The trigger assembly of the 07 is a reliable design and is used almost intact in both the .30 M1 Carbine and the Model 50/59 shotgun. However, it has a very slight amount of takeup creep. More significantly for our investigation, the trigger does not move at all - no creep - when the crossbolt safety is engaged. 

At the range, when the trigger is pulled on a live round, the trigger does not move. There is no takeup creep. At home, when the trigger is pulled on a dummy round, the trigger takes up very slightly and then "fires" the dummy with an audible firing pin strike on the dead primer. 

The firing pin assembly is not blocked, as can be verified by other means as well. It is the trigger stroke alone that is blocked and there are only two things that can block it:

1. Manual engagement of the crossbolt safety by pushing the button in the trigger guard.

2. Automatic engagement of the crossbolt safety by the "out of battery" lever:  the spring loaded lever installed in the left wall of the lower receiver,  directly over and connected to the crossbolt safety. Under spring pressure this lever is held vertically at full extension and the trigger is blocked. At full extension this lever rides along the bottom of the breech bolt. There is a bulge or block at very end of the bolt, such that when the bolt is in full battery the lever is depressed, unlocking the trigger stroke. 

The rim thickness dimensions of the live and dummy rounds are virtually identical. Both seat fully in the chamber, as can be confirmed visually. The live rounds are Western factory. Insufficient headspace is not an issue.

The most likely reason the trigger is blocked at the range is the failure of the bolt safety lever to be fully depressed, for some reason. 

At the range,  I failed to bring the set of dummy cartridges, to try after the live rounds would not fire.  That would have probably revealed cartridge dimensions aren't the problem. 

I carried the 07 to the range disassembled in a Boyt takedown case. This particular 07 has never been taken down very much and all the steel edges are sharp and unworn. If not lubricated, the upper and lower receiver are difficult to manipulate into position and close fully. The takedown bolt requires a screwdriver to firmly close the two halves. 

I now believe the lower receiver can be installed with enough of a barely noticeable gap that the bolt safety lever is not fully depressed.   The lever is on the lower receiver, along with rest of the fire control mechanism. The breech bolt is in the upper receiver. 

When I came home from the range, it was a couple of days before I cleaned and reassembled the gun. Before I did so, I decided to "season" all the internal steel with BreakFree CLP, to impregnate the pores and make a slick, molecular-level bond. It has made assembly and functioning significantly easier. Of course, after I assembled it and tightened the takedown bolt with a Brownell MagnaTip, it shucked and "fired" dummies without issue. Repeatedly. 

The most likely cause of the trigger lockup is that the internal, spring loaded, bolt-out-of-battery safety lever mounted in the left wall of the lower receiver is not being fully depressed. I can prove or disprove my theory just by bringing dummies and live ammo to the range. "Firing" a dummy and then loading a live round. What I should have done before. 

I am a slow learner and a sloppy investigator.

Somewhere there must be factory literature advising the anticipated round count when the buffer should be replaced. Or at least advising inspection and a minimum size gap.

As Bert said, they aren't noted for target accuracy but a cop, armed with one and a 10-round magazine of metal cased slugs, could deal a Depression Era bootlegger's V8 Ford and its occupants a lot of grief. The 351 round had an appreciably better trajectory than the Thompson's 45 ACP. Having owned and shot the Remington Model 8,  it's more powerful but not as compact or handy.  

A prison guard, faced with a full-on riot, would take comfort from having one in his hands loaded with ten 180 grain softnose rounds. 

The late, unlamented Homer van Meter was of the same opinion,   

Bert H. said

MidwestCrisis said
Well my targets are a little too embarrassing to show but I was able to get some good groups.  I noticed last night that the front sight was a little loose in the dovetail so I super glued a .001 shim to the bottom and drove it back in with blue loc-tite. I was hitting where I was aiming once I figured out the correct sight picture.  At my 130 yd steel I was hitting low, but I did ring it a couple times.  My stock repair held up. So now I’ll see if I can get the butt stock to match 
  

The Winchester S.L. Rifles are not known for target grade accuracy... 2" groups @ 50-yards are superb.
Bert
  

Well that makes feel better.  I couldn’t see my hits at 35 yards. I shot a group, then tried a 6 o clock hold.  That’s the low ones.  Then I checked the target and shot the two that look good.  Then I threw $50 at the 130yd steel.  

MidwestCrisis said
Well my targets are a little too embarrassing to show but I was able to get some good groups.  I noticed last night that the front sight was a little loose in the dovetail so I super glued a .001 shim to the bottom and drove it back in with blue loc-tite. I was hitting where I was aiming once I figured out the correct sight picture.  At my 130 yd steel I was hitting low, but I did ring it a couple times.  My stock repair held up. So now I’ll see if I can get the butt stock to match 
  

The Winchester S.L. Rifles are not known for target grade accuracy... 2" groups @ 50-yards are superb.

Bert

TXGunNut said
I think patience is the key with adhesives on wood, old guns in general. I use Gorilla Glue when building or rebuilding knives. I prep, apply the adhesive, clamp carefully and walk away. I've learned the key to working on old guns for this amateur is knowing when to walk away. I resume the project the next day. These guns we love have been around a long time. Getting in a hurry to fix them is almost always a mistake. 
 
Mike
  

What Mike said. Walking away from an unpleasing result is the hardest thing for me to do. Not doing so has cost me hundreds of dollars in gunsmithing fees to fix what I did next -- that I would not have done next in the morning.

I have a mantra, developed recently:

"Well, $#@$%^. It ain't worth dying over. Lets go to the house. "  Sometimes it works. 

The color on the forearm and the invisibility of the cracks is really good. Don't hesitate to paint with stain to layer it over a flattened topcoat, then re-topcoat. 

Layering takes days between steps, not hours. But it is the secret to concealing flaws. 

In the future, I recommend you go for a factory look but with modern materials, rather than worrying about what the factory used. What they used is all they had.

While you are not anxious to get a project that doesn't exist done, put in an order for some Birchwood Casey TruOil, a quart of Bullseye clear Shellac, some form of ebony wood filler, and a can of General Finish brand satin ArmorSeal topcoat or its waterbased equivalent.. The TruOil you can get from Amazon or Midway. The shellac and other stuff from Woodcraft Supply, all online. The shellac is for layer separation. Order some Acraglass gel from Brownell's.  You will be glad you did. It is dark brown, not gray, and is what professionals use. You can add powdered aluminum or bronze for strength on interior surfaces. 

Mike

The preceding posts beg the question, if someone becomes the caretaker of a Model 1907 in good condition would it be prudent to reinforce the fore end if one intends to shoot it more than a few rounds? 

Mike

MidwestCrisis said
Here’s the rifle back together. I had to repair a couple cracks in the fire stock.  Both sides were pretty much all the way down.  I used JB weld and reinforced with fiberglass cloth.  

Adam,  I can't see the JB Weld at all. Did you cover it with something or did the lacquer turn the gray to black? I like the forearm better than the buttstock but all you may want to do is lower the gloss to satin on both pieces. Otherwise I think you're done. 

In the spirit of scientic inquiry, my two colleagues are going go help me convert some loose vintage 351 ammo into brass. An important part of the process will be testing the Caldwell Brass Trap. 

We've got Skeet to shoot and at least two Model 50 shotguns and the aforesaid Model 25 to pattern. 

And a 1931 Savage 99F .303 to sight in. 

All before 11AM when Satan finds Hell is too cool for him and rents space in North Texas.