Month: October 2019

It’s the last Monday in October. Boy has this year flown by.

Last week was a busy week for me, we’ve been working on the design evaluation and redesign of the 3D printer before we start making chips. Here’s a write up covering that:

3D Printer: Design Change Y-Axis Linear Motion Shafts

The VZ-58 Build is wrapping up, we are installing the last few components in the fire control group. We started with the magazine hardware

VZ-58: Installing Magazine Latch Hardware

For those who are interested more in the manufacturing of ammunition, we kicked off a series of write ups on Variation. This one is an introduction to much of the terminology and measurements use to quantify variation within a data set.

Introduction to Variation

A few months ago I built some tooling for my bullet swage press. I’m was not happy with how rough some of it turned out, so I am rebuilding the tooling so it has a little more polished look. I’ve shared the design, and my build process here.

Bullet Swaging: Draw Die Housing Part 1

Thanks for taking the time to subscribe. You may have noticed there’s a lot of frying pans in the fire, which is good. It allows me to work on a few different things while I wait for parts to arrive.

If you have any questions, comments, or suggestions regarding the website feel free to reach out. My email is jayandrew338@gmail.com, but you can also check us out at The Ballistic Assistant Facebook page.

Thanks again for checking us out!

The Ballistic Assistant

Good Monday Morning! Hard to believe we are almost through October!

We have had a busy week. I’ve been able to get a lot of work done on the VZ-58 Build. I am at the point where I am waiting on some parts to come in. As I get those parts in I’ll continue to share how that build is going. We are on the tail end of things and I am anxious to get out an put some rounds down range!

VZ-58: Receiver Press Fixture

Updated Barrel Block Prints for the VZ-58

VZ-58: Pressing the Receiver onto the Barrel

VZ-58: Headspacing Correction – My Oops

Since we are wrapping up on the VZ-58 I will be kicking off a few more projects. These are projects that have sat on the back burner for a few years. I’ll be working on them as time and money allows. You’ll find these projects under the projects menu on the home page.

3D Printer: Introduction – Model and Frame

There’s been a lot of focus on the VZ and other projects, but I do not want that to detract from the main theme of the site, looking at internal ballistics. I’ve debated on several ways to try and kick this off, here’s what I came up with as a general overview.

Project Management for Load Development

If you’d like to know the general process from load conception to product release, this is the article for you. This will also introduce the testing that is conducted as part of the Load Development Process. There will be more Write Ups on each test later, so look at this as an introduction.

All of the write ups that pertain to developing a load for the commercial market will be found under this menu option:

Professional Load Development

Thanks again for subscribing! If you haven’t already join the conversation over at Facebook. Our page can be found here. As always if you have an corrections, concerns or questions feel free to email me at Jayandrew338@gmail.com.

Thanks,

The Ballistic Assistant.

If you have read the previous article you will know that I pressed the receiver on the barrel, and I mentioned there were some issues. Here’s the the problem and what I ended up doing to fix it. Hopefully you won’t run into this on your build but if you do, hopefully you are able to avoid the pitfalls I ran into.

When I pressed the receiver onto the barrel I had installed the bolt, the locking lugs, and the Go Headspace gage. What I didn’t realize is that the lugs we not fully locked. This resulted pressing in the barrel too deep. When the bolt was closed the locking lugs dropped but only about 1/16″ of an inch. The issue became apparent when I installed the bolt carrier. It would not close all the way.

I don’t have any dykem on hand, so I used a sharpie to check the lug engagement. At this point my assumption was that reason the bolt was not closing all the way, was the locking lugs we not dropping into place.

At the time it seem reasonably that only a little material needed to be removed from the receiver to get the lugs to fully drop into place. I had hoped that a little polishing would be all it would take to resolve the issue.

I worked the stone across the contact points regularly checking my progress. There was no change. So I did the next logical thing, got a better abrasive to remove material a little faster.

I carefully ran a few swipes across the receiver. I wanted to remove as little material as possible and get the action to close. There was no progress made. At this point I stepped back and reassessed what I was doing. Once the material is removed, it is very hard to put back. With this receiver costing ~$440 I didn’t want to risk permanently damaging the receiver.

I slowly worked the bolt back and forth and tried to determine where the hold up was. Well I figured it out, and it had nothing to do with the locking lugs. The bolt face was making contact with the breech of the barrel bringing the whole assembly to a stop. Yes, we could insert the headspace gages and we would find that the Go Gage slipped in, and the No-Go gage set the bolt back a little preventing the lugs from dropping at all.

There was only one way to fix this. I had to slowly press the barrel back until the distance was correct. This was the one thing I did not really want to do. I did not have a good way to press that barrel out. What I ended up coming up with, I’m not proud of, but remember, I am doing this build for myself and not for anyone else.

Slowly applied pressure until I was able to observe the barrel move, took it out of the fixture and check the action.

Luckily my approach worked and by pushing the barrel out I was able to resolve the issue. The issue was never with the locking lugs and I regretted filing on the receiver. However I checked the action, and when a Go gage is inserted the action is tight with no play. I am confident that my ill advised attempt to stone/file down the lugs did not do any lasting damage.

Since I altered the lugs in the receiver I checked to see how evenly the contact was between the left and right lug. Again I used a Sharpie to mark up the lug and check for wear.

In this case I stoned the left lug to bring it down and allow the right lug to make better contact with the receiver. The even support between lugs will equalize stress on the receiver and the lugs which will help reduce wear. I suspect these components will wear together and be mated during the “Break In Period” still I wanted to see if I could get it a little closer.

I felt that I was able to make a bit of a difference. Plus I was able to polish up the surface, and hopefully that will reduce the potential for galling.

As I stated when I began this write up. This isn’t the ideal thing to do, had I not made the mistake that I did, we could have skipped all this together. However since I made the mistake, I suspect that others may too. This is how I corrected it.