I would have to agree with Walkalong that Longshot is probably not an ideal powder for this caliber. From my experience using it for a different caliber (38 Super) it tends to only work well (complete burn) with heavier 158gr bullets out of my pistol, 100gr would not reach an adequate pressure for good burn and would hit a velocity plateau and leave unburnt powder in the barrel (just like your friend). Here's what QL estimated for a general idea for 5.6gr of Longshot:
5.7x28mm Trials (pic heavy)
- Thread starter Trent
- Start date
- Status
I don't know your exact measurements of everything(bullet length, fired case capacity 12.3?H2O, etc.), but this is what QL gives:
Code:
Cartridge : 5.7 x 28 FN
Bullet : .224, 40, Hornady V-MAX BT 22241
Useable Case Capaci: 10.052 grain H2O = 0.653 cm³
Cartridge O.A.L. L6: 1.586 inch = 40.28 mm
Barrel Length : 16.5 inch = 419.1 mm
Predicted Data for Indicated Charges of the Following Powders.
Matching Maximum Pressure: 48000 psi, or 330 MPa
or a maximum loading ratio or filling of 110 %
These calculations refer to your specified settings in QL 'Cartridge Dimensions' window.
C A U T I O N : any load listed can result in a powder charge that falls below minimum suggested
loads or exceeds maximum suggested loads as presented in current handloading manuals. Understand
that all of the listed powders can be unsuitable for the given combination of cartridge, bullet
and gun. Actual load order can vary, depending upon lot-to-lot powder and component variations.
USE ONLY FOR COMPARISON !
Powder type Filling/Loading Ratio Charge Charge Vel. Prop.Burnt P max P muzz B_Time
% Grains Gramm fps % psi psi ms
--------------------------------- -----------------------------------------------------------------
Ramshot Enforcer 99.4 9.4 0.61 2687 96.9 48000 4177 0.754 ! Near Maximum !
Alliant 2400 100.2 8.8 0.57 2682 96.1 48000 4184 0.755 ! Near Maximum !
Accurate 4100 102.0 9.8 0.63 2634 93.2 48000 4046 0.760 ! Near Maximum !
Alliant BLUE DOT 104.7 7.9 0.51 2633 99.6 48000 3788 0.758 ! Near Maximum !
Accurate No.7 79.9 8.0 0.52 2633 99.9 48000 3704 0.759 ! Near Maximum !
Accurate No.9 87.5 8.7 0.56 2627 97.7 48000 3876 0.759 ! Near Maximum !
Vihtavuori N105 104.3 7.6 0.49 2617 100.0 48000 3303 0.756 ! Near Maximum !
Alliant POWER PISTOL 86.6 6.4 0.41 2602 100.0 48000 3411 0.756 ! Near Maximum !
Vihtavuori 3N38 98.9 7.5 0.48 2565 100.0 48000 3293 0.766 ! Near Maximum !
Accurate No.5 65.3 6.8 0.44 2557 100.0 48000 3251 0.763 ! Near Maximum !
Accurate 5744 110.0 9.5 0.62 2506 78.9 43434 3962 0.797 ! Near Maximum !
Hodgdon HS-6 71.6 6.6 0.43 2438 100.0 48000 2722 0.782 ! Near Maximum !
Vihtavuori 3N37 87.6 6.3 0.41 2427 100.0 48000 2681 0.785 ! Near Maximum !
Alliant HERCO 99.9 5.8 0.38 2414 100.0 48000 2670 0.794 ! Near Maximum !
Hodgdon Longshot 68.2 6.4 0.41 2414 100.0 48000 2638 0.786 ! Near Maximum !
Ramshot True Blue 67.5 6.4 0.41 2411 100.0 48000 2626 0.787 ! Near Maximum !
Vihtavuori N350 90.8 6.1 0.40 2409 100.0 48000 2608 0.786 ! Near Maximum !
Winchester 540 66.5 6.4 0.41 2409 100.0 48000 2621 0.787 ! Near Maximum !
Alliant UNIQUE 89.4 5.3 0.35 2370 100.0 48000 2524 0.801 ! Near Maximum !
Alliant BULLSEYE 79.3 4.9 0.32 2369 100.0 48000 2551 0.793 ! Near Maximum !
Winchester WAP 73.2 5.9 0.38 2366 100.0 48000 2498 0.794 ! Near Maximum !
Ramshot Silhouette 72.9 5.9 0.38 2362 100.0 48000 2487 0.795 ! Near Maximum !
Vihtavuori N340 86.7 5.3 0.35 2297 100.0 48000 2273 0.808 ! Near Maximum !
Accurate No.2 64.6 5.0 0.32 2293 100.0 48000 2271 0.807 ! Near Maximum !
