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Posted: 1/21/2012 6:20:24 PM EDT
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I bought a used 9mm upper, and was going to have the bolt ramped. My bolt doesn't look like any of the pictures I've seen on any websites. Do any of you recognize this bolt? Is it the colt style? Should I have it ramped? Also the Upper has AF cast into it. Does that mean it's a Bushmaster? My current plans for it are Spikes Tactical mag block for my Bushmaster lower. Metal form mags, spikes 9mm buffer. Swaping out my notched hammer for a M16 or DPMS hammer. Will all this work with my bolt? Thanks for any help.
http://i1201.photobucket.com/albums/bb359/Cornnuttz/IMG_0578.jpg |
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I want to say Olympic but I think they use an ejector in the side of the receiver. Is there a clearance cut on the side of the bolt for an ejector? It almost looks like someone has done a hand ramping job on it already.
ETA its NOT Colt its Olympic Arms. Colt style bolts will not work in the upper and its designed to use either modified Sten mags or unmodified ones in conjunction with a magazine block for the Olympic system. They're not known for having problems with notched hammers so you shouldn't need to do anything there. |
That looks a lot like an Olympic bolt. Does the upper have a cross-pin about 1/3 of the way back? Like this:
If it does, then it's an Olympic-type upper. Olympic uses a different system for holding the magazines, with a block welded on the magazine (the mag in the lower left of the picture) rather than having a magazine block in the lower and using more conventional-looking magazines (the mag in the upper right). Lots of people like those guns, but I haven't seen one in real life, so I don't have any opinion. |
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That looks to be a VERY OLD Olympic bolt.
My Olympic bolt is over ten years old, and Olympic started making them in two pieces before that time - the bolt itself is actually removable from the carrier, and they have heavy weights threaded tightly into the back of the carrier to add mass.  
 
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| Thanks guys. It does look a lot like the olympic examples you have posted, but my upper doesn't have the cross pin or a hole for it. Do you think this bolt will work with this upper?http://i1201.photobucket.com/albums/bb359/Cornnuttz/IMG_0580.jpghttp://i1201.photobucket.com/albums/bb359/Cornnuttz/IMG_0581.jpghttp://i1201.photobucket.com/albums/bb359/Cornnuttz/IMG_0582.jpg |
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With no ejector, it will basically be a single-shot - jamming on the empty each time it tries to cycle. Perhaps that upper is meant to work with a magblock that contains an ejector? I'm not familiar with really old Oly systems, and a number of things could have changed since the early days.
AF forge mark just means that the upper raw forging came from Alcoa Forge - gives no real clue as to which company did the finish machining. |
That is a Oly bolt as I have had many designs since they started doing pisol cal uppers
. You will need to drill the ejector holes in the upper for it to work and you will need the PC28 parts here . 
Do you have a 9mm Oly barrel to go with that bolt ? |
| The package I bought was the upper pictured. Came with bolt, receiver and barrel. I'm not sure what barrel it is. Only marks I can find are 9mm stamped into the base. Could I forget about the bolt I have and buy a ramped colt style? Would that work with the rest of my upper? Should have just bought new would have cost less, but I bought this setup from a guy a work. Thought I was getting a good deal. Is the other option to buy the PC28 parts and drill my upper to install them. That would be cheaper, but not sure if I want to drill. Also I would prefer the colt style. |
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You need to make sure what barrel you have first, if the back of the barrel looks like this then it is a colt style
and you will need a colt style bolt. 
. If the chamber entrance is coned shape like a funnel then its the oly barrel, the coned shape oly bolt will fit inside the entrance. going off your pictures it looks to be a complete Oly barrel and bolt but the receiver needs the holes and parts to be complete. |
| Looks like an Oly barrel. So now my options are to buy PC28 kit and install or buy a colt style barrel/bolt and the lower parts. If this is correct and I go the colt style I could have bought a whole rifle for less than I would be into it. How hard is it to install the PC28 kit and when done does this system function well? Can I bring my upper to a gunsmith to have the kit installed?http://i1201.photobucket.com/albums/bb359/Cornnuttz/IMG_0584.jpg |
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Looks like an Oly barrel. So now my options are to buy PC28 kit and install or buy a colt style barrel/bolt and the lower parts. If this is correct and I go the colt style I could have bought a whole rifle for less than I would be into it. How hard is it to install the PC28 kit and when done does this system function well? Can I bring my upper to a gunsmith to have the kit installed? Finish what you started and get the PC28 kit and yes have a gunsmith drill your holes. The Oly system will run good and just about every shape of bullet will feed unlike some of the colts that dont like some shapes of bullets. I have many pistol caliber AR's both colt and Oly style and even my own style and they all run good. I dont know how much you payed for the upper but you could sell it if you are set on the colt style. Forgot to add that Oly has mags to use with that upper without using block in the lower and no need for a 9mm hammer or buffer as it will run fine with a regular 223 style buffer and spring. |
