Mat Price Posted February 25, 2012 Share Posted February 25, 2012 I am not sure why but going from a mid 168 PF to a solid 170 ( 170.8) made a HUGE differance in how my trubor 9mm major performs. My usual load is 7.1 Gr of auto comp behind a 124 gr JHP with a wolf SRP I get 168- 169 PF. feels good, shoots soft, decent dot movement hits the top of the lens drops right back to center. For no reason in particular I tried 7.3 grains of auto comp. Well I thought maybe i could get a little less dot movement. What i found was that i didnt get any less motion but WOW. This is a trubor with a T-2 comp. It has not been cut on at all but has had all the bells and whistles every place else. trigger ect. OK @ 170 power factor in this gun it just flat shoots! I can't really explain it. The slide seems to cycle faster is feels softer to shoot it feels balanced. It feels tuned. just that little bit of difference in power factor. I did not get any huge difference in actual movement of the dot in the lens. But what happens is the dot moves much slower and just a little less high in the lens and quickly snaps back to center. Is this a common thing and i wonder if I moved it up to 171 solid if i would get a little bit better performance. However with that said I was seeing 1 in maybe 10 rounds with the ever so slight evidence of primer flattening. here is my data 7.3 grains of auto comp 124 grain precsion delta JHP @ 1.165 OAL wolf SRP 5 shot groups string1 string 2 avg 1370 1374 hi 1388 1393 low 1351 1366 es 37 27 pf 170 170 I am thinking about bumping up to 7.4 grains to be certain i am always just a bit above above 170 BTW it seems my bbl is slow compared to what others report @ this charge. Link to comment Share on other sites More sharing options...
CStrabala Posted February 25, 2012 Share Posted February 25, 2012 Don't be telling people, it's a secret. Link to comment Share on other sites More sharing options...
Aircooled6racer Posted February 25, 2012 Share Posted February 25, 2012 Hello: You are starting to work the comp better I found that my open pistol likes the power factor up in the 171-173 range and shoots flatter there and even softer than 168PF. Hard to believe untill you try it. You may want to give Hodgdon HS-6 a try also. It has lots of gas like beer and beans Thanks, Eric Link to comment Share on other sites More sharing options...
Mat Price Posted February 25, 2012 Author Share Posted February 25, 2012 (edited) I have tried HS-6 but never really cared for it. But i never really run it up to 170 +. I am toying with the Idea of trying some hs-6 with some 115s or since i have 8 lbs of auto comp getting some 121 ifp Edited February 25, 2012 by Mat Price Link to comment Share on other sites More sharing options...
Aircooled6racer Posted February 25, 2012 Share Posted February 25, 2012 Hello: I shoot 115's in my 9mm. I like them better than the 121's. Thanks, Eric Link to comment Share on other sites More sharing options...
Mat Price Posted February 25, 2012 Author Share Posted February 25, 2012 yeah i am just a little iffy about 115's and a/c no one seems ot have tried it with much success. and since i have 8 lbs of it i think the easier thing is to try 121's before trying a new powder. Link to comment Share on other sites More sharing options...
blaster113 Posted February 25, 2012 Share Posted February 25, 2012 I noticed the same thing working up loads for my open gun. I was playing with loads in the 168-170pf range and didnt like the dot movement or recoil impulse. went through a couple of powders and tried different weights. I ended up with a nice feeling 175 pf load (by accident:D, was trying to load for 171 and ended up with 175 at Area 2) and found that the gun shot as soft or softer than with the lower pf loads. as aircooledracer said, it seems like the magic with comps happens in the 171-175 pf range. Link to comment Share on other sites More sharing options...
