[Rex in OTZ]

When I started this project, Id been money ahead to buy a complete set of new springs and wear parts like firing pin and extractor claw, if I only knew.
But I thought itd be just ONE thing to fix, tweak or replace or else something was sticky in need of a cleaning with a few dabs of solvent.

In the end Ive just dabbled n tinkered with just a few things.
Instead I should have declaired total war on that trigger assy and replaced every pin and spring in the thing, or coughed out the dough and bought a new trigger assy.

I could have thrown money at it till it worked.
Instead I pecked away at it.
I think Ive learned more about the Remington 552 than I originally bargained for.
But I do like a good puzzle.
And this .22 has kept me entertained a good while.
One the longer winter projects Ive dealt with.

 

[SGWGunsmith]

If I knew I could reach a Reminton tech that could give me the measurements of what a new uncompressed spring was.
Then I could pull a spring and measure it, knowing the new x-unit spring measures 2.3256"
The x-unit spring from your rifle measures 2.2004"

So far on replacing springs, only one spring was longer than the new spring, that was the bolt return spring that was over a inch longer if my hazey memory serves.
I suspected the previous gun tinker had over streched it to strengthen it.

I'm not a tech at Remington, but I think I have a hammer spring in my Remington parts bin. I'll check it if I do and get back here.

Stretching a weak spring will only last a very short while. It will go back to its weakened length quickly.

 

[SGWGunsmith]

If I knew I could reach a Reminton tech that could give me the measurements of what a new uncompressed spring was.
Then I could pull a spring and measure it, knowing the new x-unit spring measures 2.3256"
The x-unit spring from your rifle measures 2.2004"

So far on replacing springs, only one spring was longer than the new spring, that was the bolt return spring that was over a inch longer if my hazey memory serves.
I suspected the previous gun tinker had over streched it to strengthen it.

It's not real easy to exactly measure a 'springy' item with a caliper, and I don't have current access to an optical comparator, but here are the Remington hammer springs I have in stock:

But, these new and unused springs do not measure to the dimensions you posted above. I get an average length of around 1.840 OAL. the two springs on the top are used and you can see that they have 'set' to their working length.

 

[SGWGunsmith]

Rex- you have touched me with the tale of your plight with that Remington,

In the back of the safe there is an immaculate SpeedMaster. If I leave before you do, I'll ask the daughter to ship it to you.

What, are you moving ?

 

[Rex in OTZ]

I know that in aviation the engine shop use a type of press, the ram has a scale that reads in Pounds and the spring in compressed to a specified compressed length and pressure is checked against a chart a Go, No-Go scale to see if the valve springs are acceptable or not.

In the case of a single .22 hammer spring its way cheaper to huck the old spring and buy a new OEM part.

In the case of a defunct companys product, oft times your on your own when fabricating a replacement part the spares are scattered far and wide or completely depleted.

I had a booger of a time fabricating a Missing High Standard Sentinel IV hammer stop that is just a bit of piano wire with two different length legs bent at 90° a set distance appart.
Getting that proper demension was tough, esp in OTZ where piano wire the correct demension is impossible to find.
Funny where one find's suitable steel stock to repurpose in fabricating parts.
In aviation industry its called counterfeit parts, in gunsmithing its called a replacement part.

 

[c3shooter]

What, are you moving ?

Sooner or later, to that undiscovered country from whose bourn no traveler returns.

Mind you, I am not planning that trip anytime real soon...

 

[SGWGunsmith]

Well, that's certainly GOOD to read.

 

[Rex in OTZ]

This has been a good week.
The new Brownells rem 552 hammer spring arrived today!

I have a couple other gun-fixing projects going on as well.
Tweaking a MAS 49/56 Century Arms converted 7.62x51 rifle.
The last owner was afraid of it.
Had a handfull of some argentine 7.62x51 that he said he used in it.
I just finished installing an adjustable gas valve that needs adjusting.
That and when century indexed the barrel they never quite set true the front sight.
In order to hit POA I have the windage run all the way to one side to compesate at 100yds.
So will be off further out.
I want to reindex the front sight.

 

[Rex in OTZ]

Well today we went out, and tried the 552 after replacing the hammer spring, I stoked it with 10 rnds Federal silver box, cycled in the first round, which fired, the second didnt and neiter did the 7th & 9th rounds tried.
So 7 out of ten fired!
Then tried another six and only one fired, then I tried some old CCI minimags and every one of them duded out on me.
This evening I pulled the barrel and bolt unit.
While out I noticed some fresh scuffing on the hammer.
Front Lt side of the hammer, something is scuffing that hammer, If its hitting on firing and killing off the hammer blow force to the firing pin, then I need to figure out why

So is the hammer the problem
(Possible shim the hammer with some brass shim stock?
If that was a remington issue they would have been tons of posts about sloppy hammers.

