Tutorial How to fix a chewed up RSA side walls

[Mooner]

Here is an example of a chewed up RSA side wall. This was @Alex post on "+P Ammo In Our Builds"
Alex was using a hot load but I'm getting the same damage with just range ammo.


@Racer88 G34 has no visible side wall damage with close to 2K. It is not a round count issue. For me, this damage is happening to only ported barrels and window cut slides. I have been plastic weld fixing it but it is getting tedious and annoying. I have been trying different solutions without success. But I think I found a promising solution.


This is the RAW RSA wall channel.


This is a base metal plate of no name brand mesh pencil holder. It's a perfect size.


I cut and sanded to match the front of the RSA channel wall.


CL frame - used soldering iron to push the metal plate a little, also plastic weld to hold the plate.
Michele's G19 frame - this one I used epoxy to hold the plate.

Both look promising... will come back after testing...

 

[Racer88]

I'm lost. What is causing this? What is impacting this area?

 

[Mooner]

I'm lost. What is causing this? What is impacting this area?

I could be wrong but I think ported barrel is increasing slide velocity where the slide RSA insert part is hitting RSA walls.

 

[Racer88]

I think ported barrel is increasing slide velocity

Why would it increase the velocity? If anything, I would expect it to take some of the energy out of it. The slide cuts (removal of mass) could do it, though.

the slide RSA insert part is hitting RSA walls.

Pardon my ignorance. But, I'm not following. Wait... I think I get it. The part of the slide (metal hoop thingy) where the front of the RSA fits? That's slamming into the front of the channel wall.

My semi-educated guess is that it's an RSA that is too light / weak. Let's see what the real experts have to say.

 

[Mooner]

Why would it increase the velocity

It is counterintuitive I know, not an expert but that what I think it happening to cause the damaged. I'm using OEM RSA by the way.

 

[Michele]

wow, I have not seen this issue. Maybe @GSW10 has an idea?

 

[Racer88]

So, it's this part of the slide that is slamming into the channel wall, right?

 

[GSW10]

I could be wrong but I think ported barrel is increasing slide velocity where the slide RSA insert part is hitting RSA walls.

Errr, no. Sorry, not the issue. @Racer88 is correct, all else equal (Recoil Spring-weight, Guide Rod type, slide weight, and especially the ammo itself, a Ported barrel will yield LESS energy available to cycle the slide rearward. Therefore, the slide will have LESS kinetic energy (velocity) with which to strike the frame at the stops ("Posts").

The problem is almost certainly the slide itself, in this case. As the 'windowed' and 'lightened' and 'ported' slides begin to lose mass, by virtue of the material being machined off of the 'blank', the energy transmitted into it via the ammunition's reactionary force is not 'absorbed' by the heavy slide, and with all else being equal, the same amount of energy pushing the slide rearward WILL result in a faster slide action. This transmits MORE (not less) energy into the frame-stops, gives the Recoil Spring LESS time to slow the slide's action, and may very well cause the damage you are seeing. The best thing to do is weigh the windowed/lightened/ported slide vs a comparable-model Glock slide, to determine how much percentage of the slide's mass (as engineered) has been removed.* This can help you to determine if stepping-up the Recoil Spring weight may be necessary... Which gets complicated when then adding a Ported barrel, which LOSES energy more rapidly, and you may end up in a corner with too much Recoil Spring, and too little reactive force to reliably cycle a slide that is made too light. Fortunately, Glocks (and their clones) are over-simplified, and offer a very wide functionality range.

*In this picture, you can see that Glock has engineered different 'weights' to their slides, it is all a balancing-act to get the most reliable, highest performing 'action' from their designs, able to use the widest possible loads of ammunition for any given caliber, without allowing the slide to beat the frame to death in the process. This is a 9mm vs 40-cal, yes also Gen 3 vs Gen 4, which also have dramatically different RSA characteristics, but this still illustrates my point:

IF more troubles are seen with Ported barrels REGARDLESS of slide-weight however, and I find it unlikely, then I would consider the added TEMPERATURE within the firearm caused by Porting the barrel, especially on aftermarket barrels that may have issues expelling the Ported gasses at a high enough velocity -configurations that often leave excessive carbon build-up in the channel area. This additional heat COULD theoretically reduce the tensile strength of the frame's polymer, leaving it 'soft' and malleable..

A good solution without hunting through a stack of Goldilocks-seeking Spring-Weights (this one is Just Right!) is to use a recoil 'cushion', similar to what you are doing with the metal insert, but very much in the opposite direction -soft cushioning rubber or silicon instead. Most likely, that steel insert will eventually deform, leading to reliability problems, or continue to damage the frame, or in all likelihood will eventually damage the slide itself. The rubber cushions are already on the market, I have seen them for VERY cheap, if you buy a lot of them, and they are fast and easy to install. I just keep forgetting to actually get any for testing... [Sigh].

Edit: here is an example of a harder poly variant, under $1 each in a six-pack, I also found 12-packs at under 50-cents per buffer: Search for "Glock Buffer" or "Glock Recoil Buffer"

Recoil Buffers For Glock 1-3 17, 17L, 18,19,20,21,22,23,24,31,32&37(USA) 6 Pack | eBay

This buffer is made out of a durable polyurethane material, and is easily installed between the recoil spring guide and the end of the slide. This part is to be replaced every 1,000 rounds.

www.ebay.com

 

[Racer88]

Errr, no. Sorry, not the issue. @Racer88 is correct, all else equal (Recoil Spring-weight, Guide Rod type, slide weight, and especially the ammo itself, a Ported barrel will yield LESS energy available to cycle the slide rearward. Therefore, the slide will have LESS kinetic energy (velocity) with which to strike the frame at the stops ("Posts").