Hodgdon Universal 83.1 4.9 0.32 2254 100.0 48000 2214 0.827 ! Near Maximum !
Vihtavuori N330 82.1 5.0 0.32 2228 100.0 48000 2104 0.827 ! Near Maximum !
Accurate Solo 1250 88.9 4.9 0.32 2211 100.0 48000 2054 0.826 ! Near Maximum !
Winchester 231 71.5 5.0 0.32 2205 100.0 48000 2069 0.829 ! Near Maximum !
Ramshot Zip 63.8 5.0 0.32 2205 100.0 48000 2069 0.829 ! Near Maximum !
Hodgdon HP38 70.0 4.9 0.32 2191 100.0 48000 2035 0.832 ! Near Maximum !
Alliant GREEN DOT 88.0 4.5 0.29 2168 100.0 48000 2017 0.848 ! Near Maximum !
Vihtavuori N320 81.6 4.4 0.29 2134 100.0 48000 1889 0.849 ! Near Maximum !
Alliant RED DOT 90.2 4.2 0.27 2121 100.0 48000 1926 0.856 ! Near Maximum !
Hodgdon TiteGroup 59.8 4.5 0.29 2109 100.0 48000 1861 0.854 ! Near Maximum !
Vihtavuori N310 70.1 3.8 0.24 2000 100.0 48000 1628 0.886 ! Near Maximum !
Vihtavuori N32C Tin Star 110.0 5.1 0.33 1983 100.0 47131 1570 0.900 ! Near Maximum !
IMR TrailBoss 110.0 3.4 0.22 1593 100.0 21668 1155 1.196
Actually, that looks pretty damn good for what I want; a high velocity 40gr load for the 16" barrel.
That chart is pretty close to what velocity I hit in the 16" PS90 barrel. 5.6 gr was showing pressure signs on the primers (using the thin cup CCI 400's). The velocity is in the range of what I want. If I re-work the load with thicker primers (Federal, arsenal #44, or Remington 7 1/2) the primers should stand up to a little more pressure without blowing out.
The downside is the arsenal #44 and remington 7 1/2 primers are a bit hotter so the pressure curve will hit more rapidly. That *might* make the load a bit more suitable to the pistol (with a slightly reduced powder charge), as it'll ignite the powder more rapidly. The idea of using magnum primers is not about igniting a big charge fully, but rather, getting the burn going more rapidly on a smaller charge. That should get it scooting right along in a shorter barrel.
I have to conjecture here but I believe the load that popped that primer was in the 5.8 or range, or .2 higher than the RCBS 1500 scale indicated. That's the most I've ever measured the RCBS 1500 being off. It happens when you trickle powder slowly in to the pan. The scale tries to average out and "hold" the current weight. The noise reduction algorithm they have in the scale works against you if you don't drop powder fast, makes it less accurate than it really is, without the programming "help" they gave it.
The only way to get it back to a true reading is to empty the pan, hit zero, and then re-weigh. (This is where I've found charges .2gr off from previous reading. simply removing the pan and re-seating it *sometimes* works but only if it's .1 gr off. If it's .2 gr off I've found you have to re-zero the machine to get it back to normal).
The chart from Quickload show really backs up the burn rate of Longshot being more ideal for the PS90 rifle than the FiveSeven pistol. (For the same reason you were finding it wasn't ideal for 38 super; too short of barrel.)
I'll keep experimenting in it with the PS90, go through the primer combinations, and see if I can get the spread down. The powder is fully burning in the 16" barrel, so now it's just a matter of getting the right amount of flame on it to even it out. (Not the first time I've fought a velocity problem with CCI #400 - I stopped using them on 223 a couple years ago for the same reason as I couldn't get Varget to ignite good and even with them. Remington 7 1/2 did it much better / more reliably.)
Dunno. The whole point of the scientific method is to postulate and prove (or not). I've postulated. Now we get to see what the test shows. As always failure is an option.
Higgite; one of many questions I hope to answer in this thread.
I'm keeping all brass sorted by individual lot of 5, to determine if "soft loaded" brass outlasts "hot loaded" brass, etc; I'll know the full "history" of every piece of brass as it goes from one generation to the next.
The risk is if I can't detect when brass is ready to let go.. will the gun blow up?
These things don't fail gracefully, when they fail. I have yet to see a "nice" kaboom on an FN PS90 or FiveSeven. 50,000 PSI vs. Plastic, plastic don't win.
I'm keeping all brass sorted by individual lot of 5, to determine if "soft loaded" brass outlasts "hot loaded" brass, etc; I'll know the full "history" of every piece of brass as it goes from one generation to the next.
The risk is if I can't detect when brass is ready to let go.. will the gun blow up?
These things don't fail gracefully, when they fail. I have yet to see a "nice" kaboom on an FN PS90 or FiveSeven. 50,000 PSI vs. Plastic, plastic don't win.
