It could be taken a step farther in a different direction and make the pipe pistol use .44 which would allow the damage on it to be buffed pretty substantially as it'd be balanced out by the relative rarity/cost of the ammo type early game. Then another popular suggestion that
@Gazz actually asked me about on stream was to make the pipe machinegun fire 9mm. With these two changes, all ammo types would be useful early game but it'd also have other balance implications.
Machinegun users will use more 7.62 when they get a "real" machinegun, so by letting their primitive tier weapon use 9mm, they'll be able to save the more expensive 7.62 for later. This also opens up the door to make the pipe machinegun have it's damage lowered (as it's using a weaker ammo type) but still keep a healthy enough ammo capacity so it feels like a machinegun still. Since machineguns don't use 9mm later in their build, they wouldn't feel bad about going full auto and using all their 9mm, but they'd still have interesting friction points early game choosing between 9mm to use today or 7.62 to use eventually when they finish quests or buy from traders. Devil's advocate though - how do we convey to players that _this_ submachinegun is governed by the machinegun perk while this different submachinegun is governed by the pistol perk without confusing the player base?
The pipe pistol and LAR being changed to .44 means that the ammo type could be made more common and from an earlier game stage (it's incredibly rare in loot now even on day 70 in the wastelands). Pipe pistol could have it's damage buffed pretty substantially as it'd still be using the most rare and expensive ammo type, combine this with a slower rate of fire and it's already long reload animation and it'd be a perfect early game magnum and would transition perfectly into the .44 magnum at tier 2 which is fairly late game for pistol users, but they'd still have access to early game pistols (including toilet pistols on day 1 even) to use 9mm. Also, agility has access to the bow skill early game, so if their pipe weapon uses fairly rare and expensive ammo, that's ok because they have a perfectly viable other type of primitive ranged weapon.
The LAR would make more sense using .44, but it'd also create another interesting balance point for the rifle skill similar to how SMG exists in pistols. Presently, the new buff to the crossbow makes it massively out-damage and out-stealth the sniper rifle and they both have functionally the same range as it's limited by the draw distance. By retooling the LAR to do more damage (to compensate for the rarity and expense of the ammo type) it could be like the reverse balance of pistols (nice asymmetric balancing that TFP like). Their tier 2 weapon could be their big damage and pretty high fire rate gun, while the sniper could become more specialized in sniping. This could be achieved by making the gun naturally more quiet and or giving it an innate stealth attack bonus similar to bows/xbows.
None of this is a big deal though, just food for thought if the devs are still looking for a way to balance the pipe weapons and also considering other ammo type changes.