[Dr. Thornton Reed]

Hi All,

I am very new to this semi-auto rifle thing. I took the zero miles RDB out for a walk this weekend for it's first shoot about and for some reason I had a mental lapse (excitement) and forgot that the manual stated to only use "Premium Ammo", I am guessing 20 rounds for $12.99 is NOT! Premium; Yes?

What's crazy is I had the manual with me and reading it again while at the bench during the gas setup. Boy or boy... what a real horror show.

I did a search before posting this new topic and saw the writings from others about their issues with bent casing and stuff. But I did not see anyone with the outcome I was had. So maybe someone can clue me in on what the heck is Bolt Norris doing to these round casings.

What I am trying to figure out is what is actually happening with the steel case lip and why my RDB is trying to roundhouse kick the shell casing in the lips vs ejecting them to the floor.

Here is a picture of the carnage during my attempts to set the gas settings.

When I had the gas set where the bolt did not lock back. No Damaged Shell casing; No Shell Casing Ejection.
(ex: See 1st Guy in the Row)

When I had the Gas set where the bolt locked back but got all kinds of Mega Shell case damage, No Shell Ejection.
(ex: See The Rest)

My Question is what is causing the casing damage??

I understand expansion issues with steel case. But I don't understand what is inside the gun that could ripping the lips off these casings. I shot 10 times with one round in the magazine. I stopped as it was clear I needed a Paul Harrell type figure to help me with the analysis.

I have not disassembled the gun post shooting session to see what damage I may have done to this new gun. Maybe a positive is that no pieces fell out the gun.

I did take it apart to clean and oil it before it's first shoot as instructed by the manual. Just wondering if I jacked something up when I did the reassembly.

Thanks All!

Additional Notes:
===================

Ammo: Red Army .223 55Gr Steel Case.
(Range House Ammo They don't allow you to shoot rifle ammo from outside the shoppe)

Gun: New RDB-D Cleaned and Oiled and hopefully reassembled correctly.

If the Gun is not bent. I will be using Green Tip XM855 5.56 in the future.

 

[gxer]

Your gas is not sufficient. Even if you got the bolt lock on last round you still need to dial the gas up for good measures.

The deformation you see on those shell was caused by failure to eject, as the bolt carrying the empty shell traveling to the ejection port there's not enough gas to push the bolt that far so the shell cannot fully clear the opening. As a result, as the bolt travels back forward, the neck of the shell is caught on the bolt hold open, which is a sharp metal bar right in front of the ejection port. This is why you see the damage in the picture. Check your bolt hold open, you should see some impact marks left over by those shells.

Try giving it full gas for steel ammo, if that doesn't work for you then stay away from them. I haven't shot any steel with my RDB-C but normal brass ammo works just fine.

 

[amstel78]

I shoot a lot of steel with my RDB. I'd estimate its had at least a case of Tula through it already. My gas is set 1 or two clicks past the point of it just barely locking open. I've never had any issues with case lip deformation. This applies to both suppressed and unsuppressed use.

 

[Dr. Thornton Reed]

Thanks Gang! I appreciate the feedback!

 

[IamScotticus]

Here, I made this vid :

shoot brass case, adjust gas so you have:
(1) last shot bolt hold open
(2) slightly dented case necks
Id like to add that the jams you are having aren't unusual. Many have what I would consider break-in and familiarity issues while learning what works and what doesn't. I had horrible brass gouging and jams.
The majority of my problems were from being under-gassed. I was trying to see how soft this could shoot. Its not going to begin to be able to shoot at its sweet spot until its broken in and the gas head has a build up of carbon where your gas output stabilizes. Until then, expect to keep adjusting the gas.

 

[IamScotticus]

@Dr. Thornton ReeDr
"Premium ammo" isn't like premium gasoline, in that you get better fuel with a higher price because it has a better blend of additives.
The manual is suggesting to not buy
"not the cheapest thing around because the quality is probably poorer for the price".

In ammo world, the largest manufacturers of ammo are usually the best quality and best price when availability is good. Remington, Winchester, PMC, Federal are all good quality in that they produce for the military and Law enforcement. control standards are very high.
You can pay more for specialty ammo, and you may get the best accuracy with a specific kind, but your RDB is designed to function on good quality bulk ammo.

I stick with Federal and usually am paying $.30 a round, on a good day. If I were a high volume shooter, I would have to go cheaper to afford it. But if you're not that guy, pay for quality and get good results now. I haven't had an ammo failure from Federal.

 

[BJK]

I have yet to see any manufacturer state, "Use the cheapest ammo possible in this firearm.". But I'm pretty sure it's universal that I've read "use only really good ammo", or words to that effect.

Those cases looked like mine when I was learning. As previously stated by others it's undergassed. Drove me bonkers and then I realized I was turning the adjuster in the wrong direction.

 

[Dr. Thornton Reed]

Here, I made this vid :

shoot brass case, adjust gas so you have:
(1) last shot bolt hold open
(2) slightly dented case necks
Id like to add that the jams you are having aren't unusual. Many have what I would consider break-in and familiarity issues while learning what works and what doesn't. I had horrible brass gouging and jams.
The majority of my problems were from being under-gassed. I was trying to see how soft this could shoot. Its not going to begin to be able to shoot at its sweet spot until its broken in and the gas head has a build up of carbon where your gas output stabilizes. Until then, expect to keep adjusting the gas.

This was awesome... Getting to see how it all works inside there is pretty amazing. I will field strip mine this weekend to see what type of scars got left from my little misadventure into semi auto rifle world. Thanks for this very helpful video!

 

[Dr. Thornton Reed]

@Dr. Thornton ReeDr
"Premium ammo" isn't like premium gasoline, in that you get better fuel with a higher price because it has a better blend of additives.
The manual is suggesting to not buy
"not the cheapest thing around because the quality is probably poorer for the price".

In ammo world, the largest manufacturers of ammo are usually the best quality and best price when availability is good. Remington, Winchester, PMC, Federal are all good quality in that they produce for the military and Law enforcement. control standards are very high.
You can pay more for specialty ammo, and you may get the best accuracy with a specific kind, but your RDB is designed to function on good quality bulk ammo.

I stick with Federal and usually am paying $.30 a round, on a good day. If I were a high volume shooter, I would have to go cheaper to afford it. But if you're not that guy, pay for quality and get good results now. I haven't had an ammo failure from Federal.

Fantastic info and thanks for the guidance!! My only foray into the 5.56 /.223 world was using the stuff with my manual bolt action Mossberg MVP LC.

When I got that guy I bought some Green Tip m855 62. Then I got some of that Tula 62g stuff. This semi auto action is all new to me and I am so blown away by the communities willingness to help and educate.

Thank you all!

 

[BJK]

Yeah, a bolt action can swallow almost anything. Semi-autos are much more finicky. Adjustable semi-autos... well, they're both good and bad. If they have no adjustment they're generally over-gassed to make them work with a wide range of ammo. If they're adjustable they can maybe work with a wider range of ammo w/o stressing the gun anywhere. But it also opens the potential for operator error.

 

[IamScotticus]

Yes. I train myself to catch and examine case necks from first shot every magazine.
Yes gloves are helpful.