Revolver? Die on the vine?

[-JCN-]

6 hours ago, perttime said:

I don't remember if you've mentioned what bullets you are using in the Alien. A local Alien guy says that his is cleanest with a bullet that is totally enclosed with copper. Especially the base. He is also enthusiastic about using Vihtavuori N340 for powder. I was surprised that he chose such a slow burning powder for his Alien at Minor PF.

I’m committed to Syntech which is a polymer coated total encapsulation bullet. 
 

The reason I am committed is that I shoot indoors a fair amount, and my lead levels get pretty high when shooting traditional ammunition with lead styphnate primers. 
 

The Syntech is special in that it has one of the only non-leaded primers that doesn’t suck. 

 

Traditional leadless ammunition still has leaded primers. Syntech is the only exception that I know of, except for some old-school really crappy hard “other types” of leadless primer.

 

With the frequency of shooting that I do, I also don’t want any lead residue coming inside the house with me and affecting my daughter.

 

I am more committed to the ammunition than I am the gun. I would gladly go back to CZ in a heartbeat over changing the ammunition. 
 

But more importantly, I think that having a piston system in a 9mm cartridge as opposed to a high velocity rifle cartridge will necessarily change the amount of drag on the system with build up regardless. Some types of ammunition may build up faster, but I think it’s inherent in the mechanism of the system.

 

I knew it going into the gun.

 

There is a non-zero chance that I’ll wind up going back to CZ. 
 

Different ways it could play out:

*Make GM a classification goal for LO. Then when I make it, I go back to CO with Shadow 2s because I’d be GM in both and there’s no hiding anymore. 
 

*Make GM in LO and then go to open with CZs…

[-JCN-]

My back feels good today. V's back is healing. She might be able to shoot this weekend a little.

 

We were both kind of dejected at the thought of having to be out for a while, but looks like we be okay.

 

I was able to take a breath and get some perspective.

 

It's not a big deal to clean the gun, but I just have to do it.

 

It's hard sometimes to find time, but I tried a new routine tonight that I think will work out well.

 

I normally sit and do math with my daughter for 30-45 min per evening...

 

Tonight I had her do it next to me downstairs while I cleaned the gun rather than while I dry fired.

 

It works out pretty well. Cleaning is mindless so it's actually easier to proctor and help doing that than dry firing with focus.

 

So I'll stick with the Alien longer. I really can't scrimp on any of the reliability procedures. That includes lubing cases for this squeaky clean Federal ammo.

 

I have a tentative classifier strategy I'd like to try. It's particular to what I'm trying to accomplish and the level I'm at.

 

Classifier matches: shoot at match+ pace. Work more kinesthetics with less visual confirmation. Basically go at Hundo pace where a miss or a no-shoot safely pulls the run down under 85% and gets thrown out.

 

Classifiers within a match: if feeling really strong and I'm "on point" shoot at match+ pace. If not feeling strong, then shoot at "all alpha" pace... which will likely be sufficiently slow to be under 85%... but still high enough to not lose points or position at a match.

 

 

 

 

[-JCN-]

Backwards

 

I was thinking of the Alien gas system wrong. I was trying to understand what was happening a little more and it dawned on me that I had it reversed. 

This picture is from an online article

 

I was thinking of it as a piston like an MPX / MCX…

 

But it’s actually the reverse. It’s there to retard blowback movement, not push anything forward. 
 

Normally the Alien slide speed is really fast and it’s designed to be more vigorous in impact. 
 

That would allow the piston to move farther into the chamber as the gasses were dispersing. 
 

I’m using milder ammo and trying to make a slower moving slide system. 
 

So it makes sense that the piston isn’t getting forced into the chamber aggressively and only the first 2-3 rings are getting fouled excessively. 
 

Basically if I’m only using 2-3 rings instead of distributing the fouling over 7-8 rings it’ll take 2-3x the cleaning. 
 

I might consider notching the first couple rings to allow some blow by in order to use more of the piston baffling, but that would change the recoil impulse and timing. 
 

It might still be worth it, though. 
 

This is my typical piston utilization:

 

 

Using only about half of the piston. 
 

.

Edited July 18 by -JCN-

[Farmer]

It sounds like it’s a self compensating system. Have you tried different springs?

[-JCN-]

45 minutes ago, Farmer said:

It sounds like it’s a self compensating system. Have you tried different springs?

Yes, that is the mainstay of my tuning. Early on I experimented with different spring weights. There aren’t aftermarket springs available (I even sent measurements to Wolff) but thankfully the system is oversprung for my ammo power so I only had to reduce spring. 
 

Because stuff gets gummy, there’s a limit to how light you can go before FTRB becomes an issue when dirty. 
 

