Help w/ 1377 steel breech install

lburgguy · May 11, 2012, 02:52:25 PM

I'm having troubles installing the Crosman steel breech on my 1377 (newest model). I do everything as instructed but when I cock the bolt the action is not smooth and I don't get that click of it being cocked unless I loosen the rear sight screw (not using the rear sight, but that screw). It all seems pretty straightforward to me and I can't imagine what is going on. Any suggestions?? Thanks in advance!

KevinP · May 11, 2012, 03:03:11 PM

Sound like you need to install a shorter screw ... Might be binding the spring ?

eric · May 11, 2012, 03:10:04 PM

what kevin said

lburgguy · May 11, 2012, 03:33:15 PM

Okay that makes sense. In the kit they provide a replacement rear screw. I got them mixed up but noticed one was a few millimeters shorter, perhaps I installed the longer of the two erroneously. I'll try that when I get home. Thanks! I can't believe how nice the metal breech is though. I think with my scope mounted onto it I should be consistently hitting a dime at 50 ft. Much better solution that mounting a scope using Crosman's silly $10 barrel bracket things.

KevinP · May 11, 2012, 03:38:43 PM

In the kit they provide a replacement rear screw

Mine didn't have the screw ....

cmj21973 · May 11, 2012, 03:57:07 PM

Quote from: lburgguy on May 11, 2012, 03:33:15 PM
Okay that makes sense. In the kit they provide a replacement rear screw. I got them mixed up but noticed one was a few millimeters shorter, perhaps I installed the longer of the two erroneously. I'll try that when I get home. Thanks! I can't believe how nice the metal breech is though. I think with my scope mounted onto it I should be consistently hitting a dime at 50 ft. Much better solution that mounting a scope using Crosman's silly $10 barrel bracket things.

Steel breeches, from Crosman, reuses the screws from your airgun. I haven't order a kit in a while so they might have started including a short rear sight screw, for this reason.

You might discover that your hammer spring is bent, mine was. CP#781A051 $1.15

Make sure that the safety is on and the hammer cocked back before installing the rear sight/breech screw.

Xgecko · May 11, 2012, 04:44:06 PM

make sure the screw in the breech is tight as well.

AZAG · May 11, 2012, 06:35:57 PM

Just file the screw down a little if its still hitting the hammer spring.

1377x · May 11, 2012, 06:41:32 PM

its been a long time since i used a stock bolt
if you tighten the bolt handle too tight ,does it go though the bolt and dig into the other side of the breech making the gun hard to charge?

lburgguy · May 11, 2012, 07:02:13 PM

Thanks for the help. I'm at work so I can't try any of the suggestions until I'm home. I'll post what I come up with. Thanks again everyone!

AZAG · May 11, 2012, 07:12:08 PM

Quote from: 1377x on May 11, 2012, 06:41:32 PM
its been a long time since i used a stock bolt
if you tighten the bolt handle too tight ,does it go though the bolt and dig into the other side of the breech making the gun hard to charge?

As I remember when I first installed the bolt it was hard to cock. I removed the bolt handle, rotated the bolt 180 degrees, and reinstalled the bolt handle. Then the bolt would slide freely in the breech.

BDS · May 11, 2012, 07:28:35 PM

Quote from: AZAG on May 11, 2012, 07:12:08 PM
As I remember when I first installed the bolt it was hard to cock. I removed the bolt handle, rotated the bolt 180 degrees, and reinstalled the bolt handle. Then the bolt would slide freely in the breech.

+ 1

to all the good comments here and... the bolt handle threads (8-32 thread) are often too long by about .060". You can unscrew it a little or... better yet, hit it on the grinder to take off about .060", clean the leading thread up and blue loctite into the bolt.

lburgguy · May 12, 2012, 02:25:33 AM

Turns out the rear screw was binding the hammer spring. But goodness I had to grind off like 1/4 inch or so of the bolt. And that's the NEW bolt they supply which was a few 16th's shorter than the original. I'm still not really satisfied with the action though. When I put a pellet in and move the bolt forward, the pellet seems to bind a bit and not go into the barrel without me making the gun vertical and wiggling it around a bit. Like the barrel is not lined up with the breech properly. Then when I go to pull the bolt backwards to load it, it feels like it sticks - could this be the rubber O-ring binding in the barrel? Also, my accuracy which I thought would be greatly improved is the same as it was with the cheap Crosman adapter things. It's almost as if the cocking of the gun is jarring the scope out of alignment each time - is this possible? It's a $10 Barska 4x15 scope. At this point I'm very frustrated. Oh, I forgot to mention, the bolt handle stripped the bolt hole and I had to rotate the bolt 180 to the other side where it seems okay. I'm not incompetent at all, it just seems like nothing is going right with this gun/kit at all. Thanks for letting me vent.

cmj21973 · May 12, 2012, 03:39:05 AM

1) Pellet might be snagging on the front breech screw/hole.
a) Make sure that the small front breech scew is below the pellet tray,trough. See if it loads better now.
b) If not, loading a pellet by hand past the front breech screw/hole and then closing the bolt.

2) When opening the bolt it should have a little resistance. With gun cocked, point muzzle up and rotate bolt up out of the notch. The bolt should stay in place. This is a good thing.

3) Check to make sure that the scope rings fit the dovetail rail. Post a pic of the rings.

4) Even though the bolt handle is hexagon, do not use a wrench or crescent wrench to tighten. Hand tight only.

P.S. Number 4 was a little humor, just cutback on the spinach. If you did use a wrench on the bolt handle, keep mum about it and I apologize.

lburgguy · May 12, 2012, 04:19:31 AM

Thanks!

4: I didn't use a wrench. I hand tightened and after like twenty or so test shots noticed it kept loosening from the bolt and realized it was stripped! Rotated bolt 180 and now it seems fine.

The old breech the pellet loaded really smoothly, but if there's a bit of a catch it's no big deal? As long as it enters the barrel right?? And yes, that small screw under the bolt was tightened properly.

Also, the front set screw from the breech to the barrel - can this screw, if overtightened skew the alignment of the barrel? I know that sounds like a strange question but think about it, as you tighten that set screw it wants to put distance between the breech and the barrel. I was sort of thinking that I was bending the barrel and that was why the bolt was tight but typing it out makes it sound nuts.

I'm disappointed that my accuracy is all over the map. I won't try to upload a pic but suffice it to say the rails do fit and are very secure. I'm suspecting the inner workings of the scope are getting whacked when I pump up the gun but I don't know.

Thanks for everyone's help. I don't want to wear out my welcome here with too many questions though.