thinking of replacing 5.56mm as my go-to cartridge

[Lycidas Janwor]

i was doing some ballistic comparisons, including two x39 loads (common 123 grain military load and a less common but more accurate 154 grain load) two 5.56 (common 62 grain SS109 and 75 grain match load) and what i discovered is the 62 grain SS109 easily beats out 123 grain x39 beyond 200 yards.. the 154 grain x39 though beats out the 75 grain 5.56 out to 800+ yards, but this isnt a common x39 load i'd be stocking up on and i dont see the 123 grain 7.62x39 load being significantly better than 5.56 inside 200 yards, and its weaker with more drop outside of 200.. so i do not think i will trade in 5.56 for 7.62x39

so i decided to compare some other loads, including .300 blackout which was weaker than both x39 and 5.56 at just about every range, seems no point in this cartridge outside of suppression.. and of course i compared the 6.5 grendel and 6.8SPC, what i learned about these two is the grendel by far beats every other cartridge with a modest 123 grain load, an added benefit is it can be made from cheap x39 brass and uses a more common (especially in eastern bloc rifles) 11.35mm bolt, meaning no bolt mods for converting 7.62x39 rifles to 6.5 grendel, only barrel and mags

what i learned about the 6.8SPC though does pretty well, by far it easily beats out 7.62x39, 5.56, and .300 blackout, falls short when compared to the grendel, and a downside is you need specially made brass for it, cant convert anything else, and this means you need to modify the bolt face and extractor.. however, most 5.56 bolts can be machined out for 6.8 and doesnt look too hard to modify an extractor for it so if i went that route im confident i'd be able to buy another AK-74 kit, machine out the bolt face, tweak the extractor, slap on a custom contoured barrel, and use 6.8mm AR-15 magazines via a riveted on magazine well adapter.. so that conversion is doable without too much work (id likely have to use an AR-15 magazine adapter for a grendel conversion too), and the SPC appears to me like a cartridge that may have less feeding problems in an automatic

so.. has the support for the grendel and SPC died out yet? id like something i can at least hope to find ammo for once in a while, though almost all my ammo is going to be handloads but i think after thinking about it a bit more, upgrading from 5.56 to 7.62x39 seems pointless to me, so if i do it i am considering the 6.5 grendel or 6.8SPC over anything else

I love the 6.5 Grendel, it's a fantastic cartridge.

 

[justin22885]

i cant help but feel the grendel doesnt really live up to all it could be, due to constraints present within the AR.. like a lot of compromises have been made just to pander to a lesser rifle.. an example would be the rated max pressure being generally low due to the weaker lugs of the AR-15 and the higher bolt thrust of the cartridge.. and it doesnt seem like the magazines for it are all that well optimized, can grendel cartridges all stack efficiently in both columns or do we have gaps in between given the wider body of the cartridge and the narrow magazine?

if the AR-15 didnt have a magazine well, you could have wider bodies magazines for wider cartridges, if the lugs werent as small as they are, you could squeeze more pressure out of it too.. fact is, the AR-15, though you can easily switch calibers, only seems to work well with a small group of calibers, its not truly "multicaliber" when any caliber used in it has to either pander to the constraints or be incredibly unreliable

that is why i have no interest in the AR.. i think its too restrictive, too poorly designed

___

all that aside, has anyone with grendel experience in an automatic experience any feeding issues?.. the cartridge seems very similar in general shape to the 5.45x39 which seems to be quite reliable in automatics

 

[nathan]

All of them are good to go. I wouldnt worry too much for they are all battleproven calibers. It all boils down on how much you can afford and willing to spend.

 

[nathan]

The hottest 7.62 x 39 ammo i tried in all these years were the Yugo brasscased FMJs that were sold 6 yrs ago . They were the most accurate, too, in my AKs and SKSs. Sad to say they re gone .

