Alrighty then - two weeks ago we had this Whatziss, the Czech RPG-7 sub-caliber trainer.
Here's a picture of the Arsenal's RPG-7 with the PG-7 sub-caliber trainer inserted. Note this is the basic RPG-7 - not an RPG-7V, which is more common. The RPG-7V has the provision for the telescopic sight, though it's not always fitted. The original RPG-7 was just an evolutionary step up from the RPG-2 - in terms of a bigger warhead with a greater range, and adjustable iron sights, vice fixed. The markings on the trigger group of the Castle's RPG (which is deactivated, though I'm considering applying to reactivate it so that I can use the trainer in it) are not the ones you commonly find on Soviet RPGs, which has led to speculation that the one we hold at Castle Argghhh! (which came out of captured stocks sold by Israel) may be one of the early prototypes. But, we don't know, that's just speculation from the experts who've examined it. It could also just be from an unknown maker in some Pact nation. It's not Chinese.
Now that we know what it is... let's address the "why's" of those features that led you down the primrose path - the 'eccentric' nature (that is, off-center) of what looked like a splined shaft and bearing, which in fact was a rifled barrel held in place by a fixed collar.
So, here's a few views of the trainer to refresh your memory. Now that you know what it is - the question becomes, "Whyziss?"
A view without the collar.
Why is it made the way it is?
Here's a picture of the Arsenal's RPG-7 with the PG-7 sub-caliber trainer inserted. Note this is the basic RPG-7 - not an RPG-7V, which is more common. The RPG-7V has the provision for the telescopic sight, though it's not always fitted. The original RPG-7 was just an evolutionary step up from the RPG-2 - in terms of a bigger warhead with a greater range, and adjustable iron sights, vice fixed. The markings on the trigger group of the Castle's RPG (which is deactivated, though I'm considering applying to reactivate it so that I can use the trainer in it) are not the ones you commonly find on Soviet RPGs, which has led to speculation that the one we hold at Castle Argghhh! (which came out of captured stocks sold by Israel) may be one of the early prototypes. But, we don't know, that's just speculation from the experts who've examined it. It could also just be from an unknown maker in some Pact nation. It's not Chinese.
Now that we know what it is... let's address the "why's" of those features that led you down the primrose path - the 'eccentric' nature (that is, off-center) of what looked like a splined shaft and bearing, which in fact was a rifled barrel held in place by a fixed collar.
So, here's a few views of the trainer to refresh your memory. Now that you know what it is - the question becomes, "Whyziss?"
A view without the collar.
Why is it made the way it is?
John,
My guess would be allow the sub-calibre training round to more closely emulate the flight characteristics of the actual RPG.
The slower RPG will have a more parabolic flight path than the higher-velocity training round, and so you want to see the training round hit where the RPG is supposed to.
Anyway, that's my 2-cent's worth :)
a)
1) Yellow because that's an easily seen 'training' colour
2) Barrel (and 'gun') to provide an emulation of the force and shock of using the real RPG for training familairisation purposes
3) Bolts in order to allow the angle to match the direction of force in the real RPG
4) Paint to ensure the angle isn't played with by the hoi polloi
5) the collar, ring etc is for structural reasons.
b) it's cheap.
Whyzzat?
Boresighting.
As for the rifling, I cannot imagine why they'd rifle anything like that, and I'd give a dollar to see the round after it exits that muzzle.
the normal land/groove for a 7.62 round is 308 groove diameter and .300 bore diameter (land diameter)
The sub-caliber trainer mimics a rocket.
Completely missing the Whatziss/Whyziss point, I know, but fascinated to know who the RPG minters de jour are. I want to add them to my mailing list.
Most of the new manufacture rockets (as far as I know) have a Chinese or Iranian origin.
But that's me. Now how do I put the *good tequila* back into the catapult suspension?
Uh-huh... Then you'll want to get the DEWAT M109, then you'll want to REWAT it so you can set up the reduced range and use all your reduced range FDC stuff, then you'll be saying, "You know, I've got enough land for a 5 Green Bag..." Before you know it you'll be upsetting the neighbors. :p
I mean, used to be we could just pick 'em up on the side of the road next to the unfortunate whose tried to fire it at us, but what about one (suitibly demiled) to mount on the wall behind the bar?
"Whyziss?" - Making room for the "gun" part of the trainer? Positioning it flight of the training round to replicate the flight of the war shot? (The SMAWs spotter rifle operated under the same idea - duplicating the flight path of the main rocket...)