It’s basically designed around a certain type of ammo power and timing. 
 

In looking at the piston further, the first two baffles are narrower and seem to stay cleaner. The build up concentrates on the thicker third and fourth baffles. 
 

I might experiment with shaving the third through sixth baffles and see how that affects the build up. 

[-JCN-]

 

Not my prettiest work, but it’s just a proof of concept. 

 

 

Will be interesting to test recoil impulse and see how it holds up to fouling. 

[-JCN-]

That is pretty promising. 
 

 

150 rounds tonight on the left trimmed piston. Much more even fouling and use of the baffles. 
 

It’s not as soft shooting but there is more margin and likely won’t foul as easily. 
 

It does change the recoil impulse some so will have to either get used to it, tune spring some more or trim fewer baffles on the next iteration.

 

 

[-JCN-]

Testing extreme and backing up from there. 
 

When tuning equipment, I often will take what I think will be an extreme change so that I can get a sense of what the magnitude and scale of change is… An anchoring data point if you will.

 

That requires having the equipment availability to have a likely sacrificial data point.

 

But it helps me get to optimal rather than just stop at what I feel is pretty good without knowing if it could get better.
 

Left side is the trimmed baffle piston, right three are traditional ones. 
 

 

Right now with my ammunition and spring choices for optimal shooting, I’m having to lube casings and clean the gun mid match if I want 100% reliability.

 

It is doable, but it’s a lot of work.

 

I really like the recoil impulse. 
 

For the trimmed baffles, I think reliability will be much better but I’m not as thrilled at the recoil impulse. 
 

So I might try trimming just the two most fouled baffles as a compromise. 
 

 

 

 

[-JCN-]

Version 2.0 success

 

I just thinned the two most draggy baffles. 
 

 

Still feels good. Much more subtle alteration to the recoil to trigger timing. 
 

 

Max split doubles at 10 yards. 
 

This might be a good compromise. I’ll have to shoot some more and look at the piston after more rounds before cleaning. 

[-JCN-]

My goal would be able to have 100% reliability with a freshly cleaned gun for a 10 stage match without having to do any chamber brushing or piston swapping or case lubing. 
 

Having the gun stay consistent in the recoil impulse is strongly preferred. 
 

I’m pretty observant and reproducible so even 1# effective spring weight differences are noticeable to me. 
 

I would accept hot swapping the piston mid-match if I didn’t have to do anything else. 
 

Changing the piston baffles is essentially like changing the slide weight  of a tilting barrel gun. 
 

If this does what I think it’ll do, it’ll improve the reliability of the gun quite a bit. 
 

If I can’t get it with the two baffle modification then I’ll do the 5 baffle modification and tune springs. 
 

I like solving problems and learning how things work on a granular level. Set up is kind of fun for me because it usually winds up helping me understand the human - firearm interface better. 

[-JCN-]

As more clarification, I love the current balance of the gun but fouling of the first two baffles causes malfunctions when the baffles get caked and drag on the expansion chamber. It basically turns into 2-3x the width and makes things slow and drag so that there’s FTE and FTRB. 
 

If I can distribute the fouling over the first four baffles and reduce the peak drag by decreasing the contact width it should do what I want it to do. 
 

Hopefully without changing my preferred recoil timing too much. 
 

 

[Farmer]

What would happen if the diameter of the rings was reduced gradually? Like 1st -.002 second -.004 etc. or would it just carbon up and be at square one? I’ve never been into one of these guns so I would need to study it more. Just throwing that out there. Curious again. 

[-JCN-]

2 minutes ago, Farmer said:

What would happen if the diameter of the rings was reduced gradually? Like 1st -.002 second -.004 etc. or would it just carbon up and be at square one? I’ve never been into one of these guns so I would need to study it more. Just throwing that out there. Curious again. 

I went for narrowing the thickness of the rings rather than reducing diameter because with the current rings, it carbons up on the flats rather than passing through. So I figured reducing the flat thickness to help flow. 
 

I get the sense that if I reduced the diameter then it would cake up and fill the gap, but I don’t know that for sure. 
 

What I do know is that it’s easier to grind the side than shave it down (with a Dremel). Plus the coating of the rings are TiN I think and I wanted the contact surface with the chamber to remain treated. 

[Farmer]

17 hours ago, -JCN- said:

I went for narrowing the thickness of the rings rather than reducing diameter because with the current rings, it carbons up on the flats rather than passing through. So I figured reducing the flat thickness to help flow. 
 

I get the sense that if I reduced the diameter then it would cake up and fill the gap, but I don’t know that for sure. 
 

What I do know is that it’s easier to grind the side than shave it down (with a Dremel). Plus the coating of the rings are TiN I think and I wanted the contact surface with the chamber to remain treated. 