 

[crazysccrmd]

If you're looking to stockpile quality ammo there really isn't a price advantage for the 5.56 over the 6.8 or 6.5. Checking on gunbot.net shows the cheapest 5.56 load that isn't a 55 or 62gr ball is a HSM 75gr BTHP at $0.68/round. You can get high quality S&B 110gr 6.8 for $0.63/round and decent steel case Wolf 100gr 6.5 for $0.51/round. The 300BO really doesn't compare to all three of those in terms of effectiveness and is also more expensive. Cheapest, decently effective supersonic load is a 120gr OTM at $0.80/round.

The 6x45, 25x45, 277WLV, etc, though nice chamberings, really don't seem to mesh with what it seems you intend them to be used for.

 

[justin22885]

the only 5.56 ammo i shoot is 62 grain military surplus, green tip stuff, i dont really use any other ammo for anything else.. i've been considering finding a good 75 grain load to take my AK deer hunting though.. ive also priced out the cost of a ton of once-fired brass, ss109 bullets, powder, primers, and found i could make about 1,000 rounds for $250 which aint bad at all.. it would cost me almost twice as much to make the same amount of 6.8 or 6.5 ammo

 

[C-grunt]

Sheet metal is okay. But, I have witnessed M855 just fragment upon impact with windshield while in Iraq. The driver only had non-critical flesh wounds.

That very well might be the case but that doesnt always happen. We shot a good amount of Iraqi Army soldiers inside trucks in 2003. High velocity projectiles sometimes do crazy things but in my experience M855 will usually penetrate windshields with enough force to kill people inside.

During my 05 tour the guy on my FOB with the most kills was our cook. We were all out on a HVT mission and he was working the gate when some dudes tried to drive through in a SUV. He killed 5 guys in that SUV with all the shots from his M16A2 going through the windshield or upper hood/dashboard area. Three of the guys were in the back seat and several of the rounds went through the front seats to hit them.

Again Im not saying there are not better options. But in my experience the M855 works pretty well.

This is a pretty decent test. I would like to see a new windshield with each shot but I bet that would be pretty expensive. If I ever get rich Im going to do a bunch of these type of tests.

https://www.youtube.com/watch?v=Twc_d8wImo8

 

[justin22885]

thought m855/ss109 had a big steel penetrator for getting through barriers?

anyway.. while pricing out handloads, i found it would cost me roughly the same to handload 1,000 rounds of 6.8SPC or 6.5 grendel as it would for me to handload 1,000 rounds of 7.62x51/.308 and the added weight dont bother me.. i have also learned i can buy 7.62x54R surplus ammo at a lower cost than i could manufacture my on .308 winchester.. so, i think im going to focus on one of them

one of the upcoming projects i had in mind was taking a PSL or RPK kit and converting it to a 16 or 18" AK style rifle, im not sure if such a conversion would be possible with .308 winchester or not, perhaps, but i'm going to pick one of these and focus on that

 

[M1key]

That very well might be the case but that doesnt always happen. We shot a good amount of Iraqi Army soldiers inside trucks in 2003. High velocity projectiles sometimes do crazy things but in my experience M855 will usually penetrate windshields with enough force to kill people inside.

During my 05 tour the guy on my FOB with the most kills was our cook. We were all out on a HVT mission and he was working the gate when some dudes tried to drive through in a SUV. He killed 5 guys in that SUV with all the shots from his M16A2 going through the windshield or upper hood/dashboard area. Three of the guys were in the back seat and several of the rounds went through the front seats to hit them.

Again Im not saying there are better options. But in my experience the M855 works pretty well.

This is a pretty decent test. I would like to see a new windshield with each shot but I bet that would be pretty expensive. If I ever get rich Im going to do a bunch of these type of tests.

https://www.youtube.com/watch?v=Twc_d8wImo8

Thank you for your service.

Decent test. Even fired at an oblique angle. Comments from Dr. Roberts?

