FN FiveseveN Warning *Picture Heavy*

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More questions I have about the reloading process:

1. What length did you trim you brass to?
2. OAL of the cartridge?
3. OAL of the remaining cartridges after the kB?

I asked early in this post if you could provide a few close ups of the ammo, can you do that?

Can you get a pic of the primer that produced the kB?
 
Is it possible that the primer could have been seated improperly? I've always made it a point to go over them with my finger, and re-seat or discard any that did not feel kosher.

-Sans Authoritas
 
A couple of things about reloading 5.7 are different one is shoulder position. During firing the shoulder moves about .050" forward to help slow slide movement. Also it is a light bullet round less than 45gr IMO. 55gr seems to much. OAL and case length is very important. The case allways needs trimming. In my experience if the case mouth is to far forward pressures are very high(chrono readings flash up 350fps above normal) and the gun doesn't function. Here are a couple of pics on case position.
First is a normal factory round in barrel notice case head is unsupported to 360 degrees and how far it sticks out.
OOB5.7.png
Next is a unsized round you can see lots of unsupported area and yes my 5.7 fired this far out of battery.
OOB25.7.png
So I think it is a combo of improper case sizing/trimming and shoulder not just right with a heavy bullet. The pressures spiked and the case head seperated. :)
 
I'm sorry to hear about you experience I do hope you heal up well.

If you have any expectations of a filing a law suit, I would have not posted this in the two forums you posted it on, or any forums until your case is settled.
 
BSlacker illustrates and answers some of the questions I had. It looks like a tedious and finicky gun to load for; and the OP went beyond what it would handle. It is, after all, a throwaway piece for government agents.
 
As I said earlier
brass was trimmed to 1.280 + or - .002
OAL was 1.580in + or - .003in

Primers were seated properly, I check every primer after priming my cases. Any that don't feel right I try and re-seat and check again.
 
"I did not double charge this load, everything was well within specifications."
In all seriousness. How do you know? You THINK it was within specs... of course you wouldn't have fired it if you thought it wasn't.
Maybe it was ammo... maybe it was out of battery. Can't be sure. How maybe KB's are out there with this gun? This is the first one I've seen - first one I've heard about.
 
Wow!

Looking at BSlacker's pictures would make me kinda nervous about reloading for this caliber/gun combination. That's a lot of unsupported case there.
I would feel comfortable shooting only never-before-used factory ammo.

My fear would be that reloaded brass would be weakened at the base and would end up being a recipe for a kaBOOM!
 
brass was trimmed to 1.280 + or - .002
Click to expand...
This is way to long. The listed trim to length in the Ramshot Powder site is 1.143" max. My personal measurements on hundreds of unfired factory rounds is 1.134" very consistant. But the more important measurement is shoulder position. From the datum line of the shoulder to the case head is .939" +_.003. If you are not measuring every round for shoulder length and you were at 1.280 trim length then had a 55gr projectile you were way out of this world and no wonder it blew up. If one has not read the abstract of the patent of the operating system at the least and they understand what and where L1 and L2 are in the gun and what they do. I would suggest stopping reloading 5.7X28 right now before you get hurt. :evil:
 
For those of you who do not believe me...

http://www.youtube.com/watch?v=_T_XQFzCyR8

This is a video provided to me by Ryan @ EliteAmmunition that shows the OOB firing with a primed empty case. The measurement reads 0.240inches I believe.
Click to expand...

Okay, I don't believe the measurements.

I watched the four OOB videos and looked at the pics. NONE of the videos look to be as out of battery as the pictures. In fact, the closeup in this video http://www.youtube.com/watch?v=jukArOoS2P0&feature=related shows that the distance is more like 1/8" of an inch, not 1/4.

I also could not tell what was being measured. Slide movement was being measured from the rear, but could not tell exactly what was being measured or how it differed from the zero point.

As far as the exactness of the measurement, 0.240" as stated, I am not sure that using one's grip to hold the slide open a given distance is reasonable or could be considered accurate. There is no way to believe that there wasn't a change from when the gun was fired to when it was measured, at at measurements of 1/100 of an inch precision. I also could not read the caliper in any of the vids.

I would have been much more impressed if he used an out of spec case in the chamber that held the chamber open (versus using his hand) and measured BEFORE the firing and that we could see a closeup of just how far open the slide was.

I liked the way the guy in the video scanned his left hand with the muzzle during second #7. http://www.youtube.com/watch?v=o5oaOaiSmGs&feature=related

Loading 55 gr slugs for a Fiveseven is about like loading 305 gr .45-70 slugs into a .45 acp, if it could be done.