Here is the same variables except for 5 inch barrel:
Herco and Unique (flake powders) may have better case fill than Longshot, HS-6, and True Blue (ball powders). They may also ignite better without the use of magnum primers, but that may not be an issue. The ball type powders are definitely a better choice if you plan on using a progressive press. One thing to keep in mind when looking at these charts is the "P muzz psi" can be an indicator as to how loud the cartridge loading will be, just use Power Pistol as a reference. These types of threads are very interesting, hopefully these charts aid you in your experimentation. Great work, stay safe
Code:
Cartridge : 5.7 x 28 FN
Bullet : .224, 40, Hornady V-MAX BT 22241
Useable Case Capaci: 10.052 grain H2O = 0.653 cm³
Cartridge O.A.L. L6: 1.586 inch = 40.28 mm
Barrel Length : 5.0 inch = 127.0 mm
Predicted Data for Indicated Charges of the Following Powders.
Matching Maximum Pressure: 48000 psi, or 330 MPa
or a maximum loading ratio or filling of 102 %
USE ONLY FOR COMPARISON !
Powder type Filling/Loading Ratio Charge Charge Vel. Prop.Burnt P max P muzz B_Time
% Grains Gramm fps % psi psi ms
--------------------------------- -----------------------------------------------------------------
Ramshot Enforcer 99.4 9.4 0.61 2007 84.5 48000 16114 0.358 ! Near Maximum !
Alliant 2400 100.2 8.8 0.57 2003 83.5 48000 16023 0.358 ! Near Maximum !
Alliant POWER PISTOL 86.6 6.4 0.41 2000 98.7 48000 14808 0.353 ! Near Maximum !
Accurate No.7 79.9 8.0 0.52 1996 92.5 48000 15360 0.358 ! Near Maximum !
Accurate No.9 87.5 8.7 0.56 1980 86.7 48000 15149 0.356 ! Near Maximum !
Vihtavuori N105 102.0 7.4 0.48 1974 97.6 44992 14866 0.367 ! Near Maximum !
Accurate 4100 102.0 9.8 0.63 1974 79.5 48000 15226 0.356 ! Near Maximum !
Vihtavuori 3N38 98.9 7.5 0.48 1972 95.5 48000 14349 0.356 ! Near Maximum !
Accurate No.5 65.3 6.8 0.44 1971 97.7 48000 14159 0.353 ! Near Maximum !
Alliant BLUE DOT 102.0 7.7 0.50 1939 90.4 44900 14787 0.369 ! Near Maximum !
Hodgdon HS-6 71.6 6.6 0.43 1922 100.0 48000 12335 0.355 ! Near Maximum !
Vihtavuori 3N37 87.6 6.3 0.41 1920 100.0 48000 12082 0.356 ! Near Maximum !
Vihtavuori N350 90.8 6.1 0.40 1912 100.0 48000 11788 0.354 ! Near Maximum !
Hodgdon Longshot 68.2 6.4 0.41 1911 100.0 48000 11922 0.355 ! Near Maximum !
Ramshot True Blue 67.5 6.4 0.41 1909 100.0 48000 11870 0.355 ! Near Maximum !
Alliant HERCO 99.9 5.8 0.38 1909 100.0 48000 11880 0.363 ! Near Maximum !
Winchester 540 66.5 6.4 0.41 1908 100.0 48000 11846 0.355 ! Near Maximum !
Winchester WAP 73.2 5.9 0.38 1884 100.0 48000 11141 0.355 ! Near Maximum !
Alliant UNIQUE 89.4 5.3 0.35 1884 100.0 48000 11227 0.362 ! Near Maximum !
Alliant BULLSEYE 79.3 4.9 0.32 1883 100.0 48000 11110 0.354 ! Near Maximum !
Ramshot Silhouette 72.9 5.9 0.38 1882 100.0 48000 11091 0.355 ! Near Maximum !
Vihtavuori N340 86.7 5.3 0.35 1845 100.0 48000 10253 0.358 ! Near Maximum !
Accurate No.2 64.6 5.0 0.32 1843 100.0 48000 10188 0.356 ! Near Maximum !
Hodgdon Universal 83.1 4.9 0.32 1808 100.0 48000 9820 0.367 ! Near Maximum !
Vihtavuori N330 82.1 5.0 0.32 1799 100.0 48000 9448 0.363 ! Near Maximum !
Accurate Solo 1250 88.9 4.9 0.32 1789 100.0 48000 9234 0.359 ! Near Maximum !
Winchester 231 71.5 5.0 0.32 1780 100.0 48000 9195 0.360 ! Near Maximum !
