Crosman 760 air rifle easy power mod, hello youtube this is my Crossman 760.you might recognize it from my Crossman.760 rifled m4 177 barrel mod I put the.smoothbore barrel back on it and this is.really an excellent gun with a.smoothbore barrel and I’ve got plans for.that rifled barrel in another 760 I got.but today with this gun I’m going to.disassemble it and show you guys.hopefully a couple easy power mods that.you can do and hopefully increase the.power of this thing a little bit and.let’s get started I’m gonna disassemble.it and we’ll start in.okay so this is a velocity test of the.Crossman pump master 760 so let’s see.what we got.ok let’s do the final shot all these.shots there are at 10 pumps let’s see.how we do.ok and that’s 5:11 so now this is the.stock 760 ok guys as you can see here I.got the tongue pump tube disassembled.and I’m fixing to take out the pump Cup.and inspect that and see if I can mod it.a little bit but before I do that I need.to check this right here I need to make.sure that there’s no burrs in there and.I stick my finger in there to see if I.can feel burrs around these holes and.it’s real important because when I slide.the pump Cup out which is right there.when it slides past then burrs it will.scar it up and make the feeling really.horrible so I have me a piece of.sandpaper here and I’ll simply put it on.my little finger and stick it in there.and it’s kind of working around a little.bit.there we go and this make sure that them.holes are smooth on the inside and that.way I know that I won’t scar up that.pump cup as I pull it out so I took my.little piece of sandpaper and see if.yeah yeah that’s that feels nice and.then I just slide the pump Cup out and.there we go.and it’s all smooth and everything so.yeah but be sure to check them holes.sometimes they get burrs on the inside.of them here and when you slide the pump.Cup through it sometimes scars it and.cause problems for ceilings so this make.sure it’s smooth before you take the.pump assembly completely out of the tube.there okay.okay guys right here when I just semble.dit right here is the pump Cup and.that’s what I’m gonna be focusing on so.let’s see I’m gonna ease it out real.easy there we go.okay yeah so what happens is a lot of.modding they’ll put a spacer in here and.then they’ll put it back together you.know and it’ll obviously it’s space.space it out a little bit so yeah there.we go I think I’m gonna make something.and see what we got okay guys I got me a.coffee can lid here it measures about 25.thousands maybe a little bit more in.thickness and I’ve decided to use this.as my spacers so cut some holes out of.it kind of experiment a little bit and.I’ve made me a little spacer right here.I don’t know if you can see that and I’m.going to put it inside here and if I.made it right it I’ll slip right in.there so let’s see.mm okay well.now let’s see how it looks.sit down I think it’s a little bit big.yet hmm.may need to pull that back out and trim.it a little bit more okay um so I’ve.trimmed it down a little bit maybe it’ll.fit a little bit better so I got it.there and got my extension here so I’ll.fit it in there and see and see if I.trimmed it down enough mmm not really.good let’s fit it in here all right yeah.that looks that looks really good.now that really that may look like it.really does the cow but actually it.don’t you see this gal there’s a gap.right around in here and that gap is.actually a problem if you uh if I.assemble this thing like it is it may.look like my pump cups extended a little.bit but actually what happens when it.gets under pressure that gap is actually.pushed back by the air and it actually.either makes it as if I didn’t do.anything or actually makes my velocity.drop so that that’s kind of a problem I.really can’t I can’t have that flex like.that so I’m gonna try something okay now.so I put this in here now what I did.here was I actually put a little piece.of this stuff here and I just put it.around this and trimmed it where it.really fits nice around there and so let.me put it together now I need to be easy.taking this apart and put it in together.and mess around with I don’t want to.break it so.there it is and I’m a lot more happier.with that I think that’ll work out just.fine so I think I’ll put it in there.test it and see what I have but I really.think that’s going to be a good deal.actually so there’s a little bit of gap.there but I think I’m real I think.that’s going to be great so as it as it.comes down on compression it’ll flex but.not really that much no more than it.would if I didn’t have any spacer at all.so you know if it was this stock I think.it probably had that much gap anyway so.I don’t know I’ll put it together and.see how it works.okay next is the bolt now the bolt as I.fit it in here I just had my barrel.laying in a receiver here in it it’s.extremely loose it don’t feel well at.all now as far as what to do with the.bolt you know I have a little probe here.and I could put it in there you know.slide the magnet out maybe you just a.little bit and then fit it pretty good.but what if I didn’t have this what if I.didn’t didn’t you know what if this.wasn’t here and you know I really if I.were to make a groove in the bolt here.in the end of the bolt there I’d.actually run out of space and and get.down to the magnet and actually cut the.end of it off I don’t I don’t really.think that a it’d be a good deal at all.so what I thought about doing was.actually taking some superglue and going.around the bolt in increasing the.diameter a little bit.now I grabbed up a stick and I actually.did this first on a stick to where I.kind of got familiar with what’s going.to