5.7x28 Love or Hate? (Page 1 of 3)
Posted: 8/4/2026 9:46:25 PM EDT
| Any 5.7x28 owners out there? Pistol or carbine, do you love it or hate it ? What are you shooting? |
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Pistols Rock/FSN/TIsas PX 57 > Ruger 57 > S&W M&P > PR57 PDW P90 / RBD MK57 > Ruger LC Charger > Diamondback DBX, Keltec P50/KT50, AR57 - X57 untested/not in production yet. PCC / 16" barrel PS90 > Ruger LC, Keltec Sub 2000 (heavy bolt weight recommended), Possibly the S&W FPC, Keltec R50. People shit on PSA, but they built a really solid pistol with the Rock. The P90 just simply works, but if you don't like the mags, CMMG's RDB MK57 runs, but it isn't as compact as it's AR based. |
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Good to have, expensive to shoot. I love having it, but shoot other guns mostly. Very easy to shoot, even for novices. Makes a great home weapon that the wife or daughter can use with not too much training. Can keep on target with little recoil. Flat shooting due to velocity, which ups accuracy similar to Creedmoor vs .308 or 300Blk Large capacity mags means a lot of firepower, even if it has a reputation of being underpowered per round. Lot of boolits means confidence you will not easily run out, great for suppressive fire, multiple hits on target vs the competition (also partly due to no recoil, muzzle flip and negligible flinch reaction). Suppressive fire often ends the fight, with the perps running away at the first sound of shots coming their direction. Mass shooters often exit and head off to shoot themselves dead before the police get a chance to do it. That is pretty routine now. Terminal effects are debatable given its deadliness in a couple noteworthy cases in the news. Not too many failures to do the job in reality (vs. conjectures based on bullet weight and energy.) Would like to read of such actual failures to perform in actual gunfights. Small, light ammo means you can carry that much more. Less likely to over penetrate. Important in many circumstances/buildings. Shoots almost as easily as a 22 but is centerfire, so more reliable. PS90 is highly reliable. The ease and low recoil will be appreciated as you age out with weapons (let's say vs. a .357 magnum Airweight snub nose). Not going to promote an arthritic hand and wrist (which I did find with my .357) Pierces up to most level IIIa body armor. Might or might not be super important depending on who you are up against. Can now add FRT's to these guns, making them one of the ultimate personal weapons, really giving the P90 a run for the money. Some say it's boring due to how easy it is to shoot. Boring here gets the job done without breaking a sweat. Good home defense weapon, IMO. (and at stopping mass shootings, not to mention being used successfully by a mass shooter, unfortunately.) |
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HUGE FAN Once you understand WHAT it is and WHAT the cartridge can do, its hard not to like. When you need to shoot through something, nothing else will do. Stay AWAY from the heavy +30 grain "plinking" and subsonic and hollow point rounds they are like putting last years lawn mower gas in your Ferrari. The 5.7 was designed for light bullets (think 30 +/- grains) |
| I'm intrigued by the cartridge. I responded in a previous thread that the catalyst, at least for me, in acquiring a firearm of that caliber would be stumbling across a great deal/sale on ammo. I'd only purchase the firearm AFTER I'd scored some ammo. PSA and Ruger both have very reasonably-priced pistols that pop up on sale from time to time. A PS90 would probably be fun, too. |
Posterity! You will never know, how much it cost the present Generation, to preserve your Freedom! I hope you will make a good Use of it. If you do not, I shall repent in Heaven, that I ever took half the Pains to preserve it.---John Adams
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Originally Posted By intheburbs: I'm intrigued by the cartridge. I responded in a previous thread that the catalyst, at least for me, in acquiring a firearm of that caliber would be stumbling across a great deal/sale on ammo. I'd only purchase the firearm AFTER I'd scored some ammo. PSA and Ruger both have very reasonably-priced pistols that pop up on sale from time to time. A PS90 would probably be fun, too. Has anyone compared the ballistic performance for the compact 5.7's (Keltec PR57 and PSA Rock) against the original ~10 in barrel the cartridge was designed around (if my understanding is correct)? |
