HK45 Not Locking Back with Suppressor

[ScotchMan]

Just got back from the range testing my newest toy, a Ti-Rant 45M on my HK45. The 45M is modular meaning you can have it in a long or short config. In the long config, the slide on my HK45 doesn't back on an empty mag; I am positive I was not inducing the error and never have had this issue before. With the short config it locked back every time.

Is this normal? I am assuming either the additional weight up front, or the additional slide velocity from the increased blowback, or both, are to blame, but I'm not sure if this is something I should worry about or not. If the suppressor was ever put into a defensive role it would be in the short config anyway, but if there is something I can do (different RSA, etc) to resolve it I'd be interested.

[CCT125US]

How freely does the piston move when you work it forward? It may be on the edge where the extra weight plays a role. May just need to clean and lube the o-ring and booster housing.

[Evil_Ed]

How freely does the piston move when you work it forward? It may be on the edge where the extra weight plays a role. May just need to clean and lube the o-ring and booster housing.

+1 to this, the function of a Browning tilting barrel-type gun is really sensitive to how well the piston can move in a can with a Nielson device...I found this out the hard way with a very similar question. It might not totally fix it but it'll help.

Wear googles when shooting, so the excess oil you squirt onto the piston/o-ring doesn't blind you until the excess is blown off. Either that or use some kind of dry lube, though I don't know how long those would last. https://www.amazon.com/Hornady-99901.../dp/B007TNXGMK - Hornady One Shot cleaner & lube - seems to work pretty well for me, but YMMV; I haven't tried it on a piston yet. Maybe a project for this weekend hmm..

[ScotchMan]

Ok thanks, will try and report back.