Tech Tip - Remington 550-1 .22 Semi-Auto Rifle

Discussion in 'Technical Questions & Information' started by CountryGunsmith, Apr 19, 2003.

  1. We've seen three 550 series rifles in the past couple of months with sear problems, all due to improper disassembly/reassembly.

    Apparently folks are removing the sear spring case from the bottom of the receiver. This appears as a large slotted screw that just begs to be removed, but it is lightly staked in place at the factory. Inside the sear spring case is, of course, the sear spring which is nothing more than a coiled wire spring that bears upward against a detent in the bottom of the sear. There is no real need to remove this assembly for routine cleaning, and it is best left in place.

    What people do not realize is that the diameter of the sear spring case acts as a travel limit on the sear, preventing it from rising too far upward. After you overcome the staking and are removing the case, you will hear a loud click as the sear is released to travel the remaining fraction of an inch upward under pressure from the sear spring.

    You will now notice you cannot replace the sear spring case, since a shelf on the sear prevents it from seating fully into the threads. The problem here is that people DONT see that, and figure a little more force will surely work - which ends up crossthreading the whole works, kinking the sear spring and rendering the rifle useless.

    To properly replace the sear spring and case you will need to remove the bolt, safety and trigger. Insert a tool from the rear of the receiver to hold the sear close to the bottom of the receiver, which clears the shelf out of the way. Place the sear spring into the sear spring case and make sure the spring engages the detent in the bottom of the sear. Keeping the sear held close to the bottom of the receiver, push the sear spring case into the threads and carefully engage a few turns. Be very careful not to crossthread. The case should screw in easily to full depth. You will now notice that the sear is under spring tension, but is limited in upward travel by the sear spring case.

    Next, install the safety then the trigger, pivoting the trigger into place so the trigger return plunger engages the safety cam.

    These 550-series rifles are great shooters, but they can be somewhat frustrating to reassemble without prior knowledge of the tricky parts....;)
    GreyHammer likes this.
  2. terrybee

    terrybee New Member

    Nov 25, 2006
    Thanks!!! That is EXACTLY the information that I needed to get my grandmothers old 550-1 back together after cleaning out 50 years of old gunk. works like a dream now.

  3. deanzanne

    deanzanne New Member

    Mar 22, 2008
    No feed problem fixed
    Last edited: Mar 26, 2008
  4. JAhammer

    JAhammer New Member

    Mar 12, 2009
    I got these rifles from my cousin. (a Remmington 341 and a 550-1) They were nothing but rust and dirty parts and the finish on the wood was all but gone. I gave them a good cleaning and a new shine. Thanks to Firearms Forum I was able to get the 550-1 back together!

    Attached Files:

  5. PetahW

    PetahW New Member

    Jan 3, 2009
    State of Despair
    Good post, CG - Thanks for taking the time & making the effort.

    I'm sure many more lurkers/surfers will benefit, and reduce the total of paperbag/cigarbox guns, brought into a gunsmith, for reassembly. ;) :)

  6. JAhammer

    JAhammer New Member

    Mar 12, 2009
    Thanks for the reply! I put the first five shots in the bullseye @ 25 yards with the 341. The 550-1 is on center but shooting high. Oh well, more fun sighting it in!!
  7. prplflh71

    prplflh71 New Member

    Jan 23, 2011
    I realize this post has some age but it is very relative to my recent issue with a 550-1. Hope you don't mind my resurrecting it.

    So, I had the bright idea to dabble in a "restoration project". Something I've always wanted to do as a hobby. I found an old 550-1 in my step-dad's safe that looked like a prime suspect. The stock was a mess, the metal had rust; all in all it had it's best days behind it, so I figured I couldn't hurt it. I got my step dad's blessing and carried it home.

    I have the stock back to something I'm proud of with a Tru-Oil finish. I originally planned on a re-blue but did some reading and discovered a little turpentine and 0000 steel wool made all the difference. A couple of nearly unnoticeable stains remain, but heck it gives it character :) I've given it a good soaking in Diesel fuel, cleaned the action and have the bore shining like a new dime! It really did clean up nice, it was REALLY caked up before hand!

