Temperamental Last Shot Hold Open?

andishdi · Nov 15, 2015

Hi Guys,

LSHO seems to have been hit and miss for me recently; I've read over time mags can wear which may lead to the issue but I have 4 mags and this seems to have happened fairly universally despite them having unequal use.

The rifle is less than a year old and probably goes through about 200 CCI Standards / Blazers a week, I used to clean it after every trip but now only once a month (regardless, dirty / clean it still does it).

Any ideas please of what I can look for?

rickyblaze · Nov 15, 2015

Have you checked the bolt release? Make sure it's moving freely. Check for burrs on the bolt rail, maybe polish it. Also the recoil spring guide rod, look for wear ridges.

trebor127 · Nov 15, 2015

i had the same happen,and all i did to rectify the problem

was to strip down the magazines and turn the mag springs

around 180 degs (ie top to bottom)

keith

RedNeck Jim · Nov 15, 2015

Past advice from the Majorlk, Tacticool22 & others:

This is a not uncommon problem. It comes from a combination of two things: a too-strong spring in the bolt latch and a too-weak spring in the 25-round magazine. The solution has been known for several years, now.

Drift out the pin holding the bolt latch paddle and cut two turns off the bolt latch spring, then reassemble. Problem solved forever.

It also helps to put a single drop of CLP or other cleaner/lubricant on the bolt latch pivot point.

If you search, you will see many discussions regarding this. I did this on my first 15-22 & have never had that problem again.

Here is one of the past discussions but there are plenty more:
http://smith-wessonforum.com/smith-...ot-hold-open.html?highlight=bolt+latch+spring

andishdi · Nov 22, 2015

Thank you for the posts and details.

I removed the spring and tried for while to find something that'd cut spring steel (and failed!), had to take it to one of the workshops where I work and a technician kindly used a Dremel on it... Put a nice flat seat on it too.

Took 1.5 coils off and tried it yesterday with plenty of mags - only had one occasion of it not working and that could've just been me, either way I think I'll leave it be now.

Thanks again for the help.

Majorlk · Nov 22, 2015

andishdi said:
Thank you for the posts and details.

I removed the spring and tried for while to find something that'd cut spring steel (and failed!), had to take it to one of the workshops where I work and a technician kindly used a Dremel on it... Put a nice flat seat on it too.

Took 1.5 coils off and tried it yesterday with plenty of mags - only had one occasion of it not working and that could've just been me, either way I think I'll leave it be now.

Thanks again for the help.

I have cut several with ordinary dikes (diagonal cutter), no problem at all.

tacticool22 · Nov 30, 2015

Also be sure to not hold the mag. Or even touch it or rest it on the bench.

andishdi · Feb 1, 2016

So... A couple of months on and 7/8 mags failed to hold open today despite this being fixed when I reduced the spring.

I chopped 1.5 coil off the first time, do I just keep chopping? In two months time am I going to have to chop more off until there's nothing left? :S

Can someone advise me on a total safe amount to remove to sort this for good or whether I should be considering other things (rifle is cleaned regularly, rails are smooth... Only thing I can think of is the NDZ SBR...)?

Thanks again chaps

Destructo6 · Feb 1, 2016

You didn't accidentally flip the follower upside down, did you?

Seen this once and the magazine function normally, but wouldn't lock back the bolt on last round.

andishdi · Feb 2, 2016

Unless it can cause it to work for two months without issue... Then turn itself back to the correct way around before I take the pin and latch out then probably not...

I've got the spring out but I'm concerned about chopping it more though the problem might be even worse than it was in the first place with the LSBHO.

After I chopped the first 1.5 coils off I occasionally got 1/20 mags that failed to hold open but since then it's back to nearly all.

Do I keep chopping or is there something else I can consider (such as, is it part of using the SBR?) because the rifle isn't a year old yet.

trebor127 · Feb 2, 2016

I had 2 of my 7 mags doing the same and with some advice

from a forum member "try just turning the mag spring 180deg"

for some reason that work

keith

andishdi · Feb 2, 2016

I did turn the magazine springs before chopping the slide release spring and it helped very briefly but it didn't cure it.

I have considered losing a few rounds capacity and shimming the magazine spring seat... Might be worth an experiment.

What I have done though is talk myself out of cutting the spring down more, I read in Tacticool's post that at -1.5 coils there was already very little preload and it could potentially rattle.

My plan of action is strip the magazines, give the inner part of the latch of thorough clean and add a drop of CLP whilst reassembling (didn't do this previously as I was concerned about oil getting in and causing the pin to walk), then test it with/without the SBR... Aside from that I'm out of ideas...

tacticool22 · Feb 2, 2016

What is NDZ SBR?

Majorlk · Feb 2, 2016

A gummed up bolt latch will cause the same problem. Make sure to keep it lightly lubricated after cleaning.

Majorlk · Feb 2, 2016

tacticool22 said:
What is NDZ SBR?

Speed Bolt Release from NDZ.

tacticool22 · Feb 2, 2016

It's probably that release. Especially if it weighs anything.
They are really nothing more than a gimmick that becomes problematic.

GhostMutt · Feb 2, 2016

tacticool22 said:
It's probably that release. Especially if it weighs anything.
They are really nothing more than a gimmick that becomes problematic.

That may well be that it is the issue but i have an actual Magpul BAD lever on my 15-22 and have had no issues with it at all, in fact other than the trigger swap this has been the best addition i have made to the rifle.

andishdi · Feb 2, 2016

Agreed, I love the SBR (especially being a lefty) and seeing as I had no issues after I fitted it or after I chopped the springs I'm inclined to all but rule that out.

Stripped all the mags and thoroughly cleaned them, bolt assembly got stripped and cleaned plus removed the latch and cleaned it aswell as the slot it sits in - gave its pivot CLP too.

Threw pretty much all I could at it for now... Will have to see how it goes at the weekend but if there are any other suggestions I'm all ears.

tacticool22 · Feb 2, 2016

Why would you need the funky bolt release if you're a lefty?

GhostMutt · Feb 2, 2016

tacticool22 said:
Why would you need the funky bolt release if you're a lefty?

That is exactly what i was thinking.

Temperamental Last Shot Hold Open?

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