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Originally Posted By backbencher: I'm thinking of replacing the Gen 5 26 w/ a PR-57, and making a Smith FPC the car gun. I sell quite a few PR-57s and 5.7 SUB2000s. I enjoyed my AR57 upper on my Lyndon. I really like my mine |
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"HAVING GUNS AND AMMO IS A BIT LIKE HAVING TANGIBLE STOCKS" Me
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USMC Distinguished Pistol Shot 1997
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"HAVING GUNS AND AMMO IS A BIT LIKE HAVING TANGIBLE STOCKS" Me
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Originally Posted By NN300BLK: Has anyone compared the ballistic performance for the compact 5.7's (Keltec PR57 and PSA Rock) against the original ~10 in barrel the cartridge was designed around (if my understanding is correct)? That same load from the 10" is like 2,700 fps. Normal SS198LF from the 10.4" is about 2,400 fps.. Ammo choice is fairly important in the pistol barrels |
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The FRT for the FN PS90 is a TOTAL GAME CHANGER!!!!! 5.7 offers accuracy, extremely low recoil, flat trajectory, and reasonable stopping power in a TINY, LIGHT package. My youngest son got his ATF Form 1 approved in 23 days (I filed mine today) I trust the 5.7x28 so much I carried it on duty for the last few years of my Law Enforcement career, but I didn’t load it with crappy ammo. I carried Elite Ammunition S4M that clocked 2,400 FPS out of my handgun. The absolute worst ammo is Federal American Eagle followed by FN SS197 (Blue Tip) Both are loaded by Fiocchi in Ozark, MO. I spent WAY TOO much time running down BULLSHIT supposed Law Enforcement shootings like the perp was shot 17 times and asked the Officer to please quit shooting him! One shooting is HEAVILY DOCUMENTED, the Fort Hood shooting. The shooter was carrying FN SS197 (crappy lower velocity ammo) he KILLED 13 people with body cavity shots and put many more out of action with extremity shots. He hit a responding Officer in the Femur (the LARGEST bone in the body) and shattered it into 120 pieces!!! You can bitch all you want about the round but it protects my family & I. |
"When trading bullets it is better to give than to receive" _____________________
"People sleep peaceably in their beds at night only because rough men stand ready to do violence on their behalf." - George Orwell
"People sleep peaceably in their beds at night only because rough men stand ready to do violence on their behalf." - George Orwell
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Originally Posted By Buffman_LT1: But why. You can buy a much better pistol than the PR57 for not much more. Originally Posted By Buffman_LT1: Originally Posted By Novelty: I am looking forward to getting a KelTec PR57 and KP50 But why. You can buy a much better pistol than the PR57 for not much more. I've sold several. It's very thin, very light, I've run 80 rounds total through a couple of em, there's no recoil. The trigger's nothing to write home about, but it's not heavy. I'm not sold on the accuracy yet. If I can make hits at 100 yds w/ a red dot, I'll probably sell the 26. The PR-57 is unique - a concealable 21 shot handgun that's the same basic outline as a Glock 19, but much lighter & thinner. There's also the Mexican Match thread, would seem the FMJ loads are intentionally downloaded, but even anemic Fiocchi from a PR-57 is going to penetrate more than .22 Mag, and that looks adequate. |
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Originally Posted By Buffman_LT1: Yes. From the PR57 you need Elite Ammo's S4 to get the velocity that SS198LF would get from the 5.2" Rock. That load normally does 2400+ in the 5.2" That same load is about 2275 fps from the 4.3" Rock Compact. That same load from the 10" is like 2,700 fps. Normal SS198LF from the 10.4" is about 2,400 fps.. Ammo choice is fairly important in the pistol barrels Thank you for the detailed reply!  I was wondering how viable these new compact pistols were given the high velocity requirements of the cartridge, but it sounds like there are some viable loads now for the more compact 5.7s at least (such as the S4). |
