Search found 14 matches

by galexander
05 Mar 2022, 22:42
Forum: 5.7x28 Reloading
Topic: magnetic induction vs 5.7 brass (for science)
Replies: 0
Views: 2657

magnetic induction vs 5.7 brass (for science)

Anybody understand the physics of magnetic induction annealing? My induction annealer will melt the other cases of similar diameter I have used it on in 4 to 5 seconds, but even after making a smaller diameter coil it doesn't even get 5.7 brass hot enough to change the color at all after 20 seconds....
by galexander
09 Aug 2016, 12:05
Forum: 5.7x28 Reloading
Topic: Some observations about reloading for the Five Seven
Replies: 6
Views: 11323

Re: Some observations about reloading for the Five Seven

I found that ultrasonic cleaning for 16min with 10% Simple Green removed quite a bit of my lacquer and didn't much clean the brass otherwise. From previous conversations (particularly about the FN patent) here I was also under the impression that case friction with chamber was required to slow the s...
by galexander
25 Jul 2016, 08:19
Forum: 5.7x28 Reloading
Topic: Min Velocity for Reliable Expansion w 40gr VMax?
Replies: 25
Views: 35618

Re: Min Velocity for Reliable Expansion w 40gr VMax?

I think you mean the Ft. Hood shooting. Ft. Bliss involved a .380, no? The issue is expand into what? Even more so when the V-Max does not expand traditionally anyway. Get it going past 1700fps and it will perform. Keep in mind the Ft. Bliss shooter used SS197 that uses the same bullet but slower an...
by galexander
03 Dec 2015, 07:03
Forum: FiveseveN handguns
Topic: Physics and Five SeveN operation.
Replies: 9
Views: 12790

Re: Physics and Five SeveN operation.

bayside: Yes, it does. My general conception of the operation has been corrected with this thread, but I have a of cogitating yet to do. I'd love to see a computer model with the times, forces, and velocities, quantified, but I doubt that will ever happen. Thank you.
by galexander
28 Nov 2015, 10:55
Forum: FiveseveN handguns
Topic: Physics and Five SeveN operation.
Replies: 9
Views: 12790

Re: Physics and Five SeveN operation.

The barrel and slide are moving (albeit at different speeds proportional to their position on the cam) before the bullet exits the barrel? The cam connection from the slide to barrel only slows the slide to the point that the case is not extracted too far too fast while the pressure drops? About whe...
by galexander
28 Nov 2015, 06:17
Forum: FiveseveN handguns
Topic: Physics and Five SeveN operation.
Replies: 9
Views: 12790

Re: Physics and Five SeveN operation.

I am just posting this reply so that it will be obvious that I added the patent link to my original post. You are correct in that I had assumed many were familiar with it. https://www.google.com/search?q=US5347912.pdf&ie=utf-8&oe=utf-8" onclick="window.open(this.href);return false; Posting a questio...
by galexander
25 Nov 2015, 11:00
Forum: FiveseveN handguns
Topic: Physics and Five SeveN operation.
Replies: 9
Views: 12790

Physics and Five SeveN operation.

I am afraid that I confuse easily. I am also not terribly good at finding info on this forum. I apologize for the latter. I had originally thought that bullet friction kept the gun from beginning to cycle until the bullet exited the barrel. The FN patent 5,347,912 only shows and speaks of the bullet...
by galexander
30 Sep 2015, 16:39
Forum: NFA Weapons
Topic: 5.7 suppression
Replies: 34
Views: 77690

Re: 5.7 suppression

The Gemtech seems to be unavailable right now. One dealer told me Gemtech had a problem with one of their production machines and another told me Gemtech was making changes and that the can would likely to cost more when it was available again in 3 or 4 months. I find it irritating that Gemtech (and...
by galexander
29 Sep 2015, 10:57
Forum: NFA Weapons
Topic: 5.7 suppression
Replies: 34
Views: 77690

Re: 5.7 suppression

Thanks, Jay. Does the Gemtech's having been designed (and thus volume tuned) for the Five Seven result in it being measurably more reliable than the 5.7 rated rimfire cans?
by galexander
29 Sep 2015, 08:44
Forum: NFA Weapons
Topic: 5.7 suppression
Replies: 34
Views: 77690

Re: 5.7 suppression

Can anyone here speak to the possibility that a larger volume suppressor like the Sig 5.56 (9.8oz, 6.4x1.7) would help with back pressure issues. My only suppressor experience with a suppressor so far has been with a larger bore AR. I found a gas busting charging handle and a very large suppressor t...
by galexander
20 Apr 2015, 10:23
Forum: 5.7x28 Reloading
Topic: Pulling Bullets
Replies: 13
Views: 13178

Re: Pulling Bullets

Okay, I found that just really tightening the puller down and then really tightening the collet did less damage than the seating die. Ican live with this amount of deformation.
by galexander
14 Apr 2015, 12:20
Forum: 5.7x28 Reloading
Topic: Pulling Bullets
Replies: 13
Views: 13178

Re: Pulling Bullets

Thanks Jay. I am embarrassed that I thought and spoke so carelessly about airflow. All of my thinking about it has been with much larger objects at well under the speed of sound. I conflated the actual bullet with one the size of an airplane where the deformation would have been inches deep. Well, t...
by galexander
13 Apr 2015, 20:41
Forum: 5.7x28 Reloading
Topic: Pulling Bullets
Replies: 13
Views: 13178

Re: Pulling Bullets

The CH4 only came with only one seating plug and it really noticeably puts ring dent around the tip. It is as if the plug is a simple 1/8" tube. I am pretty sure that it will effect the airflow over the bullet. The collet puller I am using is the RCBS. I only have 150 or so of the 195s and will happ...
by galexander
13 Apr 2015, 13:09
Forum: 5.7x28 Reloading
Topic: Pulling Bullets
Replies: 13
Views: 13178

Re: Pulling Bullets

I can't remember if I found the answer to this earlier but anyway I couldn't today. My 195s are glued in too well to simply pull with a collet puller. I thought I had read that the best way to fix this was to use the seating die to break the glue. However, I have to use enough force in the press tha...