quote:

Originally posted by K.O.A.M. in FL:

quote:

Originally posted by Tomster:
Does anyone know when the next FL sig shoot is? It would be a great opportunity for folks to get a hands on and provide feedback on their impressions!

When and where for the shoot? I'm north of Orlando.

I donno??? 220ST (steve) usually organizes the FL sigshoots. We used to do it over in Ocalla at the public range. Maybe he will chime in and let us know when the next shoot is planned.

quote:

I donno??? 220ST (steve) usually organizes the FL sigshoots. We used to do it over in Ocalla at the public range. Maybe he will chime in and let us know when the next shoot is planned.

I'd drive to Ocala for a look at your rifle. I'd even bring a bunch of .357 Sig ammo.

quote:

Originally posted by mstruck137:
Interesting idea. However, I dont see the advantage of the .357 SIG over 9mm in a carbine.

The only reason I say this is that the overall cost of 9mm vs. .357 SIG and the fact that the muzzle velocity of the 9mm is enhanced when utilizing a carbine platform. Add to this the availability of existing 9mm AR parts and mags without the need to modify, for my $ Ill stick with the 9mm.

Good follow through though.

Interesting comments, however I don't agree about the performance of 9mm being close to that of the 357 sig. Fair enough though. I feel that because the 9mm is a blowback gun, a lot of energy is wasted because the case is being pulled from the chamber immediately upon ignition. Examine your cases and you will probably note all the soot that is evidence of this. In a gas operated gun, the case remains in the chamber longer until the gas pressure has subsided and has expended its energy pushing the bullet out the bore.

Next time I get out to the range, I will take several of my 9mm carbines (7", 10.5", and 16") and chrono some defensive loads and measure their performance. I will do the same with the 357 sig AR and report the findings. I suspect that they will not be close.

The AR parts I am using for this project are standard parts available anywhere. Nothing special went into this gun with a few exceptions. Let me put it this way, if a replacement part was needed, you would have no problem going out onto the open market and getting what you needed.

I cannot argue your point that 357 sig is more expensive than 9mm. However, due to the increase in 9mm prices, 357 sig has become more cost effective to shoot in relation to 9mm in the last few years. 9mm winchester white box used to cost about $11/100. Now it is $20/100. Standard winchester 357 sig is available at walmart for about $23/50 which is up from about $18/50. 9mm has risen at a faster rate than 357 sig and that has made it more cost effective than it used to be.

Enough of the comaparison shopping though. This AR was not created to compete with a 9mm. It is a specialty firearm that shoots a specialty round. If there is not enough interest in something like this on the open market, that would be fine. It will remain a one of a kind. I built this gun because I feel the 357 sig is a superior cartridge. I respect your opinion about the 9mm. So much so, that I own many 9mm based AR15's. But I can say this for sure, for those that feel like I do about the 357 sig cartridge, a 9mm just ins't the same thing.

What makes this gun special is that it has done something that has never been done before, it shoots a 357 sig pistol cartridge that operates a direct impingement gas system.

I love the 357 Sig cartridge, it's an excellent round. I'd love to see a carbine like this go into production.

quote:

Originally posted by pompier:
I love the 357 Sig cartridge, it's an excellent round. I'd love to see a carbine like this go into production.

It appears that there is not enough demand to warrant full scale production. I think this baby will remain a one of a kind.

I would be interested in an SBR Upper....
thanks

That would be so fun to shoot in full auto. How about a .357SIG version of the MP5 next?

quote:

Originally posted by flesheatingvirus:
That would be so fun to shoot in full auto. How about a .357SIG version of the MP5 next?

LOL, I can't even generate enough interest in a 357 sig AR upper let alone a 357 sig MP5.

The foremost factor is ammo cost. Just like airline tickets, all people want is cheap, cheap, cheap. That explains why so many have bought 22LR conversion kits for their ARs. I challenge anyone to find a ciener conversion kit for an AR 15. Again, people are wanting to shoot for less and there is not a lot of disposible income today as there was in times gone by.

