Fullauto_Shooter Posted July 29, 2008 Share Posted July 29, 2008 I've heard a lot of talk about "working the Comp" on an open gun and that hotter loads "work the comp" better than milder loads. I'm currently shooting some 168PF loads in my STI Trubor but the gun feels just a bit less flat than some others I've shot. Should I increase the PF to make better use of the comp? Know that it varies from shooter to shooter and probably gun to gun, but what is a generally acceptable PF range for an Open gun?? One more question - does load data vary between .38 Super and .38 Super Comp? I'm guessing that load data is pretty much identical with the only difference being the external composition of the case? Am I right or wrong? Thanks for the help, Doug Link to comment Share on other sites More sharing options...
BritinUSA Posted July 29, 2008 Share Posted July 29, 2008 Some rimless .38 cases may have slightly less internal space than others, so it's always a good idea to drop a few tenths and then work back up.. Open guns used to run 175PF, though many would go to 180PF to make sure they did well at the Chrono stage. As you state, changes in comp design and recoil spring can affect how well the ammo works the gun. I always try to run 5PF over the Major PF just to be safe on the chrono. I have heard of some people going up to 175PF or higher as it works their gun better. My advice is to work up the loads (to make sure you are not too hot) then load up 100 of them and try them for a local match. Just loading 10 or so probably won't give you enough feedback. Link to comment Share on other sites More sharing options...
Flatland Shooter Posted July 29, 2008 Share Posted July 29, 2008 Also your powder selection plays a role in the effectiveness of your comp. If you can get some samples from other shooters in your area, see if you gun likes a slower or faster powder than you are now using. Bill Link to comment Share on other sites More sharing options...
shred Posted July 29, 2008 Share Posted July 29, 2008 You'll do better to change to more of a denser powder to get more comp action. Upping the PF beyond 170 or so is largely a losing game... Link to comment Share on other sites More sharing options...
larry cazes Posted July 29, 2008 Share Posted July 29, 2008 I too will run 171-172PF minimum so that I have a comfortable margin to make major PF at matches that check. My wife and I shoot 5" full length open guns that all seem to like 170+ PF loads for both function and "working the comp". At area 2 last year, my loads chrono'ed out to 4+ PF less than they measured at home. Had I loaded to 168PF, we both would have been shooting minor. Link to comment Share on other sites More sharing options...
Fullauto_Shooter Posted July 29, 2008 Author Share Posted July 29, 2008 You'll do better to change to more of a denser powder to get more comp action. Upping the PF beyond 170 or so is largely a losing game... Thanks for the info. I'm currently using N350 and the case is pretty close to full (7.9 grains) - can you recommend a denser powder? I'll probably bring the pistol to ALSPPC, Alpha Mike, or the Waco match to get some live-fire opinions from more experienced Open shooters - maybe my recoil expectations are unrealistic?? Link to comment Share on other sites More sharing options...
shred Posted July 29, 2008 Share Posted July 29, 2008 You'll do better to change to more of a denser powder to get more comp action. Upping the PF beyond 170 or so is largely a losing game... Thanks for the info. I'm currently using N350 and the case is pretty close to full (7.9 grains) - can you recommend a denser powder? I'll probably bring the pistol to ALSPPC, Alpha Mike, or the Waco match to get some live-fire opinions from more experienced Open shooters - maybe my recoil expectations are unrealistic?? Sure, no problem letting people play with our toys (although mine's setup for steel right now.. that would be a mean trick to play on somebody ). Denser than 350 is looking at 4756 & 3N38 kinds of loads. Since you probably can't go grab a can of 3N38 off the shelf at the store, 4756 may be the one to try. There should be loads posted here that are reasonable. Link to comment Share on other sites More sharing options...
tomface Posted July 29, 2008 Share Posted July 29, 2008 I just tried 2 new loads with 3N38. They both work the gun nice, and are both 170 pf. 124 Rem JHP 8.9 grains 1.235 oal 115 Rem FMJ 9.8 grains 1.235 oal bbl length is 5.5 Ultimatch, no holes, 4 chamber comp Link to comment Share on other sites More sharing options...
G-ManBart Posted July 29, 2008 Share Posted July 29, 2008 You'll do better to change to more of a denser powder to get more comp action. Upping the PF beyond 170 or so is largely a losing game... Thanks for the info. I'm currently using N350 and the case is pretty close to full (7.9 grains) - can you recommend a denser powder? I'll probably bring the pistol to ALSPPC, Alpha Mike, or the Waco match to get some live-fire opinions from more experienced Open shooters - maybe my recoil expectations are unrealistic?? My N350 load with MG 121 IFP's was right at 7.9gr as well. That gave me right around 170pf. Switching to 10.0gr of 3N38 and MG 115 JHPs also gave me 170pf and a noticable drop in dot rise. I'm running 10.5gr of N105 with the MG 115 JHP now (also right at 170pf) and it's a touch flatter and softer than the 3N38....probably just a bit more gas volume to work the comp a bit better. Both the 3N38 and N105 fill the case up pretty well, but not so bad I'm spilling powder and it's only slightly compressed (38SC cases). The one thing I have noted is that 3N38 meters exremely well through the Dillon powder measures. I'm seeing .1gr of variation at most and the SD and ES are very low. N105 doesn't meter quite as nicely (probably because the sticks are longer). Link to comment Share on other sites More sharing options...
benny hill Posted July 29, 2008 Share Posted July 29, 2008 115jhp & 11gr. of ww571 really works the comp & gives a whole new meaning to flat shooting. The more dense powder you can use, the more it will burn in the comp instead of the barrel. Link to comment Share on other sites More sharing options...