| Ok great Thanks for all the help. I just thought the PC28 kit installed in the upper looked a little cheasy, but if it works then that is the route I will go. Can you recommend a mag block for this set up? Looks like Sten mags are the way to go. I will be using my bushmaster 556 lower and switch between the 556 upper and this 9mm. Do I need to change my notched hammer and should I get a heavier buffer? Anything else I need to do to get this rig running? |
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Whoops just noticed you said I don't need to change the buffer or hammer. Can you get a block and use the Sten mags. I like the look of the skinny long mag out the bottom. Yes you can use the sten mags and here is a block here |
| Awesome thanks again. I ordered the PC28 kit. Now I just need to find a gunsmith in Spokane who can install it. I'll get the Hahn adapter and some sten mags. Then I should be good to go. I bought the SSAR15 stock and am eating through my .223 ammo to fast. The 9mm should be much easier to feed. |
| Called Olympic today they said no way since it isn't their receiver. The guy was a jerk about it acted like he couldn't believe I would even ask such a thing. What are my options now? I'm thinking about trying to drill the holes myself off the drawing above. At this point what could it hurt right? I think Olympic sells a striped receiver I could buy, but I'm not 100% sure of the condition/age of my bolt. Maybe I could sell all this and move on? What do you guys think it's worth? |
| Forgot to mention Olympic said that this would not work on a regular upper receiver has to be a 9mm receiver. How do you tell the difference between the 2? Mine has a hole for the gas tube so I am assuming its a regular 556 receiver. The bolt, barrel and charging handle all fit and seem to work???? |
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The guy you talked to is full of chit as any upper receiver can be used if you drill the holes that are needed.
The colt style 9mm upper receivers are nice to use as they dond have the forward assist that is not needed and they look clean. I have drilled a few of my own and it was easy 
This is a Oly 45 that I used a 9mm upper receiver 
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| Thanks guys that is awesome news. I'm going to give it a shot. We have a decent sized drill press at work I can use. Layout and jigging it up will be the hardest part. I didn't think there was a difference, but I'm not an AR expert. That is an awesome 45 love it. Where did you get the mag? Do they make 9MM mags like that? It looks like you dont have to use a adapter right? Thanks for the drawing of the hole location I would have never found that. |
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Thanks guys that is awesome news. I'm going to give it a shot. We have a decent sized drill press at work I can use. Layout and jigging it up will be the hardest part. I didn't think there was a difference, but I'm not an AR expert. That is an awesome 45 love it. Where did you get the mag? Do they make 9MM mags like that? It looks like you dont have to use a adapter right? Thanks for the drawing of the hole location I would have never found that. That is a dedicated grease gun mag lower so no mag block/adapter is needed. |
| Bought the ar armorers tool so I can take my barrel off and get started laying out the holes. Where do you get the sten mags that have the extra metal welded on so you don't need a mag block? Those would be cool since you could use the normal mag release button. |
| Mag block will be here Friday and I have 2 mags now. Drilled the holes at work today. How much pressure should the spring put on the bolt? I didn't have my lower at work today, but its a tight fit not sure if the buffer spring will be strong enough to close the bolt. I'll bring it tomorrow and check it. Do I maybe need to tweak the spring a little so it doesn't press against the bolt so hard or are they supposed to be that way? |
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Don't fiddle with it until you know if it's going to be a problem.
Take some pliers with you to the range when you live fire it the first time so that if it DOES need adjustment, you can do it right then and there. On my Oly, the spring ejector does put a fair amount of pressure on the bottom of the bolt - it needs to ride tight in the groove provided for it to eject crisply. |
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Got it all done. Looks like it will work the bolt closes. Still feels a little hard to pull back hopefully the 9mm will be enough to push the bolt back. Thanks for all the help guys. Couldn't have done it without it. Tomorrow I'll get to test it. I'll let you know how it goes.
http://i1201.photobucket.com/albums/bb359/Cornnuttz/IMG_0611.jpg http://i1201.photobucket.com/albums/bb359/Cornnuttz/IMG_0610.jpg |
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Well took it out and it worked well as a single shot. Wouldn't fully eject the spent case. Weather sucked cold and raining so I didn't fiddle with it much. What should I try? I'm guessing it has something to do with the spring, but not sure. Is there something on the bolt that kicks the shell out the side after it hits the spring?
