{"id":1100,"date":"2014-07-26T14:23:15","date_gmt":"2014-07-26T19:23:15","guid":{"rendered":"https:\/\/david.bookstaber.com\/Interests\/?p=1100"},"modified":"2024-01-05T16:53:26","modified_gmt":"2024-01-05T21:53:26","slug":"1022-precision-rifles","status":"publish","type":"post","link":"https:\/\/david.bookstaber.com\/Interests\/2014\/07\/1022-precision-rifles\/","title":{"rendered":"10\/22 Precision Rifles"},"content":{"rendered":"<p><a href=\"https:\/\/david.bookstaber.com\/Interests\/img\/10-22s.jpg\"><img decoding=\"async\" src=\"https:\/\/david.bookstaber.com\/Interests\/img\/10-22s-640.jpg\" alt=\"KIDD 10\/22 in Archangel stock, Ruger 10\/22 with Feddersen barrel in Vantage stock\" \/><\/a><\/p>\n<p>These are both Ruger 10\/22 style rifles built for shooting .22LR with maximum accuracy. On top is an $860 rifle built entirely by <a href=\"http:\/\/www.coolguyguns.com\/\">KIDD Innovative Design<\/a>. The receiver and trigger are milled from aluminum, and the bolt from hardened steel. The single-stage trigger is also a crisply machined assembly that adjusts down to a pull of just 1.5 pounds. The lightweight barrel is guaranteed to group inside of half an inch at 50 yards. The gun here is screwed into a comfortable $100 ProMag Archangel Target stock<\/p>\n<p>Do you have to spend $1000 to get an accurate .22 rifle? Expert barrel maker <a title=\"Feddersen 10\/22 barrels\" href=\"http:\/\/www.1022rifle.com\/\" target=\"_blank\" rel=\"noopener noreferrer\">Fred Feddersen<\/a> says one of his $170 barrels will turn an off-the-rack Ruger into a gun that can compete with any custom autoloader. So the second gun shown is a standard Ruger 10\/22 receiver and bolt onto which I swapped Feddersen&#8217;s barrel. Of course I don&#8217;t think I can really shoot that well with a standard trigger, so to be fair I bought another $200 KIDD trigger assembly for it. The gun is shown here screwed into a beautiful $175 Tactical Solutions Vantage laminated stock.<\/p>\n<h2>Testing<\/h2>\n<p>The ammo shortage continues to plague the market for .22LR, so I consider myself lucky to still have four different types of ammo on hand. I screwed an AAC Element suppressor to each barrel, put each rifle in the Archangel stock, mounted the same high-power scope, and shot ten-round groups at 50 yards with the following subsonic 40gr loads:<\/p>\n<ul>\n<li>Eley Match<\/li>\n<li>SK+<\/li>\n<li>CCI HP<\/li>\n<li>Aguila SuperExtra<\/li>\n<\/ul>\n<p>I have plenty of the Aguila on hand, so I used that for sighting and shot two groups with that. The Ruger\/Feddersen fired all 50+ shots without any hiccups. The KIDD began to bog down at the end, experiencing a few failures to fire or extract on the Aguila. Cleaning the chamber and bolt face and testing some more showed it&#8217;s capable of running smoothly when clean, but evidently it doesn&#8217;t like too much of the copious .22LR fouling to build up. Do those tighter tolerances translate to higher precision?<br \/>\n<!--more--><br \/>\nThe question of precision is a mathematically interesting one that has been embarrassingly neglected by the shooting industry, which is often content to simply measure the extreme spread of 3 to 5 shots and leave it at that. With 10 shots per group I have more statistically significant samples. I use <a href=\"http:\/\/www.ontargetshooting.com\/\">OnTarget software<\/a> to digitize the targets. It automatically calculates the sample radius and spread for each group. But those measures vary with the number of shots per group. As explained on <a href=\"http:\/\/ballistpedia.com\">Ballistipedia<\/a>, when we test and compare precision we should use invariant and unbiased statistics like Circular Error Probable (CEP), which is the radius of a circle that we expect to cover exactly half the shots \u2014 no matter how many we fire. Daniel Wollschl\u00e4ger, a statistically savvy developer, has built <a href=\"https:\/\/dwoll.shinyapps.io\/shotGroupsApp\/\">an exceptional open-source web app based on R<\/a> that takes the output of OnTarget and performs the difficult calculations to provide unbiased estimates of CEP (and many other statistics).