Fullauto_Shooter Posted July 29, 2008 Author Share Posted July 29, 2008 115jhp & 11gr. of ww571 really works the comp & gives a whole new meaning to flat shooting. The more dense powder you can use, the more it will burn in the comp instead of the barrel. Benny, Thanks for the info - I'm hearing that denser powder is better. What benefit do you get by having the powder burn in the comp instead of the barrel? To a new Open guy like me, it seems like the powder burning in the comp does nothing to increase velocity; does the powder burning in the comp "work the comp"? I know you shoot a lot of guns, but do you recall your impression of the recoil of mine with the ammo I gave you to test fire? It was the Trubor I gave you at the 3-Gun match you MDed a couple weeks back - you tweaked it and had it ready to go in only a couple days. Thanks, Doug Johnson Link to comment Share on other sites More sharing options...
ong45 Posted July 29, 2008 Share Posted July 29, 2008 115jhp & 11gr. of ww571 really works the comp & gives a whole new meaning to flat shooting. The more dense powder you can use, the more it will burn in the comp instead of the barrel. 571 still available? Link to comment Share on other sites More sharing options...
Larry White Posted July 29, 2008 Share Posted July 29, 2008 115jhp & 11gr. of ww571 really works the comp & gives a whole new meaning to flat shooting. The more dense powder you can use, the more it will burn in the comp instead of the barrel. 571 still available? If you look for it you can still find some. HS7 was the same stuff, now its going away too.--------------Larry Link to comment Share on other sites More sharing options...
shooterbenedetto Posted July 29, 2008 Share Posted July 29, 2008 Can we use 115g bullet for USPSA or ipsc matches? I thought that the minimum bullet must be 121g? If so, i will change my load. Anyone? Link to comment Share on other sites More sharing options...
BritinUSA Posted July 29, 2008 Share Posted July 29, 2008 IPSC has the bullet weight restriction so you can't use 115 in IPSC matches but you can in USPSA. Link to comment Share on other sites More sharing options...
HoMiE Posted July 29, 2008 Share Posted July 29, 2008 (edited) Can we use 115g bullet for USPSA or ipsc matches? I thought that the minimum bullet must be 121g? If so, i will change my load. Anyone? 112 gr. min. for USPSA / 120 gr. min. for IPSC ...in Open division Edited July 29, 2008 by HoMiE Link to comment Share on other sites More sharing options...
shooterbenedetto Posted July 29, 2008 Share Posted July 29, 2008 Cool!! I mostly shoot in the U.S anyway! Just checked powder valley and there's no H7?? what other powder to try with 115g Link to comment Share on other sites More sharing options...
Larry White Posted July 29, 2008 Share Posted July 29, 2008 Cool!! I mostly shoot in the U.S anyway! Just checked powder valley and there's no H7?? what other powder to try with 115g AA#7---------------Larry Link to comment Share on other sites More sharing options...
mda Posted July 29, 2008 Share Posted July 29, 2008 Fullauto If the powder is all burnt in the barrell there will be less gas to work the comp which is why you need to use a slower powder. When some of the powder burns in the comp it is still creating gas volume. This gas will push the barrel down and forward. This is just the oppiste of non-comped guns where you want all the powder burnt before the bullet leaves the barrel. IE. Fast powder heavy bullet. MDA Link to comment Share on other sites More sharing options...
Keninaz Posted July 29, 2008 Share Posted July 29, 2008 (edited) Cool!! I mostly shoot in the U.S anyway! Just checked powder valley and there's no H7?? what other powder to try with 115g Longshot and IMR 4756 will work. IMR 7625 will also work with 115's Kendall Edited July 29, 2008 by Keninaz Link to comment Share on other sites More sharing options...
ebg3 Posted July 29, 2008 Share Posted July 29, 2008 I have a 5 port hybrid barrel with a 3 port comp. 8grs Longshot and 10grs 3n38 give the same power factor with a 124jhp. The gun feels much softer with the Longshot. Both are flat and make the gun function well, the 3n38 recoils a lot harder in my hand though. Link to comment Share on other sites More sharing options...
shred Posted July 30, 2008 Share Posted July 30, 2008 You can see over in this thread: http://www.brianenos.com/forums/index.php?...st&p=744468, the powder burning and the comp 'working'. Interestingly, even though the gun doesn't really flip until the slide hits the frame, different powder burns do create quite different recoil patterns. Link to comment Share on other sites More sharing options...
1911jerry Posted July 30, 2008 Share Posted July 30, 2008 115jhp & 11gr. of ww571 really works the comp & gives a whole new meaning to flat shooting. The more dense powder you can use, the more it will burn in the comp instead of the barrel. 571 still available? I have some 571 if someone needs some. Stored correctly and still sealed in 3# kegs. I will not ship, but I travel a bit. Jerry Link to comment Share on other sites More sharing options...
Al Capizzo Posted July 30, 2008 Share Posted July 30, 2008 It is true that Hogden is no longer selling HS7, but they are saying, "if you liked HS7, you'll love Longshot". Well I don't know about all that, but I do like Longshot in the Super. Link to comment Share on other sites More sharing options...
benny hill Posted August 5, 2008 Share Posted August 5, 2008 The gun in the viedo is one I built & is useing 12.2 gr. Accurate # 7 & a 115 jhp. As you note, it is totally flat till the slide hits the frame. With a stronger recoil spring to slow down the slide, it would be flater. I have used this load for 15 yrs & nothing is flater. Link to comment Share on other sites More sharing options...
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