M

 

[justin22885]

what do you guys think about the .308 and 7.62x54R?.. .308 will cost probably a bit less than 6.5 or 6.8 considering i can get tons of once fired brass for it for not much.. but what about the 7.62x54R?.. $100 for a 440 round can.. i can achieve my 1000 round requirement for just a tad over $200, as cheap if not cheaper than i could do the same for even .223/5.56 and have all the power and range of the .308.. thats a very cheap solution for a big increase in firepower

but i have decided ill stay with 5.56 for the smaller rifles, and instead focus my time, efforts, and finances on building up a bigger caliber as my primary

 

[TestPilot]

That very well might be the case but that doesnt always happen. We shot a good amount of Iraqi Army soldiers inside trucks in 2003. High velocity projectiles sometimes do crazy things but in my experience M855 will usually penetrate windshields with enough force to kill people inside.

During my 05 tour the guy on my FOB with the most kills was our cook. We were all out on a HVT mission and he was working the gate when some dudes tried to drive through in a SUV. He killed 5 guys in that SUV with all the shots from his M16A2 going through the windshield or upper hood/dashboard area. Three of the guys were in the back seat and several of the rounds went through the front seats to hit them.

Perhaps the details of the situation explans the difference in results.

The failure I've witnessed was a round fired from the ground level shooting at the windshield from the front. Only 1~3 rounds were fired at a passenger car.

Military trucks have perpendicular windows.

In the case of the cook and the SUV, several rounds were fired. The probablity of the round shattering becomes less when the windshield strength is compromised by cracks with multiple shots. If cook pulling gate guard was in elevated position, that even makes the hit angle less oblique.

 

[No4Mk1*]

Regarding your 308 vs 7.62x54R decision i would lean toward 308 for ammo compatability with fellow battle rifle shooters, and I prefer M1A/M1 Garand (308) / AR-10, etc to the semiauto 7.62x54R choices. Not sure you will get acceptable accuracy from SURPLUS 7.62x54R from a PSL???

 

[Art Eatman]

Sorta hard to figure a civilian's legal self-defense necessitating shooting at a car.

 

[M1key]

Sorta hard to figure a civilian's legal self-defense necessitating shooting at a car.

Being shot at from a car.

M

 

[justin22885]

well, i shoot for 2MOA in a battle rifle.. dont need anymore, dont really want any less, and it seems just about any battle rifle with regular ammo can do this.. anyway, the idea with the PSL would be to use the PSL receiver, bolt, carrier, dust cover, and trunnion.. probably an AK-100 series side folding stock, and an RPK rear sight block, handguard retainer, and gas block.. use an RPK barrel (like green mountains) and ream it out for the x54R cartridge, barrel hacked at roughly 16" length and the AK-100 series front sight block / muzzle device.. the flash suppressor for the 7.62x39 should work just fine

that would give me a 16-inch AK-100 series style rifle in a full 7.62x54R caliber and i'd have to buy a bunch of lahti 20 round magazines to be used with this, and i can stick with a platform im already familiar with

__

i've had an M1A, liked it, but theres not all that much that can be done with it, its pretty legacy at this point, i like the ability of having a folding stock for compact storage, like the option of being able to add scopes or red dots at will and the only way to do these with the M1A is with some rather pricey stocks.. im my opinion i hate the aftermarket tacticool stocks for the M1A, id probably stick with the straight walnut stock

i've also had the PTR-91.. i really liked it, brutally reliable, incredibly accurate, but by far the heaviest of the group.. but just destroyed brass, and since i will be creating most my stock of ammo (if i focus on .308), preserving brass from the range is pretty important, i cant have fluting marks and creases on them

the only other two options is try to find a used saiga 308 or yugo M77 that i could convert to an AK-100 series style rifle, or the FN FAL which i dont have any experience with at this point.. i'd be open to other .308 cal options but i dont think there are any.. of course, im not including the AR-10 or the really high end stuff like the SCAR-17s

lastly, i could just design and build something myself in .308.. in the last couple weeks i've been working on designing a simplified sheet metal version of the FG-42, using a sheet metal receiver, exterior trunnion, and i was even considering adapting what i already have to use M60 bolts and trigger groups (semi trigger group of course).. and the other thing ive been working on is creating a new two-lug rotating bolt action thats compact enough to fit into a 1.5" square tube steel upper with a low profile-long stroke gas system either using AR-10 barrels with a custom barrel-extension with interrupted threads on the exterior of it for the ability to quick-change a brrel, or just a simple thread or press in barrel... but since i dont have a CNC mill yet, i'd have to outsource a local machine shop to make the bolt, carrier, trunnion, gas system parts, etc and that could be costly

 

[M1key]

Saiga is a still affordable option. I bet you could find one for around since they aren't as cheap to shoot as most folks would like.

