Building the new Bridge (76%) frame ?

The G19 is the 76%.
Patriots helping Patriots round here please share your technique, tools used and some photos of your work. Looks like you left a hint in your photo with the carving set. 🙂

@srjdsmith What’s a wiggle-cutter ? ? Sounds interesting.
 
For the life of me, I can't figure out why P80 made the trigger pocket so hard to clear out. It is impossible to remove all those fins/sprue without compromising the frame. Meaning... the walls of the frame become too thin. Seems to me one obstruction would have satisfied the new rules/regs. Or to provide a means of 'snapping' those fins out with pliers and finishing with a burr would have been better.

These P80 bridge frames are a joke. Total film flam. Even when you put in all the time and patience to carefully prepare the frame, you are left with a bodged piece of junk. The barrier between the mag well and trigger pocket is rather thin even on a finished factory gun. The frame is also rather thin around the curve of the beavertail.

Even under the best of circumstances and performed by skilled hands, the P80 76% frame isn't worth the time and effort. I dislike having to buy a serialized frame thru the FFL process for a DIY project, but the alternative - which results in a piece of shit - isn't better. Might as well make a zip gun out of a stapler.

Screenshot 2023-03-19 at 5.07.24 AM.png
 
I'm still awaiting my new tools. Fully excited to get going on this project to tackle this new challenge. I plan to share my experiences here. So far this is my plan.

Tools:
1) I'll be using the standard tools recommended in the MGB videos to complete the frame. Click on more under the video at Odysee to see the list of tools. Here's a post of the tools I suggest to get started if you are new to building.

2) The resource center has tools for new bridge frame suggested by the community and MGB. Tools will be added/deleted as the community works together as a team to brain storm best practices to get a FTQ build.

3) New tools I'm going to try:
Micro Sander- This is a knock of of the Micro Mark power sander...cuz Im a miser :LOL: too cheap to spend the money on M.Mark. Takes forever to get to USA from chiiiiina
View attachment 9739 View attachment 9740
Electric wood carving chisel - another piece of cheap china junk. I returned the 1st one it was bound/frozen and wouldn't work. Getting another today. Only good thing I have to say about this tool is it's a one day ship. Hoping this next one works. Does not work with the Dremel as the fitting is too large. Chuck it up in a drill.
View attachment 9741View attachment 9746

This chisel tool oscillates. Im hoping the vibration will cut through the polymer. There are 2 flat blades the small one fits nicely in the pockets the large at the rear rail area.
View attachment 9743View attachment 9744View attachment 9745

Ill post up more as I get on this. 🎉
I haven't bought anything new lately.
I'm finishing up what I have. This new 76% frame is new to me. Why the hell did they do that?? Are the older designs no longer available?
 
Here is a few pics of my new 76% frame with rails and trigger housing fitted. I think if you use a jewelers saw and take your time you can cut out the bridging without to much damage to the frame. All the pin holes are drilled and lining up properly as well. I use an old frame and marked the front hole from another frame.
 

Attachments

  • IMG_20230319_074150972.jpg
    IMG_20230319_074150972.jpg
    830.2 KB · Views: 280
  • IMG_20230319_074003642.jpg
    IMG_20230319_074003642.jpg
    1.3 MB · Views: 295
  • IMG_20230319_074028143.jpg
    IMG_20230319_074028143.jpg
    1.4 MB · Views: 287
  • IMG_20230319_074115303.jpg
    IMG_20230319_074115303.jpg
    1.3 MB · Views: 295
I recommend that you cut the bridging along the magazine wall first before you try and clip any material away with nippers.
 

Attachments

  • IMG_20230319_075352627.jpg
    IMG_20230319_075352627.jpg
    1.8 MB · Views: 246
Here is a few pics of my new 76% frame with rails and trigger housing fitted. I think if you use a jewelers saw and take your time you can cut out the bridging without to much damage to the frame. All the pin holes are drilled and lining up properly as well. I use an old frame and marked the front hole from another frame.
You did a nice job on that. You are a better man than I, Gunga Din! Certainly more patient.

My aim was to determine if I can make a pistol as good as factory. My conclusion, having given it the old college try, is "not possible".
That ended it for me. I do realize that others may be happy with it. I'm too OCD. A rough surface, anything off by a millimeter or two... every time I look at it - it will piss me off. Perfection is impossible, even with a factory gun, but these carved up frames aren't even close to being acceptable - in my not so humble opinion.
I do believe that it was possible to get very close to factory quality with an 80% frame. But 76%... ? It may functionally perform but in my opinion it does not compare to a factory Glock or a decent clone, such as Shadow. Or even the most inexpensive Glock copy, like the Dagger. If it were 50% cheaper to build a complete gun I'd shrug and say... OK, it has a niche. But by the time you are done, these 76% abominations cost more than an actual Glock. A week of work to complete. And it still looks like rats were chewing on it. F__k that.