Ramshot Zip 63.8 5.0 0.32 1780 100.0 48000 9195 0.360 ! Near Maximum !
Hodgdon HP38 70.0 4.9 0.32 1771 100.0 48000 9052 0.361 ! Near Maximum !
Alliant GREEN DOT 88.0 4.5 0.29 1748 100.0 48000 8892 0.371 ! Near Maximum !
Vihtavuori N320 81.6 4.4 0.29 1732 100.0 48000 8471 0.366 ! Near Maximum !
Alliant RED DOT 90.2 4.2 0.27 1712 100.0 48000 8422 0.368 ! Near Maximum !
Accurate 5744 102.0 8.8 0.57 1692 59.7 34499 11852 0.415
Vihtavuori N310 70.1 3.8 0.24 1632 100.0 48000 7259 0.371 ! Near Maximum !
Vihtavuori N32C Tin Star 102.0 4.7 0.31 1550 100.0 41009 6663 0.408
IMR TrailBoss 102.0 3.2 0.21 1203 100.0 19098 4776 0.577Herco and Unique (flake powders) may have better case fill than Longshot, HS-6, and True Blue (ball powders). They may also ignite better without the use of magnum primers, but that may not be an issue. The ball type powders are definitely a better choice if you plan on using a progressive press. One thing to keep in mind when looking at these charts is the "P muzz psi" can be an indicator as to how loud the cartridge loading will be, just use Power Pistol as a reference
. These types of threads are very interesting, hopefully these charts aid you in your experimentation. Great work, stay safe "The first thing to pay attention to is that the 5.7x28mm platforms are are blow-back operation. To facilitate this mechanism the cases are coated in a super-ultra-mega-secret-concoction of dry film lubricant. (Many attempts have been made to duplicate this coating and no one has been able to successfully do so, to the best of my knowledge.)"
Hmm, wonder if nickel plating would work?
Hmm, wonder if nickel plating would work?
ClickClickD'oh
Member
Trent said:
Yes, they are blowback operated and run off the AR-15 buffer. Mine uses the same spring and buffer that I use for my other SBR uppers in 5.56.
They are good guns once you get the hang of mag switching.
Conservidave
Member
- Joined
- Apr 16, 2013
- Messages
- 367
Trent, i have 60 pieces of the 5.7X28 brass if you need extra for experimenting.
Well, there you go. You must scrap them before they do. When is that? The guys on the fiveseven forum have some insight on that.
Before I read about not tumbling, I did, but I never had any feeding problems in the AR57, using the same mags as the PS90.
I have some brass I could donate to the cause. I'll have to check to see if it is all tumbled, but I think I have some I never did anything with, I think. I'll check.
You want bullets with a long full diameter section for good neck tension. Sort of like .357 Sig. (Not like the 50 Gr TNT. *Sigh*)
http://www.fivesevenforum.com/viewtopic.php?f=19&t=2054
Last edited:
Conservidave - thanks for the offer, but I've got about 5,500 once fired casings here, I won't run short on 1x anytime soon!
Walkalong - my major concern is separation at the shoulder, since it's pushed around so much. The concern there is if it separates as the case is stretching on firing, it's going to release the tail end of that brass in to the action at ~40-50,000 psi, with all the accompanying nastiness associated with a rupture.
If that happens, bad news. Even if it's not an overcharge that causes the rupture that's still a lot of high pressure gas to vent and the FN platforms aren't designed to vent well. I've heard of guys removing the loaded chamber indicator on the FiveSeven to create a vent hole for testing (to give gas SOMEWHERE to flow out of). Really nothing you can do that's similar on the PS90 rifle, though.
Fortunately on the PS90 there's a great big opening above and below the action (mag well hole, and the huge ejection port). But even so, if a round ruptures there's no guarantees things will go smoothly. I've only seen pictures online of one PS90 blown up; was a from a new reloader that had a double charge. The receiver of the PS90 came apart violently (3 people were injured, if the story behind it was accurate).
I may seem paranoid to everyone, for doing test loads with body armor draped over the rifle, but I'm not taking chances with my face being that close to the breech, and nothing between it except a relatively thin layer of polymer receiver.
My goal is to find all "safe" loads for my rifle and then do accuracy testing to settle on something that works well for the rifle, focusing on the 40gr projectile. I just want to see what the true potential is. I still haven't broke my high power range record last year that I set with the PS90, even when I mounted a dang scope on my SCAR17... which is both irritating and fascinating.
The SS195 round was incredibly accurate (especially out of the pistol) but it's gone for good, and that round was a bit light for longer range stuff (wind + 28 gr projectile = all kinds of suck at 200 yards...). The American Eagle stuff is very accurate and reasonably consistent velocities, but I've had some scary feed issues with it setting back bullets. SS197 sucks, at longer ranges, due to the velocity spread it strings out.
