After watching the "video", it appears that the first Blank chambers, and is then ejected when you pull the charging-handle/bolt-assembly to the rear. This is all correct with an SA34.....no problems. The chambering issues later in the video appear to be from slowed chambering and/or another Blank in the chamber that was not picked up by the bolt's extractor (due to incomplete chambering by the slowed bolt going forward.).
You are going to have a few "challenges" when loading an SA34.....unless you have a hold-back-device, you will have to line up the first round to chamber. The "challenge" here is that as the bolt moves forward, the charging-handle-assembly will slow these parts down slightly (and is normal).
The issue of required hand-power when moving the parts to the rear in an SA34 is also normal due to the added spring-pressure of the semi-only firing-pin-spring and hammer-spring-pressure that has to be overcome. Here, you can take time to polish the operating-channel for the bolt, and at any contact points of the moving-parts to lessen this requirement.
Also, please check in the MG34-Section for references to "up-dates" to the SA34 to lessen these spring-pressures.
Last, when talking about "Blanks".........I would not use the wooden-tipped-8x57mm Blanks due to "long-term" availability at reenactments. I would tend to stay in the "mainstream" and use either the full-length PPU 8x57mm Blanks.......or attach the shorter feed-tray-spacer to your spare feed-tray and use the shorter 8x57mm Blanks made from re-sized 30/06 Blanks. That "spacer", once mounted, holds the front of the Blank down so that it does not stop/catch on the forward cutout of the feed-tray. I did that for years prior to the PPU Blanks becoming available. The re-sized 8x57mm Blanks made from 30/06 Brass should be available at almost all reenactments, and cheaper in price. ....or you could load-your-own Blanks.
Another option is to set-up and use 7.62x51mm/.308 Blanks.........(?).
US Army, RetiredBlanksguy2001@outlook.com