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Originally Posted By DOG556: So as far as ammo. I only have FN ammo The FN Blue box 27g and blue box 40g. Are these good defensive rounds? I’m going to buy some of the FN Red Box ammo eventually. I’m probably going to catch flack for this but I’m of the opinion that FN SS197 is range ammo! The velocity doesn’t reach 1,700 fps! And quality control (at least in the past) SUCKED! It’s not cheap but either Elite Ammunition S4 or T7B is MUCH better and it is your life on the line. |
"When trading bullets it is better to give than to receive" _____________________
"People sleep peaceably in their beds at night only because rough men stand ready to do violence on their behalf." - George Orwell
"People sleep peaceably in their beds at night only because rough men stand ready to do violence on their behalf." - George Orwell
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Originally Posted By DOG556: So as far as ammo. I only have FN ammo The FN Blue box 27g and blue box 40g. Are these good defensive rounds? I'm going to buy some of the FN Red Box ammo eventually. https://www.recoilgunworks.com/fn-ss198lf-5-7x28-27gr-green-tip-hp-2-boxes-ship-free/?ref=4 The problem with Blue box SS195 and 198 is that ammo wasn't designed with FBI ballistics in mind. it won't reliably penetrate any deeper than 7-8" in gel. Whether you believe 2000 fps + is the magic number where temporary stretch cavity turns permanent or if it's 2,200 fps +  Has SS198LF 5.7x28mm Been Upgraded? When we shot it in pork years ago it seemingly made a wound cavity like .45 Ranger T  5.7x28mm SS198LF: Pork Shoulder Ballistics My recommendations have been; If you want pistol like wounding with an expanding round that will touch FBI min vs bare targets, go Hornady Black or any V-MAX that's loaded to at least 1800 fps. If you want deeper penetration and an ability to defeat the barriers 5.7 is known for, coupled with the velocities that it's supposed to have, you want something like Vanguard Outfitters Black Dragon Fang, or Elite Ammo's T6B.  5.7x28mm, 34gr PFP, Vampire Fang, Vanguard Outfitters |
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I'm taking the plunge and only becuase I've always been intrigued and Kel-Tec's (yeah, I know) new KP50 really piqued my interest as a PDW platform project. For me, these larger PDW platforms (like the P90, KP50 types) fill a unique niche application and 5.7x28mm serves a role that most conventional handgun cartridges can't compete with but also do so in much smaller, lighter form-factors than rifle-cartridge PDWs. For me, I don't love it or hate it (never owned one before), but I respect the concept and performance from the right ammunition used within its performance parameters. ROCK6 |
"The tree of liberty must be refreshed from time to time with the blood of patriots and tyrants" - Thomas Jefferson
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Originally Posted By DOG556: Doesn’t SS198LF Red Box go 2200fps? Buffman is being shy - here's his YouTube channel where he's tested about every 5.7 firearm & load on the market: https://www.youtube.com/@BuffRANGE |
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Originally Posted By backbencher: Buffman is being shy - here's his YouTube channel where he's tested about every 5.7 firearm & load on the market: https://www.youtube.com/@BuffRANGE Good stuff. I would be curious (can't find the specs) if the Kel-Tec KP50/MP50 is designed to handle the hotter stuff. The frame and receiver are not polymer and it says it's designed for military and law enforcement use (MP50). My assumption is that the KP50 is bullt to the same tolerances minus the selectfire capability and "should" be designed to handle those hotter loads. Hopefully more comes out in the aspect of what it can handle. I'll have some of the SS198LF stuff on hand by the time I receive my KP50, but since I'm paying out of my own pocket, I'm not too hip on doing destructive tests on it  ROCK6 |
"The tree of liberty must be refreshed from time to time with the blood of patriots and tyrants" - Thomas Jefferson
