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CZ was close to 1/1000 inch, which is quite good and dramatically limits case stretching. Unfortunately, leade length in both the CZ and the Savage is such that seating most tested bullets close to, or touching, the rifling gives less than ideal seating depth. I prefer at least 2/3-caliber of shank seating depth, which is about 0.15-inch in 22-caliber guns. However, I will handle the car- tridges carefully and accuracy is more critical to me, so I will settle for less seating depth, when necessary, to keep bullet-to-rifling jump closer to zero, which I have proven is how to get best accuracy from this gun. MaxiMuM Pressure LiMit In the CZ, which fully supports the
case head with a front-locking action, I am personally comfortable using loads that undoubtedly exceed SAAMI maxi- mum pressure. However, this does not mean that I am comfortable suggesting that anyone else use any such load in any gun. I have attempted to assure that the suggested loads would not generate excessive pressure, as loaded and tested in this gun. I cannot know what pressure your nominally similar loads might gen- erate in your gun — it is always incum- bent upon the individual handloader to use due caution and good judgment when working up to maximum loads. When using pistol primers, pierc-
ing was an issue in the stock CZ 527. CZ designed this gun to deliver a robust striker blow to properly ignite rifle primers. Therefore, it is a bit much for pistol primers and the firing pin tip oc- casionally punched a hole through the cup where the tip came to rest on the
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anvil. This resulted in a tiny (generally harmless) gas leak but I would not want to use such loads continuously as it would be apt to result in striker damage. I solved this problem in my CZ
by removing two coils from the striker spring. On the 527, this is a simple pro- cess. I was able to take the bolt down and remove the spring using only my hands! Just follow the instructions. The resulting reduction still left the striker with plenty of energy to set off rifle primers. The downside is that it slightly increased lock time but I do not care about that aspect. If you have a rifle with such a ro-
bust striker that it pierces pistol primers or a gun with a lighter striker and spring (such as the Contender) where blanking with pistol primers occurs with other- wise usable loads, it is necessary to use rifle primers. Use extreme caution when substituting primers — reduce charge at least one grain and start load develop- ment again, as you will be working with an entirely new load! Note that, generally, primer flat-
tening or blanking is an unreliable pres- sure indicator, because of variations in guns and primers. Conversely, in any strong action that fully supports the case head, regardless of primer used, case rim expansion is a good indicator of maximum usable Hornet chamber pressure. Test three shots with identical loads using new Hornet cases. Mea-
surable case rim expansion exceeding 4/10,000-inch in any one case or an average expansion exceeding 2/10,000- inch for three cases suggests excessive pressure. Reduce charge at least half a grain below the charge level where an average of 2/10,000-inch average expan- sion occurs. Rarely, but occasionally, we en-
counter softer-than-normal Hornet cases. These will show significant case rim expansion with normal loads. Such cases should be ignored for this type of testing. This is why it is necessary to fire at least three shots of each test load — one case that expands significantly more than the other two in such a test probably had a soft head. Discard that case and repeat the test with three new cases. If a similar result occurs, it is possible that the propellant and primer combination are not producing con- sistent results. This is sufficient cause
to discontinue testing and use of that combination of components. I worked up loads with each
tested component combination until rim expansion was about 2/10,000-inch, on average of three cases. I reduced this charge by one-half-grain and tested the resulting load for velocity, ballistic uniformity, and accuracy. Resulting data from that testing is presented in the data tables. (A clarification is in order: Many
listed loads contain all the propellant I could possibly get into the case. It should be obvious that I cannot know that a charge that is heavier by ½-grain or less would not have generated case rim expansion — I could not test such a charge. In these instances, I used primer appearance and other indicators as a proxy for case rim expansion. As those of you who have read my piece on read- ing pressure signs will know, this is far from an ideal approach but it is the best that I could do.) For this testing, I was sufficiently
conservative so that these suggested loads (after taking into account all cor- rections previously accounted for in this article) should be safe in any modern, quality, gun (that fully supports the case head) that is in proper condition and working order. Nevertheless, headspace is always a concern and any gun with excessive working headspace is apt to demonstrate potentially dangerous case head separations after reusing cases one or more times with any load generating anywhere near full Hornet pressure (as the loads presented in this article will produce). Similarly, any rear locking ac- tion, regardless of how tight headspace might be, will reduce case life as one increases load pressure. To extend case life, stay at least one grain below the suggested maximum loads shown here. To assure maximum case life in
a gun with excessive headspace, all a handloader can do is reduce the charge until firing the round does not reseat the primer (if the primer is not reseated at all, the case walls did not stretch). How can you know if the primer is partially reseated? Simply full-length resize a case, prime it, chamber it, and fire the primed-only case in the gun of interest. Primer protrusion from that case rep- resents headspace. Generally, a charge reduction of about 11/2 to 2 grains below the loads listed in the following tables
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