The rush to short barrel Grendels

[DRW]

I just finished a 12.5? Grendel build for thermal pig hunting, seems to drop them as well as my 18? G.

[andrewtac]

Converting my Liberty Leonidas to grendel. I never shoot 300blk and won't (especially after the barrel swap). I got it for short range hunting, rather have the grendel 200ish and in rather than 75ish and in.

[G Tidewater]

Great thread . I knew the capability of the Grendel at longer ranges but was misinformed of it's potential with a short barrel. Many of my friends jumped on the BO bandwagon but I was never convinced aside from SS suppressed . I have shot a few of those with 50 yard zeros and you need to hold big time at 200. Makes sense for a door kicker but not for an all around SBR. Going to look into 6.5G for a shortie as it makes more sense .

[PrecisionFirearms]

Don?t forget precision firearms offers short barrel Grendel?s too.

You are welcome Mark

Hey Thanks so much for the vote!!

[PrecisionFirearms]

Sabre 14.5" cl is interesting, thought I recall some of their barrels having a chamber issue? Possibly as I age I may not be recollecting that correctly.

I have a bunch of these if anyone is interested

[CaptnC]

Not trying to be controversial or start a flame war or cartridge contest, especially as a new guy to the forum. So with all due respect I ask what value is there in a short-barreled Grendel? The wasted powder and lost velocity would seem to me to negate the benefits of the cartridge design. Don?t get me wrong, to each his own, and I?m not calling your wrong for buying one, but I?ve been of the mindset of use the best tool for the purpose, so if I needed an SBR then I?d consider a 300 Blackout or something in a pistol cartridge, or move to a 16? gun and train to make it work. I just don?t see the Grendel as the best tool for the job in an SBR build. That said, I do hope you enjoy any rifle you build/buy. I am a firm believer in the right to pursue happiness.

Hang it up bro...I've gone down this road with this crowd...they are a bit hard headed on the issue. Several here have blocked me so they don't have to see my stance against such short barreled 6.5's.

So I dont stop by very often any more...the barrel makers want to make money. If you want and beg them to do something, regardless how good an idea it...they are here to make money. I'd never own a 6.5 G with a barrel shorter than 16", but if made barrels I'd sell these guys all they want!

[CaptnC]

Powder is burned within the first inch or two of the barrel near the chamber, unless you're using a really poor choice for subsonic without full conversion.


Guess what an AK's 16.3" muzzle velocity is with a 123gr? 2290-2360fps

Even the 10.5" Grendel smokes the AK, both shooting the exact same bullet weight, same basic case size/length.

The AK goes subsonic around 500yds. The 10.5" Grendel is still supersonic at least to 800yds.

I know your looked upon very highly here...nearly God like...but your numbers are cooked to make your point. Import factory ammo disigned for guns built in the late 40's, up against modern factory guns and like ammo!

My 16" 7.62x39 AR's with hand loads equal my 6.5 velocities. I've been using CFE BLK powder and staying inside max loads. I have developed quite a new feeling for the hated AK round!

[CaptnC]

Sorry for the back to back post but I work for a living and post from my old phone.

Back to the 7.62x39 vs 6.5 Grendel...with like barrel lengths the Grendel will still leave my 7.62x39 AR's in the dust because of bullet BC.

But you throw your 12.5 up against my 16" 7.62x39 AR your numbers above will not be supported. My muzzle velocity is o well over 2400fps with 123 Barnes bullets. IIRC I'm running 30.2gr of CFE BLK in a bunch of mismatched cases in three different rifles (well one doesn't really count in this discussion because it has a 20" barrel) and hold MOA out to 400yds.

Well...I'm out...got deer and hogs to shoot...arguing over silly 12.5 barrels gives me a headache!

[LRRPF52]

I know your looked upon very highly here...nearly God like...but your numbers are cooked to make your point. Import factory ammo disigned for guns built in the late 40's, up against modern factory guns and like ammo!

My 16" 7.62x39 AR's with hand loads equal my 6.5 velocities. I've been using CFE BLK powder and staying inside max loads. I have developed quite a new feeling for the hated AK round!

