I finally got to shoot some loads I worked up for my Witness.
Using Longshot powder and 200gr Xtreme plated bullets CCI300 primer
Cases were single use Starline brass all from previously shot Underwood ammo.
Eaa Witness Standard with 4.5" barrel w/ flat bottom FP stop, 20lb hammer spring, at 8.6gr I swapped the 20lb recoil spring for a 22lb because I was seeing a bit more velocity variation than I like... and I had one.
Primers were obviously flatter in the heavier loads but nothing I would call alarming and none of the brass measured at the web showed excessive expansion.
I wasn't really noting the accuracy this time out so I'm thinking since the velocity is a know, I want to run at least a partial test again to see if I see any accuracy nodes. It was also cold as crap here so kinda rushed a bit.
I was noticing that the higher velocity loads seemed to be going off target more so I hope the plating isnt stripping but I was shooting at 25 yards at a small target(paper plate) and I find shooting over the chrony distracts my accuracy a bit. I think I'm more worried about not hitting the Chrony than I am in hitting the target.
Anyway, The velocity seems pretty linear even though I dropped to 1gr increments at 9.0gr. Almost get 1300fps from a 4.5" barrel. Not sure of what the pressure is to do that but it's definitely a snappy load. Got a few errors on the Chrony at the upper limits, probably too close to the gun and the blast messed up the reading.
Loadft/sec ft/sec ft/sec ft/sec ft/sec Mean SD Delta
7.2 1005 1020 1004 Error 1010 1010 7.320063752
7.4 1021 1012 1038 1044 1032 1029 12.9151074328 20
7.6 1055 1067 1074 1101 1074 1074 16.8730554435 45
7.8 1068 1086 1043 1087 1039 1065 22.8757513538 -10
8.0 1078 1098 1103 1119 1092 1098 15.0166574177 33
8.2 1075 1108 1131 1078 1101 1099 23.04994577 1 Warning MAX LOAD recommended by Hodgdon for 200gr jacketed bullet
8.4 1140 1130 1103 1121 1147 1128 17.195929751 30
8.6 1152 1159 1160 1160 1160 1158 3.4928498393 30
8.8 1113 1167 1170 1140 1159 1150 23.6579796263 -8
9.0 1188 1188 1173 1176 1186 1182 7.155417528 32
9.1 1182 1193 1201 1167 1206 1190 15.6428897586 8
9.2 1200 1188 1163 1190 1167 1182 15.8839541676 -8
9.3 1192 1213 1212 1207 1208 1206 8.443932733 25
9.4 1239 1258 1212 1200 1219 1226 22.9847775713 19
9.5 1228 1217 1216 1221 1260 1228 18.2838726751 3
9.6 1213 1252 1240 1239 1252 1239 15.9279628327 11
9.7 1237 1262 1242 1283 1283 1261 21.8242983851 22
9.8 1274 1256 1249 1275 1245 1260 13.9892816113 -2
9.9 Error 1295 1295 1272 1282 1286 11.1654228163 26
10.0 1237 1294 1294 Error Error 1275 32.9089653438 -11
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Warning the MAX LOAD recommended by Hodgdon for Longshot with 200gr jacketed bullet is exceeded in this loading
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Hodgdon list 8.2 grains as max with a 200 grain jacketed bullet at 1170 fps and 35,000 psi. Plated might run a bit lower in pressure for the same velocity depending on how thick the plating is.
Maybe I am blind, but how long did you load these? COAL in the Hodgdon load is 1.260". Most 10mm actions and magazines don't support rounds much longer than this, so not any "margin" to be picked up there anyway.
These were all loaded with COAL of 1.250". I do realize that these are well over Hodgdon list of 8.2 grains for a 200 grain jacketed bullet but are in line with loads posted for Swampfox pull downs and his were with jacketed bullets. I am sure these exceed SAAMI pressures for the 10mm but with the tank like build and full supported chamber of the all steel Witness and springs to support a closed action I wanted to push the limits a bit to see what the 10mm could really do.
Guess I should have stated that these are above max recommended loads in my post, although I found no list of max loads for this particular bullet. I modified my original post a bit to show that MAX load is exceeded.
coat4gun, thanks for the very detailed range report. 8) And seeing you were using the CCI 300 primers. I conversations with AKA Mudrush (Mike Willard) of Swampfox Ammo we talked about the denser charges of LongShot and using the magnum primer to get a more complete ignition. Therefore I load the 200 grain XTP with 9.4 grains of LongShot but I use the CCI 350 primer which pushes right at 1240-1250 fps from my S&W1006 5".
If you wanted to try this loading it would be great to see how your results track...
I didn't mention in my first post but this is my first loadings for 10mm. I've been handloading since the late 80's but mostly rifle.... and 41mag, but I sold that several years ago. It was a Taurus Ti frame revolver that was plain painful to shoot. A 25oz gun shooting full house 41mag will bruise the hand.
In testing this load I also ran some Underwood 200gr XTP and 220 lead just to get a measure of the web expansion. Following are the velocities I got. Funny how the lead got essentially the same mean velocity even though it was 20gr heavier. The lead with the wide meplate isn't 100% reliable in my gun. Stovepipes now and then which is not a good thing for a defensive round.
I have been thinking about working on a 200 gr XTP load as well, but decided to start with the 200gr Xtreme RNFP plated lead first because I wanted a deep penetrating round for big animal protection, second because it is way cheaper. From what I read the XTP seems to penetrate less when it is driven faster.
I do want to do some penetration tests on the Xtreme bullet at some point but I first want to make sure it is not stripping the copper plating at the speeds I would like to push it. Don't usually get much penetration when the bullet goes through the target sideways.
Load ft/sec ft/sec ft/sec ft/sec ft/sec Mean SD
Underwood 200xtp 1201 1156 1173 1161 1157 1169.6 18.8095720313
Underwood 220lead 1184 1148 1166 1144 1160 1160.4 15.8996855315
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It is understandable about the mis feeds with the wide MEPLAT nose (especially those that have the sharp edges as compared to the rounded edges, it tends to change the tipping angle of the cartridge making it longer across the angle as it tries to tip over and enter the chamber.
Double Tap, actually seated theirs shorter to 1.2420" to improve the feeding...
Scroll through this post to see more; http://10mm-firearms.com/reloading-10mm-ammo/what-over-all-length-for-10-mm/msg42886/#new (http://10mm-firearms.com/reloading-10mm-ammo/what-over-all-length-for-10-mm/msg42886/#new)