I really liked this comment from Accurate on the 5.7x28 cartridge and reloading...
1) This is an extremely sensitive caliber, please adhere closely to indicated loads and COL guidelines.
Click to expand...
http://www.accuratepowder.com/data/5.7x28 FN vs Accurate only.pdf

Gee, I wonder why they would say that?
 
The trim to number so stunned me:eek: that I lost my mind. After a short soak in the hot tub to recover, I realized this must be a mistake, it must be, the case can not stretch that much. I measured some fired cases and nothing could make the case stretch that far but you only have to be .008" over 1.143" to have a problem.
This case stretches over .050", yes you read that right, during firing. It is a part of the operating system to slow the slide down while pressure is still present. If you had a bolt action that stretched the case head to shoulder .050 you would freak out. IMO the brass is stretchy for this reason. I do my load develoment in this round on a Contender G2 platform with a custom MGM barrel. It has a tight chamber and I have been to the edge and looked down to see a spent primer on the bench after opening the action. This round in the pistol is very touchy. It was not intented to be reloaded period. I have 30 years reloading experience and have more close calls with this round than ever before. I don't let friends or family shoot my reloads only factory ammo for them.
So is trim to of 1.280" a error? :confused:

It is clear that the ratio L1/L2 of the lever 1 depends on the ammunition used.
Click to expand...
 
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NONE of the videos look to be as out of battery as the pictures.
Click to expand...
In the 5.7 pistol the breech face is inset with the round being "hooded" as it were. That is why the round looks so unsupported in the barrel and the "hood" is the reason the blast went mostly down. So from the top they don't "look" as far OOB as they are, you need to measure and look at the bottom of the slide to see the real deal. It takes a bunch of OOB to see the breech face seperate from the barrel unlike a recoil operated pistol one would notice a small amount of unlock.
It is a moving barrel delayed/retarded blowback action most blowbacks are fixed barrel this one is different in this one the barrel is attached to the slide by Lever 1 that is comprised of sections L1 and L2. It shares some attributes of a recoil system in that the barrel and slide are locked at the beginning of the cycle then slide and barrel are seperated slowly during the remainding high pressure portion of the cycle then unlocked for the ending ejection portion of the cycle when pressures are low. The ammo determines the ratio of L1/L2 :eek: I will type that again for the hard of reading the ammo determines a componet of the firearms operating ratio :what:. This is where the case very large stretch is happening during the locked but moving away high pressure portion of the cycle. All one has to do is read the patent. This pistol operates like no other and is ammo dependent right down to brass and coatings and bullet weight and powder speed. If 55gr loads worked the factory would have done it by now.
Now to the reloading dies used. If they were RCBS and they have not had .010 cut off the bottom then your shoulder was at least .008 to far forward.
Stock early dies should not be used if uncut.
Info and loads you see on a FN forum may or may not reward one with a good outcome. YMMV :)
If cases are to long Lever 1 will take the stress and break and the case head will move out of support during the high pressure phase. Check your gun to see if the take down lever is broken.
 
Wow.
If this had happened with factory ammo, I'd be much more inclined to fault the gun.
There's a reason why reloads void warranties.
Hope everything heals up as good as new.
JMO
-Ted

Oh and if they give you a deep discount on a new one, take them up on it, even if you don't want it. Sell it on Gunbroker or something...recoup some expenses.
 
Reload or not,IMO-any gun that can fire out of battery,is unsafe. It could have just as well been a factory round that was slightly out of spec. Add that fact with the polymer body,and you have the results you see here.It could have been worse. I'm not a big fan of polymer framed guns,but I keep on open mind when it comes to them. I've handled the 5.7's several times at gun dealers and IMO-they feel very lightweight, and I wouldn't feel safe shooting them-esp with a high pressure round like that.
JL
 
Reload or not,IMO-any gun that can fire out of battery,is unsafe. It could have just as well been a factory round that was slightly out of spec.
Click to expand...
The FN 5.7 like any firearm has a mode where it will fire with the slide barrel not exactly in battery. Do you have any suggestion as to what firearm has absolutely no chance of OOB firing. Yes they have disconnects and such but that doesn't cover everything that could happen even foreign matter may cause it. And yes firearms by their very nature are unsafe.
It could not have been a fresh factory round as no one makes a 55gr load, maybe this is why.
Most of the centerfire pistol cartridges out there above 9MM have a higher pressure than the 5.7 what plastic pistol would you be shooting then? :)
 
It could not have been a fresh factory round as no one makes a 55gr load, maybe this is why.
Click to expand...
Might be,and that is a very valid point.
I just wonder if the 5.7 had been framed with anything other than polymer-would the total and absolute destruction of the firearm have happened?
JL
 
FN has produced a 55grain load, it is the subsonic SB193 available only to LEO/Mil.
 
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