Switch from .308 to 6.5 Grendel. Bad idea?

[zulu]

I'm looking to build a 6.5 Grendel vs using my current .308.

I'd like to go with a shorter 12" so that my overall length will be similar with a suppressor. My question is will I be disappointed in performance vs the 308? I've never had issues with the .308 knocking deer down fast so I'm a little concerned about a smaller lighter round.

Shots are typically within 100yds and farthest would likely be around 325.

Uses would be for whitetail and maybe some hog hunting.

Thoughts?

 

[WCB]

Is your .308 a standard barreled gun say 20+ inches.

At 12" I would think you are going to loose 300-400 FPS so lets just say 2200ishfps with a 120gr bullet. At 300 you'll have about 650ftlbs of energy moving mid 1500s for velocity (what is the bullet operating velocity?) I know you said most shots are under that but my biggest consideration would be at my longer ranges. At 100 yards and in I don't think you will have a problem killing them however you'll be 1,000+ ft lbs behind say a 20" .308 at 100 yards.

I personally would say yes you will on average see a difference.

 

[FLATHEAD]

I just bought a .308.

 

[zulu]

Is your .308 a standard barreled gun say 20+ inches.

At 12" I would think you are going to loose 300-400 FPS so lets just say 2200ishfps with a 120gr bullet. At 300 you'll have about 650ftlbs of energy moving mid 1500s for velocity (what is the bullet operating velocity?) I know you said most shots are under that but my biggest consideration would be at my longer ranges. At 100 yards and in I don't think you will have a problem killing them however you'll be 1,000+ ft lbs behind say a 20" .308 at 100 yards.

I personally would say yes you will on average see a difference.

Excellent response with real data behind it.

I'm probably hoping for too much wanting a shorter/lighter package.

 

[justinspicher]

Here is some data from the internet, maybe it’ll help, maybe it wont.

 

[PredatorSlayer]

I have a 12.5” 308. Its awesome. I was going to get a 6.5 CM, but read somewhere that the larger diameter bullets will lose less FPS in shorter bullets…so I went 308.

 

[zulu]

I have a 12.5” 308. Its awesome. I was going to get a 6.5 CM, but read somewhere that the larger diameter bullets will lose less FPS in shorter bullets…so I went 308.

Hope its suppressed, otherwise that has got to be quite the fireball

 

[PredatorSlayer]

Hope its suppressed, otherwise that has got to be quite the fireball

Its not, just braked right now. It breathes a little fire

 

[Glendon Mullins]

At one point I had an AR-10 in 308 which I pig hunted with, had no problems dropping pigs 1 shot (obviously)

Switched to a 6.5 Grendel because its lighter, 16 inch barrel i am pretty sure, and still drop pigs with 1 shot.

I am sure whitetail would be the same result

Most of my shots are 100yds and In, so I cannot speak about 200-300 yard shots.

I have predator hunted with the grendel as well, but haven't had the opportunity to shoot that far either... yet

The Grendel is a fun little gun to hunt with.

 

[Newtosavage]

I'm looking to build a 6.5 Grendel vs using my current .308.

I'd like to go with a shorter 12" so that my overall length will be similar with a suppressor. My question is will I be disappointed in performance vs the 308? I've never had issues with the .308 knocking deer down fast so I'm a little concerned about a smaller lighter round.

Shots are typically within 100yds and farthest would likely be around 325.

Uses would be for whitetail and maybe some hog hunting.

Thoughts?

Nobody can answer that question but you. However I was pretty disappointed in the performance of the 6.5 Grendel compared to my trusty 7mm-08's. It was especially disappointing because I had really high hopes for the Howa Mini 6.5G I had been working on. I spent a LOT of time cutting down the stock and shortening and recrowning the barrel, and sourcing a hinged floorplate for it. That gun shot absolutely lights-out. As in, maybe the most accurate rifle I've ever owned, including 4 Tikkas.

So after shooting a few deer and a few pigs, I was frustrated. They just weren't going down as quickly or leaving as much (any, really) blood on the ground. I used 130 Gamechangers, 120 Speers, NBT's and ELD-M's and got similar results from all of them.

Went back to my 7mm-08 the next year and got a bunch of bang-flops or 20 yard dirt dives with plenty of blood trail.

I'm not going to waste any time trying to sort out what that is exactly. I just know what I saw. I literally HATED selling that little rifle because of all the work I put into it. But I knew I was going back to my 7mm-08's the next season.

 

[Newtosavage]

I will add Zulu, that on the final day of the season that I hunted with that Howa Mini 6.5 Grendel, I had a rare chance to take one of the target bucks on our lease. I was in a box blind and he came out at a measured 250 yards. I held on him for about 4 seconds and just couldn't pull the trigger. I just didn't feel good about the ability of that round to anchor him on the property after what I had seen from the does and pigs I had shot with it earlier. So I guess you could say that lack of confidence I developed in the 6.5 Grendel may have cost me a pretty decent buck.