So, I'm trying to "build a better SS197". I'm sure the V-Max bullets will be fine (I've used them in 22-250 before), the trick will be getting a highly consistent velocity.
Walkalong - my major concern is separation at the shoulder, since it's pushed around so much. The concern there is if it separates as the case is stretching on firing, it's going to release the tail end of that brass in to the action at ~40-50,000 psi, with all the accompanying nastiness associated with a rupture.
If that happens, bad news. Even if it's not an overcharge that causes the rupture that's still a lot of high pressure gas to vent and the FN platforms aren't designed to vent well. I've heard of guys removing the loaded chamber indicator on the FiveSeven to create a vent hole for testing (to give gas SOMEWHERE to flow out of). Really nothing you can do that's similar on the PS90 rifle, though.
Fortunately on the PS90 there's a great big opening above and below the action (mag well hole, and the huge ejection port). But even so, if a round ruptures there's no guarantees things will go smoothly. I've only seen pictures online of one PS90 blown up; was a from a new reloader that had a double charge. The receiver of the PS90 came apart violently (3 people were injured, if the story behind it was accurate).
I may seem paranoid to everyone, for doing test loads with body armor draped over the rifle, but I'm not taking chances with my face being that close to the breech, and nothing between it except a relatively thin layer of polymer receiver.
My goal is to find all "safe" loads for my rifle and then do accuracy testing to settle on something that works well for the rifle, focusing on the 40gr projectile. I just want to see what the true potential is. I still haven't broke my high power range record last year that I set with the PS90, even when I mounted a dang scope on my SCAR17... which is both irritating and fascinating.
The SS195 round was incredibly accurate (especially out of the pistol) but it's gone for good, and that round was a bit light for longer range stuff (wind + 28 gr projectile = all kinds of suck at 200 yards...). The American Eagle stuff is very accurate and reasonably consistent velocities, but I've had some scary feed issues with it setting back bullets. SS197 sucks, at longer ranges, due to the velocity spread it strings out.
So, I'm trying to "build a better SS197". I'm sure the V-Max bullets will be fine (I've used them in 22-250 before), the trick will be getting a highly consistent velocity.
Torian, correct.
There is one other ulterior motive here. There's so much bad publicity out there regarding 5.7x28mm platform kabooms and reloading this little round, that I want to see (personally) if it can be safely done. I've let myself be dissuaded from reloading it for 5 years now - I bought the dies back in 2008... just never used them.
I got to thinking the other night and if I let every kaboom I've seen on the Internet dissuade me from reloading that cartridge, I wouldn't be reloading for AR's, Glocks, etc. But I've loaded tens of thousands of rounds for both without issue.
Yes, it's a little different, but after doing my homework I feel it can be done safely, if done carefully. We'll find out. Since I'm doing this "in the public eye" and everything is heavily documented, if something DOES go wrong, we'll all know where and why.
I'm a long way from being confident enough to do this stuff on a progressive press. After 500 or 1000 rounds? Who knows. Maybe I'll be spitting these little buggers off my Dillon press at the rate of 1,000 an evening.
There is one other ulterior motive here. There's so much bad publicity out there regarding 5.7x28mm platform kabooms and reloading this little round, that I want to see (personally) if it can be safely done. I've let myself be dissuaded from reloading it for 5 years now - I bought the dies back in 2008... just never used them.
I got to thinking the other night and if I let every kaboom I've seen on the Internet dissuade me from reloading that cartridge, I wouldn't be reloading for AR's, Glocks, etc. But I've loaded tens of thousands of rounds for both without issue.
Yes, it's a little different, but after doing my homework I feel it can be done safely, if done carefully. We'll find out. Since I'm doing this "in the public eye" and everything is heavily documented, if something DOES go wrong, we'll all know where and why.
I'm a long way from being confident enough to do this stuff on a progressive press. After 500 or 1000 rounds? Who knows. Maybe I'll be spitting these little buggers off my Dillon press at the rate of 1,000 an evening.
It can be loaded safely, you just have to scrap the brass before it fails at the shoulder. When is the $60 question. I just got bored with it in an AR type rifle. It would be really cool in a Contender, and you would not have the shoulder issues. It would load like any other bottle necked cartridge.
Yeah in a bolt action, or a gas operated locked breech design, it would be fine. No worries about the film lubricant, etc.
Maybe, at some point, another designer will adapt it to a gas operated / locked bolt design, or at least a true locked-breech design (in the handgun; e.g. browning). The only thing that makes this round so difficult is it's blowback operation. Remove that from the equation and it is a game-changer; easier to reload for, less stressful on the case, and FAR safer.
I'm not sure if it is possible though. The cartridge case is miniscule, you can only put so much powder in, and finding the right port pressure for a gas operated / locked bolt design without sacrificing velocity on the gas bleed off would be far more difficult than say, a 223.
