Sallinen Posted January 23, 2012 Report Share Posted January 23, 2012 Didnt find a topic dedicated to this, so I made a new one. So, is there anybody out there who doesnt use hop up when using a sniper rifle? I currently have a ongoing sniper project and the regular hopup is awful and fabricating a new one will be either tough or pricey. So I thought I'd give this a try and try setting my gun to shoot .40 BBs at 140-150 m/ps with a easily "calculatable" trajectory without a hopup, no spin at all. Then just shoot and shoot on head sized targets until its grown a habit on me. Some low magnification scope with a good crosshair to estimate distances would be on shopping list also. The max distance of engagement as my goal would be no farther than 60 meters, but with spot-on accuracy and silent weapon. Minimum engagement distance would be 20 meters. One thing to adjust the trajectory would be the different centering of the inner barrel, ie. turn it a bit up and get a more real gun like trajectory. Any ideas and suggestions are welcome. Link to post Share on other sites
LordElpus Posted January 23, 2012 Report Share Posted January 23, 2012 Can't say ihave done any research into hopup function, but i was under the impression that it's the spin that gives the BB the ability to go passed 20m. Link to post Share on other sites
Sallinen Posted January 23, 2012 Author Report Share Posted January 23, 2012 Yes, but this can be compensated with moving the gun, like real firearm is when shooting at longer range. One problem though could be that the gun could require excessive angle to shoot any longer than 40 meters and that the sights viewrange wouldnt be enough to show the target at any longer range. Link to post Share on other sites
j33v3s Posted January 23, 2012 Report Share Posted January 23, 2012 Without hop your spherical bb is just going to flop to the ground before it's of any use. Think someone with a cheap springer... In fact, I have a no hop "revolver" springer. Standing about 10ft from another person standing still, only one of the 6 shots hit him. Link to post Share on other sites
farrasdevell Posted January 23, 2012 Report Share Posted January 23, 2012 what is your base rifle? any hop is better than non. pictures are also helpful Link to post Share on other sites
Dagonet Posted January 23, 2012 Report Share Posted January 23, 2012 It's doable but the angle of aim will not be practical, and range will be an issue. I used to shoot crossbow in 3D field and set range FITA target. The trajectory of a crossbow arrow is very curved indeed at the power levels for Target use. I had a Horten hunter, nice thumbhole stock, draw length and prod weight came in just under Target limits, i used a custom made multi pin sight with a fixed peep rear. Scopes are not permitted in Target shooting. Now the interesting bit. The Horten had a rear scope rail/mount that had a dial-able tilt to over come the limits of Scope not being able to cope with the flight path/trajectory. You just alter angle of tilt for desired range. It may be possible to create you own adjustable scope mount. It would be a lot of work, and may not work. Many would say just save up and get a VSR, or try to make your own hop work better. You haven't mentioned what rifle you are using. Link to post Share on other sites
Sallinen Posted January 23, 2012 Author Report Share Posted January 23, 2012 Well, my base rifle is what I havent found out yet either Bell or Tanaka M700, which was sold to me as a KJW I have had a VSR and it isnt going to serve the purpose of the rifle Im going to build. I am building a bullpup sniper rifle with the said base gun as the way to propel the BB. I have thought about ordering a M16 hop up chamber with R-hop if the guy is willing to do one for me. The gun will be used on HPA so the cooldown is no issue. The gun would use MP7 short mags. I already have everything needed but hop-up is still a question. One possibility would be to center the barrel to imitate LRB effect... Link to post Share on other sites
farrasdevell Posted January 23, 2012 Report Share Posted January 23, 2012 any sketches? I just cant see it in my head. Link to post Share on other sites
The Bushman Posted January 24, 2012 Report Share Posted January 24, 2012 I saw a guy once who had a high powered bolt action APS (original) with no hop up. It could not even shoot to the edge of the MED. He was gutted. HOP UP is essential if you want range. Good Hunting Link to post Share on other sites
LordElpus Posted January 24, 2012 Report Share Posted January 24, 2012 Isn't the KJW a clone of the Tanaka? Link to post Share on other sites
Leshy Posted January 24, 2012 Report Share Posted January 24, 2012 G&g make a hop unit for the m700 $20. If thats of help ehobby, tmc or airsoft global should stock it. Link to post Share on other sites
Sallinen Posted January 24, 2012 Author Report Share Posted January 24, 2012 As I'm not much of a sketch artist, I decided that a photo could tell more than I can. What I do tend to take its final form during the process of making it. In this picture I have attached what I have thought as the base "skeleton"´with base "features" I might use the front end of the M700 stock all the way from front end to the area of magazine. As I have a spare G3 trigger lying around, I'll be using it. White line marks the end of the barrel. Red box marks the BB channel, The M700 mag will be shallowed to 1 BB per row. Yellow box marks the 6mm hose for HPA, the final position may differ. Does the amount of backspin affect the accuracy? As I have lived under thought that hop-up effectively messes up with the accuracy. E: the goal for this gun would be lightweight, small size, decent accuracy, moderate power and silent weapon to be used a few times during Berget 10. Materials for the stock would be Plywood and possibly fibreglass. Link to post Share on other sites