Didn't break my heart. My freezer was already full. But that was the first time I can remember passing on a good clean shot at an animal because I wasn't 100% sure my rifle was up to the task.

 

[justinspicher]

I have hunted deer and coyotes with a 6.5G. I had issues with the SST ammo under 100yds. For hunting I used the Hornady black or american gunner ammo. Both are HTBP ammo and would drop the animals where they stood. The furthest shot was 80yds.

 

[zulu]

All good info here. Really appreciate everyone's replies and real world experience using the Grendel. Seems like maybe I should hold off on a Grendel build for now. While I think it would work for most scenarios I might be giving up too much. Perhaps I'll look into a lighter AR10 setup.

 

[Tahoe1305]

I’ll let you know what my 12” Grendel gets tomorrow (range time) vs my 20” (2625fps) with 123 SST. I’m guessing it will be very close to that stats page posted above. If you hand load, some of the Grendel chambers are a bit long (Grendel II) and can put up some impressive numbers.

FWIW I also own a very lightweight AR10 in 6.5C w/16” barrel. If I recall gun is 5.6lbs naked. I’m guessing as light as my 12” Grendel. But it cost 3x as much.

My 6.5C AR-10 with 16” (2650fps w/143) barrel is pretty close to ballistic match to 24” 308 FWIW (2900fps w/165). 308 has more energy until about 500 yds but then 6.5C surpasses.

In my testing the 16” 6.5C bests the 20” 6.5G by 200fps. Guessing it will best a 12” 6.5G closer to 400fps.

A short Grendel will never beat a normal length 308 in killing power IMO. But it will be a lot of fun to shoot and “likely” get it done.

MTF tomorrow!

 

[Tahoe1305]

I’ll let you know what my 12” Grendel gets tomorrow (range time) vs my 20” (2700fps) with 123 SST. I’m guessing it will be very close to that stats page posted above. If you hand load, some of the Grendel chambers are a bit long (Grendel II) and can put up some impressive numbers.

FWIW I also own a very lightweight AR10 in 6.5C w/16” barrel. If I recall gun is 5.6lbs naked. I’m guessing as light as my 12” Grendel. But it cost 3x as much.

My 6.5C AR-10 with 16” (2650fps w/143) barrel is pretty close to ballistic match to 24” 308 FWIW (2900fps w/165). 308 has more energy until about 500 yds but then 6.5C surpasses.

In my testing the 16” 6.5C bests the 20” 6.5G by 200fps. Guessing it will best a 12” 6.5G closer to 400fps.

A short Grendel will never beat a normal length 308 in killing power IMO. But it will be a lot of fun to shoot and “likely” get it done.

MTF tomorrow!

So range results were a tad disappointing.

8” of Grendel barrel cost me exactly 300fps. So 123s at 2325fps.

Honestly I think for shorter barrel options I’d be hard pressed to say I like the 6.5G over a similar length 300blk with Barnes 110. The 6.5G will have a bit more energy but those Barnes are great. Both are about identical velocity with similar barrel lengths.

 

[zulu]

So range results were a tad disappointing.

8” of Grendel barrel cost me exactly 300fps. So 123s at 2325fps.

Honestly I think for shorter barrel options I’d be hard pressed to say I like the 6.5G over a similar length 300blk with Barnes 110. The 6.5G will have a bit more energy but those Barnes are great. Both are about identical velocity with similar barrel lengths.

Great feedback. Looks like the chart is pretty accurate to your real world results as well.

 

[35remy]

I recently purchased a side-charging 16” grendel upper from BCA. Cheap to buy, and has functioned well for the first 400 rds I have put through it. I’m reloading 123gr SST’s over LVR for hogs and the occasional coyote. Seems to be a good combo, and my can keeps it relatively quiet.

 

[Titan_Bow]

My son has shot a handful of deer and antelope with the 6.8 SPC AR that I built him. The 6.8 is very comparable to the Grendel. I used a 16” barrel in our build. I’ve been really happy with its performance on game. I’ve been using 110gr Nosler Accubonds. Every animal it’s taken has dropped right there.
In a small carbine M-4 platform, Grendel would be a handy little rifle; super lightweight (depending on components you use) easy to pack around with collapsible stock, almost nonexistent recoil, and fast follow up shots if needed. With a little vortex scope I think ours weighs 6 to 6.5 lbs total. It shoots consistently 3/4” MOA with Nosler factory ammo.


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[Longleaf]

6.8spc performs well out of short barrels, I’ve seen 90gr going 2980 out of a 14.5, smoked a 10pt at 150yr.

 

[Rich M]

While not a grendel, i went from 3006 to 350 Legend. Still throwing 150 and 165 gr bullets but a bit slower. The shock and awe of the 3006 power slamming the deer is lost on the Legend but it does kill them. Have to accept that i may need to track some now.