Top a photo of the bolt and barrel tipped muzzle up so the firing pin was hanging down out of the bolt, then tipped muzzle down so the firing pin dropped back into the fired position.
Then a photo of trying to get see hammer side play deflection.

 

[Rex in OTZ]

As I was cycling the bolt I noticed the torsional twist slighty counter-clockwise the last bit on closing.
Could it be twisting slightly enough that its interfrearing?
The grooves on the bolt body engage in the bolt guide/ejector, if there is any wear in either would allow the bolt to rotate about its axis slightly and when fired would account for the ding on the hammer.
So I cut a bit of post-it sticky pad next to the ejection port as a refrence.
I might try replaceing the bolt guide first the chespist alternative.
Then its possible the bolt body itself if the bolt guide groves are worn beyond limits this might allow for a torsional twisting of the bolt.

 

[1911NUT]

This starting to sound like a REALLY sad country song.

 

[Rex in OTZ]

Well I got to pulling it down last sunday.
I must have haf it appart 4-5 times.
Studying why the hammer dropps sounding strong but hitting light.
And the rocking bolt CCW each time the bolt goes into battery.
Could the Bolt guide/ejector be contributing factor? It certainly ejects just fine, yet the bolt freely rocks.
I had pulled the Ejector/bolt guide from the barrel extension and gave it a couple raps with a hammer on a anvil to square the engagement area, used a prybar to open the side that rides in the bolt grooves by spreading open a tad to take some of the rotational slop out of the bolt and reassembled the whole thing.
Then it sat till last night.
Sunday My Oldes daughter wanted to go shooting.
She said life was stressing her out and she wanted to go do some
Shooting Therapy.
So I loaded up the sled and warmed up two snowmobiles (yes April 29 and ice and snow still here)
Grabbed the 552 and a new .22 Id shot a little bit a month ago.
A Chippia M1-22 (.22 cal M1 carbine) and some 9mm.
I was dreading what if any improvement the 552 may hold.
I loaded 5 cartridges and fired them off.
Paint me amazed! 5 uninterrupted shots! Wow!
I loaded 15 rounds and had 15 go off as I pulled the trigger.
Then I got off task and was overseeing the loading of a 9mm.
My son loaded and fired off 10 rounds in the M1.
It definately fired every round in the magazine. But it had problems.
A safety Issue cropped up, I will have to address.
In the mean time the 552 was around the 100 round mark when it started to Fail To Fire.
The FTF's numbers got greater as more rounds were loaded and tested.
So now Im thinking the bolt guide/ ejector may affect this operation more than any other.
So new ejector is on the way.

 

[Rex in OTZ]

Im still stumped.
It just flat out strikes light.
Could it be a headspacing issue?
Ive checked the contact area between the bolt and barrel, both are shiny bare metal.
So its not a compacted build-up of powder residue.
I guess I could fire it and measure the spent brass casing.
Then fire a .22LR from another semi-auto like a Ruger 10/22 and compare the spent case demensions.
Someting is just plain out of spec.
I just have to figure what that might be.
I wonder if the chamber was enlarged from dry firing and ironing, youd think Id have picked up on wierdly deformed brass or possibly a crack in the brass from being unsupported.

 

[Rex in OTZ]

I tried searching for Remington 552 light hammer strikes.

I did find a 572 post addressing this issue.

https://www.google.com/amp/s/www.rimfirecentral.com/forums/showthread.php?t=398878&amp=1
Eye Relif's post 11:47 AM 06-20-2011
'problem with light strikes, and first round feeding. Look at the back of the bolt where the deep V notch is. In the center of the V notch is where the firing pin sits captive by a small pin. The firing pin has a small slot allowing forward movement from the hammer strike. My 572 and 552 are over 30 years old, and I discovered that the hammer had "peened" the slot the firing pin sits in, deforming it slightly and limiting the movement of the firing pin. I drove the pin out of the side of the bolt, removed the firing pin, and used a dremel to clear the slot of rolled over metal. I needed to use a new reinforced carbide wheel on the dremel in order to have enough reach to make it to the slot. You could also use a flat file if you could find one thin enough (a fingernail file might work), will need to be the same thickness as the firing pin or less. Also check to make sure that your firing pin has not flared at the back from the hammer strikes. I dressed the back of my firing pin with a flat file. Take the same flat file and dress the sides of your hammer. With a lot of rounds, my hammer had flared out slightly which could slow down as it passes into the V groove resulting in light strikes. While you have it apart, clean the firing pin and the channel that it sits in well. When finished, the firing pin should slide effortlessly back in forth in the reassembled bolt. This problem may be a result of excessive dry firing. The reason that I was having trouble feeding the first round was because the firing pin travel was limited the firing pin was sticking out just far enough to hang up the back of the case as it was sliding into position. There was enough inertia on follow up rounds to force the round into battery. The limited travel of the firing pin caused the light strikes as well, not allowing the firing pin enough forward motion to set off all rounds. Solved my problem.'