(It would also take a great deal of testing equipment which I don't have any desire to build or fund...)
Anyway we'll leave that for firearms designers. I just want to build a really good rifle load for it.
Maybe, at some point, another designer will adapt it to a gas operated / locked bolt design, or at least a true locked-breech design (in the handgun; e.g. browning). The only thing that makes this round so difficult is it's blowback operation. Remove that from the equation and it is a game-changer; easier to reload for, less stressful on the case, and FAR safer.
I'm not sure if it is possible though. The cartridge case is miniscule, you can only put so much powder in, and finding the right port pressure for a gas operated / locked bolt design without sacrificing velocity on the gas bleed off would be far more difficult than say, a 223.
(It would also take a great deal of testing equipment which I don't have any desire to build or fund...)
Anyway we'll leave that for firearms designers. I just want to build a really good rifle load for it.
Also, going back to my popped primer on the 5.6gr tests yesterday...
If I were a betting man, I would think that round would probably be safe, on a pressure level for the rifle. FN Herstal Fiocci and American Eagle ammunition does far worst things to primers. But those are epoxied and crimped in at the factory.
I'll try to take some precise measurements of that case, compared the other 4 fired from that string, to see if the primer pocket or head expanded at all. As mentioned before, based on the velocity of that round, I think that powder charge was probably 5.8gr in weight, so we know the max load of Longshot in the PS90 that can be used with CCI400 without doing something extra to secure the primer, is 5.6 or 5.7gr.
I wouldn't want to pop out primers on a regular basis, hot gasses do bad things to bolt faces (that thing was a real treat to clean.) Once reamed there's no real easy way to re-crimp the pocket. I've read of people using loctite to secure primers in 5.7x28mm. But I'm not sure if I'm ready to go there. The velocity I got from the 5.5gr load was adequate for what I'm looking for; no need to push things to the brink (except to find out where "the brink" actually is.)
Anyway, until the weather clears and I get more testing done, this thread will rest for a few days.
Stay warm!
Revised recommendation for Longshot w/ 40 grain Hornaday V-Max in the PS90 using CCI #400 primers:
Starting load 4.9, max load 5.6gr. Proceed with caution in .1 increments.
Other notes; don't use an electronic scale. Use a beam scale - gravity don't lie. Also, don't dump by volume if you are close to max load. I measured differences of - .1 to +.3 in my Lyman powder dispenser last night, running new batches to get touched off by Remington 7 1/2 primers. That Lyman dispenser is the most accurate (consistent) one I have available; longshot just isn't consistent enough to dump by weight if you are close to max load.
If I were a betting man, I would think that round would probably be safe, on a pressure level for the rifle. FN Herstal Fiocci and American Eagle ammunition does far worst things to primers. But those are epoxied and crimped in at the factory.
I'll try to take some precise measurements of that case, compared the other 4 fired from that string, to see if the primer pocket or head expanded at all. As mentioned before, based on the velocity of that round, I think that powder charge was probably 5.8gr in weight, so we know the max load of Longshot in the PS90 that can be used with CCI400 without doing something extra to secure the primer, is 5.6 or 5.7gr.
I wouldn't want to pop out primers on a regular basis, hot gasses do bad things to bolt faces (that thing was a real treat to clean.) Once reamed there's no real easy way to re-crimp the pocket. I've read of people using loctite to secure primers in 5.7x28mm. But I'm not sure if I'm ready to go there. The velocity I got from the 5.5gr load was adequate for what I'm looking for; no need to push things to the brink (except to find out where "the brink" actually is.)
Anyway, until the weather clears and I get more testing done, this thread will rest for a few days.
Stay warm!
Revised recommendation for Longshot w/ 40 grain Hornaday V-Max in the PS90 using CCI #400 primers:
Starting load 4.9, max load 5.6gr. Proceed with caution in .1 increments.
Other notes; don't use an electronic scale. Use a beam scale - gravity don't lie. Also, don't dump by volume if you are close to max load. I measured differences of - .1 to +.3 in my Lyman powder dispenser last night, running new batches to get touched off by Remington 7 1/2 primers. That Lyman dispenser is the most accurate (consistent) one I have available; longshot just isn't consistent enough to dump by weight if you are close to max load.
Probably not, since the dawn of the cartridge era highpower blowback mechanisms have required active lubrication.
This was written in the 1950's:
The shooting community has totally forgotten the myriad of mechanisms that used oilers and greased ammunition. I was surprised to find that Mauser's semi auto matic rifle required greased 8 mm ammunition. Chin's book shows these mechanisms as examples of oilers:
I don't understand why FN did not use chamber flutes
Instead they use a dry lubricant to make the mechanism work, and while nickel will reduce case to chamber friction, I am confident it does not reduce it enough to prevent case separations.