Mat Price Posted February 25, 2012 Author Share Posted February 25, 2012 yeah just seems like 7.4 grains of auto comp to get 171 -172 is a lot of powder to what others are seeing in there similar guns. I am going to load up some 7.4 and re chrony and see what i get. Link to comment Share on other sites More sharing options...
shooterbenedetto Posted February 25, 2012 Share Posted February 25, 2012 (edited) If your happy with the recoil, then stop there and shoot it. How's the accuracy shooting doubles @ 10,15 20yds. Edited February 25, 2012 by shooterbenedetto Link to comment Share on other sites More sharing options...
Aircooled6racer Posted February 26, 2012 Share Posted February 26, 2012 Hello: I use Winchester Auto Comp for my 115grain loads also. Works well but hits harder on the hand than HS-6. It is very accurate at 25 yards. My barrel is a 1:32 twist. I would try the 115's and see what you think and use a timer to see what works better for you. Thanks, Eric Link to comment Share on other sites More sharing options...
OpenDot Posted February 26, 2012 Share Posted February 26, 2012 my load in colorado got me 175.7PF 7.4 AC 1.175 WSRP Junk Brass Here in phx it's probably 170PF or so...if that Link to comment Share on other sites More sharing options...
OpenDot Posted February 26, 2012 Share Posted February 26, 2012 Hello: I use Winchester Auto Comp for my 115grain loads also. Works well but hits harder on the hand than HS-6. It is very accurate at 25 yards. My barrel is a 1:32 twist. I would try the 115's and see what you think and use a timer to see what works better for you. Thanks, Eric 1/32 twist and 115 is awesome Link to comment Share on other sites More sharing options...
Mat Price Posted February 26, 2012 Author Share Posted February 26, 2012 Eric what are you loading behind a 115? Link to comment Share on other sites More sharing options...
itlogo Posted February 27, 2012 Share Posted February 27, 2012 I had a similar experience loading 7.0gr of Auto Comp behind 124gr MG JHP. Loaded at 1.13 OAL, it felt softer than 6.5gr (which made 168pf for me) loaded at 1.15. 7.0 made about 175PF. I went to 7.4gr and 1.165 OAL, but it started feeling snappier at that point, and PF was way in the 180's. BTW, I have a 5" barrel. For my gun, 7.0 at 1.13 with 124gr is just about optimal. Link to comment Share on other sites More sharing options...
Whoops! Posted March 1, 2012 Share Posted March 1, 2012 (edited) I know exactly what you're talking about and will add that it depends on the weight of the recoiling mass and the spring weights. With a lighter slide you can have that faster, better feeling with a slightly lower power factor and thus, less muzzle rise. That being said, not enough less for most to notice. Edited March 1, 2012 by Whoops! Link to comment Share on other sites More sharing options...
Aircooled6racer Posted March 1, 2012 Share Posted March 1, 2012 Hello: I am loading 7.5 grains of Auto Comp with the 115 Montana Gold JHP's at 1.170" OAL. I am also using either small rifle primers or Winchester small magnum pistol primers. Thanks, Eric Link to comment Share on other sites More sharing options...
thebridge Posted March 3, 2012 Share Posted March 3, 2012 WAIT!! Whoops, could you please talk a little more about slide weights/ bullet weights and PF as it applys to felt recoil....I am all ears. Link to comment Share on other sites More sharing options...
Whoops! Posted March 3, 2012 Share Posted March 3, 2012 (edited) Sorry, I don't really know enough about it to do a narrative with numbers and what not. Just physical perception with regard to lighter slides and recoil springs on the 2011 and Tanfoglio and M&P platforms on varying loads of N105, 3n38, HS6, and Autocomp. In general - if you feel the gun is only cycling fast enough after you bump the charge to above what your class requires in terms of power factor, you need a lighter slide to be optimally competitive in that class. That is also, if you feel you have the perfect recoil and main spring setup already. I'm sure someone else can chime in with some hard numbers. Edited March 3, 2012 by Whoops! Link to comment Share on other sites More sharing options...
thebridge Posted March 6, 2012 Share Posted March 6, 2012 I am playing around with slide weight now. great info! Link to comment Share on other sites More sharing options...
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