Let's talk PDW's

[Pit]

Reflecting on shooting this, this is basically a big pistol that shoots Barnes rifle bullets, optimized for a realistic personal defense distance envelope. I think I am going to add a bit of MLOK rail with a light and call it good.

Attachment 52591

I've kept mine w/o a light. I've found thru presentation training repetitions, the more I put on the Rattler the more likely I was to snag something. I had to change up the sleeve I use to make sure the front sight, which I leave up, doesn't snag or slow me down. There's already enough going such as keeping eyes on the threat, unzipping bag, getting a good grasp on pistol grip, unfolding the brace, etc. that I'm trying to eliminate anything that isn't 100% necessary. A weapon light is a nice to have not a must have based on my experience.

JW

[Tokarev]

Comparing short barrel 300 BLK to pistol cartridges like 327 Federal Magnum and 7.62x25mm Tokarev is also interesting.

300 AAC Blackout makes for a VERY powerful "pistol".

327 Fed Mag throws a 100gr bullet to almost 1500 FPS from a snubbie revolver so it appears to do what the 30 Carbine does from a 12" barrel.

https://www.americanrifleman.org/art...ed-32-magnums/

https://www.americanrifleman.org/art...sor-m1-pistol/

[El Cid]

For those with a Sig Rattler... what if any parts are common to AR’s? Would it require spares that are proprietary? Do Geissele triggers work?

[mmc45414]

Observing me shoot, my wife thinks the 8 inch .300 BLK is well quieter than a 16 inch 5.56

300 AAC Blackout makes for a VERY powerful "pistol".

I've been thinking it's basically a .357 Magnum, maybe a little more, like .360 DW or .357 Max, with more aerodynamic projectiles loaded in cartridges that feed from common and inexpensive magazines.

IMO much of the appeal of 300BO is it is a rifle cartridge that runs on pistol powders. More performance in short barrels, more complete combustion in longer barrels.

[OlongJohnson]

That works because the bullet is nearly the same diameter as the case, so the dynamics are like those of a pistol. I'd go so far as to say it's closer to being a pistol round than a rifle round. The contained combustion volume increases very rapidly relative to the fairly small case volume, which is why the faster burn rates of pistol powders are needed to maintain pressure on the bullet as it moves down the barrel. And the total mass of gas that can be produced by the modest powder charge mass is limited, so the return on a longer barrel is less.

Another reason for the greater performance in short barrels is that the larger diameter of the bullet means that for a given pressure, the force accelerating the bullet is greater. For a .308 diameter, the area is ~90 percent greater than for a .224 diameter. So more work is done (energy transferred) to the bullet in a shorter distance. Maintain the same pressure profile on the back of the bullet at each longitudinal point as it travels the length of the barrel, and you will impart ~90 percent more energy to the .308 bullet. (Simplifying the example by ignoring friction.)

At the other end of the spectrum, a .243 Win can use some of the same powders that work in big belted magnums, because the relationship of case volume to contained volume as the bullet moves is very similar. And they tend to be notably less blasty and gain more performance with a barrel at the longer end of the spectrum.

Personally, I didn't really see the point of .300 BLK as a rifle round. But this thread got me thinking about it as a pistol round, and for that, it's pretty cool.

A similar argument could be made about .350 Legend. It's straight wall, and uses the same powders as .357 Magnum and .44 Magnum. But it burns roughly the same mass of powder as a .44 Magnum while filling a .357 bore; I suspect a 20-in barrel is likely ballistically close to optimum. Should be quite amenable to handy 16- and 18-in barrels and even SBRs.

[Pit]

For those with a Sig Rattler... what if any parts are common to AR’s? Would it require spares that are proprietary? Do Geissele triggers work?

This is my understanding.

Compatible:
Muzzle device with SIG supplied adapter
Sights
Grip
Safety selector

Trigger are compatible if you remove the SIG firing pin safety.

JW

[EPF]

I've kept mine w/o a light. I've found thru presentation training repetitions, the more I put on the Rattler the more likely I was to snag something. I had to change up the sleeve I use to make sure the front sight, which I leave up, doesn't snag or slow me down. There's already enough going such as keeping eyes on the threat, unzipping bag, getting a good grasp on pistol grip, unfolding the brace, etc. that I'm trying to eliminate anything that isn't 100% necessary. A weapon light is a nice to have not a must have based on my experience.

JW

Interesting. For your purposes it really is similar to a pistol in that priority is a “speed draw” fast presentation to first shots against a close quarter immediate threat. Except with a rifle round.

The more I think about it the more I think that yes, it’s a niche weapon for an armed professional because an armed professional has a lot of long weapon options whether .mil or .gov/police. It seems like the rattler actually fills a larger percentage of the long gun roles in a civ capacity where concealment, portability, and discretion are more often top priority than to most armed professionals not similarly constrained. It’s a lot of capability for the size, the ultimate “bag gun” maybe?

Assuming any social use of a long gun by a law abiding citizen to be a “niche” from the jump, I’d say an extremely compact, reasonably controllable, highly concealable “long gun” launching a powerful rifle round to 100yrd might actually fill a much higher % of an average civilians need that the % of cops or commandos who could more easily move about with a traditional carbine.

I don’t think anyone would choose a “bag gun” to fight with all things being equal.

[Velo Dog]

327 Fed Mag throws a 100gr bullet to almost 1500 FPS from a snubbie revolver so it appears to do what the 30 Carbine does from a 12" barrel.

The 327 Fed Mag appears to perfectly match 30 carbine velocities from longer barrels.
http://ballisticsbytheinch.com/327mag.html

The 7.5x27mm FK Brno is another PDW cartridge that the 300 BLK compares to favorably.

In this video the 7.5 FK is compared to 9x19mm against body armor and against loaded AK magazines.

[HeavyDuty]

I've been thinking it's basically a .357 Magnum, maybe a little more, like .360 DW or .357 Max, with more aerodynamic projectiles loaded in cartridges that feed from common and inexpensive magazines.

Also realized that the whole braced pistol thing works just as well with a Contender, if you get the Choate M4 adaptor. So you can have a braced 14-in. .44 Magnum, if you think you might be OK with having your face that close to the muzzle of a .44 Magnum when it's fired. Might have interesting possibilities against squirrels with an HM2 barrel. But there's another thread for those ideas.

I’ve had a thing for stocked Contenders since I was a teen in the late 70s - the Gander Mountain store in Wilmot, WI (the *real* GM) always had a display of them. Some day I will scratch the itch. But, as you said - that’s out of scope for this thread.

[Corse]

It doesn’t seem like any of those pistol rounds come anywhere close to a 300 blk at similar barrel lengths, especially at the same bullet weights for the smaller calibers (327, 7.5 weird, etc).