“hop-up” in BB guns

[NRADAVE]

I’ve been amazed at accuracy achieved by use of the hop-up devices that are incorporated in many of the airsoft and some bb replica guns produced mostly by the asians. They are much more accurate than the daisy guns. And I think it’s mostly due to the spin the hopup produces on the projectile.
Really enjoyed the daisies (since 1950) and have bought many for kids and gkids. Good point and shoot guns. But try to get serious and they disappoint.
Recently got into the airsoft replica guns and they shoot a plastic “bb”. Something I didn’t expect much from, thought they’d make good training aids. Much to my surprise they are very accurate. Got to wondering if daisy or an aftermarket gun or replacement barrel was available——-or thought about?
Any thoughts ? Thx.

 

[cobalt327]

That's something I find very interesting but I 've never seen a BB gun so equipped. I have heard rumors they exist though. For that matter, I've never seen a hop-up as used in an airsoft gun either except photos. So I have a lot to learn!

The most accurate BB smooth bore barrels we've seen so far are those used in the Daisy 499B. They're just 9" long, though. Recently a member here, hinz57, grafted two of the 499 shot tubes together and machined one end to fit the shot tube abutment of a new production Red Ryder. He hasn't shot it for accuracy yet but he got a record-high MV for a Daisy lever action repeater BB gun of over 450 fps using them. Click on photo to see more photos and details.




I'd also like to try a choked smoothbore BB gun barrel. I've looked into choked LW smooth bore barrels and they are available but the cost is around $150 shipped. Some people have choked their own barrels using various techniques and that would be a lot more affordable

 

[NRADAVE]

That's something I find very interesting but I 've never seen a BB gun so equipped. I have heard rumors they exist though. For that matter, I've never seen a hop-up as used in an airsoft gun either except photos. So I have a lot to learn!

The most accurate BB smooth bore barrels we've seen so far are those used in the Daisy 499B. They're just 9" long, though. Recently a member here, hinz57, grafted two of the 499 shot tubes together and machined one end to fit the shot tube abutment of a new production Red Ryder. He hasn't shot it for accuracy yet but he got a record-high MV for a Daisy lever action repeater BB gun of over 450 fps using them. Click on photo to see more photos and details.




I'd also like to try a choked smoothbore BB gun barrel. I've looked into choked LW smooth bore barrels and they are available but the cost is around $150 shipped. Some people have choked their own barrels using various techniques and that would be a lot more affordable

Have several of the “buck” Daisy’s laying around for the G’kids and bought several boxes of the “match grade” daisy bbs. They’re about .002” larger in dia and very concentric and $$$. But the guns improved with them. So I went and bought a new daisy carbine from Wally World. Stuck a “lasso” mount and scope on it. Very disappointing. The bucks would be difficult to scope. But I really believe they shoot better than the red rider I bought —-May have a poor example. Shoots 6-8” group at 50’ off a rest.
Have a “KWC” brand Replica Colt CO2 pistol that imploys a piece of rubber in top of barrel to hold the chambered bb in place, as daisy uses a spring or magnet, that also produces “backspin” when fired. Works great. Shoots into 3” with a 74 yr old pulling trigger. Has maybe a 4” barrel. 325 FPS on my Chony. Just tells me, there’s much that could be done to improve these great old guns. Thx for the reply, enjoy these posts.

 

[cobalt327]

Do the airsoft guns have the hopup at the breech? I seem to remember reading that the BB spun backwards for the length of the barrel.

 

[NRADAVE]

Know very little about the airsoft technology. Lot of info on utube, of course
I got interested in the replica gas operated pistols that shot steel .177 bbs. Very realistic with slide blow back and the weight/size of the real thing. And doesn’t break the bank to practice with.
I was surprised at how straight the bbs flew even out to 30+ yds. No slicing or hooking. Got to looking at the barrel and saw the small “rubber” (not sure of the matl ) piece extending down from the top of bore. I think this holds the bb in place but also puts a spin ( backspin) on the bb creating the “Magnus” effect.
And yes the airsoft systems I’ve seen puts the spin on the bb at the breech.
I bought the airsoft pistol just to see how a 6 mm plastic bb could possibly be fired for 150+ ft and hit anything. And it does —-due to the spin.
Always loved the air guns, pellet and bb. Bb for plinking and training the kids. Pellets for longer range accurate shooting.
I just got to thinking about how to modify a daisy shot tube to hold a piece of rubber like matl as in the airsoft guns ? Got a couple older red riders laying around, easy to pull the tubes. Might have to get the dremel out ——.
Got any ideas/thoughts.

 

[cobalt327]

The Daisy repeater uses an air tube, it hits the BB like a pool cue hits a cue ball. If the air tube were shaped to give the BB English for backspin, that may work. Taking the billiards analogy a step further, it might help if the end of the shot tube had a texture or different material that acted like chalk on a cue.