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Originally Posted By ROCK6: Good stuff. I would be curious (can't find the specs) if the Kel-Tec KP50/MP50 is designed to handle the hotter stuff. The frame and receiver are not polymer and it says it's designed for military and law enforcement use (MP50). My assumption is that the KP50 is bullt to the same tolerances minus the selectfire capability and "should" be designed to handle those hotter loads. Hopefully more comes out in the aspect of what it can handle. I'll have some of the SS198LF stuff on hand by the time I receive my KP50, but since I'm paying out of my own pocket, I'm not too hip on doing destructive tests on it ROCK6 |
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Originally Posted By Buffman_LT1: About 2,250 on a good day in the pistols with longer threaded barrels, and about 2,400 + in the P90/10+ barrels Yeah, I just purchased a few boxes of this stuff. I'll make sure the KP50 runs okay on the cheap shit first ROCK6 |
"The tree of liberty must be refreshed from time to time with the blood of patriots and tyrants" - Thomas Jefferson
I consider testing by the late great Paul Herrell as the definitive field test documentary: the meat target. FN FiveseveN vs The Meat Target I own: S&W 5.7 pistol Sub2k 5.7 Ruger Charger 5.7 |
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Originally Posted By ROCK6: Yeah, I just purchase a few boxes of this stuff. I'll make sure the KP50 runs okay on the cheap shit first ROCK6 Originally Posted By ROCK6: Originally Posted By Buffman_LT1: About 2,250 on a good day in the pistols with longer threaded barrels, and about 2,400 + in the P90/10+ barrels Yeah, I just purchase a few boxes of this stuff. I'll make sure the KP50 runs okay on the cheap shit first ROCK6 I'm very interested in the KP50 as well. Probably because I'm still hating myself for selling my CMR30. This is a great review if you haven't seen it already.  New KelTec Pistol Holds 101 Rounds of 5.7 |
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Originally Posted By SquatchAv8: @ROCK6 I'm very interested in the KP50 as well. Probably because I'm still hating myself for selling my CMR30. This is a great review if you haven't seen it already.  https://www.youtube.com/watch?v=W9NdlN768wkThanks! I'll watch it this evening. My KP50 is finally getting shipped and will likely pick it up Monday or Tuesday. I already have a half dozen mags loaded For the record, the Kel-Tec P90 mag loader is really simple, easy and fast. I can load a 50 round mag in just over a minute and no sore thumbs. I'm going to likely use a Griffin Armament taper-mounted suppressor as I have the short titanium tapered flash suppressor that will be used for mounting. ROCK6 |
"The tree of liberty must be refreshed from time to time with the blood of patriots and tyrants" - Thomas Jefferson
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Get a PS90, SBR it, suppress it, FRT it. Downsides- It’s tearing up my steel targets. I don’t get to use my fancy earpro. I load the 50 round mag, but when I pull the trigger and hold it till it stops, I swear it only shoots 20 rounds, but my mag is empty. Where did they go? $22.50 per long trigger pull bites. I still love it, it’s my truck gun. |
Diplomate, wikigoogle upstairs medical kindergarten
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Originally Posted By Snozberry: https://i.ibb.co/Txz90T8R/20260316-124826.jpg Need an FRT for the ruger  Attached File |
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Originally Posted By DOG556: I never knew of the KelTec KP50. Is it durable ? Because when I think of keltec I think of plastic garbage- & I hope I’m wrong. Is everything plastic in this gun minus the barrel and bolt? Waiting ….. Originally Posted By DOG556: I never knew of the KelTec KP50. Is it durable ? Because when I think of keltec I think of plastic garbage- & I hope I’m wrong. Is everything plastic in this gun minus the barrel and bolt? Waiting ….. I'm still waiting (slow shipping from Bud's for some reason) but should have hands on tomorrow or Tuesday. I'll be able to confirm this review below: KelTec also replaced much of the original gun’s polymer-heavy construction with a more substantial, metal-centric assembly. The company describes the KP50 as