happen so I just keep on rotating it.just around like that as I add some glue.and keep on rotating it just to keep it.from having a glob at one end or the.other and I’ll do this basically until.it’s dry and hopefully it won’t take it.long before it’s dry it’s that you know.super glue after all so I’ll just keep.doing this and this rotating it around.getting it nice getting as round as I.can now I’ve got some 800 grit sandpaper.so what I’ll do is I’ll wait till it’s.dry and then I’ll start sanding it to.size now of course I don’t want to stick.this in the barrel wall it’s wet because.that will ruin both the receiver on the.bear or the barrel support and the bolt.so you know that’s not something I.really want to do but anyway so I’m just.going to rotate this until it’s dry and.that way I’ll uh I’ll be able to sand a.little bit and maybe increase the.diameter and thus sand it down to size.to where it’s relatively round and it.seals a whole lot better than what it’s.actually doing because the sealing part.of this bolts actually you know it’s.really not great at all so this gives us.a few minutes and let it dry and I’m.going to continue to rotate it.okay um hear that like I like spun it.for like two minutes.and it like I wasn’t really satisfied it.was dry then I I kind of stood it up.like this against something to wear dry.the rest away it was like ten minutes so.if this didn’t dry instantly like I.thought it would and you know I want to.make real sure it’s dry because if I.stick it into my barrel support here.it’ll ruin it I mean it’s it’s I don’t.want superglue inside the barrel support.at all and that’s if I can get the bolt.back out there still won’t going to be a.superglue in there so that’s that’s.something I want to avoid completely so.I got my 800 grit sandpaper here and I’m.just going to go around it real lightly.now after about ten minutes I’m thinking.it should be dry but if it’s not I want.the superglue on the sandpaper not.inside my barrel support there so I’m.just going to fold it around it real.gentle and they start turning it trying.to get it round.easing it out and hopefully I’ve.increased the diameter a little bit okay.that looks pretty good let’s see yeah.you’ve taken a little bit off and I’m.just holding it real gentle and it’s.moving it around and trying to get it.round that that’s really what I’m trying.to do I’m not really trying to take any.of it off okay so you know it took a.little bit material off there so let’s.see how it fits let’s see if this.actually worked I mean you know I’ve got.my my bolt stop right here that I’m.using and the barrels is laying in there.so I’m just going to push it up there oh.it won’t even try to go in all right so.I’ve increased the diameter actually.quite a bit I didn’t really expect it to.do that much so now I’m going to get a.little bit more aggressive with it.and really try to sand on a little bit.trying to keep it round and true.make it to where it it really fits in.there nice I may have to get some.heavier sandpaper 800 grit might not.might not be coarse enough to cut this.real efficiently so but okay well yeah.let’s see how it looks now all right.well it slid in there a little bit.further but still not it actually.increased the diameter a lot more than I.expected it to so let’s try it some more.mmm.okay.see.all right let’s take a now boy yeah I’m.only have to get more aggressive about.this so I’m gonna have to hunt me up.some more sandpaper okay I hunted me up.some some 120 grand that’s pretty coarse.and I send a little bit on it and what.I’m trying to do here now is I’m trying.to sand this area smaller than the very.end of it I want this area to be big by.a little bit that way when I when I work.the bolt it it comes undone really easy.it don’t try sticking or nothing like.that.so I’ll grip it kind of in this area.right here and this kind of worked my.way out like that and I’m actually.having to put a pretty good grip on it.and I’ll rotate it as much as I can and.that super glue is really tough I had no.idea that it would take that much.sanding to get it down and it built up a.lot more than I thought it would so okay.let’s try it now that 800 grit I don’t.think oh yeah that’s beautiful okay that.at that 800 grit wasn’t really going to.cut it I had to have like I said I got.120 grit and that seemed to cut it a lot.better and I think it’s doing actually.pretty well so yeah it feels pretty.round to its.yeah it’s pretty good actually I really.like that you know it’s kind of.time-consuming and it took a lot longer.than for that super glue to dry than.what I expected.but that’s actually fitting pretty good.now and okay yeah I think I’m happy with.that I think I’ll assemble it and see.how it does.okay guys assembled the gun back course.I gave it a little bit of oil there and.you can this may be barely see my little.plastic spacer that I made there right.there so hopefully everything will go.okay okay the guns back together now and.I already do some chrony test so let’s.see how this goes and hopefully we’ll.get some good results.okay that seems to be I’d say probably.an average of 575 so that’s about maybe.5.4 foot-pounds of muzzle energy and it.probably retains maybe 3 foot-pounds.that say 20 to 23 yards or something.like that.so that ain’t too bad we’ve increased it.quite a bit I think we’ve increased it.60 feet per second with this mod so.that’s not bad at all.you.okay YouTube that’s it I appreciate you.watching Thanks. I be mad for plugins, because they are adorable!!
I like WordPress plugins, because they are the smart!! This is a mod for the pump cup and also the bolt.
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