I aced Physics in college.
Certified geek!

F=ma (Force = Mass X Acceleration). aka Newton's 2nd Law of Motion

The problem is almost certainly the slide itself, in this case. As the 'windowed' and 'lightened' and 'ported' slides begin to lose mass, by virtue of the material being machined off of the 'blank', the energy transmitted into it via the ammunition's reactionary force is not 'absorbed' by the heavy slide, and with all else being equal, the same amount of energy pushing the slide rearward WILL result in a faster slide action.

Yep. See above. If the force is the same, but the mass is reduced... the acceleration must increase, according to Newton's 2nd Law equation.

This transmits MORE (not less) energy into the frame-stops, gives the Recoil Spring LESS time to slow the slide's action, and may very well cause the damage you are seeing. The best thing to do is weigh the windowed/lightened/ported slide vs a comparable-model Glock slide, to determine how much percentage of the slide's mass (as engineered) has been removed.* This can help you to determine if stepping-up the Recoil Spring weight may be necessary... Which gets complicated when then adding a Ported barrel, which LOSES energy more rapidly, and you may end up in a corner with too much Recoil Spring, and too little reactive force to reliably cycle a slide that is made too light.

Hey! Nobody said we were gonna have to do math!

I would consider the added TEMPERATURE within the firearm caused by Porting the barrel, especially on aftermarket barrels that may have issues expelling the Ported gasses at a high enough velocity -configurations that often leave excessive carbon build-up in the channel area. This additional heat COULD theoretically reduce the tensile strength of the frame's polymer, leaving it 'soft' and malleable..

That's a thought. I think it would take a lot of repeated rapid fire to actually raise the temperature of the polymer to where it would melt and deform. But, I wonder if over time the polymer's "temper" changes and affects the durability of the material. In any case, I think that is a bit more "far-fetched" than the hypothesis that the plastic is just getting hammered due to the increased velocity and force by virtue of the reduced mass.

And, that has precipitated my next thought: Add mass back to the slide! Starting with the obvious... an optic, if the slide is milled for one. Beyond that... we're getting into experimental shit. I'm not sure how I'd add mass back. Tiny adhesive lead weights.... similar to wheel weights? Where would you put them?

I love me some science! LOL!

 

[Mooner]

Thank you GSW10. I will have to try the recoil buffer pad, didn't know that was a thing, would have saved me a ton of time

 

[Code_Name_Eric]

I aced Physics in college.
Certified geek!

F=ma (Force = Mass X Acceleration). aka Newton's 2nd Law of Motion


Yep. See above. If the force is the same, but the mass is reduced... the acceleration must increase, according to Newton's 2nd Law equation.


Hey! Nobody said we were gonna have to do math!

That's a thought. I think it would take a lot of repeated rapid fire to actually raise the temperature of the polymer to where it would melt and deform. But, I wonder if over time the polymer's "temper" changes and affects the durability of the material. In any case, I think that is a bit more "far-fetched" than the hypothesis that the plastic is just getting hammered due to the increased velocity and force by virtue of the reduced mass.

And, that has precipitated my next thought: Add mass back to the slide! Starting with the obvious... an optic, if the slide is milled for one. Beyond that... we're getting into experimental shit. I'm not sure how I'd add mass back. Tiny adhesive lead weights.... similar to wheel weights? Where would you put them?

I love me some science! LOL!

How much do those Glock cocking handle thingys weigh? Just a thought for something that would be easy to add for a bit more slide mass.

 

[Michele]

I suggest bringing this issue with photos & documentation to 80P builders attention. Maybe they can correct the problem- include the buffer pad as an add with those type slides.

 

[Mooner]

I suggest bringing this issue with photos & documentation to 80P builders attention. Maybe they can correct the problem- include the buffer pad as an add with those type slides.

Must be not a common issue, I have only seen it twice, once on the old MGB forum and Alex's post recently. I am a professional lurker on Reddit and Facebook and can't remember anyone else having the same issue.

Besides what kind of builder would I be if I send all my issues to the vendor?

 

[James]

Yup, seen this more than a few times with custom guns (any moded gun really, just some more than others like race guns). Same power of load but less weight in the slide = more slide velocity / cycle speed (read slide / frame battering). A lot of the RDS cut slides with windows and side milling don't see this issue because the addition of the RDS (weight) adds back into the slide and it washes or at least minimizes it until a really high rnd. count.

I personally have seen this on one WWII Browning HP with a totally out of spec spring and mod'd guns that don't have a RDS installed and or are using the super light weight CF / composite plate if you don't install the dot. A "shock buff" is the semi permanente fix or a heavier spring is the long term solution. I have a Colt Delta Elite that will show marking with nuclear 10mm loads but not avg. range loads, so not enough to worry about long term. Were I training on a weekly basis with full house defense loads........ yea. So think about your ammo use on your mod'd / lightened slide and ported paper killers. Running hot loads, home rolled or +p may make a difference.

I have marked suspect or potential contact areas with liquid paper to show up the points of contact / battering and if it's hitting it will mark almost immediately (1or 2 rounds). Work from there, try some 115 124gr. light range ammo, no marking? You need at least a buff if not a spring swap FOR THE AMMO YOU WANT TO RUN. If you train with the light cheap stuff and carry or load defense loads but rarely if ever shoot them (or very little anyway), maybe not a huge worry?

 

[Alpa Chino]

Have not started building yet but was playing around with the idea of gluing in a metal washer cut and shaped.
Sealing washers have a bonded bit of neoprene.

Then again why reinvent the wheel with $4 ebay buffers......just to see if it works