Springfield 03A3 Trigger Replacment

L

lscraig

Inactive
All:

I am a noob to this forum so if this is an old topic please feel free to re-direct to the FAQ. But here goes my question:

I have a 1943 Springfield 03A3 built by Smith Corona. The rifle was customized by my dad in the '60's to hunt deer. He gave it to me when I learned to hunt. I have shot the rifle for almost 30 years with the same old military trigger. I Love and treasure the old rifle, but I hate the trigger. My dad did some polishing on the sear and trigger to smooth it out but it is still REALLY CREEPY and stiff as a board. I know I can get a different spring, but I wanted to change the trigger altogether to get more in the 2.5 to 3lb range and eliminate the creep.

I ordered a Timney Sportsman from Brownells and was going to swap it out, but the slot milled in the receiver is rounded at the tang from the mill bit and not squared, so the Timney trigger is slightly too long.

Here is the question: Can I square up the sear slot with a file or do I need a mill?

I am NOT a gunsmith. My "Smithy" experience is limited to glass bedding a stocks, stock carving and finishing and replacing drop in parts. I know how to polish a sear notch and trigger to relieve creep, but filing or grinding on the action itself is intimidating. Is the steel hard or mild. I have a good friend who is a pro gunsmith, so I know he can fit the trigger, but I wanted to be self sufficient.

Your thoughts?

Shawn Craig
 
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A file might not hack it, those receivers are pretty hard. You might have to use a Dremel tool with a cutting wheel to square off the corners.

Jim
 
Another option is to buy a square diamond needle file.
The diamond will cut even the hard steel of a Springfield.

You can buy diamond needle files in many hardware stores or online.
 
The timney is a great way to go.I recently built a 1903A4 clone,and even after carefully doing all the careful square,sharp stoning and polishing I considered the pull heavy,creepy,and mediocre.

In the wee hours of the morning researching 1903 trigger jobs,I found an old,archived CMP forums post.I have not been able to find it again.The gentleman who posted it was listed as deceased.I did not get his name.He apparently wrote a book on gunsmithing,or Springfields .He referred to some page numbers in his book,he also reffered to "Crossman"

He said the arsenal had it wrong to keep everything square,as the sear swings about the sear pin on an arc.If it is square,it is camming the striker back as it swings.

Now,this idea only applies to the portion of the sear in effect during the 2nd stage of pull.

What I did,pulled the barreled receiver out of the stock.Then I put some cold blue paste on a q-tip(weapon clear) I pulled the trigger through the first stage,stopped at the second stage.I applied cold blue to the sear face that I could see,which is the first stage.

That done,I pulled the sear pin and removed the trigger and sear from the receiver.I could clearly see approximately .035 in of unblued land at the sear tip .That is the 2nd stage sear engagement.That is all I was concerned with.

I had a small drill press handy.I put a pin in the chuck the same size as the sear pin.

We are not turning the drill press on,just establishing an axis to work the sear around.I raised up the table so I could rest the sear on the table,and swing it around the sear axis pin in the chuck.The sear rests flat on the table,normal (square)to the axis.

Then I just held a fine,1/2 in square india sear stone stationary,down flat on the table,so the sear would just contact it swinging by.It does not take much, I try 10 strokes and look at it under magnification,try 10 more.When the little land is down to the edge of the cold blue, I switch to a hard Arkansas and give it a little shine.

I don't let my stones move as I do this,and realize I am taking off very little steel,probably less than .002 and only putting that arc from the sear pin to the sear tip on that .035 land of the 2nd stage.

I got a real big grin when I tried it,it rivals the Rock River Arms 2 stage NM trigger on my AR.Great improvement.

OK,I told you how I got a good trigger.The safety still has to work perfectly,it has to be jar/shock safe,and if I partially pull the trigger and stop,the sear return spring must fully reset the trigger.

I guess about 3.5 to 4 lbs.There is overtravel,I just follow through with it.

It might be fun to try before you get the "Dermul tool" out
 
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