You're making the same basic mistake I used to do when all we had was muzzle velocity data, not downrange data from ballistics calculators.

16.3" AK is roughly 80-150fps faster at the muzzle than a 10.5" Grendel shooting the same bullet weight. Now watch what happens once both have reached 100yds:

10.5" Grendel, 123gr SST with a .462 G1 BC (derated actual BC, not inflated published BC), 2210fps

100yds 2038fps 1135ft-lbs

125yds 1997fps 1089ft-lbs

150yds 1956fps 1045ft-lbs

200yds 1875fps 961ft-lbs

225yds 1836fps 921ft-lbs

16.3" 7.62x39, 123gr FMJ, .266 G1 BC, 2350fps

100yds 2047fps 1144ft-lbs

125yds 1975fps 1065ft-lbs

150yds 1904fps 990ft-lbs

200yds 1768fps 854ft-lbs

225yds 1703fps 792ft-lbs


So now you're left having to explain to me why I should carry around a longer rifle to get less performance. You're not going to do yourself many favors with increasing the velocity with it by hand-loading, because the 7.62x39 .310" bullet selection doesn't break .300 G1, so no real practical differences in performance when you push it a little, and bolt thrust is considerable with the high case taper in that cartridge.

No deities here, and no hate, just applied physics. If you think I'm wrong, feel more than free to lay out the ballistic argument and I'll go get dies and components to load up my 20" SKS and 16.3" AKs....but I can save you the effort and tell you they'll probably be for sale sooner than later while I enjoy my 12" and 10.5" Grendels.

Your argument is an excellent case study though for those who might not have seen the comparison side-by-side of how shorter barrel Grendels exceed the ballistic performance of even the 20" SKS as you start to look at 125yds and farther.

Now if you're shooting stuff within 100yds in really tight terrain, then absolutely yes, you will have slightly faster impact speeds, but from my POV, that's another case for the shorter weapon vs a much longer barrel, that also allows you to punch into occasional farm fields and still maintain over 900ft-lbs past 225yds, whereas the 7.62x39 from a 20" SKS at 2400fps will still not maintain 900ft-lbs to 200yds, and the 16.3" only keeps 900ft-lbs out to 175yds.

So you look down at the two options and see that there aren't a lot of selling points for the 7.62x39 no matter how you slice it.

[A5BLASTER]

Sorry for the back to back post but I work for a living and post from my old phone.

Back to the 7.62x39 vs 6.5 Grendel...with like barrel lengths the Grendel will still leave my 7.62x39 AR's in the dust because of bullet BC.

But you throw your 12.5 up against my 16" 7.62x39 AR your numbers above will not be supported. My muzzle velocity is o well over 2400fps with 123 Barnes bullets. IIRC I'm running 30.2gr of CFE BLK in a bunch of mismatched cases in three different rifles (well one doesn't really count in this discussion because it has a 20" barrel) and hold MOA out to 400yds.

Well...I'm out...got deer and hogs to shoot...arguing over silly 12.5 barrels gives me a headache!

Then why did you just post all that drivel?

It's kind of simple if you don't want it. Then stay off of threads about it.

Until you post YOUR data proving otherwise I'm going with what my ballistic data and what LRRPF52 says about it.

[LRRPF52]

I just got a 10.5" Grendel Criterion pipe from Precision Firearms.

Once I get through all the other work I'm doing right now and get it together, I'll go see what kind of velocities I will get with several factory loads, and take it out to distance just for fun.

Think about that though for a minute. More retained energy/impact speed at 150yds and out from half the barrel length shooting the exact same bullet weight compared to a 20" SKS.

And people still wonder why so many are buying short barreled Grendel uppers, barrels, pistols, etc.

Also, the recoil and muzzle climb with my AKs feels like 1920s cog machinery banging around compared to Grendel, even in the much smaller AR15 pistols. You can also still have a smaller, lighter package with a suppressed 12" than an unsuppressed AK.

Here's a graph I made comparing my 16.3" Maadi AKM with optimistic mv vs the 12" Grendel.

