Anschutz 64 Ignition Troubleshooting

[Leuchtkafer]

When I tested out the new IBI barrel a few months ago in the winter, I noted an excessive amount of Fail-To-Fire. I chalked it up to the cold at the time. It is no longer winter and the issue persists. This warranted further investigation. I harvested a box of once-fired cases for testing/diagnosis purposes. Oddly enough, there was not a single malfunction with this ammo, SK Semi-Auto. Some ammo has more failures than others, the worst offender is RWS Rifle Match and this crosses over to my CZ PRS rifle. This issue could be slightly complex, combining firing pin penetration and headspace sensitive to rim thickness, given tight below SAAMI spec headspace which may be crushing some rims, possibly disturbing priming compound. This is a work in progress and I will go through the data and results as I document them. I haven't measured the ammo yet to gain any insight into rim thickness correlation to the malfunctions, but I will do so in the near future.

I performed a case head penetration test is several conditions; As-Is uncleaned, given I've had the rifle some 8-9 years and never fully disassembled the bolt to clean and lubricate. This involves punching out a cross pin so it's not user-friendly regular maintenance, Anschutz just says add a drop of oil to the striker pin exposed at the cocking piece end. I need a baseline to determine what effect any work from here that I do has. Second test cleaned, lubricated and polished, but installed unintentionally in the opposite orientation. It shouldn't matter since the part should be symmetrical, but it did make a difference. Cleaned, lubricated, polished in original orientation, and finally with a new striker spring. Here is the data.



This is the test setup, I positioned the once-fired case with the hit at the 6-o'clock orientation in the chamber, then held the trigger and gently closed the bolt so the firing pin would rest on the rim. I set the dial indicator to zero. I re-cocked and "fired". The difference between the readings is the case head penetration.



"Fired"



Disassembly



In the following two images I note some wear on the striker pin that I can catch a fingernail on, and the diameter is reduced by 0.0005" in the area shown in the second image.





A breakdown of the bolt parts



After polishing, there are gouges revealed that are too deep to practically remove without major alteration to the spec dimensions



A gouge formed on the opposite side from only 10 "firings" when the pin was installed in the other orientation. This suggests the pin is made of inappropriate metal for the application or a bad batch, either way, not impressed.



Here's where I'm at; Cleaning, lubricating, polishing and even a new spring made effectively no difference in ignition consistency or penetration depth. The gouges formed/forming in the striker pin seem to be the primary issue. The number I get for "penetration" is not definitive, it is relative. There are a variety of ways to test and measure penetration, what matters is for whatever method one uses, one notes the number where Fail-To-Fire occurs and the number where there are no malfunctions.

My plan now is to manufacture a new striker pin part #002832 out of a harder grade of steel and with modified dimensions to compress the spring a little more. This is to store more energy and thus get my penetration up to 0.020". I would like the ES of penetration to be 0.001" or less, zero or a few tenths would be ideal but being a SAP design (Spring Around Pin), this is not likely. We'll see what I can get. I will also shave 0.006" off the shoulder stop of part #002827, this is to ensure that the shoulder is 0.010" off the mechanical stop at maximum case penetration, as per Bill Calfee's recommendations. Hey, another project side quest lmfao I can't ignore this though, it is important.

 

[_Shorty]

What does the impression look like on a fired case? I don't think you mentioned shape of the end of the firing pin as a possible issue.

 

[Leuchtkafer]

What does the impression look like on a fired case? I don't think you mentioned shape of the end of the firing pin as a possible issue.

It's a standard Anschutz round tip pin, nothing looks out of the ordinary in the impression. I can't see how the shape of the pin would matter in terms of making the cartridge go *bang*, unless damage to the tip occurred giving it a larger footprint that the spring can't drive to the required penetration anymore because of the larger surface area, but there is no damage to my pin tip.

I measured the rim thickness of some rounds, troubleshooting is a process of elimination and I need to check items off the list until I hit the issue(s). This gives me some insight, and from the data I would say the headspace being tight (0.0415") is NOT the issue. I'm glad about that, while I could have increased the headspace if I had to, the amount of work involved is something I prefer to avoid unless absolutely necessary.



I noted no misfires with the SK I used to save empties for testing, it had the thickest rims, some getting a slight crush. RWS L1 (Lot# 67QR41) is the one that gives me the most issues in this rifle and my PRS CZ (I will have to do some case penetration testing in my CZ too, getting the ignition perfect is part of getting the best accuracy out of a rifle). RWS L2 (Lot#56QT21) is a new delivery not yet tested. Eley Match also had fail to fires. My analysis of the testing data so far suggests to me that this rifle is running on the ragged edge of functional case head penetration. Best I can measure the firing pin protrusion from the bolt nose is 0.025", which gives a 0.0165" gap to the breech face (0.0415"-0.025"). The max it can penetrate into a 0.038" rim is 0.0215" (0.038"-0.0165") before being stopped by the shoulder in the bolt body. It can max penetrate into a 0.041" rim 0.0245".

The spring is running out of energy before driving the pin to max depth, the penetration is not being limited physically by the mechanical stop in the bolt body. The penetration seems to be just a hair too low for 100% reliable ignition. My plan to make the new striker pin that compresses the spring more appears to be the most likely solution to this issue.

