idea for a new military rifle concept

[richalexander97]

Hi I'm new to the forum. I had an idea for a new small arms concept which A) has a drastic weight reduction over 556 packages, and B) the ammo can be shared with a handgun.

To get 556 range from a handgun round, the bullet diameter is 4.9mm (shoots extremely flat) and the bullpup rifle has a 20 inch barrel. Additionally the energies are over 1000ft/lbs because the case is very fat, basically a 10mm /. 45, necked down to. 19 caliber.

The pistol has a carefully designed grip to allow the huge round.

To achieve the weight reduction, the ammo uses aluminum cases, or possibly polymer steel hybrids. Rifle is only 2. 9kg and the light ammo allows light magazines.

Anyway the only snag points I could see was whether my extreme case shape was viable, especially trying to make it feed well. Imagine a 45acp case with very tiny 4. 9mm bullets. Any thoughts on that?

The other thing I considered was sabots, with a smaller 17 caliber bullet at extreme energies. The sabots main purpose would be to reduce barrel wear.

The problem is that sabots are hard to make accurate. The bullets would be far heavier than the 10 grain darts used in the SPEW/ACR experiments. I think that was the cause of their innacuracy.

Anyway if you can see any flaws or problems, please point them out.

Rich

 

[Hog huntin Harry]

Welcome to THR Rich, I think you're on to something, although the lightweight bullets that would be used in a .19 caliber cartridge would have trouble with barrier penetration. Also, the B.C. would be pretty low I imagine, so the velocity would bleed off pretty quickly.

 

[richalexander97]

Hi. The BC is very high.
The bullets are extremely long, with a VLD shape. This means they extend greatly from the case. Also their heavy... 50 grains like the 4. 85 British cartridge. B.C. would be roughly. 35 which is high.

If you want a rough idea of what it would look like, Google the '17-357RG' and imagine it with even longer bullets.

My main concern was feeding. Because benchrest cartridges have poor feeding.

 

[stillquietvoice]

You have to be careful with pistol grip size, too large or too narrow and most wont be able to shoot it comfortably.

 

[NIGHTLORD40K]

Fat cartridges=lower magazine capacity.

 

[richalexander97]

Yes it has a very specially designed grip. Grip angle is very shallow, contouring is minimal, and there's a cutaway in the front of the grip, so your hand is partially gripping the magazine. All this allows a longer cartridge

 

[BreechFace]

Too big of a compromise to a carbine in a rifle caliber, to hamstring the cartridge for the benefit of shared ammo with a sidearm.

Pistols are very rarely used in the military. Why? Because the suck in comparison to a carbine utilizing a rifle cartridge.

Hate to rain on your parade but the days of commonality of cartridge between long gun and handgun in regards to military are over; apart from a huge leap forward in technology (ie. caseless ammunition, etc). The performance of rifles in engagements cannot be understated.

The closest I can think of to what you are suggesting is the FK BRNO 7.5, but ask anybody on the front lines if they would accept the ballistics/energies of that round out of a 14.7" barrel as compared to what they are seeing with the 5.56.

 

[CapnMac]

Handguns have extremely limited military utility at all.
PDW answer the need of handguns far better.

Military history points us in a couple of directions. One is a light round for ease of use by all riflemen. The other is a heavier round also suitable in Squad automatic weapons.
The former could be met using something like 6arc, the latter by something like a 7x45

Note that modern 5.56x45 and 6arc are virtually the same (the latter has a bit better BC). Further, that DoD is looking at a 6.8x45 for the next generation SAW (or, basically, 7x45)

US military is fielding a less than 3kg rifle now. That platform can be pushed to 2.5kg, but not at military needs for robustness (especially the functions from -40ºC to 40ºC)

The 5.7 was an attempt to try and address this perceived need. Jury is still out on that.
A 4.9mm round might have an excellent BC, but, it will not have a lot of mass when pushed out to 300m, let alone the 600m DoD would want.

 

[DukeConnor]

I love these types of concepts.
As Breech says above, pistols are a afterthought in the military.
I don't 12 years in uniform and the only pistols I ever saw were carried by officers and MP's.

This was during the 1911 era so maybe things have changed.

 

[richalexander97]

Thanks. The idea was not to replace 556, but more to offer extreme weight savings to those who want it. And logistic savings. Also the recoil is half of 556.

Retained energy is actually rather good up to 450meters.
Again the energies are no better than an M4 but the high B.C. enables this 450m range.

EDIT:
sorry I should have mentioned, my main question was if you think it would feed reliably, like I said google the 17-357RG, it closely resembles that cartridge

 

[theotherwaldo]

The military pistol is functionally a left-over from olden days when sergeants and officers had to force rebellious or cowardly soldiers to stay in line and face the enemy.
These weapons were only incidentally supposed to be used against an actual enemy.
I'm not sure what function that they serve on a modern battlefield... .

 

[hey smepl this]

This is a cool thread

 

[NIGHTLORD40K]

The military pistol is functionally a left-over from olden days when sergeants and officers had to force rebellious or cowardly soldiers to stay in line and face the enemy.
These weapons were only incidentally supposed to be used against an actual enemy.
I'm not sure what function that they serve on a modern battlefield... .

Still useful for vehicle crew/pilots/MPs/heavy weapon crew/ and rear echelon troops who would be need to be armed, but for whom any long gun would be an encumbrance that would interfere with their primary duty.

One of the main arguments for the SIG P320 was that its lower cost over the M9 would allow more widespread issue, but for most M4 users, the extra weight of a pistol would be better spent on more 5.56 ammo, grenades, etc.