I don't see a reason why you can't leave case lube on the sized cases. I have done this on 30-06 cases when I don't have the time to wipe on Johnson Paste wax. I took one set of 308 cases 22 + reloads in a M1a, I left the cases lubed, most of the time I used Johnson paste wax as I prefer a dry lube. Case lube is an excellent lubricant but it attracts dirt.
Curious question that raise. Are chamber flutes patented by H&K?
This round might be pretty fantastic out of an MP5 type firearm.
On to the nickel question; no, I've actually loaded nickel plated brass cases to the point they'll seize up an AR-15 from expansion. Nickle makes feeding and extraction a little easier, but not by as much of a margin as this dry film lube does. These cases are "slick" to the touch, VERY easy to drop when you're trying to handle them individually. (Much to my digress, when I drop a case, it always lands on the damn mouth on the concrete floor and have to get the expander run through again to round them out.)
This round might be pretty fantastic out of an MP5 type firearm.
On to the nickel question; no, I've actually loaded nickel plated brass cases to the point they'll seize up an AR-15 from expansion. Nickle makes feeding and extraction a little easier, but not by as much of a margin as this dry film lube does. These cases are "slick" to the touch, VERY easy to drop when you're trying to handle them individually. (Much to my digress, when I drop a case, it always lands on the damn mouth on the concrete floor and have to get the expander run through again to round them out.)
Since the Germans stole the idea from the Russians, I don't see it would be patented. But I am no patent attorney and it seems that the Government is handing out too many patent monopolies for all sorts of things, so who knows?
XTRAXN has this unique spiral, and shallow, chamber flutes in their AR15 rifles. Maybe this type of flute is patented.
Well, at the request of Walkalong, I worked up 6 rounds at 5.6 gr Longshot today, using CCI 400 primers, pushing a 40gr V-Max.
Coincidentally, after firing the first round I got a first-hand look at the terminal performance of the 5.7x28mm cartridge, and I put the bullet straight through my pro-chrono digital Chronograph. The bullet struck center-right 1/2 inch from the top, skipped off the top cover while fragmenting violently, taking out all lenses / glass, blowing a dime sized hole through the ribbon cable, and exiting the rear of the chronograph leaving a little "exit wound." (There was an immense amount of lead splatter inside the body as well, tiny little jacket fragments and lead fragments everywhere. When these rounds hit something they come apart quite violently.)
:banghead::banghead::banghead::banghead::banghead::banghead:
I recovered a lot of jacket fragments inside the chronograph, will post up pictures later. (Going to try to repair it... too).
I fired 6 rounds, observing pressure signs at 5.6gr longshot (which was measured on a beam scale and "dead on" weight).
I fired the first two rounds "level", the second two rounds "powder forward" (dropping the rifle muzzle straight down, then raising slowly to level to fire), then the last two rounds "powder back" (opposite, muzzle up then slowly lower to fire).
The first four rounds looked identical. At 5.6 grains there is a light extractor mark on the case head which wasn't present at 5.5gr. The cases didn't expand at the web more than any others I've fired, nor did they grow to the shoulder any more than the others did (I measured between .03-.06 growth).
The LAST two rounds ("powder back") were remarkably different from the first four I fired. There is a heavy ejector mark on them, and the recoil and noise was substantially louder.
Four of six rounds fired showed a bright ring about .1" behind the shoulder. Using a pointed "feeler" I could feel a slight depression in the brass. I believe that if I go much higher on this load (5.8 gr, or so), it will run the risk of causing a seperation of the case at the shoulder.
I'm a little hesitant to push on further until I get a chronograph working again. I know that at 2339 fps I had a primer blowout, and I need to find the exact load that takes it up to that level, but without a working chronograph I'm kind of wary of experimenting.
Will take some "after action" photos of the chrono and brass after dinner and post up.
Coincidentally, after firing the first round I got a first-hand look at the terminal performance of the 5.7x28mm cartridge, and I put the bullet straight through my pro-chrono digital Chronograph. The bullet struck center-right 1/2 inch from the top, skipped off the top cover while fragmenting violently, taking out all lenses / glass, blowing a dime sized hole through the ribbon cable, and exiting the rear of the chronograph leaving a little "exit wound." (There was an immense amount of lead splatter inside the body as well, tiny little jacket fragments and lead fragments everywhere. When these rounds hit something they come apart quite violently.)
:banghead::banghead::banghead::banghead::banghead::banghead:
I recovered a lot of jacket fragments inside the chronograph, will post up pictures later. (Going to try to repair it... too).
I fired 6 rounds, observing pressure signs at 5.6gr longshot (which was measured on a beam scale and "dead on" weight).