 

[Rex in OTZ]

Well tonight I loaded her up for another try.
I loaded 15 rounds.
It fired 9 of the 15.
The second 10 rounds loaded 4 fired.
Then I pulled her appart on the spot, I checked the bolt, its clean, I treated the burrs ages ago.
Even ran some emery cloth folded over some lath and the bolt's hammer slot was dressed.
As I was sitting in the grass with gun parts in my lap, what I did notice was that small bump at the top edge of the hammer.
That got me to thinking.
I sat there trying to hold the bolt in relation to the trigger group, but gave up because I just dont have the geometry right.
Thinking what others had posted.
They replaced all kinds of springs, they replaced firing pins, in some cases more than once with the same results of light hammer strikes.

 

[Rex in OTZ]

After editing photos, The only way to learn something would be to get a new hammer and compare the demensions.

Could it be possible the face of the hammer has that small bump as what contacts the fireing pin, but after repeated hammer releases and battering away on the back side of the bolt that eventually it gets beaten down gradually till its out of spec.
That would reason why replacing fireing pins was only a temporary fix/marginal fix.
If you have a battered firing pin and bolt and burrs on the hammer, it stands to reason it wont have the same tolerance cushion it had when new.
Im debaiting first trying to trim back some the hammer relief to accentuate the nubbin on the hammer that contacts the firing pin.
That might be the difference between shots of just enuf force and those that dont, toss in some burnt powder smudge gumming up the works that borderline hammer just might not have the required material to strike the firing pin.
I think I will try that, there is a reason that wierd bump is on the hammer face, a reason why its not much.
That is one avinue I can try (with thoughts of buying a replacement hammer)
As I was studying the hammer I noticed it had quite a bit of side to side wobble,
Using the tip of my index finger I could get approx a 1/8 inch of movement at full deflection!
I was just reading about how folks were shimming the excessive freeplay out of the hammer on Ruger 10/22's
Looking at how much this hammer wobbles, shimming the Rem 552 hammer sure couldnt hurt.

 

[Rex in OTZ]

Rex- you have touched me with the tale of your plight with that Remington,

In the back of the safe there is an immaculate SpeedMaster. If I leave before you do, I'll ask the daughter to ship it to you.

c3shooter I appreciate your sentiment but this is just a flat out challange to me now, Im going to get to the bottom of this problem.
Which seems to afflict older high cycle 572 and the 552's.
I dont really have any attachment to this particular 552, it was given to me by one the towns elders (who passed away last fall) because he couldnt figure out its ailment, I just want to make it fire reliably.
At this point in the game, Id be happy if I could manage to fire three mags of cartridges without any stoppages.
So far Ive never checked to see how accurate it was, Ive been concentrating on the action as it cycles (when it decides to)
Im 99.9% sure this is a trigger group issue and 90% sure it has to do with the hammer hitting the firing pin.
Ive already thought of excessive head space but this blowback action cant be that far outta wack, the brass does not show excessive head space.
Its the hammer and its intermittant normal and light strikes on the firing pin.
Im thinking after a certain ammount of cycles the 552 'hammer batters itself out of tolerance' to the point it barely makes contact (inconjunction with sloppy hammer side play)
So my short term hypothisis is to file back the lower part of the hammer to accentuate the upper contact surface that impacts the firing pin and shim the side to side wobble out the hammer throw.

 

[danf_fl]

On the side play, is there some sort of shim material that could be used to reduce the play?
https://www.mcmaster.com/shims

 

[Rex in OTZ]

I could check what I have on hand.
The hardware store stocks brass sheet's of varying sizes and thicknesses.

 

[Rex in OTZ]

Well last night I dropped out the trigger group and using some tools was able to drive out the stepped diameter pin that secures the disconnector in place, funny thing is that pin is staked in place and I used a punch to drive the staked part past the steel washer used as an anvil to stake the pin end against as the trigger housing is aluminum.
Since the old disconnector was also below the sear, I made sure to also place the new one below the sear as well.

'Quote: 'disconnector is above the small lever that allows hammer to cock before the trigger resets. It must be below it'
http://gunhub.com/rimfire/58339-remington-552-speedmaster-firing-issues.html'

Since today is pretty stormy so will put off shooting till the weather clears up.

The blazing flaw that been staring at me since I photographed it Nov 11, 2017!
It has not broke, but it could!