SpudFiles

I know this section is raft with the discussion of homemade BB, airsoft, or pellet guns, but I decided, since the section didn't say anything about custom airguns, it was okay to post here.

I've already posted a little about this project on Theopia, and it was suggested to me to go ahead and post the details over here as well. So, here goes...

Back when I was real little, we used to own a Crosman 1389 Backpacker. Of course, being so old, the gun "died" quite some time ago, and recently I wanted to see if I could get another one.

Well, the only ones I could find were "sketchy", at best, and, besides, where's the fun in just buying a stock airgun? Crosman discontinued the model in 1998. So, I started a little research, and I have... a plan.

Crosman's air rifles and airguns are all remarkably similar in construction and design. I have figured out that I could make an even better version of the 1389, with parts from Crosman and some modification.

So, here's what a plan to do. The base airgun for my final design is going to be a 1377C air pistol. Here's a picture of it:

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The things I'm going to change are:

1.) Add a 1399 shoulder stock. This is the exact same stock used on the model 1389 and 2289 backpackers, except it will be attached permanently to the pistol instead of having a release lever.

2.) Replace the 10.25" .177" barrel that comes stock with the 1377 with a 24" .177" barrel from a model 1760 airgun. This barrel and the following parts can be ordered through crosman, so it's not like I'll be salvaging parts from perfectly good guns. The 10.25" barrel has a lathed down section towards the crown which fits in the barrel band, so I'll bore out the barrel band that comes with the 1377 to 7/16" to install the longer barrel, being extra careful that the fit is still tight so as not to harm accuracy.

3.) Replace the plastic breech on the stock 1377 with a steel breech, which Crosman actually sells a kit for on their website, (not as replacement parts).

4.) Sand down the brown forearm and paint matte black.

5.) Install a BSA 30mm .22 red dot scope. This scope uses clamps that fit on 3/8" dovetails instead of the larger weaver mounts, so I'm not wasting money buying a 50 dollar 11mm dovetail-to-weaver adapter.

I plan for this to be a neat little plinker. I'll still have the open sights available for use, and the red dot scope will allow "night ops" when I've got a little bit of moon.

There are numerous other modification which I could still do, but I'm going to save until later. I got most of the information to do the above from an airgun forum dedicated specifically to Crosman airguns. The address is http://www.network54.com/Index/12861.

If anybody has any comments contributing to the design of this airgun, please post them here. I have a "MSPaint" visualization underway at the moment, but that will probably take a while.

And, finally, JACK, don't tell me to get a Daystate. I've looked at them... they're decent rifles... I don't want one. Sorry.

EDIT: Check the bottom post for pictures.

Crosman does offer custom guns, but...modifying is more fun

markfh11q wrote:And, finally, JACK, don't tell me to get a Daystate. I've looked at them... they're decent rifles... I don't want one. Sorry.

Decent? DECENT?! I didn't fork out so much green to have something DECENT, it's absolutely top of the range cutting edge technology!

*ahem*

Your mod ideas sound good, since it's a precharged pneumatic the longer barrel will certainly make an already quiet gun even quieter, plus it's probably not too long as to reduce velocity.

One small suggestion, a bit complicated but I'll throw it out anyway - consider making it a bullpup.

jackssmirkingrevenge wrote:Decent? DECENT?! I didn't fork out so much green to have something DECENT, it's absolutely top of the range cutting edge technology!

I think he meant that it's a rifle for posh people.

Anyway, nice, a 24 inch barrel on a pistol? Go you!

And a little photoshopping reveals this:

First off, you do know that the Crossman steel breach doesn’t have a rear sight on it, and the stock Crossman rear sight doesn’t fit either, right?

My dad says to get the following:
1760SE breach (has dove tail)
1760SE barrel (similar to the one you planed on ordering, only this one has a flat to receive the rear sight)
1760SE rear sight (mounts on the barrel instead of the breach)
1760SE bolt (to go in the breach)

The 1760SE is relatively new so you may not be able to get part for it until later this year so another rout would be:

1377 steel breach kit
1760 barrel
760 rear sight

The 760 rear sight just snaps onto the 1760 barrel, if you inclined to do so you can file a flat were the site goes to help square things up. The 760 barrel has a flat were the sight goes.

2250 replacement stock (half the price of the 1399’s stock, but basically the same thing.)

You have to get the part number off Crossman’s website and then call them for a price inquiry and to place the order. It might be simpler to get the steel breach kit, but this rout might be cheaper and it will provide you with a rear sight


If you see anything over at the Crossman Airgun Forum (the one you linked to) by Andy in NC that’s my dad.

Jack, it’s not a PCP, it’s a multi-pump pneumatic, there be a difference.

Hmmm...

Already ordered the shoulder stock, so too late there.

The 1760 barrel is exactly what I was planning on ordering. I have all the parts numbers I'm using if you want to see em.

