Does being a bottleneck have any real effect on feeding reliability when we're talking about pointy, Spitzer projectiles? 

I'd get the benefit for pistol rounds (.357 sig vs .40 using flat tip JHP) but for spitzer, the pointy tip is so much smaller then even a narrow .224 opening that I imagine bottleneck is pretty irrelevant. 

Mr. T (MrT4) said:

Elcan being free of ITAR will c

Is that smart optic you're showing the new 'Smart ELCAN?' I had heard they were working on one but have never seen any specs or news on the project since.

ELCAN’s Specter Digital Fire Control Sight

https://www.raytheonintelligenceandspace.com/news/feature/every-soldier-sharpshooter

https://soldat-und-technik.de/2021/09/bewaffnung/28633/dsei-2021-elcan-stellt-neueste-version-seines-digitalen-zielfernrohrs-dfcs-vor/

Technically you can use compressed propellant in anything so long as you're using the right propellants.

Yes it's also compatible with High pressure though it's best to keep in mind that the higher you run your pressures the more similarity your cartridge has to a bomb if something goes wrong.

You definitely want to make sure that the guns action is rated to 25-50% more pressure than the peak pressure you want to run.

Going back to the safety aspect, if one had a TKB022 or steyr ACR with NGSW ammo, surely youd need a lot of steel round the chamber to protect from kabooms...

as for compressed powder, im surprised noone has tried to reduce 556 down to 5.7x28 size.

also the 4.6hk has 65k PSI as well.

I wonder if reverse feed guns like the PKM or boberg pistol could cope with ultra pressure ammo....in principle i mean

Somebody has, and it's been posted in this thread!

Gatnerd showed the Knox engineering design. I'll repost just so you see.

As far as needing "lots of steel"... Not really.

You need to use very good steels and well optimized bolt head designs or etc.

Yeh i saw that but the document implies that its using an advanced propellant....they didnt mention compressed propellant.

 My new thought for reducing throat wear  (most of my pet projects are very overbore) is to cut the barrel in half...the first 6 inches is separate from the rest and the user can do a quick change...

Its like a m249 quick change exept your only swapping out the throat.

The round itself is a .23 caliber FABRL which is only 42grains but has 4900fps. Hence the concerns with throat wear. 

Apparently revolving chambers wouldnt help much so the only other approach is cool propellants

If your goal is to achieve very high MV, why not going for a conical adapter or a "Gerlich" conical tube?

If you mean a squeezebore adaptor, its likely to deform the bullet enough to affect accuracy.

The concept works as planned - use the .23 / .243 caliber to get a high ME....and then add a 43grain FABRL to allow your 5000fps

Velocity related wear is easier to solve but it really needs a cool propellant otherwise this round will eat away at the throat

What would be the approximate BC of this 43grn FABRL...assuming a .243 diameter?

Note that the shape is much more refined than the original fabrl - the ogive is actually slightly inverted inwards