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6.5Grendel vs 5.56NATO as General Purpose AR15 Chambering - VASCAR2 - 10-15-2018
Sportsmans guide and Graf’s both have the 115 grain FMJ 6.8 SPC PPU ammo in stock. Graf’s has PPU 115 grain BTHP 6.8 SPC in stock. I’ve got at least 200 rounds of factory PPU 120 grain HP BT 6.5 Grendel left. I willing to contribute some of my PPU 6.5 Grendel ammo if LR1955 wants to conduct a test.
6.5Grendel vs 5.56NATO as General Purpose AR15 Chambering - stanc - 10-15-2018
LR1955 Wrote:Array of each with distances?Hmm. Good questions. To which I cannot give definitive answers.
Give the strength of 'mild steel' please.
CMU blocks appear to vary in toughness and thickness, which would affect the maximum range at which they can be penetrated.
I have no idea what the spec is for the steel used in US Army tests, or where to find it. But IMO, any "mild steel" is okay for informal testing, as long as all rounds are fired at the same plate. Obviously, the strength of the particular "mild steel" used would (as with CMU's) affect maximum penetration distance.
6.5Grendel vs 5.56NATO as General Purpose AR15 Chambering - stanc - 10-15-2018
biodsl Wrote:It would be kinda cool to put this thing to bed once and for all. I'd be willing to financially contribute to the effort. Stan needs an answer!Stan sometimes gets fixated on a subject, and doesn't know when to drop it. I see now that is what I've done with this matter. :eek:
Such test data would've been really nice to have had years ago during our discussions about replacing 7.62 NATO with 6.5 Grendel, and it would've been really, REALLY nice to have had back when I was writing "6.5 vs 6.8" magazine articles.
However, those reasons no longer exist, and in any case, it was unreasonable of me to expect other members of the Horde to conduct testing that I alone wanted done.
My apologies to all, especially LR1955. :o
6.5Grendel vs 5.56NATO as General Purpose AR15 Chambering - LR1955 - 10-15-2018
Stan:
No need to apologize to me about this. Shooting through cinder blocks or mild steel is something I can do now that I couldn't a year ago due to proximity to locations where it would be safe.
There is a rockwell hardness of 'mild steel' but that wouldn't be the problem. The problem would be cost for twelve each one foot square steel plates. I would make a box to secure three of them separated by five or six inches (yaw / pitch and bullet integrity as it penetrates) and would shoot one shot, inspect for penetration and photograph, then take 9 more shots sustained fire. Effects test with small arms ammo, particularly for automatic weapons, normally consists of a hundred or more rounds fired at a large target to see the effects of multiple hits. One hole through steel will weaken the steel so you have to shoot new steel with each cartridge. I imagine the steel alone would cost $500.00 so would have to ask the guys if they had any. Machinists and welders tend to have this stuff as scrap.
Cinder blocks are cheap and I would buy them myself. How they should be arrayed I don't know. Probably three or four deep. Shoot them to the right or left of that center support, inspect and photograph, then shoot 9 more shots sustained fire.
I am not really sure what anyone expects out of this. The targets would have to be close enough for the five minute Grendel ball so probably fifty yards. Too close for a realistic test because supporting fires would be over 100 yards in most cases. Anyway, the M-80 ball would absolutely dominate in penetration and sheer destruction because at that range, it hasn't lost a lot of velocity, its shape is basically a hybrid VLD, its jacket is very thick, and it is heavier than the other rounds. The M-855 with its steel tip would be next in penetration and destruction due to its velocity and steel tip. It will do what it was designed to do. Next I would give more than a 50% that the 6.8 would show more penetration and destruction than the Grendel ball, primarily due to its higher velocity.
Although interesting, enough of these types of tests have been done (better) that it is pretty obvious that a 2500 fps 6.5mm bullet that probably wasn't made for service use won't outperform bullets at much higher velocities that were made for service use.
And that higher velocity (6.8 ball) will outperform lower velocity (6.5 ball) given both bullets are constructed the same way with the same material.
What would be more interesting is jel tests but we have hunters here who have hunted with the Grendel ball I believe and probably the 6.8 ball. I doubt there is much difference in lethality on hogs and that is better evidence than shooting into jel for me.
LR55
6.5Grendel vs 5.56NATO as General Purpose AR15 Chambering - JASmith - 10-15-2018
Stan's concern about strength variations can be at least partly satisfied by doing a hardness test. Hardness and tensile strength of steel are linked.
