 2025
@ 07:43 pm (GMT)

Joel Brown

Hey guys,

Just wanting some advice about the 6.5 Grendel if anyone has had real world experience with this cartridge. My brother in law is in the market for a new medium range cal for fox work (kangaroos under permit of course) wild dogs and fallow deer within the cartridges limitations. Looking at the 120sst or the 123 eld m.

We originally funneled down to the 223 with a 1:8 twist running 75gr eld m as iv had success culling with these out to 350m. But then stumbled on
The 6.5 G thinking this may be a better fit.

Factors driving the choices are Noise- small scale farms in
Close proximity Efficiency & cost

Looking closely at the Howa Mini action and at $570 barrelled action new it sounds kind of hard to pass up.they also do have some chassis options to choose from that I’m trying to steer him away from 😅

Any thoughts or suggestions would be greatly appreciated

Cheers lads

Replies

11 Oct 2025
@ 08:52 am (GMT)

Quote this

Nathan Foster

Re: 6.5 Grendel

Hi Joel, there is a great deal of hype around these cartridges just now including a trend involving the use of small cals for body shooting large game weighing up to and above 300kg. The cartridges in question include the 22 ARC, 6mm ARC and 6.5mm Grendel and are based on the 22 and 6mm PPC which are in turn based on the 7.62x39. The main focus around each of the newly minted items was optimizing performance in the AR-15, specifically for competitive shooting or in the case of the 6mm ARC, for military use though I don't think this went very far.

To bolster sales, these cartridges have been advertised as being suitable for hunting medium game with some very bold claims. Although such feats can be achieved, I would strongly urge my readers to not go down this path. If Hornady and the general hunting populace want to go the woke route, then so be it. I expect more from my own readers - stronger principles and values including the self discipline and determination to 'use enough gun' when hunting larger bodied animals.

Ok, with that out of the way...

Let us go back to the .243, a known performer on fallow, roo and wild dogs. We can lump the .25-303, Humdinger and .25-06 in with this. These cartridges fire light weight bullets (e.g. 75 to 100 grains common for dogs) at high speeds. Increasing speed squares the kinetic energy of the projectile. In addition to this, the projectiles feature very thin jackets which aid expansion at distance where energy is very low. These are the keys to the wow factor - high speed and light construction.

If you remove the speed but without adding bullet weight, performance diminishes accordingly. Performance also diminishes considerably at distance if using a tough bullet. Both the 6mm and .25 can produce terrible results at distance using monos.

The 7.62x39 case design does have a power advantage over the .223. The increased power in conjunction with modern twist rates allows us to shoot heavier bullets with high BC's which retain higher energy down range.

The key however to all of this is bullet construction, just as it was when the .243 was developed. A soft bullet is the key to the good results obtained with the ARCs and Grendel.

It is also important to understand that much of the development of these cartridges is centered around double base (high energy) ball powders. If using ADI single base stick powders, velocities may be 100fps or more below the more enthusiastic results published. In some instances, velocities are no higher than the .223, but energy is higher (due to bullet weights) and this energy can utilized to enhance expansion and wounding.

So yes, there is an advantage over the the original .223 provided other factors are taken into consideration. None are ideally suited to large animals. For example, if a standard bullet is used, it may fail to penetrate the shield of a mature boar (contrary to Hornady's claims). It may also break up on the shoulder bones of a large bodied deer. If instead a tough bullet is used, energy transfer (wounding) is limited, especially at distance. If your brother in law is buying on the basis of the Grendel for all game, you do need to be aware that it has some limitations.

More specifically to your purposes, BC's are around .450 to .5 for the Grendel, not earth shatteringly high. Velocities run from around 2500 (123gr) to 2700fps (100gr). Using a soft projectile, wounding is actually fairly broad at distance. It is however best to try to aim to strike the center shoulder to encourage expansion / secondary bone fragments at distance. This is a bit of a bug bear for me as this advice can be misinterpreted as 'use on bigger animals at distance to encourage expansion'.

The Arcs and Grendel may be an adequate fit for what you are wanting. I might perhaps suggest looking to the 6mm ARC due to subtle differences in bullet construction versus the 6.5. The 6mm ARC is however quite slow, about 2600fps in a short barreled rifle using ADI powder. It really does require double base and a 22 to 24" barrel to get up to speed.

In my testing, the 6mm works well at distance. But this pertains to the ELD-M bullet only. If you change the bullet, the performance decreases quite dramatically at distance (width of wounding / length of dead runs / death in minutes not seconds).

You are already familiar with the 75 grain .223. It does the business on light animals but can come acropper on larger animals. It is adequate down to about 2000fps (roughly the range you stated) where energy is extremely low at around 700 ft-lb. The 108gr ELD-M can be used at slightly lower impact velocities due to its similar construction but with increased weight and higher downrange energy. it is also more uniform than the .223 regarding penetration and less erratic should you encounter slightly larger body weights.

The 6.5 utilizes slightly stouter projectiles which are of course good for hunting Fallow deer at normal hunting distances. The heavy (compared to .223 and 6mm) projectiles retain more energy at longer ranges but is this offset by the very subtle differences in construction, resulting in similar effective ranges.

Both the 6mm ARC and 6.5 Grendel are definitely adequate. The 7.62x39 based cartridges don't have the wow factor of the fast twist 22 Creedmoor, 6mm Creedmoor, .243 or 6.5 Creedmoor when used on light framed game. But that is not what you were asking about.

To summarize, there is a slight advantage over the .223 regarding effective ranges and also uniformity of wounding at closer ranges. But these are modest differences. Would I recommend a 6mm ARC or Grendel over the .223? Actually yes, but again, I would not want to set up false expectations with such minor improvements. Given the choice, I would prefer an altogether more potent cartridge. But this does not take your noise and cost factors into consideration.

As yet another final reminder, bullet construction is the critical factor in all of this. Small changes make big differences when dealing with low power. It is the combination of increased weight, weak construction and suitable twist rates that give these cartridges an advantage over the 223 cartridge regarding killing performance.

Regarding the Howa Mini, a good action but like many things, quality has dropped a bit in recent years. Using the accurizing book, you should hopefully work through any bore issues. The main concern just now is rough barrel threads versus high torque settings. The receiver thread may gall, should you ever want to replace the barrel.

Your question was well timed as I have been spending much time studying this topic of late, testing (on game) in the most minute detail.

Hope this helps a bit. All the best.