[CaptnC]

LRRP,
Not sure if you missed parts of my post or what happened. But I'm not shooting a SKS...I own several AR-15 rifles chambered in 7.62x39...2 that are 16" and one that's 20".

Now for the ammo...not Russian junk...my personal hand loads with Barnes TAC-X 123 with a modist. 270 G1

As you can see in the below photo, the magnetospeed is reading 2470fps...the pictured tatarget was shot at 100yds with my old NV scope which is only 3x. The 7.62x39 barrel is a 16" SS from BCA. If you want to use a 20" barrel...my 20" 7.62x39 AR-15 has a bit fast MV than the 16" pictured below.

So please stay with the facts...

A5B seems to be off his meds again...he kind of flippn' out!

To be honest LRRP not not saying a 7.62x39 AR-15 is better than the 6.5 Grendel (hell...I own 4 of them) but for the average shot on a WT deer in 90% of their normal range they are both just as dead at the end of the day...just because you feel the need to shave off 4" of barrel doesn't make it better.

[CaptnC]

I have a bunch of these if anyone is interested

Oh...just an FYI...my earlier comments where made before I read all the posts. I was by no means try it insult you.

I guarantee you, if I was in the barrel business, I would be cutting 6" 6.5 Grendel barrels if people would buy them. After all business is business!

[A5BLASTER]

LRRP,
Not sure if you missed parts of my post or what happened. But I'm not shooting a SKS...I own several AR-15 rifles chambered in 7.62x39...2 that are 16" and one that's 20".

Now for the ammo...not Russian junk...my personal hand loads with Barnes TAC-X 123 with a modist. 270 G1

As you can see in the below photo, the magnetospeed is reading 2470fps...the pictured tatarget was shot at 100yds with my old NV scope which is only 3x. The 7.62x39 barrel is a 16" SS from BCA. If you want to use a 20" barrel...my 20" 7.62x39 AR-15 has a bit fast MV than the 16" pictured below.

So please stay with the facts...

A5B seems to be off his meds again...he kind of flippn' out!

To be honest LRRP not not saying a 7.62x39 AR-15 is better than the 6.5 Grendel (hell...I own 4 of them) but for the average shot on a WT deer in 90% of their normal range they are both just as dead at the end of the day...just because you feel the need to shave off 4" of barrel doesn't make it better.

Lmao. More drivel lmao. Why must you do this too every short barrel thread?

You sure it's me that's off my meds?

[LRRPF52]

LRRP,
Not sure if you missed parts of my post or what happened. But I'm not shooting a SKS...I own several AR-15 rifles chambered in 7.62x39...2 that are 16" and one that's 20".

Now for the ammo...not Russian junk...my personal hand loads with Barnes TAC-X 123 with a modist. 270 G1

As you can see in the below photo, the magnetospeed is reading 2470fps...the pictured tatarget was shot at 100yds with my old NV scope which is only 3x. The 7.62x39 barrel is a 16" SS from BCA. If you want to use a 20" barrel...my 20" 7.62x39 AR-15 has a bit fast MV than the 16" pictured below.

So please stay with the facts...

A5B seems to be off his meds again...he kind of flippn' out!

To be honest LRRP not not saying a 7.62x39 AR-15 is better than the 6.5 Grendel (hell...I own 4 of them) but for the average shot on a WT deer in 90% of their normal range they are both just as dead at the end of the day...just because you feel the need to shave off 4" of barrel doesn't make it better.

I read every detail of your posts. Not sure where the ball is being dropped. An AR15 chambered in 7.62x39 is never going to be able to handle the loads that an SKS or AK will if you hand load, unless you're shooting the CMMG Mutant.

Even if I hand-load my 20" SKS with that Barnes TAC-X, it will never be able to keep up with the downrange performance of even a short 10.5" Grendel shooting factory ammo. The SKS will of course be faster at the muzzle, but because of the extremely poor BCs of the .310" bullets in that weight class, they lose energy rapidly due to their fat/short/flat-base form factor, even within the short distances.

They both will kill just fine, but you pay a rifle length/weight/bulk penalty that is always there when you are not shooting, while getting less performance and effective range.