FALs for about $1000-$1200 (DSA) are another option.

M

 

[constructor]

If I had to choose one with factory ammo to do it all it would be the 6.8. Fortunately I reload so I chose the SIX5(6.5 in a 6.8 case).

 

[hatt]

Sorta hard to figure a civilian's legal self-defense necessitating shooting at a car.

https://www.youtube.com/watch?v=Uw-0nfVC2Rk

 

[Zerodefect]

Sorta hard to figure a civilian's legal self-defense necessitating shooting at a car.

For now. Turn the power off. Society only lasts 2 weeks with the power off. That's all it takes. Then it's mob rule. Natural disasters or war can do so much worse. I'd rather be a have, than a have not. Sure, America isn't South Africa or Monrovia. But nothing lasts forever.

That being said. Lets go shoot some junked cars. 5.56 flies right through..

 

[justin22885]

curious though.. is 6.8SPC or 6.5 grendel currently gaining more popularity, or are they fading away yet?

 

[crazysccrmd]

curious though.. is 6.8SPC or 6.5 grendel currently gaining more popularity, or are they fading away yet?

Neither will be fading away anytime soon. The 6.8 is increasing in popularity for hunters using AR15s as probably the most effective cartridge for medium game in a standard AR with 16" or shorter barrels. Since I started shooting the 6.8 and its variants about 3 years ago there has been a large increase in industry support and ammo/component availability. The 6.5 is just as popular with longer range shooters with long barrels.

 

[C-grunt]

Perhaps the details of the situation explans the difference in results.

The failure I've witnessed was a round fired from the ground level shooting at the windshield from the front. Only 1~3 rounds were fired at a passenger car.

Military trucks have perpendicular windows.

In the case of the cook and the SUV, several rounds were fired. The probablity of the round shattering becomes less when the windshield strength is compromised by cracks with multiple shots. If cook pulling gate guard was in elevated position, that even makes the hit angle less oblique.

The cook was on the ground. Also when I say Iraqi Army trucks Im talking about Toyota's with a machine gun mounted in the back. M855 isnt the best option when shooting up vehicles but the people inside are not going to be having a good day when it happens.

 

[Panzerschwein]

Yes, 7.62x54mmR.

Very available, very cheap, VERY powerful! Can't ask for more.

 

[justin22885]

with roughly the same bullet weight, case capacity, COAL, and pressure, i see no reason why one would be better in "shorter barrels" unless a difference in the powder used, thats easily changed though.. what i question the grendel for is how reliably does it feed vs the 6.8, and the 6.8 to me looks like a 308 thats been scaled down.. i may build an AK soon in one of these calibers to try out

meanwhile, i cant really ignore $90/440 rounds of x54R ammo, thats dirt cheap, the cheapest of all and its steel core, packing one hell of a punch too..i also have a couple mosins and wouldnt mine picking up maybe an SVT-40, DP-28, PKM, so i have a lot of use now and coming up for the cartridge, probably more so than .308 when i think about it

oh yeah.. i can get 8mm mauser surplus pretty cheap too.. could shorten up a yugo M76.. now that could be fun

 

[crazysccrmd]

The 6.5 is limited to about 52k psi due to reduced bolt strength while the 6.8 with a smaller case head can run 55k+ psi. Case efficiency and bullet diameter plays into it as well. A 6.5G 123gr SMK is about 2650 from a 24" barrel. A 6.8 SPC 120gr SST does the same from a 16" barrel.

This is a good read about the development and testing of the 6.8 compared to 5.56 and 7.62. http://www.dtic.mil/ndia/2008Intl/Roberts.pdf