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Post by savageshooter2k on Aug 5, 2015 11:50:58 GMT -8
So I have been loading for this round with CFE 223 and XBR 8202 as they were readily available when I started loading for this round. I have been wanting to pick up some Ramshot TAC because I think the profile of that powder would work well for this round although probably be on the slow side. I was finally able to get my hands on two pounds and I had a limited amount of time to load before heading to my land to shoot. I loaded up one load at 27.5 grains and another at 28.5 just to see where they would land velocity wise and then I plan to come back and do a true ladder test to find the accuracy node. I loaded 10 rounds of each load with a 120 Sierra match king at 2.250 OAL. The results were pretty good. The first group with 27.5 grains yielded a .563" 5 shot group with 4 of the shots touching and the 5th just outside. The second 5 shot group of the same load gave me the .541" 5 shot group seen in the attached picture. The 28.5 grain load gave me a .673" 5 shot group and another group that had for shots at 1/3 MOA and a pulled 5th shot that opened it up to an inch. This is a small sample size but I am please with the initial results. The average velocity for the 27.5 was 2290 and for the 28.5 2380. I had a little bit of trouble with my chronograph because of rolling cloud coverage. For some reason my caldwell chronograph wont give you a reading unless the sun is shining on it. So of the 10 shots I only got a reading on 4 of each so I need to get some more consistent readings. These loads are definitely slower than I would like but I cant complain about the groups. I would like to see if I bump up to 28.7 or so if I can consistently get in the 2450 fps range. My barrel is an 18" 1x9 twist. I definitely plan on experimenting with some more of this. Attachments:
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Post by GLSHOOTER on Aug 5, 2015 15:59:41 GMT -8
Good shooting.
Ramshot says you can hot 28.7 in pressure. They showed 2449 out of a 20". I suspect you will be very close to your goal.
You might be able to load longer but check your distance to the lands. That will let you bump a tad too.
Greg
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Post by savageshooter2k on Aug 5, 2015 18:20:34 GMT -8
I have one reloading sheet that says 28.7 is the max and that will yield 2449 which are the numbers you just listed so I presume we are looking at the same thing. Then I saw another set of numbers Bill Alexander that showed 28.8 but I cant seem to find it. I have heard of guys pushing 30.0 but with 28.7 supposedly giving 51,6xx psi that sounds crazy.
How much velocity do you think I can see if I extend the OAL .010" ? I am nervous to do that because it should also increase pressure. I dont have alot of experience with hot loads. It seems like all of my rifles like loads right in the middle where as with this round it seems to like the max and I need to be in that range to get the velocity I am looking for. I have considering playing with H335 as it seems to have higher velocities but with TAC offering this kind of accuracy its hard to resist.
Thank you for your input.
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Post by GLSHOOTER on Aug 6, 2015 6:05:30 GMT -8
I have one reloading sheet that says 28.7 is the max and that will yield 2449 which are the numbers you just listed so I presume we are looking at the same thing. Then I saw another set of numbers Bill Alexander that showed 28.8 but I cant seem to find it. I have heard of guys pushing 30.0 but with 28.7 supposedly giving 51,6xx psi that sounds crazy. How much velocity do you think I can see if I extend the OAL .010" ? I am nervous to do that because it should also increase pressure. I dont have alot of experience with hot loads. It seems like all of my rifles like loads right in the middle where as with this round it seems to like the max and I need to be in that range to get the velocity I am looking for. I have considering playing with H335 as it seems to have higher velocities but with TAC offering this kind of accuracy its hard to resist. Thank you for your input. You have to measure distance to lands. I'm digging up an old post to explain it for you a bit better. Moving the bullet out will more often decrease velocity until you get very close to the lands. You have to bump the charge up. And before you ask don't even think about just shortening the round up to get more speed. The best way to adjust speed is through powder charges not seating depth. Look at 8208 for some speed. Leave the H335 on the shelf. Greg Here you go: Your visual. Here you go. Take a 223 load it to 2.00, 0.100 off the lands, with a bullet and decrease the case volume down with the bullet base. Stick 25 grains of XXXX 's in there. Velocty is maybe 3000. Loading all with the SAME POWDER CHARGE. Now move out 0.010, velocity will be a tad lower as volume of case is bigger. Keep doing this getting less in the case but getting closer to the lands. The bullet has a nice run at the lands and pressures drop. At some point while the volume goes up in the case the bullet is closer to the lands and speeds are down somewhat as pressures have dropped the lands are engaged with less bullet speeds and pressures slowly raise. The closer to the lands the higher the pressure goes as the bullet doesn't have that running start to engrave with. Max pressures will be seen again similar to the first loading. when we are flat up against the lands and the bullet has no place to start except right into the rifling. Now if we JAM THE BULLET pressures start getting REAL interesting and we best be dropping the charge if we were running hot before. Imagine a bell curve that goes DOWN not up. The left of the curve is the bullet seated uber-short. The right of the curve is when the bullet is at the lands. As it moves out the pressure drops and as the lowest point in the curve is past the pressures rise as the bullet is now engraving sooner. Even though the working capacity is higher it still will have raised pressures. Everyone fears bullet set back in a 9MM and 45 ACP. This is the same principal at work. If you push the 45 bullet into the lands the pressure will sky rocket the same as setting it back 0.25 into the case. Realistically loading shorter to gain velocity is a poor way to get there. Loading short means the jump is bigger.many times the bigger jump ruins accuracy. Bullet shape rules. If you jump a VLD you just done wasted $0.80 down the tube. It ain't gonna work McGee!! You jump a Sierra a bunch and it will bore in like a Georgia tick. Nice and tight. You are right Newbe. More go juice, more length and go for it. |
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Post by savageshooter2k on Aug 6, 2015 7:37:41 GMT -8
Thanks for the info Greg. I have played around with 8208 already and I have a pretty solid load with 28.5 grains of it and a 120 SMK. I runs really close to 2500 fps but it has been inconsistent for me and my initial work up with TAC has offered what seems to be better accuracy. This is the fun part of loading to me though, playing around with your loads to find that one that is "just right".
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Post by gunmutt on Oct 25, 2015 8:02:18 GMT -8
I am working up some loads with TAC today. I am starting with 26.9 and moving up 1 grain till i reach just short of max of 29.6. I will be running the 107 grain MKs rather than the 120s. I understand I will be losing BCs but I hope to make up with a flatter shooting bullet. I always start with standard coal which is usually all that will fit in a mag. I will try to post results of my ladder test and velocities when I complete the test.
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