As an engineer, I'm now convinced P80 hastily took some half-assed shortcuts with these bridge frames. My taste in pistols runs from Nighthawks to the much maligned HiPoint Yeet Cannon - which in addition to being butt ugly and cheap is one of the most reliable guns on the planet. I'd proudly carry a HiPoint before one of these 76'ers. I'll go on to say the lack of a serial number is really of little benefit. Actually, that can be a liability in several ways. But that's subject for a different thread.
 
I haven't bought anything new lately.
I'm finishing up what I have. This new 76% frame is new to me. Why the hell did they do that?? Are the older designs no longer available?
ATF new rules…p80 had to redesign and make it more difficult to build.

Here’s another type frame with post with ATF letter
 
For the life of me, I can't figure out why P80 made the trigger pocket so hard to clear out. It is impossible to remove all those fins/sprue without compromising the frame. Meaning... the walls of the frame become too thin. Seems to me one obstruction would have satisfied the new rules/regs. Or to provide a means of 'snapping' those fins out with pliers and finishing with a burr would have been better.

These P80 bridge frames are a joke. Total film flam. Even when you put in all the time and patience to carefully prepare the frame, you are left with a bodged piece of junk. The barrier between the mag well and trigger pocket is rather thin even on a finished factory gun. The frame is also rather thin around the curve of the beavertail.

Even under the best of circumstances and performed by skilled hands, the P80 76% frame isn't worth the time and effort. I dislike having to buy a serialized frame thru the FFL process for a DIY project, but the alternative - which results in a piece of shit - isn't better. Might as well make a zip gun out of a stapler.
The bridge frame isn’t all that bad. The front block area is a non issue and easily cleaned up.
The trigger housing upper section isn’t all that difficult either however before doing any work protect the surrounding frame edges so it won’t get damaged while tooling.
The hardest part is the lowest area of the TH below the curve due to a small space and difficulty lighting while working in there.

Seems a few peeps have some decent looking builds going on. If taken the time to clean out the TH with care it can be made into a fine weapon the operates as designed to.
 
Here is a few pics of my new 76% frame with rails and trigger housing fitted. I think if you use a jewelers saw and take your time you can cut out the bridging without too much damage to the frame. All the pin holes are drilled and lining up properly as well. I use an old frame and marked the front hole from another frame.
Very nice sir ! A ha …a coping saw. Great choice of tool. Perfect to get down into that lower grid work and cut any flat areas of the TH as well. I’ll be adding that to our tool list thank you sir.
 
Last edited:
The bridge frame isn’t all that bad. The front block area is a non issue and easily cleaned up.
The trigger housing upper section isn’t all that difficult either however before doing any work protect the surrounding frame edges so it won’t get damaged while tooling.
The hardest part is the lowest area of the TH below the curve due to a small space and difficulty lighting while working in there.

Seems a few peeps have some decent looking builds going on. If taken the time to clean out the TH with care it can be made into a fine weapon the operates as designed to.
I'm close to finishing the second, which is a compact. Better, because I switched tools. But I still would never carry one of these frames or fire it anywhere near my face.

We live in a litigious society. I would not be shocked if Polymer 80 gets sued when one of these 76% pistols has a catastrophic failure.

I thought the font rail/locking block would be the hard part. Not at all. The trigger pocket... bad design. There's a lot of kinetic force directed to the rear rail and the upper beavertail area of the frame on recoil. I'm projecting something that looks like this happens after enough of these bridge frames are completed and people start shooting them. I'm going to stick mine in the Ransom Rest and see what happens after a certain number of rounds.

