How could or should the 6.5 mm Grendel be improved?

[JASmith]

Aren’t the Barnes’ line of bullets lead free? I would think, based on the description, that the 120gr TAC-X would be comparable to the SOST/barrier blind rounds. Would that round not be a starting point for a military purposed round?

Am I off base on this?

Not completely... Designing and prototyping a new bullet is an expensive and arduous enterprise.

What we can do is note the likely ballistic coefficient and mass of the anticipated bullet and use bullets with similar exterior ballistics for preliminary testing. This would help tell us if it is worth the bother.

[VASCAR2]

With the way most Local government budgets are going I don't see any interest from Law Enforcement to transition away from 223/5.56. I know most Agencies are using various bonded core expanding ammo and I have seen no reports of failure to stop the bad guys. All the shootings by LE in my area using 5.56 patrol rifle/carbine have stopped hostilities with no additional rounds fired by suspect or required additional rounds from Officers. For LE use where suspects aren't wearing protective armor the 5.56 with the right ammo has been very effective in my area.

[woohoo]

Reviewing some of the interesting posts on this thread. I think I asked the wrong question.

Perhaps, I would have made life easier for myself if I had asked: what could be done to help military and LE users accept and use the 6.5 mm Grendel more widely?

The supplementary question is: is it good enough as is? If not, what could or should be done to improve it.
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I know this is old but...
Build a new lower with a wider mag well. Design new mags to fit that lower and allow the cases to stack properly with the side walls being strong enough to prevent bowing. Design and manufacture stronger bolts and extension. A few stronger designs already exist. Design and manufacture green bullets in a weight range that will give high BCs and still not so heavy to be driven at a decent velocity.
Goes without saying that's just my opinion.

[cory]

I know this is old but...
Build a new lower with a wider mag well. Design new mags to fit that lower and allow the cases to stack properly with the side walls being strong enough to prevent bowing. Design and manufacture stronger bolts and extension. A few stronger designs already exist. Design and manufacture green bullets in a weight range that will give high BCs and still not so heavy to be driven at a decent velocity.
Goes without saying that's just my opinion.

Would the improvements in performance over the Grendel really be worth the additional weight?

I think our best bet here is to get a LMG built to accommodate the Grendel and see what kind of attention that attracts.

Then if we can get a steel core FMJ bullet developed, so we can prove our assumptions.

[Trooper]

Would the improvements in performance over the Grendel really be worth the additional weight?

I think our best bet here is to get a LMG built to accommodate the Grendel and see what kind of attention that attracts.

Then if we can get a steel core FMJ bullet developed, so we can prove our assumptions.

Are you comparing weight to the 5.56 NATO or to the 7.62 NATO?

[stanc]

Would the improvements in performance over the Grendel really be worth the additional weight?

Increasing mag well size would add negligible weight, but enable use of thicker-walled, polymer or carbon steel mags. As far as the benefits of beefed up bolts, etc, I dunno.

I think our best bet here is to get a LMG built to accommodate the Grendel and see what kind of attention that attracts.

Concur. Sadly, I doubt that anybody here has the $$$$$ to finance such a project.

Then if we can get a steel core FMJ bullet developed, so we can prove our assumptions.

The mythical Wolf steel case ammo reportedly has a steel core FMJ. If it ever reaches these shores, that should provide a good basis.

However, some aspects of the military utility of 6.5 Grendel could be tested using currently available COTS rifles and ammo. It just requires sufficient interest on the part of Grendel proponents.

[cory]

Are you comparing weight to the 5.56 NATO or to the 7.62 NATO?

I was referring to woohoo's suggested redesign of the ar 15 platform, and the weight it would add.

[SHORT-N-SASSY]

Reviewing some of the interesting posts on this thread. I think I asked the wrong question.

Perhaps, I would have made life easier for myself if I had asked: what could be done to help military and LE users accept and use the 6.5 mm Grendel more widely?

The supplementary question is: is it good enough as is? If not, what could or should be done to improve it.

It has also been mentioned using high-power propellant to give the projectile increased velocity and energy.