The steel breech kit is also what I'm installing. It had the dovetail groove on top as well.

I didn't know that the rear sight wouldn't install on the new steel breech. Since I'm installing a red-dot, it might not make that much of a difference, but I'll have to get one of those 1760 rear sights, just in case.

And Necrosis, nice photoshopping.

I forgot to mention that the 1760SE breach is steel

The 1760SE parts that I told you to get will end up being much cheaper than the 1377 steel breach kit. make sure you're getting the SE parts though.

Also shipping from Crossman is $4 no mater what, or how much, you get.

So the 1760SE breech is "plug n' play" like the breech kit?

I'll have to keep all of this in mind for when I finally call Crosman for parts.

Thanks for the help.

EDIT: in the meantime, I bought the scope from Academy, zeroed it on my .22 Benjamin, and am looking forward to tonight. It's approaching half moon, so there will be adequate ambient light to play around with.

EDIT II: alright, it turns out the only parts available from Crosman as of now are the parts for the "normal" 1760, with a plastic breech, so it looks like I'll be getting that steel breech kit after all.

markfh11q wrote:So the 1760SE breech is "plug n' play" like the breech kit?

Correct.

markfh11q wrote:Thanks for the help.

You are quite welcome.

markfh11q wrote: EDIT: ... .22 Benjamin...

Dang, you are lucky…

markfh11q wrote: EDIT II: alright, it turns out the only parts available from Crosman as of now are the parts for the "normal" 1760, with a plastic breech, so it looks like I'll be getting that steel breech kit after all.

Yeah, that’s what my dad figured, that they wouldn’t have the parts yet.

I thought I read once that you had a 0.22 Benjamin. Guess that must have been somebody else. They're not expensive. Cheaper than the POS Gamo I bought last year, and lasted... a good six years more than it did.

I'll probably be ordering those parts some time tomorrow morning. Got all mah part numbers I need and the final thing is taking shape, (in my mind at least).

Now the package just needs to come in with my air pistol and shoulder stock! I thought PyramydAir did free tracking on their shipping, but it turns out that was only my last order, (the defunct Gamo), because it was over a certain amount. So that box could be popping in any time now. The anticipation is killing me. I haven't shaved in days, and it aint pretty (okay, an overstatement, I forget to shave anyways).

I'll post again when everything is finished and shooting.

Have you visited crooked barn?

I actually currently own this pistol and I have to say it is pretty accurate. I have already replace the .177 barrel with a .22 caliber one, and now it is even more powerful. The 1377 is a great base to start from for a custom mod. If you want to get parts first look here http://www.crosman.com/site/manuals_crosman_pistols at the models parts numbers, then type that number into the search here
http://jgairguns.biz/catalog/ They have almost every part imaginable for crosman if you check the part number.

Acdcmonkey1991 wrote:I have already replace the .177 barrel with a .22 caliber one, and now it is even more powerful.

You could have just bought the 1322...

Jack, they discontinued the 1322. Probably because it's such a simple mod job to convert a 1377 to a 1322.

Anyways, time to answer questions in the familiar quote-answer format.

jackssmirkingrevenge wrote: Have you visited crooked barn?

Yes, I have. I like their Ultimate Breech but I'd rather start out with stock Crosman parts. There'll be plenty of time when I've got more money to add things like flat top adjustable pistons, Ultimate Breeches (don't say it), and Ultimate Bolts later.

Acdcmonkey1991 wrote: I actually currently own this pistol and I have to say it is pretty accurate. I have already replace the .177 barrel with a .22 caliber one, and now it is even more powerful. The 1377 is a great base to start from for a custom mod. If you want to get parts first look here http://www.crosman.com/site/manuals_crosman_pistols at the models parts numbers, then type that number into the search here
http://jgairguns.biz/catalog/ They have almost every part imaginable for crosman if you check the part number.

I visited that site, and I haven't really looked intensively, but I think it'll be easier to just order from Crosman.

I'm ordering this morning, if they got me email from last night yet.

EDIT: Okay, here is what I has:

1.) Blued steel breech
2.) Blued steel bolt body
3.) Blued steel bolt handle
4.) Blued steel breech plug
5.) 24" 1760 barrel
6.) 1389 pumper arm, (looks much better)

Ships in 1-2 weeks.

EDIT II: Alright, last post...

Here's my MSPaint version of the finished carbine.

Whooie!! Finished my rifle/carbine. Range tests will commence tomorrow for accuracy of the setup. I'll have to wait until my new breech seal and mounting screw comes in to do any good velocity testing.

I decided to go with the 24" barrel and the 1389 pumper arm. So far, I don't see any problems with just boring out the existing barrel band to 7/16" to install the barrel, but there could be something unforseen. Mounted a 3-9x32 scope atop just for testing tomorrow.

Here's a few pictures.