Weimer01 Posted June 23, 2007 Share Posted June 23, 2007 Is the OAL specific to feeding, I would imagine that it affects pressure too? Has anyone played with OAL's using a chrono? Thanks Link to comment Share on other sites More sharing options...
Jaxshooter Posted June 23, 2007 Share Posted June 23, 2007 It does have an affect on pressure. In the 40 S&W it can make a huge difference. The only way to work up loads is with a chrono and keep your eye on the brass and primers for signs of pressure. Increase powder in small amounts. Be careful and get a good reloading manual to give you a referrence point. Link to comment Share on other sites More sharing options...
G-ManBart Posted June 23, 2007 Share Posted June 23, 2007 Is the OAL specific to feeding, I would imagine that it affects pressure too?Has anyone played with OAL's using a chrono? Thanks OAL isn't only specific to feeding, but that's a primary consideration. When a round is developed oal is an integral part of grip size, magazine size etc. All other things being equal, shorter oal increases pressure and (usuall) velocity. Longer oal lowers pressure and velocity. Link to comment Share on other sites More sharing options...
Weimer01 Posted June 23, 2007 Author Share Posted June 23, 2007 It does have an affect on pressure. In the 40 S&W it can make a huge difference. The only way to work up loads is with a chrono and keep your eye on the brass and primers for signs of pressure. Increase powder in small amounts. Be careful and get a good reloading manual to give you a referrence point. I followed one manual and I wound up with 1,200 fps out of my 45, needless to say, "...threw that one away". Link to comment Share on other sites More sharing options...
Weimer01 Posted June 23, 2007 Author Share Posted June 23, 2007 (edited) Is the OAL specific to feeding, I would imagine that it affects pressure too?Has anyone played with OAL's using a chrono? Thanks OAL isn't only specific to feeding, but that's a primary consideration. When a round is developed oal is an integral part of grip size, magazine size etc. All other things being equal, shorter oal increases pressure and (usuall) velocity. Longer oal lowers pressure and velocity. Is there much difference say with .005" longer or shorter? Or is it simply play with it and chrono a lot of rounds to get the recipe you want/need? I've been trying to get a load using 185 JHP's over Clays @ 1.21 OAL but they came in under my target 168 PF. I have since moved on to Plated 200 grn SWC's (2,000 of them to be exact). I see them to be the choice here... with the exception of others running LSWC's. Edited June 23, 2007 by Weimer01 Link to comment Share on other sites More sharing options...
G-ManBart Posted June 23, 2007 Share Posted June 23, 2007 Is there much difference say with .005" longer or shorter? Or is it simply play with it and chrono a lot of rounds to get the recipe you want/need? I've been trying to get a load using 185 JHP's over Clays @ 1.21 OAL but they came in under my target 168 PF. I have since moved on to Plated 200 grn SWC's (2,000 of them to be exact). I see them to be the choice here... with the exception of others running LSWC's. If you're using a load that's reasonably within limits .005" isn't going to make a huge difference. You're going to get a couple thousandths variation anyway just because cases and bullets aren't identical. Pick an oal that seems to run in the gun and then find the powder charge that gives you the right velocity for your target PF. I'd say that 168pf is a tick on the light side to be safe for big matches. Unless you've got a lot of experience with a particular combination under different conditions (mostly temp) a little more cushion might be a good thing. A lot of people seem to like a 170pf. My current load is at 171pf give or take a tick. I can't feel any difference between 165pf and 171pf. You'll likely find that the 200gr bullets will be a little bit less snappy than the 185gr at the same power factor, but they'll give you a touch more muzzle flip. After you've tried some of each you'll figure out what feels best to you. Honestly, until it's holding you back, ammo isn't a huge issue....as long as it runs reliably in your gun. Link to comment Share on other sites More sharing options...