And, just yesterday, from woohoo, ". . . Design and manufacture a stronger bolt and extension. A few stronger designs already exist. . . ."

Consider the muzzle velocities from a 16.5-inch bolt gun chambering a cartridge, which case is longer (1.92" vs 1.52"), case rim is wider (.473" vs .442), case capacity is greater (53 gr. H2O vs 35 gr.) and overall length is longer (2.82" vs 2.26"), than the 6.5mm Grendel: the 6.5mm Creedmoor --- Short Barrel 6.5mm Rifle - Sin City Precision 6.5mm Creedmoor http://www.sincityprecision.com/?p=1503.
2575 fps with the 139-grain Lapua Scenar, 2750 fps with the 123-grain Lapua Scenar, from a 6.5mm Creedmoor 16.5-inch bolt gun.

It's been reported in these pages that 2700 fps, with the 139-grain Lapua Scenar, was attained from a 6.5mm Grendel 22-inch bolt gun (CZ527) --- and, extrapolating, 2550 fps, in a 16 to 16.5-inch barrel.

All of which prompts me to conclude that an "enhanced" 6.5mm Grendel is the answer. And, all that is needed is an upgraded (read: "Big Bolt") AR-15/M16/M4 Bolt-Barrel Extension.

And, if we're ready to move to a Bullpup configuration --- allowing a still-longer barrel length, in a shorter overall length than is possible in existing AR-15-type platforms, as Tony Williams has stated --- there's an instant ambi left/right ejection design (presently incorporated in the ARX-160 and ARX100) that removes a significant downside to the Bullpup consideraton.

If only the Military Top Brass would start thinking outside the box!

[woohoo]

And, just yesterday, from woohoo, ". . . Design and manufacture a stronger bolt and extension. A few stronger designs already exist. . . ."

Consider the muzzle velocities from a 16.5-inch bolt gun chambering a cartridge, which case is longer (1.92" vs 1.52"), case rim is wider (.473" vs .442), case capacity is greater (53 gr. H2O vs 35 gr.) and overall length is longer (2.82" vs 2.26"), than the 6.5mm Grendel: the 6.5mm Creedmoor --- Short Barrel 6.5mm Rifle - Sin City Precision 6.5mm Creedmoor http://www.sincityprecision.com/?p=1503.
2575 fps with the 139-grain Lapua Scenar, 2750 fps with the 123-grain Lapua Scenar, from a 6.5mm Creedmoor 16.5-inch bolt gun.

It's been reported in these pages that 2700 fps, with the 139-grain Lapua Scenar, was attained from a 6.5mm Grendel 22-inch bolt gun (CZ527) --- and, extrapolating, 2550 fps, in a 16 to 16.5-inch barrel.

All of which prompts me to conclude that an "enhanced" 6.5mm Grendel is the answer. And, all that is needed is an upgraded (read: "Big Bolt") AR-15/M16/M4 Bolt-Barrel Extension.

And, if we're ready to move to a Bullpup configuration --- allowing a still-longer barrel length, in a shorter overall length than is possible in existing AR-15-type platforms, as Tony Williams has stated --- there's an instant ambi left/right ejection design (presently incorporated in the ARX-160 and ARX100) that removes a significant downside to the Bullpup consideraton.

If only the Military Top Brass would start thinking outside the box!

I've been messing with a case(capacity 42gr+-) that will push a 123 to around 2700fps from a 16"barrel(34gr 8208). More or less a Grendel stretched to 45mm. I'm not sure they would go for a full power round because of recoil and weight. Tony is thinking something that has a 20% weight reduction, less recoil but beats the 308 exterior ballistics.
It's wishful hoping but hey, that's how things get started.

[woohoo]

I was referring to woohoo's suggested redesign of the ar 15 platform, and the weight it would add.

Doubtful it will add even 2 oz. I have built a slim AR10 that is only 4 oz more than an AR15 and that action is over an inch longer.

