Firing Pin Fall

[NV_Dmax]

hello,
I have a new Panda Fclass with a Bix and Andy 2 stage benchrest trigger and I’m getting intermittent hang fires and several rounds failure to fire this last time out. I have been unable to get this rifle to shoot (first barrel was a 6.5 Swede IMP and now it’s a straight .284 Win) and the ES and SDs are horrible, worse than the shittiest factory ammo available with both barrels/chamberings so I’m gong to start looking at the ignition system.

My question is does anybody know what the optimal firing pin fall should be for a Panda Fclass?

 

[BIG D]

.240 is the place to be. My first panda did the exact same thing. I even changed the spring a couple times. Then I measured pin fall and was only just over .200 so I called kelblys and got the correct trigger hanger.

 

[Stingray]

Call Kelbly's = had the same problem when I rebarreled and had to get a different hanger. Measure pin fall and give them a call. Mine works now. I had all kinds of advise before getting my gunsmith to diagnose the problem.

 

[NV_Dmax]

*update*

I called Kelblys and they are sending a new hanger. Pin fall was .203”. They recommended .250” so they’re sending out a .050 hanger. I had this exact same issue with one of the early versions of the Curtis Custom Axiom actions so at least I had an idea of where to start.

 

[Tim Singleton]

I’d say that will solve it. If it doesn’t go over to bulletcentral and watch their video and double check the sear height

https://bulletcentral.com/resources/#TechCentralVideo

 

[Alex Wheeler]

Pandas start to have accuracy issues below around .230. .240-.250 is where they should be for best accuracy.

 

[Ledd Slinger]

Definitely get that pin fall up higher, but when you mention hang fires, it makes me think you also might want to look at trying a different lot of primers if you havent already.

A while back I purchased 500 pieces of Lapua 6mm Creedmoor SRP brass from a member on here. Said he couldnt get his rifle to shoot no matter what he tried. 200 of the cases were once fired, and 300 were brand new with Federal 205 primers in them. I thought this was great because I usually load my SRP rifles with Federal 205 primers, sometimes Fed 205 Match.

When I finally got around to load development using the primed brass, I was getting a decent amount of fast hang fires where I could definitely hear the strike a split second before the Boom, and even had a few FTFs. I made sure my pin fall was over .240" when I built the rifle (.243" to be exact) so I knew that wasnt the issue. I deprimed the rest of the cases that still had the previous owners Fed 205s and primed them with my own known good lot of Fed 205s. Problem solved. Rifle shoots very well now.

 

[Tim Singleton]

Bullet central carries an adjustable hanger that works great

 

[NV_Dmax]

Thanks for the responses everyone. I have one already and the adjustable hanger from Bullet Central still doesn’t get me where I need to be. I would have to modify it to work and there wouldn’t be enough meat left on the front tabs that the screw tightens up against to hold the hanger in place.

I have 5k new Federal GMM210m on the way, that definitely crossed my mind. Didn’t have the hangfires when I tested CCI but the ES and groups where completely unacceptable.

 

[Dusty Stevens]

Primers are not the issue here- lets dont drive off into the grass. You really need to send that bolt to kelblys to get it corrected and go back to the original trigger hanger

 

[Stumpy1]

Question for the experts;

When you talk about pin fall, are you talking about total fall as the firing pin goes through its full travel, OR pin fall as it would make first contact with the primer (essentially no protrusion)?

Thanks much! (trying to learn here)

Frank

 

[Alex Wheeler]

Dry fire pin fall.

 

[Tim Singleton]

Primers are not the issue here- lets dont drive off into the grass. You really need to send that bolt to kelblys to get it corrected and go back to the original trigger hanger

Yea
May want to let Kelbys or a knowledgeable gunsmith checkb it out in general
Not sure how many hands it's been thru before you
Someone may have recut the cocking piece. Sounds like it anyway

 

[Concha]

This is why you need no more than .035" protrusion. Any more and you wast pin fall potential.

 

[jackieschmidt]

This seems strange, as Kelbly is adamant about having adequate pin fall and static spring pressure on all of their actions.

Somebody has messed with it.

 

[Alex Wheeler]

I have had more than a few brand new Pandas come in with barely over .200" pin fall, sometimes stuff happens.

 

[tmwinds]

I bought a brand new untouched Panda. It had between .195 and .205 fall. I called Kelbly and they sold me, not give me, a .050 hanger to cure the problem. It cured the firing pin fall. I now have cock on close issues.

 

[Tim Singleton]

I bought a brand new untouched Panda. It had between .195 and .205 fall. I called Kelbly and they sold me, not give me, a .050 hanger to cure the problem. It cured the firing pin fall. I now have cock on close issues.

What trigger are you using?
if it’s a B&A try a jewel

 

[tmwinds]

What trigger are you using?
if it’s a B&A try a jewel

It was a Jewell. Kelbly said that was the problem, that the Jewell's were not consistent. Never had a Jewell problem with a BAT.

 

[MikeMcCasland]

Going through this now myself.

Have a new Panda F-Class/Jewell with a .308 Krieger barrel that originally appeared to hammer; was holding slightly more than X-ring vertical at 1k, ~.20 MOA @ 300 5-shot groups. Shot the same load as my last barrel, just ~.004 deeper in the case. I thought it was a dream come true.

It's been hyper temperamental as I've started shooting it in matches though. I've shot about ~6 total with it, and it's as bi-polar as can be. Some days it shoots lights out, and others...oh my.

I just got back from a two day 1,000 yard match where on day one I could hardly keep the thing in the 9-ring for two relays, and then last relay of the day it goes right back hammering. First match of day two it shoots a 198, and the second match it shoots a 180 while the rest of the field is posting ~195s in 4mph wind. Same ammo, same lots of everything etc.

I've gone through everything on gun/load, and the best thing I can come up with is the pin-fall is screwy. I don't have any specialty tools to measure, so just using the base of my calipers as a depth gauge, but I seem to settle around ~.225-.230 on average.

Just ordered a .030 hanger from Kelblys to see if bumping it up to .260 will cure some of the inconsistencies. Not sure if you'd see pin-fall ignition issues manifest on a chrono, but I didn't see it in load dev.

I've read every post on AS about pin-fall, and it seems somewhere around .220ish is where you'll run into issues. Hard to know how those issues manifest though.