loza_here Posted January 24, 2012 Report Share Posted January 24, 2012 HI, first of all its not really a bullpup design as the working parts are infront of the trigger, not behind, also, the hop-up is probably THE MOST important part of your gun as it is what gives your gun the range that is needed. You have a sniper and so to be able to counter-at an AEG you must have range to compensate for your lack of bb's. If you do what you originally proposed, ie aiming up so the bb has a similar flightpath to a real bullet will really not work and will definitely affect accuracy. You really do need a hop-up on a sniper otherwise, you will reach out to about 20m and ideally as a sniper, want to be reaching a minimum of 60m. Also, another feature of your hop-up is that is stabilises the bb during its flight and so is essential in a sniper. Link to post Share on other sites
farrasdevell Posted January 24, 2012 Report Share Posted January 24, 2012 accuracy comes for consistency. Of parts placement/solid buiding, power(air/gas), airseal, hopup pressure exerted on the round, bb weight size and density distribution. Hopup will give you the range the goal is to have a hopup that is consistent in where it contacts the bb in the chamber and how much pressure it exerts. The relationship between where the nozzel places the bb in the chamber is also important. But most of all it must be consistent. IPSC airsoft shooters use fixed hopups because they are shooting at known short distances and therefore want top consistency for thier shots. Snipers have less choice about this so have adaptable hops. There are good/better hopups available for your rifle go have a look in the tanaka thread. you will make great gains with a good hopup unit and a high quality barrel. You have HPA on your side giving you consistent power unlike greengas mags. Link to post Share on other sites
Sallinen Posted January 24, 2012 Author Report Share Posted January 24, 2012 The trigger will be in front of the magazine, its just not imaged in the picture. Well the AR pistol grip shows the somewhat direction of pistol grip and trigger. The lack of BBs is not a problem as I am carrying this as my "3rd" gun with my primary full auto capable gun and secondary pistol. As for the airseal, it is taken into consideration and will be bettered when the gun itself is somewhat ready. Link to post Share on other sites
ED-SKaR Posted January 24, 2012 Report Share Posted January 24, 2012 Does the amount of backspin affect the accuracy? As I have lived under thought that hop-up effectively messes up with the accuracy. When a hop unit is set up correctly it greatly INCREASES accuracy over a standard smooth bore barrel with no hop. You want hop, you really really want hop. Unless you are fighting CQB with maximum ranges of 10 yards, you want hop, and even in CQB you have corridors that are longer than that, so you'd want hop there as well. a 500FPS rifle with no hop will be outranged by a 300fps handgun with hop. Link to post Share on other sites
Wild_XIII Posted January 24, 2012 Report Share Posted January 24, 2012 a 500FPS rifle with no hop will be outranged by a 270fps £15 shotgun with hop. Fixed... and I'm not even joking. Link to post Share on other sites
hwagan Posted January 24, 2012 Report Share Posted January 24, 2012 Fixed... and I'm not even joking. He really isn't either, I swear I've been hit by that fekkin' thing at a good 50 metres... Link to post Share on other sites
loza_here Posted January 24, 2012 Report Share Posted January 24, 2012 Indeed, i recently bought a £20 shotgun for a laugh, turned out to have pretty decent range, so basically, hop-up is a must. Link to post Share on other sites
Lightbulb Posted February 4, 2012 Report Share Posted February 4, 2012 The only way I can remotly see this working is with low (around 1J) power and a twist barrel. Friend of mine has one it his AEG and its the most accurate AEG I have seen. However you need about 2 to 3 times the range of this thing and for that you NEED hop. If you could have something like airgun power levels this would work but clearly thats not possible for safety reasons! Link to post Share on other sites
LordElpus Posted February 4, 2012 Report Share Posted February 4, 2012 twist barrels need hop just like smoothbore. The grooves in the barrel only provide a more stable airflow giving the bb a better exit from the barrel. Link to post Share on other sites
Libris Posted February 5, 2012 Report Share Posted February 5, 2012 Wow! That's like 4-4.5J, 650-700fps with a 0.2 bb. Certainly don't want to be in the way of that, hop or not. Even at 20m it's going to have about 2J of energy. Link to post Share on other sites
slu Posted February 5, 2012 Report Share Posted February 5, 2012 I think it is physically impossible to achieve any kind of practical range without hop, or something similar, to provide lift. Link to post Share on other sites
sniperelite7 Posted February 5, 2012 Report Share Posted February 5, 2012 I think it is physically impossible to achieve any kind of practical range without hop, or something similar, to provide lift. False. Smoothbore muskets achieved perfectly usable range without hop. Now granted, you'll need to have a huge med... Link to post Share on other sites
slu Posted February 5, 2012 Report Share Posted February 5, 2012 False. Smoothbore muskets achieved perfectly usable range without hop. Now granted, you'll need to have a huge med... Haha, ok, I should say, with 6mm spherical BBs that weigh less than 1 gram. Link to post Share on other sites
Recommended Posts
Archived
This topic is now archived and is closed to further replies.