[stanc]

Needed: 6.5mm EPR

http://www.defense-aerospace.com/article-view/release/146239/us-army-cuts-lead-from-small-arms-ammo.html

"Now Picatinny's EPR team is applying the [Enhanced Performance Round] technology to improve M80A1 7.62 mm ammunition that troops are scheduled to receive in 2014."

It looks like the standard for comparison of 6.5 Grendel will soon be 7.62 M80A1, not M80. Plan accordingly.

[Tony Williams]

http://www.defense-aerospace.com/art...arms-ammo.html

"Now Picatinny's EPR team is applying the [Enhanced Performance Round] technology to improve M80A1 7.62 mm ammunition that troops are scheduled to receive in 2014."

It looks like the standard for comparison of 6.5 Grendel will soon be 7.62 M80A1, not M80. Plan accordingly.

I doubt that this will make much difference since the new loading will almost certainly match the exterior ballistics of the M80, otherwise they'd have to change all of the MG sights. And it will weigh just as much, and recoil just as hard.

The only significant difference between M80 and M80A1 performance is likely to be in hard-target penetration (and possibly soft-target effectiveness), but that doesn't affect the ballistic comparisons since these don't take bullet construction into account.

It is bad news in one respect though - the more money the US Army pours into new loadings for 7.62mm and 5.56mm, the more resistant they're likely to be to a change in calibre.

[stanc]

I doubt that this will make much difference since the new loading will almost certainly match the exterior ballistics of the M80, otherwise they'd have to change all of the MG sights. And it will weigh just as much, and recoil just as hard.

The only significant difference between M80 and M80A1 performance is likely to be in hard-target penetration (and possibly soft-target effectiveness), but that doesn't affect the ballistic comparisons since these don't take bullet construction into account.

It is bad news in one respect though - the more money the US Army pours into new loadings for 7.62mm and 5.56mm, the more resistant they're likely to be to a change in calibre.

I'd say it's bad news in two respects: The resistance to change you noted, and improved terminal ballistics, which may or may not be matched even by a 6.5mm EPR. Otherwise, I agree with all of your comments.

[Bigfoot]

I'll share. Stretch the AR mags.

Before I decided on my triplets (lightweight bolt actions w same trigger pulls, LOP, scopes etc.) I was going to build a 6.5x43, a .15" longer Grendel. That would add 4 grains O2.

Simple really, mill the corners from the magwell and cut the rear section of the mags and replace them w l_l shaped section, squaring the backs and lenghtening the OAL by .15" IIRC. AR-10s, M1As and AKs dont need a big herkin bolt hold device, why does the AR? It would need a longer follower and I'm sure you could make it catch the bolt when empty but I'm a shooter/hunter so holding the bolt open isn't a priority like it would be for others.

If using the longer PRI mags you might decide to make the brass 44mm long. Working the brass is easy too. Take Prvi Partizan 7.62x39 blanks, cut em to length, neck em down and fireform. Would it be worth the trouble for 100 fps w the 123 SST? Don't know but combine that 10% additional capacity with a Superbolt and it might be worthwhile. I decided to stick w 5.56 and my -06 Lightweight BAR for my semi autos. But there's my idea, another option to consider.

[woohoo]

Would the improvements in performance over the Grendel really be worth the additional weight?

I think our best bet here is to get a LMG built to accommodate the Grendel and see what kind of attention that attracts.

Then if we can get a steel core FMJ bullet developed, so we can prove our assumptions.

Stan, answered you on some of this. It takes a class 10 ammo manufacturer to produce steel core bullets then it can only be sold to govt agencies. Only a #7 with a type 2 stamp can manufacture LMGs. They can be designed and tested but only sold to govt agencies after approval.

Just last week I received 2 new 25round Grendel mags. Knowing already about stacking/ swelling problems I checked them out by loading rounds in the mag. The tops of the cartridges do not touch the bottoms of the cartridges above. That causes the mags to swell but the mags create pressure on the cartridges in the mag. That needs to be addressed.
The increased bolt strength adds no weight to the system.
He asked "what could be done to help military and LE users accept and use the 6.5 mm Grendel more widely?"...Well that's just my opinion on how to improve the system.