Screenshot 2023-03-19 at 9.44.41 PM.png
 
Very nice sir ! A ha …a coping saw. Great choice of tool. Perfect to jet down into that lower grid work and cut any flat areas of the TH as well. I’ll be adding that to our tool list thank you sir.
@Michele
I don't have one of these 76% lowers and didn't put two and two together in his photo intially until you made your comment. 🙏 Holy cow! I will need to dig down deep to find my old coping saw. It floats around at the bottom of an old school hand carried Craftsman tool box. I haven't yanked that thing out and used it in a very, very long time. Given all the modern power tools, I honestly never thought I'd ever use it again. I also think I have a hand-me-down from my Grandpa's days! (y)

Scroll saws are awfully useful for shaping plastics, but the height of the 76% lower probably precludes using one unless you had a huge one with a tall stroke. If you have a scroll saw in your shop, you might also consider it with other projects with 3D work, possibly finessing things into final shape or removing burs. We had and old workhorse in our old shop that was made in the 1950s and it had a 24 inch throat and sketchy old wiring! LOL. We fired it up all the time for intricate work.
 
I'm close to finishing the second, which is a compact. Better, because I switched tools. But I still would never carry one of these frames or fire it anywhere near my face.

We live in a litigious society. I would not be shocked if Polymer 80 gets sued when one of these 76% pistols has a catastrophic failure.

I thought the font rail/locking block would be the hard part. Not at all. The trigger pocket... bad design. There's a lot of kinetic force directed to the rear rail and the upper beavertail area of the frame on recoil. I'm projecting something that looks like this happens after enough of these bridge frames are completed and people start shooting them. I'm going to stick mine in the Ransom Rest and see what happens after a certain number of rounds.
??? I’m fully confused here. Absolutely no reason for these new frames to fail. They are exactly the same as the original with a few added obstacles to remove. Removing the TH grid work should not result in lack of back strap area. The only area that may possibly get damaged to the point of failure is the already thin wall between TH and mag tube . If that happens the builder can repair it with good ol JB weld and make er like new.

keep in mind-
These bridge frames are manufactured as a temporary solution. Allows p80 continue offering a frame for us to build. Thats a good thing. They could have just said F it to the whole kit and caboodle and went the way of JSD (no more 80% sig cuz no mup 1 or jig) and stop offering frames altogether.
 
Last edited:
??? I’m fully confused here. Absolutely no reason for these new frames to fail. They are exactly the same as the original with a few added obstacles to remove. Removing the TH grid work should not result in lack of back strap area. The only area that may possibly get damaged to the point of failure is the already thin wall between TH and mag tube . If that happens the builder can repair it with good ol JB weld and make er like new.

keep in mind-
These bridge frames are manufactured as a temporary solution. Allows p80 continue offering a frame for us to build. Thats a good thing. They could have just said F it to the whole kit and caboodle and went the way of JSD (no more 80% sig cuz no mup 1 or jig) and stop offering frames altogether.
Absolutely right @Michele . This area is actually in relatively little stress, compared to the front section. Although recoil forces are significant throughout both rails and FRLB areas of the frame and the Trigger Housing itself takes a beating when the Striker-Lug re-engages with the Cruciform and pulls forward on the firing mechanism, I see no reason why the 76% frames would be any less safe or structurally sound than the 80%, and no reason why THOSE would be any less safe or structurally-sound than their 100% Serialized frames.
Consider two FACTS:
1. The original P80 Specter used PLASTIC rails, cut into the frame itself as a monolithic aspect, NOT a separate component. There are some FACTORY firearms that do this too.
8e0fca949c6532eb1024cba3ee185801.jpg

2. Despite my personal reservations on the practice, I myself, and manymanymany other Builders over the last, umm, YEARS, have been running Gen 4 Trigger Housings in Gen 3 Glock frames and Polymer 80 frames. No support across the rear arch against the beavertail, none, nada, zip, zilch, bupkis. ONE documented failure from this thus-far that I know about.

Yes, the 76% frame will not be for everyone, but honestly, "worth it" is in the eye of the beholder. Nothing against Builders who get in over their heads, or faced more challenge than they wanted to bite-off, but I feel that @AKfishwhisperer has his views on this dead-on into the bulls-eye: If people are complaining that it takes too much time to work on this frame, they are tacitly acknowledging that the atf and bungling-biden are correct, that the 80% frames were just a quick-and-easy work-around, NOT a hobby interest engaged in for the fun and learning aspect of a true craft. Kind of sad to me, but then I hail from an apparently bygone perspective where more people appreciated DOING the job, not just getting the job DONE.😕 [Sigh.]
 
These bridge frames are manufactured as a temporary solution.
I hope so.