I fired the first two rounds "level", the second two rounds "powder forward" (dropping the rifle muzzle straight down, then raising slowly to level to fire), then the last two rounds "powder back" (opposite, muzzle up then slowly lower to fire).
The first four rounds looked identical. At 5.6 grains there is a light extractor mark on the case head which wasn't present at 5.5gr. The cases didn't expand at the web more than any others I've fired, nor did they grow to the shoulder any more than the others did (I measured between .03-.06 growth).
The LAST two rounds ("powder back") were remarkably different from the first four I fired. There is a heavy ejector mark on them, and the recoil and noise was substantially louder.
Four of six rounds fired showed a bright ring about .1" behind the shoulder. Using a pointed "feeler" I could feel a slight depression in the brass. I believe that if I go much higher on this load (5.8 gr, or so), it will run the risk of causing a seperation of the case at the shoulder.
I'm a little hesitant to push on further until I get a chronograph working again. I know that at 2339 fps I had a primer blowout, and I need to find the exact load that takes it up to that level, but without a working chronograph I'm kind of wary of experimenting.
Will take some "after action" photos of the chrono and brass after dinner and post up.
Last edited:
Mr.Revolverguy
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Kudos very well done and very informative. I have a set of brand new hornady dies for this caliber and once fired cases by me which I have not done anything with in 2 years for all the reasons you point out here.
Great Job and thank you for all that you are putting into this very much appreciated.
Great Job and thank you for all that you are putting into this very much appreciated.
Mr. Revolverguy; hopefully as time goes on I can dispel (or confirm?) some of the Internet hysteria around the danger of reloading this cartridge.
For now, let us have a moment of silence to mourn the loss of my 12 year old digital chronograph.
Humpty Dumpty isn't going back together easily, and it'll take more than a little duct tape to repair it.
Entrance wound.
Back of front faceplate:
Ricochet damage to front aperture (unfortunately, the round didn't cleanly exit, it stayed inside.. sigh.)
Focus of top cover starting at ricochet point
Focus of top cover on center post. (Look at the fragmentation path...jeesh.)
I couldn't have hit that ribbon cable more center if I tried..
Front face of rear cover; note the jacket and lead fragments embedded in it.
Rear face of rear cover
Exit wound.
Lead and copper fragments inside the body:
(That's actually the rear half of the copper jacket; I also found pieces of copper jacket that were tiny pin-head sized. It literally detonated when it ricocheted off the top of the case)
For now, let us have a moment of silence to mourn the loss of my 12 year old digital chronograph.
Humpty Dumpty isn't going back together easily, and it'll take more than a little duct tape to repair it.
Entrance wound.
Back of front faceplate:
Ricochet damage to front aperture (unfortunately, the round didn't cleanly exit, it stayed inside.. sigh.)
Focus of top cover starting at ricochet point
Focus of top cover on center post. (Look at the fragmentation path...jeesh.)
I couldn't have hit that ribbon cable more center if I tried..
Front face of rear cover; note the jacket and lead fragments embedded in it.
Rear face of rear cover
Exit wound.
Lead and copper fragments inside the body:
(That's actually the rear half of the copper jacket; I also found pieces of copper jacket that were tiny pin-head sized. It literally detonated when it ricocheted off the top of the case)
HAHA! this takes a little sting out of that incident.
They'll replace / repair any chronograph, regardless of condition, for no more than 1/2 the current retail cost. THAT is AWESOME!
The circuit boards in mine are fine; I can repair the ribbon cable. But the lenses are shot. (Haha, literally.)
Well, looks like I'll box it up and send it in to see what it'll cost.
"If any product returned by the purchaser is found by COMPETITION ELECTRONICS, INC., to require service not covered by warranty, COMPETITION ELECTRONICS, INC., will so advise the purchaser and request further instructions. COMPETITION ELECTRONICS, INC., will recondition to working order any product returned to us regardless of condition upon the purchaser’s remittance of payment ½ current retail price, if it is still manufactured by COMPETITION ELECTRONICS, INC."
They'll replace / repair any chronograph, regardless of condition, for no more than 1/2 the current retail cost. THAT is AWESOME!
The circuit boards in mine are fine; I can repair the ribbon cable. But the lenses are shot. (Haha, literally.)
Well, looks like I'll box it up and send it in to see what it'll cost.
"If any product returned by the purchaser is found by COMPETITION ELECTRONICS, INC., to require service not covered by warranty, COMPETITION ELECTRONICS, INC., will so advise the purchaser and request further instructions. COMPETITION ELECTRONICS, INC., will recondition to working order any product returned to us regardless of condition upon the purchaser’s remittance of payment ½ current retail price, if it is still manufactured by COMPETITION ELECTRONICS, INC."
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