Limited Pro Tuning Pains

[ammo_baron]

I'm dealing with a unique failure in the Limited Pro I am in the process of Tuning up. 

I will spare you the details of how I came to this conclusion, but long story short....  I am getting light strikes on 147 Grain Bayou Coated Lead rounds in Double Action.  Single Action goes bang every time.  The unique part is that I have 100% reliability in Double Action with 147 Grain Xtreme Plated. At first I thought the issue was my short chamber because I noticed some of the coated rounds don't plunk (that may still be part of it).  I ran a test with 20 coated and 20 plated in Double Action today.  6 of the 20 coated didn't go bang.  Surprisingly all of the failed rounds plunked in my barrel just fine when I got home.  I have a couple of theories on what I should do about this, but I would love to hear your opinions in case I'm not thinking of something.

Current list of Modifications:

Bolo Connector

Xtreme Sear

Patriot Sear Spring

Patriot Trigger Return Spring

8# Recoil Spring

Henning Extended Firing Pin

Patriot Optimized Firing Pin Spring

Patriot 14# Hammer Spring (Using Federal Primers - They should pop all day at this spring weight)

Theory #1: Need to ream the chamber

Theory #2: Recoil Spring is too light.  The failures chamber slightly out of battery (see off center strikes in picture).  The Plated RN run fine because they feed better?

[ammo_baron]

[hav3n]

147 Plated and Coated loaded at the same primer depth? right?

[ammo_baron]

Yep. The only difference on the press is the powder charge.

[B_RAD]

with federal primers I'd think you look at them and they'd go off

 

primer depth?

 

what press you loading them on?

 

Next time see if a s second DA pull will pop them.  

 

My guess is short chamber though. 

Edited January 15, 2017 by B_RAD

[ammo_baron]

They're seated plenty deep. Loaded on a 1050. Second or third pull will pop them off.

[B_RAD]

4 minutes ago, ammo_baron said:

They're seated plenty deep. Loaded on a 1050. Second or third pull will pop them off.

I'm loading on a 1050 too. 

 

Dont know now how long you've had yours or what adjustments you've made but mine needed tweaking form factory set up. 

 

I think it's chamber or primer depth.

 

Try cranking the primer seating down a little. See if that solves the problem or if not, at least you can check that off as not the cause. 

Edited January 15, 2017 by B_RAD

[hav3n]

1 minute ago, B_RAD said:

I'm loading on a 1050 too. 

 

Dont know now how long you've had yours or what adjustments you've made but mine needed tweaking form factory set up. 

 

I think it's chamber or primer depth.

 

Try cranking the primer seating down a little. See if that solves the problem.  

Primer depth doesn't explain why 147 plated loaded on the same press light at 100% where coated on the same press don't.

[B_RAD]

Just now, hav3n said:

Primer depth doesn't explain why 147 plated loaded on the same press light at 100% where coated on the same press don't.

Then, chamber depth. 

 

You got a wierd situation. You'd think if it was as short chamber then those rounds wouldn't plunk and spin. 

 

[ammo_baron]

4 minutes ago, B_RAD said:

I'm loading on a 1050 too. 

 

Dont know now how long you've had yours or what adjustments you've made but mine needed tweaking form factory set up. 

 

I think it's chamber or primer depth.

 

Try cranking the primer seating down a little. See if that solves the problem or if not, at least you can check that off as not the cause. 

I am certain it isn't the primer seating depth. I wish it was that simple - lol

[ammo_baron]

4 minutes ago, B_RAD said:

I'm loading on a 1050 too. 

 

Dont know now how long you've had yours or what adjustments you've made but mine needed tweaking form factory set up. 

 

I think it's chamber or primer depth.

 

Try cranking the primer seating down a little. See if that solves the problem or if not, at least you can check that off as not the cause. 

I am certain it isn't the primer seating depth. I wish it was that simple - lol

[B_RAD]

There will be more folks with more knowledge than me along shortly. 

 

I too have had light strikes. That's why I commented.  My problem was primer depth. 

 

You're SURE those rounds plunk and spin?

I plunk test before I shoot go to the range.  Did you? Or only after they failed to fire?

[johnbu]

The ones that failed ignition, but now PASS plunk.... are they the same oal or has the bullet recessed slightly?

 

I'm  STRONGLY suspecting they would have FAILED plunk before being hit.

What is target oal with the bayou?

I had to run 1.060 pre-ream using  bayou 135

Edited January 15, 2017 by johnbu

[johnbu]

Let's  look at other causes.

Breech face or extractor could be rough.

The rails could be "sticky " or rough slowing the action.

The firing pin channel can be rough slowing the pin.

The firing pin block can be interfering and needs to be fit. (MemphisMechanic has the pictorial thread).

The fpb channel can be rough and randomly slowing the block. Polish.

[ammo_baron]

13 minutes ago, B_RAD said:

There will be more folks with more knowledge than me along shortly. 

 

I too have had light strikes. That's why I commented.  My problem was primer depth. 

 

You're SURE those rounds plunk and spin?

I plunk test before I shoot go to the range.  Did you? Or only after they failed to fire?

That would be a good test. I should have plunked the 20 before I shot them instead of after they failed.

[ammo_baron]

14 minutes ago, johnbu said:

The ones that failed ignition, but now PASS plunk.... are they the same oal or has the bullet recessed slightly?

