Did the barrel extension originate with the AR design?

[pert near]

The critical components to contain a firearm's pressure are the barrel, locking lugs & bolt head. The AR "extension" design makes the locking lugs part of the barrel. There seem to be a lot of advantages to this. An extra-heavy action is longer required. It could be made of lighter/cheaper materials (like aluminum) with perhaps a steel bolt runway. From the Savage switch barrel design, changing bolt heads works fine.

Did the barrel extension originate with the AR design? Was this a new design or had it been done before? Seems like it would be great to have a switch barrel bolt action that would take AR barrels.

Just wondering...

 

[a5werkes]

Barrel extensions have be around since Browning's patented Auto5 design, sold to Winchester, for Belgian production in Herstal; the A-5, its steel bolt square lug locking securely mating up into the steel barrel extension during firing. 50 years later, Stoner pioneered using contemporaneous state of the art aluminum / plastics he used in his aircraft industry design career for mating lighter materials (e.g. not heavy steel receivers) for his revolutionary lighter weight AR-10 design.

 

[Slamfire]

I was told by someone that all firearms design features were patented by the 1890's. Nothing is really new, except those things now allowed by new material technology.

What has occurred since the 1890's, and more particularly since WW2, has been a Darwinian selection of the few features that we find in the firearms of today. With a few new things allowed by the advancement of material technology.

One of which, is barrel extensions. They are all over the place.

 

[WestKentucky]

A5 kinda danced around it. The most basic barrel extensions seem to have originated with pump shotguns, and auto loading shotguns generally followed the pumps. The use of a barrel extension in rifles may have started with the AR10, but it could have been earlier in pump rifles. The possibility of earlier examples in rifles, especially lower pressure rifles, that had takedown features seems high.

 

[BBBBill]

...Seems like it would be great to have a switch barrel bolt action that would take AR barrels...

That would not require much to accomplish if there was sufficient demand.

 

[a5werkes]

A5 kinda danced around it. The most basic barrel extensions seem to have originated with pump shotguns, and auto loading shotguns generally followed the pumps.

I might be getting loose and easy with facts here , but the multi-step fabrication of a heavy milled from a single block of steel receiver Winchester Model "12" ( Model 1912) had its bolt lock up into the attic of the steel receiver notch, the A-5 design preceded it. I don't know enough about the late 19th century hammer fired shotguns to opine about their bolt / barrel locking mechanism.

Incidentally, I have authored a 126 page technical manual for the M12.

 

[BigBlue 94]

I would consider trunions to serve the same purpose and those have been around for a long time.

 

[David Hoback]

I would consider trunions to serve the same purpose and those have been around for a long time.

I agree. Think about the AK. The bolt lugs lock in & headspaces off the front trunnion. Although yes, it was first a machined receiver, but still.