having a fully machined lower receiver and identifies the fire-control mechanism as its proven SU16 trigger group. It is not an AR-15 trigger system, although the replaceable B5 Systems pistol grip is familiar to anyone accustomed to an AR. KP50 feels considerably more solid than its futuristic appearance suggests. Nothing about the test gun felt flimsy or temporary. Yeah, yeah, I know. Kel-Tec is hit or miss on some designs; I'm crossing my fingers they got this one right as the concept is pretty intriguing. One of my pre-handling complaints is that they should have went with the more common AR15 FCU instead of their SU16 FCU. It's still not a bad FCU, but an AR FCU would open the aperture on better trigger or FRT upgrades. ROCK6 |
"The tree of liberty must be refreshed from time to time with the blood of patriots and tyrants" - Thomas Jefferson
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Originally Posted By ROCK6: I'm taking the plunge and only becuase I've always been intrigued and Kel-Tec's (yeah, I know) new KP50 really piqued my interest as a PDW platform project. https://tse2.mm.bing.net/th/id/OIP.V5w13BgAb1JpiHgnhEk65wHaDy?r=0&rs=1&pid=ImgDetMain&o=7&rm=3 For me, these larger PDW platforms (like the P90, KP50 types) fill a unique niche application and 5.7x28mm serves a role that most conventional handgun cartridges can't compete with but also do so in much smaller, lighter form-factors than rifle-cartridge PDWs. For me, I don't love it or hate it (never owned one before), but I respect the concept and performance from the right ammunition used within its performance parameters. ROCK6 Something like a CZ 61 Skorpion pattern in 5.7 would be pretty handy in that role. A bit better than the Skorpion’s .32 Browning. |
| Have two Ps90s one SBRd one not . Makes for an excellent weapon when considering it’s designed use of having an easier to shoot weapon for distances between carbine and pistol while not being as large as a conventional carbine. SBRd it’ll fit ready to use in most backpacks saddle bags on a motorcycle or the like. It’s not got 5.56 performance and isn’t intended to. It’s expensive to feed if your comparing it to 9mm ball compare quality ammo for it to quality ammo for your rifle or pcc and it’s on par. Pretty sure I’m running a design machine mount with a t1 on my 10”. |
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I used to own one of the early FN pistols. It was fun, interesting, but I just couldn't figure out a "need" or some kind of work for it that no other pistol could perform. If it was possible to buy some of the special "military or police" ammo for it, then there would be a need or some kind of work for it to do, but with the ammo that was available then, and with the price of that ammo, I traded the pistol off for something else. I don't have any special love or hate for the round, but without the really interesting AP ammo for it, and the cost of the ammo that is available I just couldn't figure out what it does that other guns I own can't do. |
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Originally Posted By ROCK6: I'm still waiting (slow shipping from Bud's for some reason) but should have hands on tomorrow or Tuesday. I'll be able to confirm this review below: Yeah, yeah, I know. Kel-Tec is hit or miss on some designs; I'm crossing my fingers they got this one right as the concept is pretty intriguing. One of my pre-handling complaints is that they should have went with the more common AR15 FCU instead of their SU16 FCU. It's still not a bad FCU, but an AR FCU would open the aperture on better trigger or FRT upgrades. ROCK6 I can’t blame them for not using an AR15 fire control group. There are dozens of aftermarket versions of those that may or may not be compatible with their design. By using their own proprietary FCU, they only have to worry about their own parts working in their gun. Plus, if they release a performance trigger, they get the money.
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| I gotta try some different ammo. Shooting FN 40gr blue tip I had several failures to eject. Now, it could be because the LC Charger has a heavy bolt and recoil spring due to being blowback, but I'd like to try new ammo anyway. It averaged 2,046FPS out of the LC Charger's 10.3" barrel. |