 

I'm  STRONGLY suspecting they would have FAILED plunk before being hit.

What is target oal with the bayou?

I had to run 1.060 pre-ream using  bayou 135

I will check that. I think you're probably right.

As far as target OAL, the Bayou 147s are pretty long. They are at 1.09 and they are already getting a rim at the base because it is getting in to the thicker part of the brass. I don't really want to go any shorter. One of our sponsored shooters runs a CZ shadow that hasn't been reamed and he hasn't run in to any issues with these.

Edited January 15, 2017 by ammo_baron

[ryridesmotox]

There is a picture below of how Smith's that build match revolvers instruct people on how to seat their federal primers.

Since the firing pin seems to be not striking the center, I would wager that the projectile was (at the time) hitting the lands and obstructing the slide from returning to full battery. 

Just as a food for thought kind of thing. I had tested several types of ammo in my guns via plunk test. Round nose of almost any grain was fine, even 147. But any steeper of an ogive and it would fail to plunk... Onetime I even had to clear the chamber with a cleaning rod. Go grab a box of like saaay 124gr or 115gr hollow points. You'll see what I mean

Edited January 15, 2017 by ryridesmotox

[johnbu]

Oh... ditch the Henning firing pin. The Patriot Defense pin is seriously MUCH better at setting off primers.

 

But still have the throat reamed. All profiles should pass plunk.

[ryridesmotox]

I concur with John... The Henning pin does not like to light of primers... I already attempted to fight through that for about a month. Polishing and fitting... Sucked. I run the pin that came with the gun and it's 100%

[B_RAD]

7 minutes ago, ryridesmotox said:

There is a picture below of how Smith's that build match revolvers instruct people on how to seat their federal primers.

Since the firing pin seems to be not striking the center, I would wager that the projectile was (at the time) hitting the lands and obstructing the slide from returning to full battery. 

Just as a good for thought kind of thing. I had tested several types of ammo in my guns via plunk test. Round nose of almost any grain was fine, even 147. But any steeper of an ogive and it would fail to plunk... Onetime I even had to clear the chamber with a cleaning rod. 

Deep son!

 

ha ha. 

 

 

[ammo_baron]

13 minutes ago, johnbu said:

Oh... ditch the Henning firing pin. The Patriot Defense pin is seriously MUCH better at setting off primers.

 

But still have the throat reamed. All profiles should pass plunk.

That's something I have been meaning to ask about as well. The Henning pin is lightened, fluted and hardened. Patriot and Xtreme pins are heavier. I went with the Henning because lighter and faster made more sense in my brain. I also had success with the Zev Skeletonized striker when I was shooting Glock. Seems like they're trying to accomplish the same goal by doing the opposite. I'd love for someone to do the math on which one actually hits with more force.

Edited January 15, 2017 by ammo_baron

[ammo_baron]

18 minutes ago, ryridesmotox said:

There is a picture below of how Smith's that build match revolvers instruct people on how to seat their federal primers.

Since the firing pin seems to be not striking the center, I would wager that the projectile was (at the time) hitting the lands and obstructing the slide from returning to full battery. 

Just as a good for thought kind of thing. I had tested several types of ammo in my guns via plunk test. Round nose of almost any grain was fine, even 147. But any steeper of an ogive and it would fail to plunk... Onetime I even had to clear the chamber with a cleaning rod. 

That's awesome.

[ryridesmotox]

People have done pencil tests to see how hard the various combos hit. The heavier pins are slower, but hit harder... Both ideally should light off a primer but sometimes the henning wont. Would you rather get hit my a F1 car doing 180mph or a 40 ton freightliner doing 80mph? The reason for this is because there is a firing pin spring. The spring slows the pin down quicker because it is lighter. Part of my problems with the henning pin were solved when I started clipping spring coils. But notice I said part... not all the problems went away. IMHO, lock time doesn't have much of an effect when dealing with a pin that has a spring attached. In something like an AR with a free floating pin, you want to hit the primer with a pin moving as fast as possible, and to speed up lock time, and thereby cyclic rate, a lighter hammer and spring makes sense. but with the sprung pins, you are now taking that F1 car and hitting the brakes and slowing it down to 60... the 40 ton freightliner slows down to 70 in the same length of time/distance because there is far more mass. Like I said, I polished and fitted (sanded, stoned) the block and the pin. Nothing helped and after much time wasted, I shelved the henning. I tried to give it a fair shake and tried to get it to run well. but it wouldn't. I would have accepted 90% ignition, couldn't even get to there with it

 

The F1/truck comparison is obviously an oversimplification... don't read too much into it.

Edited January 15, 2017 by ryridesmotox

[johnbu]

I've  tested pencil launch and live fire back to back (i can open the back door and shoot...legally).

The henning launched pencils shorter heights, fired fewer primers off and dimpled them less deeply.

Faster lock times / lighter weight  work well with full power springs. Using light springs....not so much.

[MemphisMechanic]

Shoot the gun with the factory recoil spring next time.

Until your gun runs reliably, you need to plunk and spin every single round before going to the range from now until the issue is resolved. It's not impossible that you've driven those particular rounds back into the case a few thousandths when you hit them with the firing pin.

I will say that none of my light strikes have ever been offcenter at all. I may be wrong, but I'd be looking for the source of an out of battery gremlin.