    I disassembled the receiver by unscrewing the receiver plug, removing the spring, bolt handle and bolt. I also removed the safety, sear cup and spring described in the previous posts. Ooops? The sear cup head had been previously mangled by an attempt to over tighten or by using an improper size screwdriver, but it seams to thread fine.

    I'm not sure if I have a problem or not. When I drop the sear spring into the sear indent and place the sear cup over it, I can push against the spring tension and thread the sear cup into the receiver. I thread until it's tight but notice the trigger seams tight until I back the sear cup off a bit. Once I do this, the trigger gets some "bounce" back as opposed to being almost stationary.

    Figuring I had a problem, I attempted to follow the directions in the previous post by further removing the trigger. I drove the smaller front pin out, no problem. The larger trigger pin will not budge! Bent my brass punch trying! I tried to drive it out both sides of the receiver, no luck. Pretty sure it drives out left to right?

    So, my question is; by removing the sear cup and spring, did I cause this issue described that so many 550's have? Since the sear cup threads seem undamaged and I can tighten it without cross threading, am I okay? (Note the cup does not seat tight against the receiver when tight, there is a slight gap where it does not thread all the way flush). Do I still need to remove the trigger and go through the steps listed in the earlier post? If so, is there a trick to getting the trigger pin out?

    Also, before I realized I may have an issue in this area, I attempted to reinstall the safety, but am having a bugger of a time with getting the trigger spring/plunger and safety in place. Is there a trick to this also, or am i just not holding my tongue right ; )

    You guys are right, this is a bugger of a gun to tinker with......just my luck on a first project! I really don't want to have to throw this thing in a box and walk into the gunsmith with my story of woe. With the TLC I've given this ole girl so far, if/when I get it back together I think it will be an excellent shooter and not bad to look at! Hope you can help!


  8. GreyHammer

    GreyHammer New Member

    Sep 1, 2015
    I discovered this too, after cross threading several sear spring screws, The tap, 3/8 - 32 plug, will correct the threads. I just don't see how this solution was missed, it's so clear once observed. I have 5 550-1, and can now assemble any in about 5 minutes.
    I digress a moment. Always remove the receiver insert assembly, which implies all internal parts, before removing the 550 barrel. I bought some 4" aluminum vice jaws off eBay for my 4" table vise. This is perfect for the 550 barrel, then, I took a 1x3 3 foot packing crate board and using a spade bit, cut two holes, one 7/8 and right below that, a second circle 3/4. Guess what, this fits the contour of the 550 receiver, and is a perfect non-marring receiver wrench. I've used this getup on six separate 550 receivers with no problem.
    Getting back to the installation of the sear cup, and from a fully stripped receiver, screw the barrel back in aligning the extractor slot with temporarily installed bolt, usually just a fraction short of center on the slot, making sure the flat service allows the insertion (from the rear) of the receiver insert assembly. With the insert assembly in place, I start the pin that holds the sear proper and the carrier/cartridge stop levers, about 1/4", just enough to install the sear. At that point, I install the sear with the pin holding precariously, so it must be tilted. Then, slide in place the carrier/cartridge stop lever w/spring and spacer bushing fully assembled. This assembly m/b tapped with a tiny hammer or something like that to clear the curved section of the receiver. It should then be captured with a punch from the left side of the receiver. At this point, the sear pin can be easily pushed thru the assembly, pushing out the punch on the other side. This is easy once you get the hand of it, and becomes much easier than re-installing the safety.
    Now, it time to install the sear cup w/spring. I use a small tool, a pick, to hold the sear in its bottom most position. Then just screw the sear cup w/spring in place by hand, noticing that the sear is now captured below the sear cup upper lip. When done, the sear cup should be tight against the receiver flat. I think Remington staked them with a punch. Forty seconds, max, to do this without stripping the treads. okay, I am stopping here, because this is about proper installation of the sear cup.

    Accolades to "Country Gunsmith" for his keen insight
    Last edited: Sep 3, 2015
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