 Like I mentioned I’m not familiar with the workings. If I could sit down and study one it would help but that’s probably not going to happen. 

Edited July 20 by Farmer

[-JCN-]

Back in the saddle

 

Went out and shot with V this morning before taking my daughter to a birthday party. Daughter came with us and they planted some wildflowers. 
 

V and I ran through some classifiers and figured out some weak spots in her game. 
 

It’s way more enjoyable than practicing for my own goals or by myself. 
 

I was really happy to have her back shooting. 
 

We might start building and training the 24 series classifiers as those will start showing up at matches. 
 

But it’s all variations of a theme.
 

Improve kinesthetics and recoil control

timing. 

[-JCN-]

Still at the birthday party. 
 

At home tonight I’m going to look at the piston and get set up for tomorrow. 
 

It felt good and consistent. 
 

I’m almost ready to commit to the two baffle trim on the other pistons. 

[-JCN-]

f*#k yeah

 

 

These chunks are what build up on the third and fourth baffle. But usually much thicker than this. 

The chunks are what cause failures. The fouling is also spread out farther up the baffles and recesses. 
 

And those minor chunks were only on one side. 

 

The back side looks good. 

 

 

From my experience so far, it should significantly extend cleaning intervals and improve reliability. 
 

I might go further on that third baffle but I don’t want to compromise the current recoil control balance. 
 

Very excited to have kept pushing to find solutions. This one is going to be important. 
 

 

.

Edited July 21 by -JCN-

[-JCN-]

It also occurs to me that I don't really know what the shiny metal chunks are from.

 

I'm assuming that it's lead. But I don't know that's true. I was just assuming because I don't know what else it would be.

 

Maybe it's priming compound from the Syntech "catalyst" primer?

 

The Syntech bullet is a total polymer jacket and I've never seen any red polymer shavings or anything that would convincingly tell me the jacket is shaving to the point of lead getting into the gas system. 

 

I do have ballistic jello of sufficient quantities that I could recover bullets and confirm that the jackets are intact.

 

I might just do that out of curiosity...

[-JCN-]

MSDS on the Syntech....

 

 

It's very possible it could be some combination of aluminum, copper and zinc from priming compound as the "chunks..."

[-JCN-]

Hmm. 
 

The more I think of it and the more I look at the metal chunks, the more I think it is priming compound (aluminum), and something about the transition of solid to gas back to solid with regard to temperature and pressure on that third baffle. 
 

Thinning the baffle helped and the thing that is striking to me is that there isn’t more buildup of shiny metal further down, it just doesn’t exist on the other baffles. 
 

If I thinned the third baffle more, would it further improve the situation or would it just redistribute the metal deposition onto the fourth baffle?

Against my natural tendencies, I’m going to avoid modifying additional pistons until I get a little more data. 
 

 

[shred]

You could test if it's aluminum by trying to dissolve it with stuff that attacks aluminum.  Lye would do it, but IIRC would eat zinc and a lot of other stuff too.

 

I would also not be too surprised to see captured bullets have the rifling engrave past the coating in places.  Land-and-groove rifled 9mm barrels have a bore diameter around .346" while polygonal is a bit larger (IDK what's in the Alien)

 

[-JCN-]

@shred Thanks! That is something I hadn’t considered! I really should capture a few bullets and check it out. 
 

I should also run the boroscope to see where the gas port comes off the barrel as well. 
 

If it winds up being the rifling by the port, I might be able to mitigate the shaving a little by some judicious Flex Honing of that area if it’s close enough to the chamber to avoid compromising accuracy. 
 

Thanks again for helping me consider additional possibilities!

 

 

.

Edited July 21 by -JCN-

[Farmer]

I’ve found quite a few coated bullets, some syntech, blues and others (check your berms) and many of them look like you could reload them. Contact with the dirt will sometimes wipe the coating off but generally it’s intact. But there could be a burr on that port that could be shaving or the psi getting by the bullet as it passes the port gas cutting the bullet. How far down the bbl is it?

[-JCN-]

 

 

Shot a bunch and the piston is in great shape still without clogging and no malfunctions. 
 

I think it’s a winner. 

[-JCN-]

Shot a classifier match with V.

 

 

I shot at match+ pace and didn't game it. Just shot at around my ability. I felt good that I'm a solid M performer.

 

V is just coming back from an injured back and didn't shoot much this week so she was a little rusty.

 

As expected, she had ups and downs. A couple decent stages. It'll be a good setup for the next phase. Inconsistency part of the growth process.

 

This is how our current percentages will update:

 

 

She's a B+ and I'm M+.

 

We will work on it during the next 12 months to crisp things up and sharpen things up and make our next benchmark.