I'm trying to get a DDLES GSF .40 with a 3.5" barrel and an Octane 45HD to like each other.
Rudy is helping out in every way he can. I did an ejector shim mod to prevent the ejector from moving and spaced the buffer to just clear the bolt catch.
I get to the range today and in 3 rounds it holds open. I pushed the release and the thing broke in half at the roll pin. It's a Spikes LPK.
Is this common? I have heard of the bolt shearing off the catch, but not much about the release breaking.

.....Rudy it did eject the 3 rounds though

It is pretty common to break bolt catches in 9mm.

If you are breaking bolt catches at the roll pin, your bolt catch has too much play (slot in lower too wide or bolt catch too narrow) and the bottom of the catch below the roll pin is contacting the back of the slot on the side of your lower causing it to break.  You can modify the fit of the bolt catch in the slot on the top of the lower so that it minimizes movement of the catch when the bolt contacts it or you could file/dremel the bolt catch below the roll pin where it contacts the lower to prevent said contact.

Running the spacer can mitigate the breakage issue, but it won't 100% prevent a bolt catch from ever breaking.

Thanks. I see what you are talking about. So shim it at the top would be the best option.
Anyone use tool steel catches? I saw seekins enhanced bolt catch is now MIM (or does that matter?)

What weight buffer and buffer spring are you running?  Heavier seems to be better with the GSF setups although my setups are 9MM, not 40 S&W.

I had a lot of problems with broken bolt catches on a DDLES GSF 9MM carbine that I later converted to an SBR.  I ran the whole gamut of buffers, springs and spacers until I finally got a Slash 9Q-T heavy buffer with the recommended Wolff XP spring plus the Seekins bolt catch.  I also did not like all the play in the bolt catch, so I made a full length shim from some old steel feeler gages that I placed in front of the bolt catch to limit the play.  So far, this setup has run without any broken parts for the last 1000-1500 rounds both with and without a suppressor.

I built another 9MM carbine on a second DDLES GSF frame and used the above setup from the very start.  So far, no broken bolt catches in the last 500-1000 rounds.

My third build is a 9MM pistol on a Joe Bob/NFA GSF 9MM lower.  On this one I used a Blitzkreig hydraulic buffer with their recommended spring.  I did not need to shim the Seekins bolt catch since  the NFA lower allows a lot less play than my DDLES lowers.  So far, no broken parts on the pistol although I only have a couple hundred rounds though it.

Hope this helps,
Pete

8.3 oz buffer. I did the same shim about an hour ago with a feeler gauge. I also used a feeler gauge to shim the ejector.
I have a DDLES SBR lower I'm running a 8.5" QC10 barrel with JP bolt,SCS, and an old seekins enhanced bolt catch in and that thing runs like a top.

This .40 is MF'er. and I think it's because it's suppressed and my 9 isn't.

I shimmed another spikes bolt catch and stretched the DDLES bolt catch spring some. It feels better. I will try to shoot it next week and report back.

I'm not giving up yet. If anyone is running a .40 suppressed on a QC10 or DDLES GSF lower give your wisdom...err knowledge transfer

Well. On round 33 I broke another one. It ejects like a champ though.

Any of you experts think a machined titanium bolt catch would hold up to abuse any better? I'm not a metallurgist so I'm genuinely curious.

 

I can send it to you.
The bolt catch went out with the trash yesterday. It was out of a Daniel Defense LPK

Thanks for the help

Federal 180 grain FMJ

I was using Spear LE Gold Dot 165 Grain GDHP

I was using the Speer as I was working out the runaway and ejection issues. I picked up a 100 pack of the Federal to confirm my shim on the ejector worked and that is when I started breaking the bolt catches. Do you think you are onto something?

Not that much noticeable, but again I was paying attention to other things.