If people are complaining that it takes too much time to work on this frame, they are tacitly acknowledging that the atf and bungling-biden are correct, that the 80% frames were just a quick-and-easy work-around, NOT a hobby interest engaged in for the fun and learning aspect of a true craft.
I haven't seen any complaints specifying the TIME that it takes. From what I'm seeing, it's a matter of whether they can actually DO it successfully. I've not seen "TIME" mentioned.... ever.

but then I hail from an apparently bygone perspective where more people appreciated DOING the job, not just getting the job DONE.
I hear ya. People have laughed at me for taking many hours to complete frame finishing. After 5 builds, it still takes me 2 - 3 hours JUST to do the RSA channel. But it's not a chore. I enjoy it. The process is a big part of the experience. That's why folks like us do it over and over. Even more... I enjoy the RESULT.

Laugh at me now!
PGB-channel-and-rails.jpg


And my builds work!

But, yeah... our culture is one that expects instant gratification. That ship has LONG since sailed.

I grew up building R/C (radio controlled) boats. Tunnel hull hydroplanes, specifically. It took weeks to build them. I had to epoxy glue the sprue framework. Then I had to curve the outer wood components with steam. I had to install the servos and make pushrod connections to the nitro-methane powered outboard engine. Now people just buy them ready to go. And most are frickin' electric now. Booooooring!
 
If people are complaining that it takes too much time to work on this frame, they are tacitly acknowledging that the atf and bungling-biden are correct, that the 80% frames were just a quick-and-easy work-around, NOT a hobby interest engaged in for the fun and learning aspect of a true craft.
That's a broad assumption. I agree with what you said about Sleepy Joe and the implied ATF overreach causing this situation. But I will have to disagree with the majority that the process of removing material, can and will be done properly and produce a safe, reliable gun. Nobody can predict that. What can be predicted is a Bubbasmith doing that work badly.

As far as the time goes... that's a personal thing. I have no problem devoting time to a painstaking process. Especially a hobby. I fabricated a lot of my own parts for vintage motorcycles because there was no other choice. It took a lot of time an effort learn how to use metal lathes and mills. Making things in general. No problem. It was a labor of love. What I refuse to do is spend a lot of time producing something I know doesn't meet any decent machinist or perhaps a skilled gunsmiths standard of quality. Certainly not mine.

The effect of heat and pressure on polymers is well established in materials science. Given enough of either, and factoring in certain design criteria, it cracks. One way to think about that is doing cutting or welding on a heat treated part. You have to know what you are doing and the downstream effect of the work you did on the material.

The ghosts of engineers, gunsmiths past and Browning himself will haunt the souls of someone who patches a pistol frame with JB Weld. :). It does work great on mufflers though!

So... will these 76ers work? Of course. Will they fail? Also yes. It's a matter of when and the skill of whoever made them, which is utterly unpredictable. Therein lies the center of my argument. Unpredictable. Fireams and unpredictability is a bad combination in my book.

To be clear, I'm not arguing against a DIY gun or the practice of doing so. For me, it comes down to this: P80 made a hasty, bad engineering decision with 76% frames and I predict those chickens will eventually come to roost. Meaning, 1. Customers will abandon/reject the 76% design and they will lose money; 2. Their lawyers will advise them to stop making them based on the potential liability. If they ignore both, they go out of business. If I were a gambler, I'd give that 50% odds.

Not to mention the mainstream gun makers want them out of business. Guess who has better lawyers and lobbyists.

I prefer optimism over pessimism most of the time and I think that what I described in these posts about 76ers can be fixed if they redesign it. Or P80 can adapt and change their business model. I suspect that they rushed these 76% frames into production because they couldn't afford not to. They aren't just struggling to comply with vague and potentially unconstitutional ATF regs. They are being sued. Even their home state of Nevada is on the attack. That's not a good sign. The pessimist in me says they go the way of SlideFire. I hope that doesn't happen.
 
Last edited:
So... will these 76ers work? Of course. Will they fail? Also yes. It's a matter of when and the skill of whoever made them, which is utterly unpredictable. Therein lies the center of my argument. Unpredictable. Fireams and unpredictability is a bad combination in my book.

The same is true for the original 80% frames. Go on the reddit P80 group, and you'll see some scary stuff (and some good stuff).

That said, I fully expect my P80 builds to last at least as long as a factory gun.
 
I suspect that they rushed these 76% frames into production because they couldn't afford not to. They aren't just struggling to comply with vague and potentially unconstitutional ATF regs. They are being sued. Even their home state of Nevada is on the attack. That's not a good sign. The pessimist in me says they go the way of SlideFire. I hope that doesn't happen.

I sure hope they survive the onslaught. They make a quality product in the original P80 frame.
 
