Very very cool. 357sig is my favorite round, I would buy one in a heartbeat. Hope you end up selling them somehow and make a million dollars. Great work.

quote:

Originally posted by 1HI4X:
what is the likelihood that a modified 226 mag would work?

Sure, with enough time and resources you can make anything work. I'm going to focus on the Colt mag system first. I don't think though that I'd adapt 226 mags for two reasons, capacity and bolt hold open.

What you propose is a redesign of an entire mag block to accept sig mags. If they were lined up out the door to buy this gun with 226 mags, then it would be worth the effort.

Sounds good about the shoot. I jsut have to have time. You'll definitely get a call when I do.

Oh yeah...seems like Rotndad and/or 220ST are too busy these days for arranging the shoot.

quote:

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

Gordon Miller had made a couple .357sig mp5's.
iirc appx 8k ea.
I'd go the ar route with 16" bbl though.

quote:

Oh yeah...seems like Rotndad and/or 220ST are too busy these days for arranging the shoot.

Too freak'n hot in ocala this time of year.

Georgia is not that far from FL, and we hold monthly shoots too. GA Arms and Ammo is not too far, and we could secure a hugh supply of 357SIG ammo. I would love to see this refined to a semi-custom project or kit. Great job.

quote:

Originally posted by detroit192:
Georgia is not that far from FL, and we hold monthly shoots too. GA Arms and Ammo is not too far, and we could secure a hugh supply of 357SIG ammo. I would love to see this refined to a semi-custom project or kit. Great job.

Parts are inbound and the barrel is being parkerized as we speak. Not too much longer for revision 2 to give more people what they want.

More to come.

quote:

Originally posted by horse:
I'd go the ar route with 16" bbl though.

Sure, your wish is my command.

It can and will be done.

A longer barrel would mean higher muzzle velocities.

I'm way ahead of you on that and that will be one of my next projects. For now, I will be putting forth my efforts to get this proto to operate with colt mags and bolt hold open.

quote:

Originally posted by toovira:
Sounds good about the shoot. I jsut have to have time. You'll definitely get a call when I do.

Oh yeah...seems like Rotndad and/or 220ST are too busy these days for arranging the shoot.

Tony started getting the last few going, so I just check now and then to see if one has been set up. Ready when you guys are.

quote:

Ready when you guys are.

Nothing like HOT!..sweat,dust,bringing the wrong tools etc..to see if all this crap we've spent money on actually works as advertised

I'm in for a mid summer sweat fest

Update:

Barrel is back from parkerizing and while it was gone, I was working on a colt/Cproducts mag solution that includes bolt hold open. As you can see from the time stamp, I got in late from a trip and just had to build it. 15 rounds from a Cproducts mag ran almost perfect in hand cycles. I will spend tomorrow fine tuning and maybe hit the range.

More to follow

It is several years behind being the world's first but it is a sweet little gun. Good Job!

I really like the concept and would be interested in having you make me a barrel sometime in the future if you start do so. 357 Sig is something that I am not shy on.

 http://www.kurtskustomfirearms.citymax.com/page/page/166325.htm 

Dave

Dave: Direct Impingment. not blow back. keep up.

Tom: I bow to your coolness.

I can't wait for the chrony number.

for the record, I'd buy one.

Four, if you only knew how funny your statement really was.

I sit corrected.

I look forward to the chrony numbers as well.

Dave

quote:

Originally posted by DaveMcDonald:
Four, if you only knew how funny your statement really was.

I sit corrected.

I look forward to the chrony numbers as well.

Dave

actually there was a missing from that.
that's what happens when I move to fast for my fingers.

Can this same upper design be used for 9x25 Dillon?

Progress report:

The left half of the double stack mag is feeding 100%. The right half of the mag is jamming at a 10% or so interval. I believe I need to tweak the feed ramp a bit more. I spent a great deal of time working with the problem and I know exactly what to do to fix it. It will involve some welding to fill in the right portion of the feed ramp and reshaping with a stone.

Better news tomorrow I hope. I could go back to using sten mags, but the cproducts/colt mags with bolt hold open would rock!!

Update:

Feed system and bolt hold open work with cproducts magazines. I plan to head out to the range tomorrow to test the colt/cproducts mag system. I will chrono some rounds tomorrow as well for those who were curious.

Time for my celebratory beverage!!!

I can see interest is fading, so this will be my final report:

Feed system/bolt hold open worked well. This gun, if going into production, is now ready.

I got a chance to chrono 9mm vs. 357 Sig. The results are as follows...

Both barrels are 7.5" and the two ammos compared are both winchester white box (standard plain jane, nothing hot or exotic)

9mm....
#1 1271.7 FPS
#2 1275.1 FPS
#3 1267.1 FPS
#4 1257.1 FPS
#5 1266.7 FPS
#6 1223.7 FPS
#7 1273.1 FPS
#8 1247.6 FPS
#9 1294.0 FPS
High: 1294.0 FPS, Low: 1223.7 FPS
SD: 19.7 FPS, CV 1.6%
MAD: 14.1 FPS, CV: 1.1%
Av: 1264.0 FPS, ES: 70.3 FPS


357 Sig.....
#1 1548.9 FPS
#2 1522.4 FPS
#3 1481.6 FPS
#4 1547.4 FPS
#5 1546.0 FPS
#6 1552.9 FPS
#7 1492.0 FPS
#8 1551.8 FPS
#9 1538.0 FPS
#10 1542.0 FPS
High: 1552.9 FPS, Low: 1481.6
SD: 25.6 FPS, CV: 1.7%
MAD: 20.2 FPS, CV: 1.3%
AV: 1532.3 FPS, ES: 71.3 FPS

Conclusion: No surprises. 124 grain 357 Sig shot about 300 FPS faster than 115 grain 9mm. If a lighter 115 grain 357 sig bullet were used there would me a much bigger spread between the two. I estimate that velocity would be about 1650 to 1700 FPS out of a 7.5" barrel. Likewise, if a heavier 9mm bullet were used from a 9mm AR, the velocity would be reduced to about 1050 to 1100 FPS.

The only comparison that this demonstrates is that the 357 sig is a much more powerful round than the 9mm. Let me put it this way, This gun cycles and functions fine with standard WWB 357 Sig ammo. I pulled a bullet from a 9mm WWB round and put the powder in a primed 357 sig case and set the 115 gr round nose bullet. I shot the above mentioned 9mm load 3 times today and it didn't have enough power to cycle the action to strip another round off the mag. It barely had enough power to eject the case.

So take it for what it's worth. This project has presented a lot of challenges and a lot of rewards. The gun is pretty much complete, I plan to tweak a few minor things here and there, but I believe I've settled on the final product.

Next, I may decide to make a 16" (non-NFA) length just to see how performance would be increased. Keep in mind, I was getting a tad under 1600 FPS out of a 7.5" barrel. A 16" barrel would produce numbers much higher .

Until then,

It was fun!

Thanks for the report Tomster. The 357 Sig is my favorite round and I really wish one of the big AR manufacturers would produce a 357 Sig AR for those of us that do not have the skills to make their own.

Four... no worries brother no offense taken. Due to an inside joke I really got a chuckle from your response.