Weimer01 Posted June 23, 2007 Author Share Posted June 23, 2007 (edited) G-ManBart, Thanks for the helpful text; I suppose my initiative is to reduce the waited rounds. I currently have 600 rounds of junk...well, to be fair, I have 600 rounds of practice ammo. My past load: 185 grn Zero JHP Clays @ 4.4 grn OAL 1.21" Winchester LPP's Winchester brass once fired Note: these didn't even break 800 fps Next go will be: 200 grn Rainier Plated SWC Clays @ 3.8, 4.0, & 4.2 to start OAL 1.21" (this may change pending how the bullet looks seated in the case) Winchester LPP's Winchester brass once fired I should be able to get these chrono'ed today, fingers crossed. Again, thanks! Weim Edited June 23, 2007 by Weimer01 Link to comment Share on other sites More sharing options...
Weimer01 Posted June 24, 2007 Author Share Posted June 24, 2007 200 grn Rainier Plated SWC Clays @ 3.8, 4.0, & 4.2 to start OAL 1.21" (this may change pending how the bullet looks seated in the case) Winchester LPP's Winchester brass once fired I was able to chrono the above rounds, not good though. I changed the OAL to 1.22, the best I got out of these was 833 fps but then again it was a spike. I went up to 4.4 grn's of Clays and 1.26 OAL. This recipie looked like the 4.2 load @ 1.22. I'll stick with the 1.26 OAL (because the bullet looked good seated) and bump the grn's to 4.6. Link to comment Share on other sites More sharing options...
elenius Posted June 28, 2007 Share Posted June 28, 2007 200 grn Rainier Plated SWCClays @ 3.8, 4.0, & 4.2 to start OAL 1.21" (this may change pending how the bullet looks seated in the case) Winchester LPP's Winchester brass once fired I was able to chrono the above rounds, not good though. I changed the OAL to 1.22, the best I got out of these was 833 fps but then again it was a spike. I went up to 4.4 grn's of Clays and 1.26 OAL. This recipie looked like the 4.2 load @ 1.22. I'll stick with the 1.26 OAL (because the bullet looked good seated) and bump the grn's to 4.6. Be careful with Clays! For 200gr LSWC, Hodgon lists, 4.3 grains as MAX (for a velocity of 888fps, i.e. PF 177), and this is with an OAL of 1.225". You do have a longer OAL, and things may be a little different with plated vs lead bullets, but I would be very careful over the max load with Clays. FWIW, I also chrono'd a couple of similar loads last weekend: 200 gr LSWC Precision bullet Winchester LPP 4.2 gr Clays 1.240" OAL Velocity: 814fps avg, 13fps SD (on a 10 shot string) --> PF 163 200 gr RNF Precision bullet Winchester LPP 4.2 gr Clays 1.235" OAL Velocity: 779fps avg, 21fps SD (on a 10 shot string) --> PF 156 Even though the OALs are almost the same, the SWCs have a higher proportion of their mass inside the case, therefore reducing the remaining case volume and increasing the pressure. Plus SWCs are supposed to be a little faster than RNs anyway I think. I am going to try the SWCs with 4.3 gr next time. Maybe load them a tiny bit shorter, but I can't go much shorter before the wide part of the bullet goes past the edge of the case. Daniel Link to comment Share on other sites More sharing options...
Weimer01 Posted June 30, 2007 Author Share Posted June 30, 2007 I think I have something to work with... Load Data: 200 grn Rainier Plated SWC Winchester once fired Winchester Large pistol primers OAL @ 1.26" Shot 10 rounds and after tossing the high and low I seen an average of ~848 fps with no pressure signs Finally! Curious, do barrels get slower or faster with age? With shooting the same loads I have found here mine is a snail. Link to comment Share on other sites More sharing options...
Weimer01 Posted July 3, 2007 Author Share Posted July 3, 2007 I think I have something to work with...Load Data: 200 grn Rainier Plated SWC Winchester once fired Winchester Large pistol primers Clays @ 4.6 grn's OAL @ 1.26" Shot 10 rounds and after tossing the high and low I seen an average of ~848 fps with no pressure signs Finally! Curious, do barrels get slower or faster with age? With shooting the same loads (I have found here) mine is a snail. Sorry, I forgot the powder... Link to comment Share on other sites More sharing options...
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