I sure hope they survive the onslaught. They make a quality product in the original P80 frame.
I agree 100% on the 80% frames. The completed, serialized P80 frame I bought thru an FFL is as good as any other in that class. Drilling holes and trimming tabs on an 80% frame doesn't raise the same concerns I've brought up re: 76%.

I truly hope the courts determine that the 80%, unserialized frame can be sold without the same regulation of a completed frame or assembled firearm. Doesn't seem likely though. It's a small company with 30 employees. Engineering issues aside, the founders are gone, and the lawsuits will bury them. I don't think anyone will come to their rescue and inject the capital they will need to keep fighting. Legal fees are probably already in the seven figure realm. Insurance underwriters won't touch them.

Nothing is impossible. If they don't adapt and innovate, unless divine intervention occurs, they are probably going to lose the game. I suspect by this time next year, we will find out.
 
That's a broad assumption.
Oh thank goodness, I thought THIS was a 'broad assumption':
Braces are stocks. Anybody who says they aren't is delusional. Everybody shoulders them. The ATF is right about that.
🤣
And this:
Unless the person is disabled and using it as an actual brace.... Which while I have yet to witness, I'm sure DOES happen. And that's what the "brace" was ostensibly designed to do.
The reality is that the VAST majority of buyers are not disabled and ABSOLUTELY are using them as stocks. Literally 100% of the people I've seen at the range with the "braces" are using them as stocks. Not 99%. 100%. I've never seen anyone use a brace as a brace (on the forearm, as designed) on one of these (gargantuan / ungainly) "pistols." Again, I'm sure it DOES happen.
And I've seen TONS of them at the range. They're very popular, though I have zero use or desire for one. I can't go to the range and NOT see them in use.
Now... I will also say that it shouldn't matter. It's irrelevant HOW they use them, if they were deemed legal to purchase and attach to a pistol. Period. The end. I don't care if they use them as a hat or a gardening implement.
The reason I am pissy about these Posts is the same reason I am pissy about the complaining regarding the 76% frames...


By publicly voicing the problem that these frames are now 'too hard' or 'take too long' to complete, (or in regards to the braces support the atf's statement that they are intentionally used in a way that directly circumvents the NFA) is handing ammo directly to the atf and any other anti-gunner, anti-PMF, and anti-accessory group that wants to cherry-pick the statements off of this site. Specifically, the atf referenced that they WILL USE manufacturer's marketing material AND SOCIAL-MEDIA STATEMENTS AND PERCEPTIONS (that is us, RIGHT HERE, with your statement AS WRITTEN condemning this accessory!) when determining the 'new' legality of firearms and their components/accessories/etc. Doesn't MATTER what your intentions were, YOU are adding fuel to THEIR fire, and it frankly pisses me off. If you agree that something is illegal under the law, say what you will, but understand that the NFA is with us. We have to work with what we've got, please don't help the other side erode more options and choices away.
And no, NOT EVERYONE misuses pistol braces, I never have... So I speak for myself, thanks... Not EVERYONE will make an unsafe or unreliable pistol from a 76% frame -saying otherwise is projecting your own inadequacies on others. Will a LOT of people make a steaming hole of shit from these things? You bet. Agreed 100% -but as stated, a lot of folks can't seem to Build from the 80% mark either. This hobby just isn't for everyone. And it shouldn't be. Someone with Tourettes Syndrome probably shouldn't be negotiating peace-treaties in the nuclear age either.
I haven't seen any complaints specifying the TIME that it takes. From what I'm seeing, it's a matter of whether they can actually DO it successfully. I've not seen "TIME" mentioned.... ever.
Of COURSE the complaints are about time. Nobody has to use the word 'time'. "I can't remove this rear grid." Why not, is blended in with carbide dust, harder than a jeweler's file? Of COURSE the complaint is that it will take TOO LONG or TOO MUCH EFFORT to safely remove that webbing. I thought it was molded thin enough to break out with pliers -boy I was wrong!:LOL: But who here truly believes that given fifteen days in a locked room with literally nothing else to do, any of these frames couldn't be completed even 1TQ by hand by shaving-out .010-inch at a time? Yes, the complaint is 'they can't be completed [by the majority of potential Builders] in a reasonable time-frame with the tools we have had at-hand for the 80% stuff.' I will agree with that statement. But I'm not going to bother bickering over what the definition of the word "is" is, and yes, the complaint is absolutely about the time these 76%s will take to finish properly.

Whew! Thanks Racer, for letting me get THAT off my chest.:ROFLMAO:
-GSW10 very, very OUT.
 
Back
Top