A friend of my dad's has one, and has been looking for a slug barrel for it. The issue is, he was recently told by someone else that they were known for cracking the receiver or stock with slug barrels. Is this true, or did he maybe misunderstand a warning that they sometimes crack the forearm if there's not enough clearance for all those moving parts?
Also, I found two slug barrels for sale today, both for the light twelve version. If his gun isn't a light, can he still use the barrel if he changes the forearm, like with the 11-87 light contour, or does he have to get a correct-for-receiver barrel?
"told by someone else that they were known for cracking the receiver or stock with slug barrels" B.S.
The only difference between the "light twelve" barrel is the ring that goes around the magazine tube has two holes drilled through it to make the barrel lighter. I'm not sure, but the barrel may also be thinner that a regular weight barrel, neither will effect longevity or cause damage to the receiver. It only saves some weight.
As on all A-5, Remington 11, Savage 720's keep the magazine tube endcap tight and you won't have to worry about the forend spliting.
Most shotguns of this type with broken stocks that I have seen are due to being worn out.
A few pointers on the Auto-5:
The barrel contour can vary over the production run of various barrels and between versions. A slug barrel contour will vary slightly from a smooth bore contour. The fore end may require it to be fitted. You can tell with the barrel at rest when it will be in the foward most position. I like to see about 1/32" clearance between the barrel and fore end.
A true light barrel is as described, it will have a barrel lug with the two lightning holes, but this usually only applies up to 1958 when the magnum 12 (3") was introduced. Prior to 1958 they have a standard weight and a light weight 12 (2 3/4") designated by a M or G prefix to the serial number. A 2 3/4" barrel will only work on a 2 3/4" receiver and the same with the 3" barrel. The extractors are located differently, the recoil springs are different, fore ends are different and the barrel extensions prevent the two from being swapped.
A slug barrel will not be any harder on the fore end than a smooth bore, the two leading issues that cause cracking are a loose fore end or improperly set up friction pieces. Maintain these two aspects and you will have little if any trouble with the gun.
I don't know about the newer guns but the old ones have lots of serial numbered parts. Mine even has the serial numbers inside the forend and the buttstock, so you know if your parts are original or replacements as most folks won't notice or bother to restamp a replacement.
Heck, mine even has the serial numbers on internal parts and even the screws that hold the darn thing together (some of those are only the last four digits of the serial number but still, lots of time/effort went into building these guns right;)