http://i1201.photobucket.com/albums/bb359/Cornnuttz/IMG_0613.jpg http://i1201.photobucket.com/albums/bb359/Cornnuttz/IMG_0612.jpg |
| Lube the ever-lovin' crap out of it, especially inside the upper. There could also be a bit of drag between the bolt and the ejector spring, so look for abrasion there and lube accordingly. What spring and buffer are you using? With everything else in the mix, you might get good results with a standard buffer instead of some extra-heavy buffer. Oly has a good track record with their 9s being solid and running well, so there is something unanticipated slowing you down here. |
| I sprayed it down pretty good with Rem oil, but next time I will try more. It has the "H" buffer not sure what spring it has. Could I get some snap caps to try adjusting the spring and cycle the action by hand? Would that be good enough to tell if what I am adjusting is working? The spring to bolt is still pretty tight, but not as bad as when I first put it together. Is there an animation or drawing somewhere on how the olympic system works. I'm not sure what the spring does. Does it just hit the back of the brass when the bolt is forced back and kicks it loose? |
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I sprayed it down pretty good with Rem oil, but next time I will try more. It has the "H" buffer not sure what spring it has. Could I get some snap caps to try adjusting the spring and cycle the action by hand? Would that be good enough to tell if what I am adjusting is working? The spring to bolt is still pretty tight, but not as bad as when I first put it together. Is there an animation or drawing somewhere on how the olympic system works. I'm not sure what the spring does. Does it just hit the back of the brass when the bolt is forced back and kicks it loose? You didn't take pliers to the range with you like I suggested... Rather than futz with it at home, you can resolve things a lot more quickly by taking some pliers to the range with you, and tweaking that ejector until things run right or you break it off. My 11-year old Oly upper has has the ejector replaced once, about four years ago. When easing the bolt forward, you can feel where it first touches the ejector, but there is not enough pressure to keep the bolt from going forward under spring pressure alone and fully closing. My Oly uses a rifle receiver extension and rifle buffer. The spring just rides in that groove on the bolt, and hits the back of the empty case to kick it out the ejection port. For that to work correctly, the extractor has to have a firm hold on the case rim, so that the case will be pivoted outward, instead of just dribbling/bouncing around in there. |
| I did bring pliers, but the weather sucked so I didn't mess with it much. I usually go to my home town on weekends out in the country can pretty much shoot anywhere. I'll play with it a little at home try to get the drag on the bolt down. The extractor is on the side of the bolt right? Is there any checks I can do to make sure it is functioning properly. This is all used stuff so I don't know the history of any of it. |
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The extractor is on the side of the bolt right? Is there any checks I can do to make sure it is functioning properly. This is all used stuff so I don't know the history of any of it. Yes, the extractor is on the right side of the bolt, and your ejector looks to be correctly installed on the left. You can function test either with snap caps, to ensure proper extraction and ejection, or VERY CAREFULLY with live ammo, if you must. I recommend removing the firing pin if you're going to be cycle testing with live rounds. |
| I tweaked the ejector spring and I think I have it pretty good now. It lines up with the groove in the bolt and has a little drag not bad at all. I hand cycled a snap cap and it still wont kick it out the ejection port. The round is knocked loose from the bolt, but not thrown out the side. I'm wondering if it could be the extractor. How would I test that? I took the bolt out of the gun and put a round at the end of the bolt where it would be if it was picked out of the mag and it's not held very tight. I couldn't figure out how the extractor would come off of the bolt I was going to check for a broken spring. |
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How do you get the extractor out of the bolt? It looks like mine is a one piece bolt and doesn't come apart like yours. There is a pin on one side, but it doesn't go all the way through.http://i1201.photobucket.com/albums/bb359/Cornnuttz/IMG_0623.jpg
http://i1201.photobucket.com/albums/bb359/Cornnuttz/IMG_0622.jpg |
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How do you get the extractor out of the bolt? It looks like mine is a one piece bolt and doesn't come apart like yours. There is a pin on one side, but it doesn't go all the way through.http://i1201.photobucket.com/albums/bb359/Cornnuttz/IMG_0623.jpg http://i1201.photobucket.com/albums/bb359/Cornnuttz/IMG_0622.jpg That's clearly a different-generation bolt assembly than mine. Mine disassembles like a regular bcg - but the "cam pin" lacks a slot - it's just a solid hole. So, firing pin retaining pin comes out, firing pin and spring comes out, "cam" pin comes out, bolt slides forward out of the "carrier". If yours is similar, but secured with that blind pin, the only way to disassemble it would be to extract or drill out the blind pin. If you have to drill it out, of course, you'll need a suitable replacement for reassembly. Anyway - if you slide a live round up into the bolt face, does it hold it firmly? Can you wiggle it around without losing the round until you hit it exactly opposite the extractor? |
| If I put a round into the bolt face it will stay, but not very stable. Doesn't take much to knock it loose cant shake it at all. If I press on the extractor with my thumb the round is really secure so I think my spring is broke in the wrong spot or something. I ordered a couple springs from Oly last night. Just need to figure out how to disassemble. I think you are right I will need to drill out the roll pin. Do you think home depot or Ace would have roll pins? Thanks again for all the help. |
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Got the extractor out today. This must be one of Oly's first bolts it doesn't even have an extractor spring. I bent it a little and now it holds the bullet real tight. I can shake it all around and it stays in. Crossing my fingers that it will run this weekend.
I'll let you guys know how it goes. http://i1201.photobucket.com/albums/bb359/Cornnuttz/IMG_0628.jpg |
| Limited success this weekend the first 2 shots functioned good, after that jam jam jam. I think the bolt is moving too fast. I hand cycled a couple live rounds at the range and they ejected good. The weather sucked again so I just tried one mag. I am going to try to put more tension on the spring see if that works. If not maybe a heavier bolt. I oiled the crap out of it. |
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