 

[_Shorty]

Might not apply to this particular case, but in some cases the firing pin can lose a lot of steam by having a tip that reaches all the way to the edge of the rim and is consequently trying to crush the brass itself. That's all energy lost that could've gone into squeezing the priming compound between the two separated portions of the rim. That's why I asked. Usually best to have a pin head shape that is just shy of reaching the fold in the brass edge to avoid that. If it's round (hemispherical) then it likely doesn't apply here.

 

[jamesharrison]

I freely admit that I know, at least when it comes to rimfire rifles, diddly-squat about what contributes, or detracts from accuracy, but wanting to increase my knowledge in the matter, how does the rifle's primer indentation values compare to an Anschutz 54, or say S&L 77 or 61 rifles?

What about spring interference & fit inside the bolt body?

In any event, since I'm wanting to learn, as my recently purchased Anschutz Model 1415/1416, is not accurate, at least to my expectations, even with S-K R.M. ammunition.

 

[Leuchtkafer]

Might not apply to this particular case, but in some cases the firing pin can lose a lot of steam by having a tip that reaches all the way to the edge of the rim and is consequently trying to crush the brass itself. That's all energy lost that could've gone into squeezing the priming compound between the two separated portions of the rim. That's why I asked. Usually best to have a pin head shape that is just shy of reaching the fold in the brass edge to avoid that. If it's round (hemispherical) then it likely doesn't apply here.

Yeah take the CZ's for example they have a firing pin that extends past the edge of the rim and crush the whole thing, though they are sprung appropriately to do this. It is a common mod to file those pin tips to hit inside the rim edge and in one of my 455's I have a reduced power spring to go along with it because the factory spring overdrives the reduced profile of the modded pin tip. We don't want to send shock into the receiver, ignition is a balancing act. The Anschutz 64 with the round tip hits just inside the rim edge by default.

See my thread on modding the 457 pin: https://www.canadiangunnutz.com/forum/threads/cz-457-firing-pin-re-profile.2488857/

I freely admit that I know, at least when it comes to rimfire rifles, diddly-squat about what contributes, or detracts from accuracy, but wanting to increase my knowledge in the matter, how does the rifle's primer indentation values compare to an Anschutz 54, or say S&L 77 or 61 rifles?

What about spring interference & fit inside the bolt body?

In any event, since I'm wanting to learn, as my recently purchased Anschutz Model 1415/1416, is not accurate, at least to my expectations, even with S-K R.M. ammunition.

This is the first time I've tested case head penetration in such a setup, unfortunately I do not own any of those other models you mentioned to do a comparison. Yes, it's possible the spring could be dragging inside the body when it's compressed, by bowing slightly on the pin. In the uncompressed state when it's straight, it slides freely in and out of the body. In my case the striker pin appears to be binding up where it rides through the hole in the bolt body, noted by the wear and gouges. This is why I want to make a new pin out of harder metal, so that the bolt body doesn't bite into the striker where there is friction.

Inconsistent and unreliable ignition degrades accuracy, an exact number on how much I'm afraid I do not have data on. The consistency of ignition matters in top level benchrest competitions, where SAP ignition systems like the 64 action are not competitive against MD-PAS (Momentum Dependant, Pin Around Spring). This doesn't mean SAP systems cannot shoot very accurately, just at that level of competition a hair of improvement makes the difference between winning and losing.

Before you give up on your new rifle, be sure to test a variety of ammo. SK RM is a mid-grade, try out some Lapua Centre X, RWS Special Match and R-50, and Eley Team and Match. If you don't see a satisfactory result from any of those, then there could be a flaw somewhere in the rifle.

 

[_Shorty]

I thought I read something by Calfee about modding the firing pins in this manner. I don't know if you have to worry about hitting too hard, though. At least, he seems to think that even with having done something like this he still likes to make sure quite a bit of power is in the hits. One of the mods he does to something like my Win52D is braze some extra metal in place to get an even larger run at it by having the pin get held back at a greater distance than the factory bolt does it.

edit: Found this one that talks about and shows some of the firing pin stuff. The pictures are a great help. I'll see if I can't still find the other one I was thinking of. https://web.archive.org/web/20090105174726/http://www.snipersparadise.com/tsmag/june2004.htm

 

[Leuchtkafer]

I thought I read something by Calfee about modding the firing pins in this manner. I don't know if you have to worry about hitting too hard, though. At least, he seems to think that even with having done something like this he still likes to make sure quite a bit of power is in the hits. One of the mods he does to something like my Win52D is braze some extra metal in place to get an even larger run at it by having the pin get held back at a greater distance than the factory bolt does it.

edit: Found this one that talks about and shows some of the firing pin stuff. The pictures are a great help. I'll see if I can't still find the other one I was thinking of. https://web.archive.org/web/20090105174726/http://www.snipersparadise.com/tsmag/june2004.htm

I've been reading Calfee's book, The Art of Rimfire Accuracy and I actually just read the chapter that is exactly the article you linked. Lots of good info in that book. He does warn against driving the pin too hard in that article. Ideal rimfire ignition is something like having just enough power behind the pin for 100% reliable ignition but no more, and doing it as consistently as possible. Calfee expressed his preference for the chisel shaped tip, and in recent years there was experimentation with a crescent shaped tip on his forum that he was excited about. He also talks about the Win52 firing pin mod he did in his book.

All things considered, I think I'm in a good spot to get the ignition in this rifle in a very good state. All I need to do is boost the spring power a little bit to get there and make sure the pin isn't binding in the bolt body anymore.