 

[daniel craig]

Welcome to THR Rich, I think you're on to something, although the lightweight bullets that would be used in a .19 caliber cartridge would have trouble with barrier penetration. Also, the B.C. would be pretty low I imagine, so the velocity would bleed off pretty quickly.

What if they were made from DU or a titanium alloy? That might help increase their penetrative ability if you could get them going fast enough.

 

[trekker73]

Do you know the exact case specs you have in mind? Case capacity water, to mouth of case and with the bullet loaded? Also the COAL? I think someone could get it to feed, main question for me would be how much energy it loses over 223 and barrel life.

 

[earlthegoat2]

I guess I would just go with 5.7x28 if I was looking to compromise wildly.

 

[John_R]

Armscor seems to think their .22TCM is good for this. https://www.armscor.com/firearms/ria/tcm-series/

 

[richalexander97]

Do you know the exact case specs you have in mind? Case capacity water, to mouth of case and with the bullet loaded? Also the COAL? I think someone could get it to feed, main question for me would be how much energy it loses over 223 and barrel life.

I'd be pushing for a 12mm base diameter. Basically as wide as a. 45. Then you add the extreme 45mm OAL, and it's essential my pistol has a specially designed grip because that's huge.

The exact amount of taper would be carefully decided. also it might have a polymer coating to aid feeding. Just. Like the 5. 7x28

much of the length is taken up by the very long VLD bullet, but case capacity would be maybe 70% of 556.
Energy is 1100, from a 20. 7 inch barrel.

Range would easily exceed an M4, the caliber and performance are identical to the 4. 7mm HK case less...... or the 4. 85 british. Which was a 500m round. The 4. 7HK had no issues with barrel wear.

simply google the 225 jaws, or the 224. Boz. It resembles that.

 

[Nature Boy]

FN already put millions into this concept with the Five Seven and the P90, didn't they?

(objectively, with mixed results)

 

[CapnMac]

but more to offer extreme weight savings to those who want it. And logistic savings. Also the recoil is half of 556.

Your stated weight is only a 5-10% reduction over existing carbines (added optics or vision devices weigh both down equivalently).
Now, were we still issuing 5kg weapons, that would be a deal.

Now, recoil reduction using a 12mm case and 4-5mm projectile may be a harder intellectual case to make. Ok, projectile is lighter and smaller, but, you are giving it a prodigious push to get it to the stated velocities. Putting that in a lightweight arm is not going to damp down that felt recoil much, either.

Physics does not like being fudged, it gets its due.

The intellectual exercise remains worthy though. We all go through these at some point or another. I had a notion about a 15x30 using sabotted 7mm high-BC rounds. After running all the numbers it really did not do anything enough better than existing. But the process of finding that out was worthwhile.

 

[richalexander97]

The weight loss is big because the ammo is polymer hybrid cases. About 7 grams a round nearly half of 556.

Recoil with a 4. 9mm is tiny, regardless of the type of case.

Total weight savings over an M4 package are 20%. mags are only 80 grams. Optic would be a custom 5x optic that's under 400grams

 

[Mosin Bubba]

Reminds me of the Five-Seven.

Anyway, the magic gap to bridge is a round that suits both a 7lb assault rifle and a 25lb machine gun. They're just close enough to maybe pull it off, but far enough away that no one's done it yet, at least not well. Bridging the gap between a pistol and an assault rifle isn't as big of a deal, but it makes for fun thread speculation nonetheless.

 

[BigBlue 94]

5mm/35 SMc is close to what you are searching for. A bit long though. Its a 20cal.

https://en.m.wikipedia.org/wiki/5_mm/35_SMc

Feeding issues can be alleviated by following Boberg's "pull out of mag" principal used on his bullpup pistols.

 

[sarduy]

Hi I'm new to the forum. I had an idea for a new small arms concept which A) has a drastic weight reduction over 556 packages, and B) the ammo can be shared with a handgun.

To get 556 range from a handgun round, the bullet diameter is 4.9mm (shoots extremely flat) and the bullpup rifle has a 20 inch barrel. Additionally the energies are over 1000ft/lbs because the case is very fat, basically a 10mm /. 45, necked down to. 19 caliber.

The pistol has a carefully designed grip to allow the huge round.

To achieve the weight reduction, the ammo uses aluminum cases, or possibly polymer steel hybrids. Rifle is only 2. 9kg and the light ammo allows light magazines.

Anyway the only snag points I could see was whether my extreme case shape was viable, especially trying to make it feed well. Imagine a 45acp case with very tiny 4. 9mm bullets. Any thoughts on that?

The other thing I considered was sabots, with a smaller 17 caliber bullet at extreme energies. The sabots main purpose would be to reduce barrel wear.

The problem is that sabots are hard to make accurate. The bullets would be far heavier than the 10 grain darts used in the SPEW/ACR experiments. I think that was the cause of their innacuracy.

Anyway if you can see any flaws or problems, please point them out.

Rich

Great idea, tell me, what this round do that a 556 can’t?

 

[DocRock]

As @BigBlue 94 above, I was immediately brought to mind of the 5-35 SMc Can’t say I know much about the feeding issues or their solution though.

The weight savings sounds impressive and ammunition interoperability between pistol and rifle is a major coup. I do question what pistol recoil would be like. Given that the NATO standard is the teeny-weeny europellet, it seems unlikely that there would be appetite for a heavy recoiling pistol round.