<\/p>\n<p>Having efficiently digested the shooting data, we are ready to compare the results, which are presented in the standardized units <a title=\"Precision Units\" href=\"http:\/\/ballistipedia.com\/index.php?title=Describing_Precision#Units\" target=\"_blank\" rel=\"noopener noreferrer\">Minutes of Arc (MOA)<\/a>, and for which I have added the 90% confidence intervals:<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/david.bookstaber.com\/Interests\/img\/KIDDvFeddersenPrecision.png\" alt=\"Precision of KIDD vs Feddersen rifles on different ammunition\" \/><\/p>\n<p>The 90% confidence intervals overlap on every estimate, which means that we really need to shoot more samples to draw any conclusions about relative precision!<\/p>\n<p>If we take the central estimate at face value then the KIDD rifle seems more accurate on only half of the four lots tested.\u00a0 After factoring in its lower cost and higher reliability I think Feddersen&#8217;s barrel is quite commendable.\u00a0 What happens if we put that remarkable Feddersen barrel on the precision KIDD receiver? I tried this and spent months trying to get it to cycle reliably. I sent it to Fred Feddersen and he blamed the KIDD springs. I sent it to Tony Kidd and he said the Feddersen barrel didn&#8217;t have a proper shoulder. The moral of that test: Don&#8217;t expect precision 10\/22 components from different companies to play nicely together.<\/p>\n<p>For reference, following are the actual 50-yard targets fired for this test overlaid with OnTarget analysis. &#8220;Max&#8221; is also know as extreme spread, and &#8220;ATC&#8221; is Average To Center, a.k.a. sample mean radius:<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/david.bookstaber.com\/Interests\/img\/KIDDvFeddersen.jpg\" alt=\"Targets from test of KIDD vs Feddersen rifles on different ammunition\" \/><\/p>\n","protected":false},"excerpt":{"rendered":"<p>These are both Ruger 10\/22 style rifles built for shooting .22LR with maximum accuracy. On top is an $860 rifle built entirely by KIDD Innovative Design. The receiver and trigger are milled from aluminum, and the bolt from hardened steel. The single-stage trigger is also a crisply machined assembly that adjusts down to a pull [&hellip;]<\/p>\n","protected":false},"author":3,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[46,133,122],"tags":[],"class_list":["post-1100","post","type-post","status-publish","format-standard","hentry","category-arms","category-ballistics","category-precision"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_shortlink":"https:\/\/wp.me\/po3d1-hK","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/david.bookstaber.com\/Interests\/wp-json\/wp\/v2\/posts\/1100","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/david.bookstaber.com\/Interests\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/david.bookstaber.com\/Interests\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/david.bookstaber.com\/Interests\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/david.bookstaber.com\/Interests\/wp-json\/wp\/v2\/comments?post=1100"}],"version-history":[{"count":10,"href":"https:\/\/david.bookstaber.com\/Interests\/wp-json\/wp\/v2\/posts\/1100\/revisions"}],"predecessor-version":[{"id":1971,"href":"https:\/\/david.bookstaber.com\/Interests\/wp-json\/wp\/v2\/posts\/1100\/revisions\/1971"}],"wp:attachment":[{"href":"https:\/\/david.bookstaber.com\/Interests\/wp-json\/wp\/v2\/media?parent=1100"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/david.bookstaber.com\/Interests\/wp-json\/wp\/v2\/categories?post=1100"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/david.bookstaber.com\/Interests\/wp-json\/wp\/v2\/tags?post=1100"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}