This gun was designed around the 357 sig cartridge. It aint cheap, and the folks who appreciate its performance know and understand its capabilities. However, supply and demand rules. The majority does not feel that it is cost effective to buy a firearm based upon the 357 sig when they can buy and shoot a 9mm blowback version at a lower cost.

Oh, and BTW, this upper would work fine in full auto with a RR. But like most, who would want to foot the bill of an afternoon of full auto fun in 357 sig (ouch)?

One of a kind.

Well damn, too bad there's not more interest.
Looks to be well done. I don't have a huge budget for "toys" but I'd definitely have to scrape together the change for that.

If you're not going to do these, can you at least tell me where I can get a barrel? I don't reload, so blown out cases aren't that big a deal to me.

quote:

Originally posted by K.O.A.M. in FL:
If you're not going to do these, can you at least tell me where I can get a barrel? I don't reload, so blown out cases aren't that big a deal to me.

My barrel was custom made.

If you want a blowback version, just get a 9mm barrel (any colt style 9mm barrel) and have it reamed to 357 sig. Any competent 'smith can do this.

Thanks. Looks like I've got to get started.

Can't wait for the chrono reads. Very curious!

Tomster,

As I mentioned in the other thread I think this is pretty cool. Would you be more adverse on giving more details on how you did it?

9mm barrel reamed to 357 sig. Barrel was threaded for a barrel extension and headspaced with a bolt that was opened up to accept 357 sig. Custom length gas port and tube. Gas tube length was established by a pressure vs barrel length chart. Bolt was opened up to accept 357 sig. Custom work on the ejector.

I spent the day working on what may be the final touch to the project. The colt mag adapter. I plan to use a Hahn dedicated 9mm mag block and I will custom fabricate a few parts and adjust others. It should work well and it will provide bolt hold open.

The barrel went out today to be parkerized. Hopefully, I will have it back soon and the gun will be exactly where I want it to be.

I don't wish to elaborate much more than that because a lot of work went into this project. If I give every little specification, what's stopping someone from marketing/producing a bunch of these for the open market.

Frankly, I put out the feelers about producing these myself and there wasn't much of a demand. I was contacted by a company who didn't want to produce them but instead market them and put their name on it. So forgive me if I dont give a blow by blow on how to make one.

If anyone wants to shoot it, my offer stands. A reasonable place to do such a thing is at the next FL sigshoot. A well respected member of this board, Toovira will shoot it next time we get together.

That's about it in a nutshell. Thanks

Ok dok I respect that. I was thinking of playing around with a 10mm DI AR-15.

quote:

Originally posted by Tomster:
who would want to foot the bill of an afternoon of full auto fun in 357 sig (ouch)?

Well, from the way the prices of .223/5.56 are going, it may not be that bad.

Let me start by saying this is very cool.

However, does this offer any advantage besides ammo commonality with a sidearm?

5.56mm Mk262 out of an SBR is still a more terminally effective round than 357SIG as 357SIG does not fragment on impact.

I guess I can see the argument being made that it is a better interior barrier penetrator.

This is VERY cool. Instead of Colt mags what is the likelihood that a modified 226 mag would work? (Just checked, it will fit in a AR lower and approx. 1/2 way into a Hahn dedicated block).

quote:

Originally posted by FlyPenFly:
5.56mm Mk262 out of an SBR is still a more terminally effective round than 357SIG as 357SIG does not fragment on impact.

I don't dispute that. The trend today is pistol caliber AR's. If offers shooting for less money and when you get away from the 22LR guns, it offers a more realistic platform in terms of operation and function. There are many agencies that use 9mm as a AR platform. Heck, Colt mass produces a 9mm version that is proliferated all through law enforcement.

I feel that the 357 sig AR is one step up from a 9mm gun. It has better balistic performance and much more energy than a 9mm.

Each gun/caliber is suited for a particular application. I feel that where the 9mm is applied, the 357 is better.