Fn fiveseven subsonic

[748]

I bought my fiveseven back in 2007, bought the efk extended 10x1mm barrel back around 2009 waited over a year for it on back order. Started reloading for 5.7 about that time. But the few fiveseven recoil boosted cans available at the time were stupid expensive, more than I paid for the gun. Fast forward to now and the gemtech monopoly on fiveseven cans broke down, gemtec SFN manufacture was discontinued due to lack of sales and the cans went on "clearance" . They went form an msrp of the $850 range, sometimes going for a cool grand, now no one cares and they are down to $450 new. All in less than 10 years. So I bought one and its in fed limbo probably for the next year.
I have a bag of 5.7 brass to reload in the mean time.
The topic : http://www.silencertalk.com/forum/viewtopic.php?f=11&t=100035 has a load I kind of liked. A "55gr bullet over 5.5gr of H110". Not sure if that will cycle a pistol since it was on the rifle forum.
I like it cause I have H110 and like to load 55gr vmax.
Found an old fiveseven forum page that had win M193, HS-6, wolf primer, 1.129 inch long case.
Start load 3.4gr 1,030fps
Max load 4.4gr 1,265fps
https://www.fivesevenforum.com/viewtopic.php?f=19&t=115
Tested in a USG so me thinks they will cycle a pistol.

Anyone have a source for more?

I can find a flood of 33 to 40 grain very super sonic pistol reloads, a little for 45gr and almost nothing for subsonic pistol.

Likely use it to slaughter coyotes. Give me a boost in range and mag capacity over my suppressed ruger mark 4.

 

[roscoe]

If it is subsonic I wouldnt imagine much advantage over .22lr.

 

[silvermane_1]

Well the only reason for sub-sonic is a suppressor set-up.

 

[DocRock]

So much cheaper...

 

[GunnyUSMC]

Well the only reason for sub-sonic is a suppressor set-up.

A subsonic fiveseven with a suppressor would be like a NASCAR with a four cylinder. There are better thing in life to waste money on.

 

[Texas10mm]

Just because you can doesn't mean you should.

It's just going to be an expensive centerfire .22 LR standard velocity.

Just be aware that H110 is not a powder to play with.

 

[748]

H110 is fine. I use it in 44mag and 357mag.
Heavy bullets and faster burning stuff like unique in a 5.7x28 is a bad idea. H110 seems to act predictably out to 65,000psi.

So much cheaper...

View attachment 856416

my suppressed ruger mark 4.

I already have a mark 4 and gemtech GM22.
Did you not read any of the post?

 

[748]

Well the only reason for sub-sonic is a suppressor set-up.

Yeah I bought the gemtech SFN.
Did you not read any of the post?

 

[748]

If it is subsonic I wouldnt imagine much advantage over .22lr.

If you look at only the mass and velocity yes. If you compare the 2 weapons and the projectile it becomes very different.
Only about 2 to 3 times the magazine capacity, more accurate and 55 or 62 grain bullet as opposed to 40.
A 62gr Spitzer bullet is about twice as long as a 40gr 22lr heeled bullet, so when it tumbles it's will turn a coyote inside out compared to a 22lr.
I have already shot a coyote with the FN using standard ammo from about 70 to 80 yards away. I'm pretty sure I couldn't do that with the mark 4.

 

[captain awesome]

Would it even cycle subsonic loads?

 

[GunnyUSMC]

If you look at only the mass and velocity yes. If you compare the 2 weapons and the projectile it becomes very different.
Only about 2 to 3 times the magazine capacity, more accurate and 55 or 62 grain bullet as opposed to 40.
A 62gr Spitzer bullet is about twice as long as a 40gr 22lr heeled bullet, so when it tumbles it's will turn a coyote inside out compared to a 22lr.
I have already shot a coyote with the FN using standard ammo from about 70 to 80 yards away. I'm pretty sure I couldn't do that with the mark 4.

But if you make a Fiveseven subsonic, you will reduce the efficiency of the round and you will just piss off a coyote at 70 to 80 yards.
Making a subsonic Fiveseven may sound good when you first think about it, but once you start talking about it, it doesn’t sound that great.

 

[748]

I'm just trying to not bother the neighbors.
If the coyotes leg gets broken by a sub sonic bullet versus a super sonic one I don't think it makes much difference.

 

[silvermane_1]

Yeah I bought the gemtech SFN.
Did you not read any of the post?

Actually i did, i should have "emphasized" the "only reason" part more.

 

[silvermane_1]

A subsonic fiveseven with a suppressor would be like a NASCAR with a four cylinder. There are better thing in life to waste money on.

Well if you want a "small cal" supressed center fire gun, a 5.7×28 isn't the worst choice.

 

[roscoe]

I'm just trying to not bother the neighbors.
If the coyotes leg gets broken by a sub sonic bullet versus a super sonic one I don't think it makes much difference.

Count me in favor of clean kills. Use the right weapon.

 

[Ohen Cepel]

How is it suppressed with super sonic ammo in it? May be tolerable for your use rather than going sub.

 

[GarrettJ]

I’ve always thought a heavy subsonic bullet in a 5.7 would be the perfect answer to those who want a subsonic 5.56 that will cycle in an AR15. Just slap one of those AR-5.7 uppers and a can on and go. It gives he same result without all of the cycling issues.

I don’t have any experience loading the 5.7, but a few things come to mind. The comment above about H110 likely has to do with loading to less than full pressure. That powder doesn’t seem to like reduced pressure loads much. And for suppressed use, you typically get the lowest sound signature with the faster powders.

Good luck. Sounds interesting.

 

[dodo bird]

Count me in favor of clean kills. Use the right weapon.

I completely agree. Humane kills should always be the intention. The neighbors wouldn’t like a wounded unpredictable animal in their yard either.

 

[748]

Count me in favor of clean kills. Use the right weapon.

My hatred of coyotes is to the point now where a 22CB to the guts is acceptable.
Allowing them to draw breath is inhumane.

 

[748]

How is it suppressed with super sonic ammo in it? May be tolerable for your use rather than going sub.

I have the ruger mark 4 suppressed the sonic boom from something super sonic like a cci stinger is deafening compared to a sub sonic.

 

[dodo bird]

My hatred of coyotes is to the point now where a 22CB to the guts is acceptable.
Allowing them to draw breath is inhumane.

Geez dude.... letting animals intentionally suffer is not cool. We all have had to dispatch nuisance animals. Keep it High Road

 

[roscoe]

My hatred of coyotes is to the point now where a 22CB to the guts is acceptable.
Allowing them to draw breath is inhumane.

Um. You deny them the right to exist? I can assure you, wherever you are, they were there first. Kill them if you must but there is no excuse for letting any animal suffer.

 

[alfsauve]

My first thought got was this defeats the purpose of the 5.7, but the OP may have something here. Hope you can get it to cycle through your gun.

 

[748]

Well I can't make the ruger mark 4 hold 20 or 30 rounds and shoot a 55 or 62gr Spitzer bullets high subsonic.

 

[748]

My nfa dealer got the SFN.
It's slightly fatter and heavier than my gm22 as to be expected.