"Mild" steel only needs a minimum tensile strength. I once saw a set of predictive calculations get invalidated because the vendor used steel that met the minimum strength, but was actually about 50% greater than the nominal strength. We discovered this only by post-mortem trouble shooting. I knew to ask the question because I had seen the problem in copper plates. BTW, a colleague had the insight to ask that earlier question so I learned from him!
The good news is that, by ensuring the test panels are cut from the same plate, comparative tests like the one being done will likely be OK.
If the added security of knowing hardness variations between the plates makes a difference, local machine shops are likely to have testers on site. Testing labs may also be able to do on-site or in-house tests too for a somewhat higher fee. Portable, even pocket-size, testers are available too.
6.5Grendel vs 5.56NATO as General Purpose AR15 Chambering - LR1955 - 10-15-2018
JASmith Wrote:Stan's concern about strength variations can be at least partly satisfied by doing a hardness test. Hardness and tensile strength of steel are linked.
"Mild" steel only needs a minimum tensile strength. I once saw a set of predictive calculations get invalidated because the vendor used steel that met the minimum strength, but was actually about 50% greater than the nominal strength. We discovered this only by post-mortem trouble shooting. I knew to ask the question because I had seen the problem in copper plates. BTW, a colleague had the insight to ask that earlier question so I learned from him!
The good news is that, by ensuring the test panels are cut from the same plate, comparative tests like the one being done will likely be OK.
If the added security of knowing hardness variations between the plates makes a difference, local machine shops are likely to have testers on site. Testing labs may also be able to do on-site or in-house tests too for a somewhat higher fee. Portable, even pocket-size, testers are available too.
Joe:
Not going to run the test after all. Stan realizes it is a bit too much and way too late.
I am sure that when ever someone gets some of the Serbian ball ammo that they intend on issuing if they go with a Grendel, that they will test it.
I am pretty indifferent towards the whole thing but won't spend money unless I think something can be realized.
LR55
6.5Grendel vs 5.56NATO as General Purpose AR15 Chambering - JASmith - 10-16-2018
Understood -- and probably a wise decision.
6.5Grendel vs 5.56NATO as General Purpose AR15 Chambering - LRRPF52 - 10-16-2018
[video=youtube_share;0ynSCv7auks]https://youtu.be/0ynSCv7auks[/video]
6.5Grendel vs 5.56NATO as General Purpose AR15 Chambering - m796rider - 10-16-2018
It'd be cool to convert one of the new Bren 2s in 7.62x39 to shoot Grendel. I wonder if the Bren 2 7.62x39 mags would feed reliably; I'm given some hope by the fact that the C Products 26 rounders look like AK mags now.
6.5Grendel vs 5.56NATO as General Purpose AR15 Chambering - VASCAR2 - 10-16-2018
It really depends on the 7.62x39 platform and particular magazine. There were people trying to use 7.62x39 mags with the VEPR 6.5 Grendel without much success. The best results with the VEPR 6.5 Grendel was with Tapco polymer 7.62x39 mags which would feed a few 6.5 Grendel cartridges after modification. In the AR-15 I’ve seen where people have used CPD 7.62x39 mags to feed 6.5 Grendel cartridges in AR-15’s. I’ve never tried to use 6.5 Grendel mags to feed 7.62x39 in a 7.62x39 AR-15.
A Friend bought a 7.62x39 upper so we might have to try a 6.5 Grendel mag with his 7.62x39 upper.
6.5Grendel vs 5.56NATO as General Purpose AR15 Chambering - m796rider - 10-17-2018
VASCAR2 Wrote:It really depends on the 7.62x39 platform and particular magazine. There were people trying to use 7.62x39 mags with the VEPR 6.5 Grendel without much success. The best results with the VEPR 6.5 Grendel was with Tapco polymer 7.62x39 mags which would feed a few 6.5 Grendel cartridges after modification. In the AR-15 I’ve seen where people have used CPD 7.62x39 mags to feed 6.5 Grendel cartridges in AR-15’s. I’ve never tried to use 6.5 Grendel mags to feed 7.62x39 in a 7.62x39 AR-15.
A Friend bought a 7.62x39 upper so we might have to try a 6.5 Grendel mag with his 7.62x39 upper.
Since the Bren 2 converts between 5.56 STANAG mags and their proprietary 7.62x39 mags with the use of a simple mag well insert, I'd guess it'd be possible to run the 7.62x39 bolt and a Grendel barrel with an AR Grendel mag... Or heck, someone could design a bigger Grendel mag to fit into the 7.62x39 mag well. I know, if wishes were horses...