 

[hinz57]

All, that’s the word I couldn’t remember, hop up. On my Maruzen APS 96 the hop up is adjustable. I just haven’t come up with a way to adapt to a daisy shot tube. I have wondered on the 499b, if the location of the magnet in the abutment causes a similar effect. I have also wondered if the rotational position of the abutment can effect accuracy. Or allow adjustment of right or left drift. Possible vertically as well. To allow closer calibration to the sights. On the Maruzen there are no sights, only a scope mount. It’s supposed to be patterned after sniper rifle. I really know very little about it. It was headed for the trash and I rescued it....

 

[NRADAVE]

Well, I gave up on the Wally World RR Carbine. Hauled it back and got a refund. bbs just “sliced” every direction, no rhyme or reason. What’s aggravating is I have a couple of the new “bucks” that shoot much better. Maybe I got a bad carbine. May have to try another, as long as Sam lets me return them.
I think I read they all have the same “power plant” ? Like to pull the shot tube and attempt to install a piece of rubber like material inside the bore to spin the bb. Can the tube be pulled on these newer guns ?
Prefer the carbine because I can mount a scope. But don’t want to start with one that won’t throw a straight bb.
You guys ever pull one of the new tubes/barrel? Thx

 

[cobalt327]

They are hit and miss (npi) on accuracy, no doubt. But even a good one will shoot poorly if the shot tube is oily, they just don't need oil down the tube! Oil from the compression chamber naturally migrates into the tube so no need to add any more. I give a new gun a cleaning using dry patches, if I see anything that looks like oil, grease or dirt, etc.I use a .177 mop and Goo Gone followed by several dry patches to clean it. I clean my gun's tubes with dry patches if accuracy starts to stray. If I suspect a gun's tube is oily, I do the Goo Gone deal.

The new production 105B Buck and the 1938B Red Ryder do share the same powerplants. The shot tube can be removed after removing the stock, lever, trigger, and plunger assembly. It comes out the rear of the gun by using a mallet to tap it free. I use a piece of wooden dowel to protect the crown. When reinstalling it, pay attention to getting the BB loaded chamber viewing port at 12 o'clock.

 

[hinz57]

Yes, on tube removal, many times.
Trick is, after removing stock, lever, trigger, you must compress the spring to remove the spring anchor. Takes a “special” tool. Mines home made. After removal of anchor, pull the plunger/spring assy out the back. Then you remove the front sight/plug. You need a something flat and thin about 1/8” wide by 0.030” thick, tapered to a sharp edge, like a tiny chisel. slip it in from the front bottom side where the shroud is split. That lets you slide the sight/plug out the front. Then with a short dowel, about 1/2 -3/4” dia x 6” long, placed on the exposed end of the shot tube, give it a sharp tap with a hammer. That should dislodge the tube. Then a longer dowel is useful to push it out the back end.

 

[hinz57]

I will be very interested to hear what you come up with for a hop up!

I agree with cobalts thoughts.

What about the rifled tube like the 880 combo? Does that put spin on a bb? Or does it just leak air because of loose fit?

 

[cobalt327]

I'd be interested in hearing thoughts on rifling for a BB. In my experience the 880 with a rifled barrel is not accurate at all with a BB but I've only used BB in a couple rifled 880s so this may not reflect other folks experiences.

Hinz57, excellent write up on removing the shot tube!

 

[NRADAVE]

Ok, thx for the tube removal info. Got a $17 Buck I’ll give it a shot.
Never thought about “oil” in barrel as a possible problem. Will ck it out.
As for the rifled barrel, I have “Drozd” Blackbird with an aftermarket rifled barrel on it. Very accurate, while launching bbs at 650 fps using a 800psi regulated tank. Will shred about anything when set at 1200 rpm. But drinks air by the gallon. But I digress
First I need a tool to compress the plunger spring, anyone sell one ?

 

[cobalt327]

I made one from a piece of scrap wood and two 6" pieces of 5/32" steel rod but after a lot of use the wood finally split on me. So I clamped the rods between the jaws of a duckbill vice grip. I used a couple pieces of popsicle sticks, they help to keep the rods from twisting. Tractor Supply sells one for $11.00 and most TS stores have a K&S Metals display rack for the rods. I would think 1/8" would also work for the rods but I wouldn't use anything larger than 5/32" due to possible lack of clearance.



People have also made them from a uber long chef's fork, a cheap-o spark plug socket, etc. The one from the plug socket is below.

 

[hinz57]

I used 2 pcs 5/32” rod and a piece of wood. Someday I will make better one....it works for now! Dave, if you start drilling, cutting, etc, and need some more material to experiment with, I have several extra 1938b tubes, I’d be happy to send you some. I’m very interested to see what you come up with. The abutment is riveted, but with a bit of careful work with a dremel and a drill. You can bolt it together and replace tubes as needed.

Lots of info about all this on Cobalts thread about a $15 daisy!

 

[cobalt327]

There's a guy selling a tool on ebay but I've not tried one. Maybe check the reviews. https://www.ebay.com/itm/Daisy-1894...Plunger-Removal-Fits-more-Models/191881893491

 

[Bob E]

Somewhere I remember reading someone mentioned using magnets on top of the shot tube to put a backspin on the bb's with a pumper. It would cause havoc with a gravity feed though...

