GTA
Airguns by Make and Model => Vintage Air Gun Gate => Topic started by: egillman on March 18, 2013, 02:11:33 AM
-
I just got a crazy idea - to modify a Crosman 500 semiauto bb repeater to a semiauto pellet repeater. I already tried putting pellets into the spring-loaded bb feeder, and they fit. I will have to modify the valve so that pellets will fit into the plastic piece that transfers the bb's from the feeder to just in front of the barrel. Maybe add a 1077 rifled barrel instead of the smooth one that comes with the 500. Anybody else ever try this?
-
Update: I took apart the valve and enlarged all pellet passageways to 3/16 inch (0.1875). I also had to make the hole in the plastic pellet transfer arm slightly longer to accommodate the extra length of a pellet. Unfortunately, I made it a little TOO long, so the pellet goes in a little too far, and then the transfer arm catches the skirt of the next pellet waiting to be loaded. More tomorrow.
-
Update: i was able to make a shim out of 3/16" aluminum tubing to keep the pellet at the proper depth when it is picked up by the loader arm. I am now able to"load" pellets from the spring-fed magazine to the loader arm, and from the loader arm to the rear of the barrel while it is still on my workbench. Tomorrow I put it all back together and try to load pellets. If that works, I may pop a CO2 cartridge in and see what shoots out the barrel.
-
Looking forward to seeing the end result. good luck with it.
-
Latest update: I was having trouble with the .177 pellets getting hung up as they entered the valve body. I enlarged both the entry and exit holes of the valve body from 3/16" to 13/64." It seems to work much smoother.
I decided to bag the Crosman spring-loaded bb magazine, because it was too hard to load the pellets into the small hole on the top of the barrel. Instead, I replaced it with a length of 7/32" aluminum tubing that extends from the muzzle to the valve body. I will insert the pellets into the muzzle end, followed by the long spring, and then fit some type of cap over the hole. I will post pictures tomorrow!
-
Latest update: I was having trouble with the .177 pellets getting hung up as they entered the valve body. I enlarged both the entry and exit holes of the valve body from 3/16" to 13/64." It seems to work much smoother.
I decided to bag the Crosman spring-loaded bb magazine, because it was too hard to load the pellets into the small hole on the top of the barrel. Instead, I replaced it with a length of 7/32" aluminum tubing that extends from the muzzle to the valve body. I will insert the pellets into the muzzle end, followed by the long spring, and then fit some type of cap over the hole. I will post pictures tomorrow!
Cool, sounds like you're on a mission to get this thing working!
-
Update: It loads and shoots pellets! After enlarging the ports on the valve and transfer arm, and replacing the spring-loaded bb loader with aluminum tubing, I put everything back together. I loaded 10 pellets into the muzzle end of the aluminum tube, jammed the long spring in behind them, and fired a few shots before it jammed. It seems to miss shooting a pellet, followed by shooting 2 pellets. I took it all apart and strengthened all springs in the trigger/hammer by slightly bending them. More to come.
-
Update: When I tried to tighten the hammer spring, I think I made it too tight. It was actually pressing against the valve and keeping it open, so all the CO2 would leak as soon as I put in a new cartridge. I think I may have it set up correctly, but it's too late to test it tonight. More to come.
-
Update: When I tried to tighten the hammer spring, I think I made it too tight. It was actually pressing against the valve and keeping it open, so all the CO2 would leak as soon as I put in a new cartridge. I think I may have it set up correctly, but it's too late to test it tonight. More to come.
Keep us informed :)
-
I have not been able to test out my new, improved pellet loader tube because I am still having problems with all the CO2 leaking out in about 10 sec after I put in a new cartridge. I think the problem is the hammer pushing slightly on the valve stem when the gun is uncocked. The valve was working perfectly before I started messing around with the hammer and trigger springs. I am going to test this theory by removing the hammer spring and then inserting a CO2 cartridge. If that works, I will probably need to buy a new hammer spring. Anybody have a better idea?
-
I just got a crazy idea - to modify a Crosman 500 semiauto bb repeater to a semiauto pellet repeater. I already tried putting pellets into the spring-loaded bb feeder, and they fit. I will have to modify the valve so that pellets will fit into the plastic piece that transfers the bb's from the feeder to just in front of the barrel. Maybe add a 1077 rifled barrel instead of the smooth one that comes with the 500. Anybody else ever try this?
I'm pretty sure I had a Crosman 500 bb repeater when I was a kid back in the 70's. I don't know about converting it a pellet repeater but I would like to have one just to shoot. Good luck with your project.
Bryan
-
Bryan,
I have another 500 that I am restoring to "almost new" condition. By this I mean that my repainting and refinishing will look better that what Crosman put on it. I would be willing to sell it once I'm finished if you are interested.
Erik
-
It's amazing how easy it is to break something by "fixing" something. I thought I was strengthening the hammer spring on the 500 by shortening it about 1/8 inch. Turns out that was enough to keep the hammer slightly pressed against the valve and causing all the CO2 to leak out. I confirmed this by removing the hammer spring entirely and inserting a CO2 cartridge. No leaks, the valve works just fine. I think my local Ace Hardware might have the new hammer spring that I need.
-
Update: the valve is holding CO2 just fine with a new hammer spring that I found at Ace Hardware. I loaded up a few pellets, but the loader jammed after a few shots. It appears that the pellet is not being pushed all the way into the plastic loader thingy that moves the pellet to right behind the barrel. I have been using wadcutter pellets, which may be part of the problem. I will try some domed pellets next, to see if they are more "forgiving" than the flat-nosed type.
