johnbu Posted March 17, 2016 Share Posted March 17, 2016 (edited) This may sound odd, but Well let me start by saying I'm a trained engineer and worked with processes for decades. A reliable, informative test is invaluable in determining the robustness of a process and to set a baseline against which changes (even wear) can be objectively compared. With pistols, I use the pencil test where a pencil is launched straight up, the height in DA and SA is measured. I've made the assumption that a higher launch will be indicative of greater ignition reliability. Increasing hammer spring rate does result in higher launches and things like rubbing the firing pin block (FPB) results in a lower launch. However...changing the firing pin return spring from EG light to the factory one results in a lower launch. So there are factors that shift the test results. Using this test, I had determined a baseline for the factory gun, put in wolff 13# Spring and EG FP spring (only those changes) and got over a foot lower launchs. Adding xtreme sear, firing pin and titan hammer with polishing resulted in launch height replicating the factory configuration. That was done previously when setting the gun up. Question 1 for the real experts (I'm just a tinkerer!): am I fooling myself playing with pencils? Yesterday, in the same gun, put in a new wolff 13# hammer spring with EG light FP spring and measured launches getting the same heights as the baseline. Then put in a wolff 14# spring which is slightly thicker wire, but overall a fair bit shorter in free length. Then, with just that change, redid the launch test and found it was 3-4 inches LOWER in launching the same pencil. Yes, lower. I was expecting higher - duh! WTF? I'm thinking they are the correct springs, coming from fresh 3 packs from wolff. The 13#'s are all longer, and have thinner wire. So, will the gun get more reliable ignition with the 14# spring compared to the 13# even though launch height is lower? I'm fighting a batch of bargain primers that are (ahem!) No bargain as they are harder than the gun likes. Thanks! Edited March 17, 2016 by johnbu Link to comment Share on other sites More sharing options...
emjei Posted March 17, 2016 Share Posted March 17, 2016 Dumb question....the Pencil test gets measured from where to where ??? Link to comment Share on other sites More sharing options...
NFLcavediver Posted March 17, 2016 Share Posted March 17, 2016 John just a question, does the firing pin indent the pencil? Might that have an effect on your test? If it hits the same spot less energy would be transferred to the pencil and if it hits just off center the pencil could be moved to the side taking energy to move it? Link to comment Share on other sites More sharing options...
kneelingatlas Posted March 17, 2016 Share Posted March 17, 2016 I think your pencil test is a good indicator of ignition reliability, but spring weight ratings across manufacturers are not. Sell your primers to a Limited shooter, buy Federals, find a reliable setup and stick to the same brand of hammer springs. Link to comment Share on other sites More sharing options...
emjei Posted March 17, 2016 Share Posted March 17, 2016 Dumb question....the Pencil test gets measured from where to where ??? Mj Link to comment Share on other sites More sharing options...
johnbu Posted March 17, 2016 Author Share Posted March 17, 2016 (edited) Dumb question....the Pencil test gets measured from where to where ??? Mj Here's what I do....I get a medium sized nut, like 1/4 - 3/8" next to a measuring suface. I use the cabinet at the reloading bench. The beaver tail is placed into the nut to just raise it up a consistent amount so the hammer can't touch the table top (which is a towel in my case) and affect the result. Using my standard pencil, shoot it straight up. I put a 2" wide masking tape strip on the cabinet and mark the average height of the pencil tip. For reference; Measuring from the table surface to the marks (when there is enough power to set stuff off) is between 30" and 48". 30" is EG light hammer and a wolff 15# with 2 coils cut -both in DA. 48" is 16# wolff in SA with EG light FP return spring. Just putting in EG light/light without polishing or extra parts, doesn't reach the cabinet. A 22# with factory FP return spring hits the ceiling! The measurements are including the length of the pencil and starting height...probably about 12", the actual numbers are immaterial as the goal is detecting changes from a known good baseline. So if failures start happening, a 10 second test can either point to the gun...or clear it as the source of the issue. A "cautious person" would put a circle on the pencil at the level with the barrel and paint it red or write "LOADED" under the line. Then if you see that...you know you're about to need to fix the roof. Just a precaution... Edited March 17, 2016 by johnbu Link to comment Share on other sites More sharing options...
