Gunsmithing Howa Mini Trigger Issues

[SixtyTen]

Hi Folks,
Due to recent events in New Zealand, we are now shooting service rifle matches with bolt actions (Actually pretty fun as I believe its harder to shoot a bolt action fast and well than a semi)

So I got myself a Howa Mini in .223 to use exclusively for service rifle open class. It is a great rifle but I have run into an interesting issue with the trigger when running the gun hard and fast.

In normal operation, the trigger functions fine at around 2 pounds. However, when I close the bolt with speed and force the trigger is suddenly extremely heavy and very gritty. If I lift the bolt to re-cock, it functions normally. This does not happen every time I close the bolt hard but it happens enough that it is impacting my performance.

I have tried another factory howa trigger in this rifle with the same result so I dont believe the issue is with the trigger.

The bolt in this rifle is particularly sloppy and has a reasonable amount of up and down movement when closed and cocked. The rear bridge hole is well oversized to the bolt. I think that this may have something to do with causing the issue, possibly the cocking piece on the bolt is riding up onto the sear lever?

I have a full machine shop and the ability to do most work, does anyone have any suggestions on what the issue could be or what could be done?
I was thinking of something simple like some JB steel putty in the rear bridge, using a machined mandrel to set the correct clearance, just to tighten up the bolt slop at the rear bridge. I dont really want to bush the bolt itself, though a short bush at the rear of the bolt would tighten the lock up but allow fast cycling.

Has anyone else run into an problem like this?

Thanks for any ideas.

 

[mcfred]

I have no idea if it will help the trigger issue, but you can weld some "borden bumps" onto the bolt where it rides under the rear bridge. They're just some weld tits you can machine-to-size to centre [sic] the bolt in the bridge when the bolt's 100% in battery. Cheap, easy, effective...

The Epoxy would probably be fine for troubleshooting, but I doubt that's a relaible long-term solution.

Otherwise you can disassemble the trigger group and stone/buff the sear, add a touch of layout fluid, reassemble and work it hard to see what parts are engaging where.

 

[gnochi]

I’d put it on the bolt and taper it instead of on the rear bridge. That way you have clearance for grit and such, but still a tight lockup.

 

[Dselman]

I have a howa mini action that will do that if I adjust the trigger pull down to low. Which I cut a couple coils off the spring and I can get it down to around 1.5 lbs before I start having any problems. I just assumed it was safety feature it had where if something happened and the sear slipped it would catch on the trigger since it wasn't pulled back. So you may try turning the trigger pull up some first and see before you start welding on your gun

 

[Loe]

I’m having the same issue but mine did t start till the other day. I’ve had this rifle 3 years. From what I can tell my actuator is worn and allowing the sear to drop past it.