luvdemcoues Report post Posted October 5, 2011 Just went out and shot this morning to see how my new load performed. Using 140 grain Bergers pushed by 61 grains of RL 17 and Federal Mag Primers, I was getting 3,125 FPS and great groups. I really want to get it about 100 FPS faster. Only problem is that I don't know when I will be able to get out with a chrono again. So my question is this, how much of an increase in velocity should I expect to see with each additional grain of powder? (By way of disclaimer, I showed no pressure signs and am at maybe 85% capacity) I hope to use this info to save some time in building up my next loads. Muchas Gracias!!! Share this post Link to post Share on other sites
ultramag Report post Posted October 5, 2011 I wish I could help. I am also searching for the right load .270wsm... I have tried h4831sc at 62gr with 140 NAB only getting 3030fps great accuracy no pressure signs at all and this shows max load. I would like to be 3200 or so. I am going to try a differant powder and see. Have you tried RL22 powder? I was thinking of trying it. Share this post Link to post Share on other sites
firstcoueswas80 Report post Posted October 5, 2011 Why do you care about the speed if the accuracy was there? 3125 is very respectable speed, paired with grat accuracy and youre there. My advise? Load up 100 of that load and go shoot! The 100 extra FPS isnt needed, its wanted. Call it a day and go shoot. Share this post Link to post Share on other sites
luvdemcoues Report post Posted October 5, 2011 Why do you care about the speed if the accuracy was there? 3125 is very respectable speed, paired with grat accuracy and youre there. My advise? Load up 100 of that load and go shoot! The 100 extra FPS isnt needed, its wanted. Call it a day and go shoot. Respectable, yes. I agree with you, and believe me I am struggling with this decision. I shot 2 rounds at 300 today, but put them within an inch and half of each other. First time I have ever done that and I was stoked. But on the other hand, I know it can do better on the velocity side. Wouldn't you want to maximize your rifle's potential? That extra 100 FPS translates into extra energy at longer distances, and with the 270 caliber I would like all of the extra energy I can get. Granted, I may not get the same accuracy with the higher charges, but at least I will know that I tried. As far as the RL 22 goes, I did try that. I was getting too much variation in velocities with temperature, plus my velocities were only around 2800 FPS. I did shoot very accurately with that load though. I was totally ok with it until recently when I realized how much drop I was getting past 3-400 yards. Thanks for the replies so far. I look forward to hearing more. Share this post Link to post Share on other sites
jeffro Report post Posted October 5, 2011 I just went and looked through some chrony data of mine. This is not a set in stone number by no means, but it may help you. On a cartridge that holds around 60gr, each .5gr was getting me around 12fps more fps. When on a 90+gr cartridge each .5gr was getting me around 10fps more each step. Now when you get up close to max your pressures will start to spike. This is where you need to be carefull. When you get into this area I have seen 30-40fps increase with each .5gr, and you can end up over pressure real quick. When I get up at the high end I usually drop down to .2-.3gr steps in the end. If your shooting a very small cartridge you can see much bigger fps changes with even a .5gr step. Another thing is that different powders will spike at different rates from what I have seen. Hope this helps a bit. Share this post Link to post Share on other sites
Red Rabbit Report post Posted October 5, 2011 With my 6.5 WSM, I was getting about a 40 fps increase with each grain of powder with 130 gr bullets. I suspect the 270 WSM may be close to the same. With the extra 100fps, you may get about 100ftlbs more energy at 600 yards, and almost 4" less drop. I would be more concerned about greater accuracy and having less deviation(shot2shot velocity spread) than the extra 100fps. Velocity deviation and accuracy may tighten up as you approach max though. Good luck. Share this post Link to post Share on other sites
firstcoueswas80 Report post Posted October 5, 2011 Again, trust me on this one.... Having the confidence and ability to put shots an inch apart at 300 yards, is much more important than the slight gain you get with 100 FPS.... Load up the load you have, and call it a day. Save some of your barrel life, and $ by using those Bergers to practice with, rather than eek out a measly 100 FPS MAX more.... Share this post Link to post Share on other sites
luvdemcoues Report post Posted October 5, 2011 Ya, after sleeping on it, I have decided to go with the load I shot yesterday. I agree with you Casey and Doug. Thanks for the input. Sounds like all the extra work won't do much to improve the results I am seeing right now. Thanks guys. Josh Share this post Link to post Share on other sites