-edit-
Found it. buried down in the comments at this link.
https://www.pyramydair.com/blog/2006/05/can-a-common-bb-gun-be-accurate/

 

[Englishmn]

On airsoft the backspin from the hop up is used to counter the drop from gravity.
Hold a airsoft gun sideways and you can curve the shot.

 

[cobalt327]

Somewhere I remember reading someone mentioned using magnets on top of the shot tube to put a backspin on the bb's with a pumper. It would cause havoc with a gravity feed though...

-edit-
Found it. buried down in the comments at this link.
https://www.pyramydair.com/blog/2006/05/can-a-common-bb-gun-be-accurate/

Unbelieveable- that's basically the same thing I was wondering about on the long Daisy thread!

Regarding magnets and hop up, what about using a strong rare earth magnet at the top of the muzzle end of the tube?

Also, what would a ring magnet do for accuracy if the magnet were placed at the muzzle end. I'm wondering if that could make the BB leave the tube the same way each shot as compared to randomly exiting the tube?

Sounds like the OP got better results that I did when I tried it, though. In my testing there wasn't any discernible difference with or w/o magnets. Could be the difference in the strength of my magnets.

 

[theairgunman]

I guess created an account here years ago and never gotten around to posting. Rediscovered the forum through cobalt327, he's the one who helped me find the 499 shot tube. I've currently got one installed on a Daisy 880 and have been experimenting with hopup. The mechanism right now is in the prototype stage and consists of silicone tubing for the bucking material, a sliver of poly tubing for the "nub", electrical tape to keep the nub in place, and a zip tie to apply tension to the nub.

I'll take pictures of how it all goes together the next time I take it apart in case anyone wants to replicate it. It has taken several tries to get it to work even close to satisfactory. Here's the result of a lot of tinkering around:



This group was shot with 10 pumps (591 fps average) at 20 yards in a light breeze from a sitting position using the insides of my knees as a rest. POA was between the 9 and 7 in the text block on the box. The results are encouraging, though I believe there to be a lot more room for improvement. At that power level, no other BB gun I have can match that group at that distance.

 

[cobalt327]

Great you were able to post here, that's some very encouraging results, no doubt! How many shots are in that group? I have been doing 10 per target, it gives a better representation than the usual 3 or 5 shots.

 

[theairgunman]

That was 14 shots. I've been trying to shoot what is in my magazine to give a better representation. It is easy to get excited about cherry picked 3 to 5 shot groups. Higher shot counts really give a realistic idea of what both the gun and shooter are capable of together. The center cluster of the group really has me hopeful!

 

[shoobe01]

The same principle is achieved several ways. Love the magnet one! Paintball guns, at least when I followed their technology in the 90s, used off-center jets of air to spin the ball first.

If no one knows, airsoft "hop up" is done by a drag piece. A hole in the barrel just forward of the "breech" is plugged with a rubber sleeve, and has a mechanism to force the rubber into the path of the pellet. The user usually has the ability to adjust this, allowing it to be "zeroed" to get the maximum straight-travel range based on current ammunition, and conditions.

 

[NRADAVE]

I guess created an account here years ago and never gotten around to posting. Rediscovered the forum through cobalt327, he's the one who helped me find the 499 shot tube. I've currently got one installed on a Daisy 880 and have been experimenting with hopup. The mechanism right now is in the prototype stage and consists of silicone tubing for the bucking material, a sliver of poly tubing for the "nub", electrical tape to keep the nub in place, and a zip tie to apply tension to the nub.

I'll take pictures of how it all goes together the next time I take it apart in case anyone wants to replicate it. It has taken several tries to get it to work even close to satisfactory. Here's the result of a lot of tinkering around:

View attachment 832981

This group was shot with 10 pumps (591 fps average) at 20 yards in a light breeze from a sitting position using the insides of my knees as a rest. POA was between the 9 and 7 in the text block on the box. The results are encouraging, though I believe there to be a lot more room for improvement. At that power level, no other BB gun I have can match that group at that distance.

I’m also trying to add hopup but to a RR, do u know how much “engagement” u have between the bb and the rubber?. I epoxied a pencil eraser into the tube about 1\2” ahead of the extended air tube. As best as I could calculate I had .010/.015” of contact on the bb. Bb seemed to fly straighter out at distance.
I used an older 107 (buck) with screw in shot tube. Easier to work on.
But the eraser didn’t hold up long enough for good testing.
Thinking of trying an O’Ring maybe try a silicone one. I just used a rat tail file to cut the notch. No way to adjust the amount of contact.
Any advice/thoughts appreciated.

 

[theairgunman]

Definitely try the o-ring! If you give it a wrap over of electrical tape, it'll help keep it in place and minimize blowby. To adjust tension on the o-ring, you could do like I did and use a zip tie. I'm using the ones from the Dollar Tree, they take up less room, and are dirt cheap.

As a starting point, tension the zip tie until the o-ring protrudes enough to just hold a BB behind it. Since the 107 is a lower powered gun, it shouldn't take much backspin to get the results you are looking for.

If that doesn't work for you, I'll send you a piece of silicone tubing for bucking and some poly tube for the nub so you can replicate what I have on my 880. Just let me know and I'll be glad to get it heading your way.