johnbu Posted March 17, 2016 Author Share Posted March 17, 2016 (edited) I think your pencil test is a good indicator of ignition reliability, but spring weight ratings across manufacturers are not. Sell your primers to a Limited shooter, buy Federals, find a reliable setup and stick to the same brand of hammer springs. Yeah...I couldn't find any primers for a while, much less federals and jumped on "a great deal" on these primers the gun doesn't like. Guess mamma was right ....I am slow and dumb, but at least I'm not good looking! Wanna buy some primers pressed out of A500 steel? Lol. Edited March 17, 2016 by johnbu Link to comment Share on other sites More sharing options...
emjei Posted March 17, 2016 Share Posted March 17, 2016 WOW ....38 inches up high ?? Mj Link to comment Share on other sites More sharing options...
johnbu Posted March 17, 2016 Author Share Posted March 17, 2016 (edited) WOW ....38 inches up high ?? Mj Yes, and the (cough cough - WOLF! - cough cough) primers still fail to fire reliably. Edited March 17, 2016 by johnbu Link to comment Share on other sites More sharing options...
TJART Posted March 17, 2016 Share Posted March 17, 2016 I only use the same pencil 4 or 5 times. After that, the dimple in the eraser will change results. Link to comment Share on other sites More sharing options...
johnbu Posted March 17, 2016 Author Share Posted March 17, 2016 Just came in and found there to be a dimple in my "standard". A new one went higher. Good point! Thanks. Link to comment Share on other sites More sharing options...
EngineerEli Posted March 17, 2016 Share Posted March 17, 2016 I only use the same pencil 4 or 5 times. After that, the dimple in the eraser will change results. Yup, I experienced the same thing. I think I was even seeing an issue where in stock form, at first the pencil would hit the ceiling, then after a few tries, it barley went up a food, turned out there is a big old hole in the eraser. I think this test really needs to be changed from the pencil test to the dowel rod test. Probably much more consistent results... 5/16" should work nicely. Link to comment Share on other sites More sharing options...
TJART Posted March 17, 2016 Share Posted March 17, 2016 I only use the same pencil 4 or 5 times. After that, the dimple in the eraser will change results. Yup, I experienced the same thing. I think I was even seeing an issue where in stock form, at first the pencil would hit the ceiling, then after a few tries, it barley went up a food, turned out there is a big old hole in the eraser. I think this test really needs to be changed from the pencil test to the dowel rod test. Probably much more consistent results... 5/16" should work nicely. That's actually a great idea. Link to comment Share on other sites More sharing options...
johnbu Posted March 18, 2016 Author Share Posted March 18, 2016 (edited) I tried a hardware store wood dowel in the past. Firing pin poked a hole quick into the end. One thought.... cutting the eraser just short of flush with the metal wrap may keep the pin from poking in so quick. Sort of like the elastomer end on a snap cap. Or.... affix a used large primer in the eraser... "Funny thing" happened the other day while launching pencils. One went up and (swear to God!) Landed in the gun barrel ready to launch again. Too bad there wasn't a camera on it or me, I bet I gave the best WTF face ever! Edited March 18, 2016 by johnbu Link to comment Share on other sites More sharing options...
EngineerEli Posted March 18, 2016 Share Posted March 18, 2016 Not sure if this is what you were saying, but if you took a spent primer, removed the anvil and just hammered the cup into the eraser of a pencil, it would be perfect, it would absorb some of the energy and protect your FP, without it penetrating the eraser and screwing with results. Link to comment Share on other sites More sharing options...
johnbu Posted March 18, 2016 Author Share Posted March 18, 2016 Not sure if this is what you were saying, but if you took a spent primer, removed the anvil and just hammered the cup into the eraser of a pencil, it would be perfect, it would absorb some of the energy and protect your FP, without it penetrating the eraser and screwing with results. Yes! That's the idea. Link to comment Share on other sites More sharing options...
Nealio Posted March 22, 2016 Share Posted March 22, 2016 I've heard of people just loading up an empty case with a live primer to see if they strike mark is good without having to go to the range. But I would never do that since that could be considered discharging your firearm in city limits.... Link to comment Share on other sites More sharing options...
johnbu Posted March 24, 2016 Author Share Posted March 24, 2016 I've heard of people just loading up an empty case with a live primer to see if they strike mark is good without having to go to the range. But I would never do that since that could be considered discharging your firearm in city limits.... Not living in city limits, I just shoot them. Link to comment Share on other sites More sharing options...
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