-
Update: the valve is holding CO2 just fine with a new hammer spring that I found at Ace Hardware. I loaded up a few pellets, but the loader jammed after a few shots. It appears that the pellet is not being pushed all the way into the plastic loader thingy that moves the pellet to right behind the barrel. I have been using wadcutter pellets, which may be part of the problem. I will try some domed pellets next, to see if they are more "forgiving" than the flat-nosed type.
I think the dome pells will feed better. You may even need to try different brands and weights til you find just the right one.
-
OK, I had to modify the plastic feeder thingy to fit the Crossman domed pellets that I bought. It seems to feed OK while still taken apart outside of the receiver. I will put it all back together this week and see if it works then. If not, I will try other brands of pellets. I keep telling myself that the Model 99 works just fine, and this 500's loader is not all that different. What brand of domed pellets worked best in your 99?
-
I finally got back to this project. I decided to replace the 500's smooth barrel with a rifled one that I got from a Crosman 1077. This required drilling out the valve port to 5/16" so the barrel fit to it. The 1077 barrel is about an inch shorter than the 500, but that should not be a problem. I also decided to use the old 500's barrel as the pellet magazine tube. It's sturdier than the aluminum tubing I had tried before. I will put it all together this week and let you know if I have the first-ever Crosman 500-P (where the P is for pellet).
-
Using an old Crosman 500 barrel for the pellet magazine is NOT a good idea! The pellets fit too tight. I had to go back to an aluminum tube slightly larger than the size of a pellet. I also shortened the barrel shroud to fit the shorter 1077 barrel. The barrel, magazine, shroud, and valve are all back together. Let's see if it feeds pellets!
-
hope you get all the bugs worked out Gilbert. i've been following along. neat project.
-
OK, I put the 500-P back together. It looks pretty cool with a "sawed off" barrel! I loaded a CO2 cartridge and all dry fired a few times. Seems to hold air and fire fine w/o pellets. I loaded a few pellets, and put the spring and push rod into the magazine. It still just shoots air, but the trigger does not "jam" as it did before. That tells me that the first pellet is not getting into the plastic "shuttle" that moves it from the magazine to the barrel. I will probably need to enlarge the hole in the shuttle and/or taper it a bit to get the pellet to slide in. More tomorrow.
-
Pellets load fine from the magazine to the barrel - while it is apart on the bench. As soon as I put the trigger/hammer assembly back in, put the receiver back together, and put in a CO2 cartridge - pellets don't load. I noticed that the trigger is not returning all the way forward after firing, which makes me think the plastic shuttle is also not returning to the position in line with the pellet magazine. More testing will be done tomorrow.
-
Exciting news - the 500P shot its first magazine of 10 pellets! In case you haven't been following this thread, I modified a Crosman 500 semi-auto bb rifle to be a semi-auto pellet rifle. I swapped out the smooth barrel for a 1077 rifled barrel, and modified the plastic bb loader shuttle to fit pellets. It's not truly "semi-auto" yet, as I have to nudge the pellets in the magazine along with a piece of aluminum tubing that I push into the muzzle end. The spring-loaded thingy that is used for bb's doesn't seem to work for pellets. My first impression of accuracy is "very good" as it should be with the 1077 barrel. I will add pics to my next update.
-
that sounds like good progress. ;D
-
I finally got back to this project after a few weeks off. What I have created is a Crosman 500 bb repeater that has been modified to shoot pellets. This includes a new in-line pellet magazine to replace the bb magazine, and a 1077 rifled barrel to replace the stock smooth barrel. The gun loads and shoots just fine if only one pellet is sent down the magazine, but "hangs up" when I try to pre-load more than one. The accuracy is very good, as expected with the rifled barrel. I think I am going to give up on the "repeater" idea and just be happy with a Crosman single-shot 500 pellet rifle. I will clean it up and post some pics soon.
-
Here is the finished Crosman "500P" (modified to shoot pellets, top) and a standard 500 bb rifle (bottom). The 500P has a rifled barrel from a Crosman 1077, which is a few inches shorter. Currently, it is a single-shot since loading more than one pellet into the in-line magazine often results in jamming. It is quite accurate, plus I think it looks pretty cool!
-
One good mod deserves another, so I decided to fit a 9 oz. CO2 paintball tank to my Crosman 500P pellet rifle. I decided to remove about half of the forestock and mount a 3.5 oz tank under the barrel. I finally got it all together tonight, the seals were tight, and I was able to dry fire it. Tomorrow I will try it out with pellets. Pictures to follow.
-
Here are the photos of the Crosman 500P bulk fill pellet rifle. I will be replacing the 9 oz CO2 tank with a 3.5 oz tank, and the long "looped" hose with a shorter one.
-
Here's the finished product. It has a 3.5 oz. CO2 tank, rifled barrel, and shoots .177 pellets very accurately at 400 fps.
-
Very nice Erik. you put a lot of time into that one. :)
-
Sometimes you have to cut your losses and move on. After trying for numerous hours to get this modified Crosman 500 to reliably load pellets (instead of bb's) I officially gave up on it tonight. I saved all the bulk-fill and other reuseable parts for another project, and the rest went in the trash. The good news is that I now have an empty slot in my gun rack, just waiting for a new vintage airgun to fill it!