228 vs 229

This question is really for Otis, since I don't think any of you others are Sig dudes.

Otis, as you know the 228 has a lower trigger block than the 229, allowing the slide to properly move back and forth.

The question is, ?do you have to put the 229 block back in when you put the 229 slide back on. I put the slide on, and it seems to function properly. The slide locks open, and goes all the way back, and seems to go into battery.

?So do I have to put the original 229 block back in, and if so, do you know why. (I'm sure if you know the answer you also know why.)

Yup. Definitely a question for "Otis My Man".

I need some help with context here.  My memory is really good, just not long.  You have a P229 in a larger caliber, if I'm not mistaken, 40 or 357.  You picked up the P228 parts kit to convert it to 9mm, I hope I on a warm trail here.

If my assumptions above are on track, yes, you do need to put the original locking insert back in when you put the original slide back onto the P229 frame.  One of the functions of the locking insert is to help stop the slide during firing recoil.  The chin of the slide can, at times, contact the locking insert.  If the incorrect locking insert is in place, it could have adverse effects.  Also, the feed ramp of the barrel is extended a bit by the locking insert.  You may have a gap between the locking insert and the feed ramp of the barrel, which could possibly lead to some feeding issues, maybe ammo dependent.  One more important function of the locking insert is to cam the barrel.  As the slide moves back in recoil, the barrel moves back in sympathy, camming down to tilt the barrel for feeding the next round.  Using the incorrect locking insert could disrupt this geometry, resulting is some not good things, a couple of which could possibly include damage to the camming lug on the barrel or the locking insert itself.

In short, yes, use the appropriate locking insert for the slide/barrel combination you are using.

You are spot on about what I have. I have an (old) 229 in .40 (with a .357 Sig barrel extra). I bought that kit you mentioned on Gun Broker - the 228 with everything but the frame. I found when I tried to install the slide on the 229, it would hang up and not go properly onto the frame. I then changed the "trigger block" - you are most likely calling it the correct nomeclature of locking block - to the one that came with the 228 - and the weapon functioned great!

I have now decided to put the original slide back on the weapon. But I found it would go one perfectly well with the 228 locking block. Slide locks open, moves back and forth cleanly, barrel seems to unlock and lock. But I have not fired it as I was a touch worried about having something bad happen when you actually put real pressure on the weapon in the form of a fired cartridge.

The two locking blocks are different in height (obviously they are the same width and have the same slots for fitting into the frame). As I have not really understood the function of the locking block, I only know how to take it out, but not what it actually DOES (other than lock the trigger in place and hold that little spring that gives tension to the take-down lever). Somewhere I will have to look for a schematic of the weapon that shows functioning. I was aware of the ramp part, but am not clear in my head how what you explain actually comes about.

Still, I will swap out the locking blocks. And thank you for taking the time to explain. I really appreciate people who know stuff.

Dev, allow me to offer up a vastly superior alternative to a static 2d schematic. My buddy Incar put a lot of time and effort into converting these animations so they can be viewed from the website. Look through them, there are several animations here, should improve your understanding of SIG's.

Classic Line Pistols - How they work in animation
http://sigtalk.com/showthread.php?p=255765

Otis2 wrote:Dev, allow me to offer up a vastly superior alternative to a static 2d schematic. My buddy Incar put a lot of time and effort into converting these animations so they can be viewed from the website. Look through them, there are several animations here, should improve your understanding of SIG's.

Classic Line Pistols - How they work in animation
http://sigtalk.com/showthread.php?p=255765

Oh, man! That is EXACTLY what I was looking for. I tried googling it but came up with either the Sig owners manual or sites trying to sell guns. Or reviews. But not this. I had to bookmark it for the future.

Thank you, thank you, thank you!

Well, the 229 locking block is back in. And the 228 slide will again not go all the way onto the frame.

I have looked at the two locking blocks. They appear to be exactly the same height, as well as the same length and width. The slots (obviously) are cut in the same places. The ramps are very slightly different - way out at the end, where they meet the magazine-presented bullet. The 228 appears straight-cut; the 229 appears to have a slight moon cut. But that shouldn't have anything to do with the movement of the slide.

Looking at them end-on, they also appear identical. The only thing I can think of is that the thickness of the top piece that captures the cammed barrel lug is very slightly thicker on the 229. That might explain why the slide won't go all the way back into recoil, but I would love to hear an engineer state so. And if the 228 locking block really IS unsafe to use with the .357 Sig and .40 S&W rounds. If that's true, then there must have been some change in how 229's are now built as they now come either way - 9 or .357/40. Perhaps the barrel lugs were changed on the 9 barrel.

