Auto-5 and Clones - Question

[MJD]

Two questions for anyone familiar with Auto-5's and the Savage 720/Remington M11 clones. I think despite the relative lack of part interchangeability between the models, this could apply to any of them.
On a Savage 720, I had to replace the locking bolt in the bolt assembly.
Picture attached with numbers corresponding to the question.

1. This problem existed prior to that. As seen in the attached image, the barrel extension pokes out a bit from the receiver. I have read this is due to the forend being battered, but the forend on this shotgun looks to be in good shape - no evidence of the barrel ring battering it, and no cracks/splits. Any ideas on fixing this or items to investigate?

2. This problem did not exist prior to replacing the locking bolt. I now have the charging handle not going all the way forward within the bolt assembly. You can see the gap in the attached image.
I am almost positive this is due to the locking bolt latch interface with the locking bolt, but wanted to hear other thoughts.

 

[WestKentucky]

Image didn’t attach, and I’m having trouble visualizing what you mean. The barrel extension on my rem11 did come out of the front end of the frame by roughly 1/4” or so and it functioned flawlessly. The model 48 looked very similar in function. I have sold off all of my long recoil action guns though as I don’t use shotguns much anymore.

 

[MJD]

Thanks - I am showing the image at the bottom of my post and was able to open it within the post, hopefully others are able to see it as well.

I laughed at your signature line. As I was typing this, I was wishing I could ask our late friend, RC....he would have me straightened out in five seconds flat!

 

[MJD]

Well I was completely wrong on #2 in my OP, but I spent a lot of time poking around in the lockwork and now have a much better understanding of the internals....

The bolt handle wasn't seating fully in the bolt in the forward position because the locking block was too large and didn't fully lock into the barrel itself. So because it didn't go all the way "up", it interfered with the bolt handle's ability to go fully forward.

A couple strokes of a file to properly fit the locking block seems to have resolved the issue.

 

[Sovblocgunfan]

Problem 1: if the forearm is not battered where the barrel ring makes contact then the recoil spring, and friction ring and its related spring need to be reviewed, and the recoil spring replaced at a minimum. The recoil spring should hold your barrel extension flush or slightly proud by 1/16” as normal.

also please ensure the forearm cap is tightened correctly as this could introduce some slop, allowing the extension to sit too proud of the receiver.

problem 2: you’ve correctly remedied the problem.

 

[MJD]

I did replace the action spring and recoil spring both, figured it was about time after 80-90 years anyways....are you able to expand on how to tighten the forearm cap correctly? I'll take any advice from more knowledgeable folks!

 

[Sovblocgunfan]

Just “tight”. Don’t bother backing off a fraction of a turn or anything. No need for torque wrenches either. Hand tighten till it wont turn anymore and done.

it’s quite possible that you needn’t bother with anything else if the gun locks up in battery and otherwise functions correctly.

however, I should ask. The recoil spring you installed-was it a new spring? Did you measure it? Bare minimum length should be 9.25”. I only ask because there is a spring made for a 3-shot model that is a bit shorter than the one for the 5-shot model. Also your bronze friction piece should be replaced too. It functions as a brake and should be a pretty tight fit on the magazine tube.

 

[MJD]

Good question. It is indeed a three shot model and the recoil spring was shorter than that - edited to add: the new spring is 7 5/8 inches. The old (and I assume original) has relaxed to 8.25 inches.

 

[Sovblocgunfan]

The three shot models are not as common as the five shot models. Cool that you picked one up.

pics of the forearm and cap assembly?

 

[MJD]

So the story goes, my wife's grandfather picked this up as a teenager in the 40s from a local duck hunter. I guess since it is a 3-shot model, it is not technically a model 720, but a 726, if my research is correct....however, an internet search for model 726 returns even fewer results!

I'll put up a pic of the forend later today....attached here is the gun cleaned up. A dunk or two in the ocean many years ago did no favors to the internals, so plenty of cleaning was in order.

 

[Sovblocgunfan]

That’s a cool gun! Browning made a 3-shot model too, but they are much rarer.

regarding the recoil spring, here’s an experiment you can try.

take the old recoil spring and manually stretch it until it’s about 9.25 or a little greater. Reinstall it and see if it eliminates your barrel extension gap. Something tells me your spring you bought may be used and entirely too short.

if that’s the case you can probably source a new browning spring for a 5-shot model and use that. Your gun will thank you.

 

[MJD]

Couple photos of the forend and cap.

In this case anyways, there is no "crimp" visible on the outside of the mag tube. There is a step-down in diameter inside the mag tube that limits the mag to two rounds in the pipe.
Seems like the mag tube would be the same length no matter in this case (I put 4 shells on the outside to confirm)....so the recoil spring would be the same length, no matter...am I thinking about that the right way?


I bought the parts from Numrich, I did specify the "3 shot" recoil spring option for the Savage 720. I'm now wondering if I should simply have gotten a 5-shot spring.

 

[entropy]

There's a Savage 720 at the LGS for $159, I suspect parts availability is why it's not priced like an A5. Tempted to pick it up anyway. But there's also a 1960 Win. Model 12 at another local shop for $299, it'd be a nice gun for Vintage shoots......in great shape.

 

[MJD]

If the one at your LGS is in 12 gauge, I'd personally buy it...lots, lots, more 12 gauge parts out there than 16 gauge.

 

[Sovblocgunfan]

Couple photos of the forend and cap.

In this case anyways, there is no "crimp" visible on the outside of the mag tube. There is a step-down in diameter inside the mag tube that limits the mag to two rounds in the pipe.
Seems like the mag tube would be the same length no matter in this case (I put 4 shells on the outside to confirm)....so the recoil spring would be the same length, no matter...am I thinking about that the right way?


I bought the parts from Numrich, I did specify the "3 shot" recoil spring option for the Savage 720. I'm now wondering if I should simply have gotten a 5-shot spring.

that’s exactly my point. Go to midwest gunworks and order a new standard (not magnum) spring for a browning auto 5. Your gun wont know the difference.

 

[entropy]

If the one at your LGS is in 12 gauge, I'd personally buy it...lots, lots, more 12 gauge parts out there than 16 gauge.

It is. If it's there next pay check.....

 

[MJD]

So to recap, for anyone in a similar position to me in the future:

Numrich has a three-shot option for a recoil spring for the Savage 7xx series of shotgun. If you order this, make sure you actually have a shortened magazine tube (I'm not sure I've actually seen this in real life, but you never know). More likely, you have a normal-sized magazine tube and it might be internally blocked to only hold two in the magazine and one in the chamber.....in which case, the "five shot" length recoil spring will work equally as well on this. Thanks to all for the help!

 

[entropy]

So I finally took that 755A ( not 720) apart, it has a broken firing pin, new one already ordered. It has a resulting partial hairline crack in the bolt from the firing pin breaking, it shouldn't be a problem however.
I picked up the Model 12 also. After going through it last week, I shot it for a 50 rd. Trap Jackpot shoot today. (-20 F) Score wasn't great, but like the gun, can't wait to try it this spring.

 

[MJD]

Good on you on both! For what it's worth, ebay had just untold amounts of 12 gauge parts for the 720/755/etc family.....a spare bolt & locking block can be come by pretty cheap, seems like they are common sources of headaches.