PDA

View Full Version : Bullet Setback in your defensive pistol


Sturmgewehre
September 9, 2011, 02:33 PM
The discussion of bullet setback came up in another thread recently so I figured it was a good subject to discuss in a video.

http://www.youtube.com/watch?v=w6PAmKLUcbc

Questions and comments are welcome.

TunnelRat
September 9, 2011, 02:53 PM
Nice video, I subscribed :).

MikeGoob
September 9, 2011, 02:59 PM
Not sure how common this would be. I've checked on my carry ammo many times and they all stay the same seated depth. I dont YANK the slide back to eject the loaded cartridge across the room, but I do so gently, upside down so the chambered round just comes out.

Do people always unload their gun full speed?

Will Beararms
September 9, 2011, 04:11 PM
I think it depends some on the caliber and the platform. I have had 1911 .45's that cram the projectile in after two administrative chamberings.

I had a Gen. 2 loose chambered Glock 22 that never did it.

My XD40 and SigSP2022 .40 don't seem to do it and I check frequently.

the duck of death
September 9, 2011, 04:12 PM
I put enough crimp on my ammo there is NO setback.

Clifford L. Hughes
September 9, 2011, 04:28 PM
Sturmgewhere:

Make sure that your sizing die is set up properly: it should size the case tight enough that a bullet can't be seated by hand. The pressure of the brass, when the bullet is seated, should hold the bullet tignt. A crimp prevents heavy bullets jumping during recoil. A crimp is to prevent bullet jump not to hold the bullet.

Semper Fl.

Gunnery sergeant
Clifford L. Hughes
USMC Retired

Jason_G
September 9, 2011, 04:40 PM
I haven't watched the vid yet, but as far as setback goes, I make it a point to clean my carry guns at least once a week, and I always inspect the ammo when I unload the mags to clean them. I have seen on occasion, some bullets that were obviously set back into the case. They get discarded, because I don't handload (yet), so no point saving the components. Bullet setback is real, and it would behoove anyone who carries to check their ammo frequently.


Jason

rose728751
September 9, 2011, 10:53 PM
Thank you for this post, I just posted a thread asking that question. JUST taper crimp the round..:D

youtube
http://youtu.be/JGpXaWwlg1Q

madmag
September 10, 2011, 08:14 AM
Good subject.

I have had some ammo that had severe set-back after just one chambering. Some I have chambered many times with no issue. Just depends on how tight in the case.

The lesson for me is you just never know. You can go long periods with no issue then get a bad batch. My worst case just happened to be Blazer Brass, but can happen to other brands.

I do agree that 1911's tend to put a little more pressure on the nose during chambering compared to some of the more modern ramp barrel guns.

Pond, James Pond
September 10, 2011, 08:41 AM
Thanks for that vid.

As a noob there are so many issues to consider that I don't even realise exist, and that was one of them! Much appreciated!

Good stuff!

Geezerbiker
September 10, 2011, 08:46 AM
I had the problem of bullets setting back in the case when I used to carry my M1911a1 as a daily carry piece.

It took me a long time to figure out what what going on. The 8 round mags that came with my Springfield Armory 1911a1 when fully loaded the top round tips down. If that first round was anything other than a round nosed bullet, it would slam on the feed ramp before making it's way up to the chamber.

I carried some rather expensive MagSafe rounds back then and from the daily unloading and reloading the gun, the bullet in the top position in the mag was beat back into the case. The solution was to only put 7 rounds in the mag. I planned to try some other mags but never got round to it...

Tony

MikeGoob
September 10, 2011, 10:17 AM
Couldn't watch the video before while I was at work but now having seen it (good video!) I had a question.

Since many people carry with a full mag plus 1 round in the chamber, would it be better to drop that extra round into the chamber by hand while the slide is open, then close the slide and load the magazine last?

This way the bullet doesn't slam into the feed ramp.

TailGator
September 10, 2011, 10:20 AM
I dont YANK the slide back to eject the loaded cartridge across the room, but I do so gently, upside down so the chambered round just comes out.

If I understand the problem correctly, setback is caused by repeatedly feeding the same round into the chamber, because the nose of the round impacts the feed ramp and the top of the chamber. So it is not landing on the ground with its nose that is the problem, it is the chambering itself. Only riding the slide would cause the round to chamber more softly, and that is a bad idea because of the feeding problems it can cause.

I make a point of rotating the top rounds when I unload my SD rounds to go the range and shoot cheap ammo.

ETA: You posted your last post while I was composing this reply, so I apparently misunderstood your comment. My apologies for that.

To answer your last question: chambering a round in the way you describe can be done safely in some guns, but it risks damaging the extractor on others. Glocks and 1911s come immediately to mind as examples of the latter, Berettas of the former.

Uncle Malice
September 10, 2011, 11:01 AM
Since many people carry with a full mag plus 1 round in the chamber, would it be better to drop that extra round into the chamber by hand while the slide is open, then close the slide and load the magazine last?

This generally considered very bad practice and can easily result in chipped extractors. The biggest problem is that you may not know when the failure happens either, and in a worst-case-scenario - you may be working with a single shot defensive pistol.

Always load your +1 from the magazine. If you want a full capacity mag +1 in the chamber, then eject the mag and add another round after you chamber the first round.

dsk
September 10, 2011, 01:27 PM
In the old days .45ACP ammunition all had a deep cannelure on the case behind the bullet, which positively prevented bullet setback. Unfortunately nobody does it anymore, not even with the premium defense ammo.

madmag
September 10, 2011, 02:09 PM
In the old days .45ACP ammunition all had a deep cannelure

Some still have a cannelure. But oddly enough one that does is Hornady Critical defense and that's what one member says he had problems with. Hornady points out the cannelure on Critical Defense as an advantage of not having set-back issues.

http://www.hornady.com/store/critical_defense

Bullets are cannelured and crimped to avoid bullet setback.

There are others with a cannelure, at least in .45ACP. Without searching my ammo supply I am not sure, but I think I have some federal rounds with a cannelure in addition to my Critical Defense rounds.

Dashunde
September 12, 2011, 05:07 PM
Sturm skims over the .40 a little - how sensitive is that particular round using a standard Glock barrel nowadays?

the duck of death
September 12, 2011, 05:15 PM
Watching that video makes me glad I reload.

Patriot86
September 13, 2011, 12:41 PM
Great video, I try to rotate what round is #1 in the chamber every other time I reload it and shoot off my defensive load (I keep (1) mag in my nightstand gun and (2) fully loaded next to it at all times) every couple of months to avoid issues.

BTW I watched some of your other videos and subscribed keep up the good work!

Will Beararms
September 13, 2011, 12:46 PM
Interesting and something I have always thought about. If for no other reason than being obsessive-compulsive. I never noticed it in the old Gen. 2 Glock 22 but come to think of it, I did not do a lot of administrative unloads.

I definitely noticed it with the 1911 platform with all types of ammo. I witnessed it after only two unload/reloads with blazer brass FMJ.

'Definitely something to monitor.

Will Beararms
September 13, 2011, 12:49 PM
I think the industry beefed up the case head area around the primer on .40S&W in general to compensate for the high pressures. I have always wondered if this played a part in some of the KABOOMS with older Glocks? Bullet setback + weak case head area = BLOOM!

The .40 concept in general was approached in the wrong manner IMHO in that the original designs were based upon the foundation of a another caliber in terms of platform instead of starting from scratch.