I personally like that I have a whole dedicated slide to 9mm. Perhaps if I had a new(er) 229 I could just buy a Sig slide/barrel combo, but I'm sure it would have cost me more than what I paid for this. I know the older 229's had other differences since I had to change the hammer strut and spring and the trigger bar spring to fit a set of E2's on the frame. I am also told that the new trigger bar spring is a world better than the old one, which was prone to breaking, and that you can still put the old grips on with the new spring, so I've lost nothing.

It has been a while since I have explored the differences between the P229 40 slide/locking insert/barrel and the P228 9 slide/locking insert/barrel. With the frame you have, it is imperative that you keep the locking insert matched with the slide/barrel assembly. If you had one of the original P229 9mm frames, you could have used the same locking insert for the two slide/barrel assemblies.

Looking at the animations I linked prior, take a look at the frame titled 7. Function Locking / Unlocking, it is post #8 of the thread linked. This shows very well how the barrel camming lug interacts with the locking insert, showing in animation what I tried previously to explain.

SIG does offer a kit that they call the X-Change kit. These kits include the complete slide assembly along with one magazine to convert your current SIG to a different caliber. These would also make the locking insert swap unnecessary, but the cost of these kits is considerably more than the P228 kit you purchased.

One other option is the Barsto conversion barrel. These typically need to be fit, which is not a terribly difficult task. But care must be exercised.

http://www.barsto.com/category_main.cfm?ID=229

You know, I stared at that for a while right after you sent the link. And I've stared at it again now again. Then I took apart my 229 and looked at the barrel lug vs the locking block.

I can tell from the illustration that the barrel locks upward on the take-down switch. This is a la 1911. What I couldn't tell easily from the illustration was what caused it to cam downward. BUT playing with the barrel and frame, it seems that what cams it down is the back of the barrel lug hitting the front of the locking block inner section as if I insert the barrel lug into that section the barrel tilts upward.

So I have to conclude that the locking block/barrel lug combination is such that the lug cannot enter the space of the locking block. Whether this is because the lug space is too small or the block edge is too thick I don't know. But that's where the difference must be.

So my suspicion is that the 228 locking block will function fine with the .40/.357 Sig slide-barrel combination as all it would mean is that the barrel lug is a little sloppy in the unlocked position. The only thing I can think of that this would affect would be wear on the locking block over time of having a barrel lug that slops when it unlocks. Not sure just what that would mean over time. But since the barrel locks on the front of the square chamber section on the top of the slide and on the take-down switch pin on the bottom, and since the holes for that switch are in the identical place in both blocks, I expect lock-up is normal. It is not a function of which block is in place.

It's too bad one can't stop the animation to look at something more closely. But that is already complaining about something that is pretty great as it is.

Interestingly, the Browning Hi-Power also has a captured spring with lug below. But IT has the slide stop pin run through a slot in the lug, which is like a raceway - tilting downward at the back and locking up at the front of slide movement. BUT such a system would make the take-down a bit more involved. As it stands, Sig has one of THE best take-down systems. It is WAY better than the Glock, and none of the other striker-fired guns comes close. M&P has something similar, but they require that you flip this little lever inside the frame, back side of the mag well. That is just annoying. And the original 1911, unless you kind of know the tricks, is a bit of a pain to put the slide stop pin in. And most annoying is the little spring stud that puts forward pressure on the back of that pin. It is always a bummer to get it in without scratching anything on the frame. 'Course in the service we weren't particularly worried about "scratching" anything - weren't our guns.

I just bought 2 Megar 228 magazines. They arrived in the mail today. I naturally tried them out.

Both fit in the 229 fine. Both will hold both 9mm AND .357 Sig. BUT interestingly, they hold 15 rounds of 9mm, but only 12 rounds of .357.

Now, I would think that you would see the rounds down to the 15 hole with the .357 if you can't load any more, but you only see them to the 12 hole. But you see the 9mm all the way to the 15 hole.

?So how come the spring will compress enough to allow 15 rounds of 9mm but not .357 Sig.

Please remember, while the 357 SIG bullet is about identical to the 9mm, the case is a necked down 40 S&W case. Being a larger case, fewer cartridges will fill the same space, your 15 to 12 reduction sounds about right. This size difference will also impact the position of the case relative to the count openings in the case. I really believe what you are seeing is perfectly normal and as should be expected.

Please remember, while the 357 SIG bullet is about identical to the 9mm, the case is a necked down 40 S&W case. Being a larger case, fewer cartridges will fill the same space, your 15 to 12 reduction sounds about right. This size difference will also impact the position of the case relative to the count openings in the case. I really believe what you are seeing is perfectly normal and as should be expected.

Well, I didn't really expect the same number of rounds of each. As you note, the case size IS different. Perhaps what I am missing is that the rounds are below the 12 hole but not all the way to the 15 hole, which they would get to (and do) with 9mm.