mindcrime

Just my experience: I bought an open glock from a reputable glock builder and could not get it to run. I spent a solid 1.5 years trying (seperated all variables, worked on all and sent back to builder). It was simply not possible to have that gun be reliable. I have since paid attention to other open glock shooters (home built and top builders) and all have had serious problems. Glocks could not be more reliable when stock or lightly modified, but when heavily modified it is easy to run into problems. The body of knowledge for Open 2011's is vast, I don't think that it is for open glocks. Personally, I quit fighting to shoot an open gun and shoot glocks in limited and production. If you are stuck on open, get an sti.

calmwater, without having a parts book in front of me for reference, I think the old blocks look like the ones for the 2 pin frames.

Rumors are fun! Shot one lots, let me try to help. 1) The mag release is reservable, not ambi. So, the old mags still work if the mag release is set up for right handers. The new mags have a new cut on the left side of the mag for when it's set up for lefties. The new mags will also work in all the old guns. 2) The frame is smaller than gen 3's. To do this they changed the trigger housing to a SF style. The reach to the trigger is now about the same as an xd. There are 2 add-on backstraps. To increase the grip size the shooter adds these backstraps to the grip by snapping it to the bottom of the frame and it is secured on top by the frame pin. You cannot stack the backstraps. The smaller one brings the gen 4 back to the standard gen 3 size. The larger one brings it to a 21sf size. 3) The trigger bar appears similar to a G37, but the dimensions are different, although it does have the dimple on the striker safety tab like the 37. Also the 37 trigger bar has the same dimensions as the 17's and 22's since all have the same frames and springs. 4) The rep claimed softer and flatter shooting because of the new recoil spring. I didn't see that, I shot the gen 4 next to my gen 3 G22 and I could not tell any difference when both had stock springs. The gen 3 was definitely flatter shooting when using a 15lb ismi, of course. We'll just have to wait for aftermarket to catch up for the lighters springs. The new spring is a captured 3 spring deal that has 3x the service life of the old ones and "fixes" the 22's problems when lights are mounted. 5) By the way, they did not fix the light problems with a new block, they changed the mag springs. The rep stated that the heavy recoiling 40 in the small frames with a light was causing more frame flex which affected the timing, so that the slide was outrunning the mag springs.

I had the chance to shoot one of these, I'll see if I can help. 1.The chamber has the same support as gen 3's. 'course this has been discussed here-the chambers are fully supported, they are just not as tight as others, e.g. STI. This is better for reliability but harder on the brass. I doubt you will ever see tighter chambers from Glock. They are first a law enforcement gun and second a competition gun. And LE guns shoot factory ammo, hence they are not worried about comp shooters trying to cook the flattest shooting handloads or brass with more than 1 firing. But, they will always demand the utmost reliability. 2. No news on when the 35's will be released. 22 and 17 are first. 3. Felt recoil felt the same to me compared to 3rd gen 22. 4. The recoil system is supposed to improve reliability with the lights attached, and the one I shot functioned perfectly with a light. 5. lots of the stuff is not interchangable-trigger bar, trigger housing, mag release and recoil rods and springs. And current magwells will not work.

The mag release is larger front to back v top to bottom. It protrudes about the same as the old ones, but less than a large frame release fitted to a small frame.

Had the chance to shoot one of the 4th gen's. I liked it. I think the backstrap configuration and the way that they are attached are better than the competitions. The new recoil spring seems ok and they claim reliability improvements over the old springs, which would be good for duty weapons, but competition shooters will not be able to use different springs or guide rods (til the aftermarket catches up) as the new assembly is a different size. The mag release was a little easier to use compared to the old standard release, but you can't put an extended size in (such as a large frame release). The grip texture is pretty aggressive and I doubt that most shooters would need grip tape, so I liked that. Aftermarket mag wells will not fit, so that will have to catch up also. The price is unchanged, unlike some (XDM's v XD). Overall, I think they did a very job and the new guns address pretty much any complaints that I have heard over the 3rd gen's. I plan to continue with my 3rd gen's for now (at least until aftermarket catches up), but I bet most shooters would pick the 4th gen's when given the choice.

Interesting thread, thought that I would chime in. I work the range for a large western police dept. We have an extensive approved list for our officers to choose from. Sig has brought the 250 in 9 and 45 down numerous times to try to get us to bite. There is a far larger market in law enforcement contracts than in USPSA. Therefore, they market the gun from an administration standpoint not from a shooters viewpoint. I can tell you that the 9mm's ran fine for the several hundred rounds that we had time for, but the 45 did not: many fail to feeds and locking slides open midstride, it seemed that the rounds in the mag were hitting the slidestop. The rep had just been to another local PD, where the gun had worked fine. Also, the slide is very heavy, and with the height of the bore axis, the gun is very hard to fire accurately at speed as it seems to go directly to the sky in recoil. Instead of arguing who has more extensive firearms knowledge, why not just test them ? My splits when firing Bill Drills with a well-set up Glock 17 or a Smith m&p are .14 to .18 with good hits. The best I could manage with the 9mm 250 was .30 to .45. Not only was I far slower and I had to work far harder, I was far less consistent. It was also really easy to shortstroke it and really mess up. My experiences were echoed by the other instructors. We did not bench rest, but the gun seemed really hard to fire accurately. Don't know if it was the trigger or the accuracy of the guns but the groups at distance were also far larger than Glocks, m&p's or xd's. And for those who think that the DAK is the answer, it's not. It is basically the same trigger as the 250 but with two points of reset. If you shortstroke it the pull is harder, to get the light dao it has to be released the same distance as a 250. It is quite a mess. Like others have said, the classics like a 226 is far more competitive for our sport. The 250 won't make it.

I tried an open glock on a g17 platform built by a reputable Glock specialist. Over a year later later, trips back to the gunsmith and eliminating every variable except the comp, and thousands of rounds later, I was never able to get the gun to run. I now shoot a Glock 22 in Ltd and I can't get it to malfunction, so I am having way more fun with it. Also, at the Nationals, a shooter ahead of our squad was using an open Glock. That shooter was having the same problems that I encountered.

Just tested a M&P 45 at our police range. The grip is identical to the 9/40 frame and the barrel is 1/4" longer. It shot very nicely and had very little muzzle flip. The safety is indeed easily removeable and will be offered as an option.