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Post by keith on Sept 28, 2015 19:13:58 GMT -5
So, I got my bullet making dies back the first week of August but I have been on the road/mountains/range/etc non-stop for the last month and half. This is only my 3rd weekend home since the middle of July and I spent all day yesterday trying to jump out of an airplane but the weather isn't playing nice. I was going to drive up and see Mike and meet Richard today but my wife has a puking bug I don't want to pass on in the event I have it. Instead, I made and tested some bullets. Since the light bullets are the thing most of y'all requested I made some 300gn (the lightest I thought would stabilize) and shot them today. I barely beat a rainstorm off the range and while the Shoot'n'See target survived the rain the paper targets from the 100yds test didn't but I was able to rough measure them while they were still hanging. I shot two groups of five at 100yds to see what was most accurate, wad or no wad, for this load. The load was 300gn BOMB, Fed 209A, and 10/50 duplex of VV N110/IMR 4198. The no-wad load shot a high of 2487fps, a low of 2473s, and had an SD of 7fps with a precision of about 1.3". The wad load shot a high of 2446fps, a low of 2437, and had an SD of 4.5fps with a precision of about 1". The wads shot better and I still had them out so I used them to do the drop test at 300yds. The load may seem arbitrary but it is one I have used before with very good precision in this rifle with 300gn MH bullets. I also knew it was on the lower end of velocity and with the 1-24" twist in this barrel would be the closest to instability I could push this bullet. If you haven't seen them before this is the 300gn variant (I will test the 340gn and 400gn variant in the coming months):  When I finished shooting my .30-30 Improved I hung it's target board at 300yds and put a 1" pasty a few inches from the top to use as my aim point so I could measure drop from a 100yds zero. Winds were picking up by the time I moved to 300yds and were from 3 o'clock at a steady 8mph with gusts to 12mph according to the Kestrel. These last three were loaded and shot with no break between as I knew a storm was about to hit:  The group is 3.11" outside to outside or 2.659" center to center for .846MOA. The group is only .62" tall which means with those low deviations it held .197 MOA for vertical. The reason I mention that is because it allowed me to very precisely measure drop at 16-11/16" (16.6875" or 5.312 MoA). Things I can tell you about this bullet right now: 1: The bullet is short and fully stabilized from a 1-24" twist at 2440fps (just like it would be in a factory Savage) with stability factor of 2.324 at muzzle. 2: Using the MV and drop at 300yds it appears the G1 BC of this bullet is in the high .4s but I need to shoot further to see because that is hard to believe but it is what the calculator says based on drop. 3: It seems to be capable of sub-MOA precision and all I did was run it through my die as it is set for the MH bullet and pick a charge to test . |
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Post by hillbill on Sept 28, 2015 19:28:56 GMT -5
looking forward to some more targets!
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Post by rojo23 on Sept 28, 2015 19:30:13 GMT -5
Keith, that is pretty cool to make a bullet and go out and shoot it. There is a gunsmith, bullet maker that I met a while back and he showed me the steps in bullet making. He said the biggest challenge for him is finding quality jackets. After you have everything set it up, seems like you can crank them out. He made a 6mm 107 bullet while I watched. He has a ton of money in his dies and presses.
great job
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Post by Deleted on Sept 28, 2015 21:02:16 GMT -5
Awesome report, I forget what size you are making these .451 or .458? If they are .451 I'd be very interested in purchasing a pack of those to try on mule deer.  ? They show allot of promise! Great job! |
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Post by Deleted on Sept 28, 2015 21:07:00 GMT -5
Definitely showing promise!
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Post by keith on Sept 28, 2015 21:07:11 GMT -5
They come out of the die at .458 but I can size them down to .452
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Post by schunter on Sept 29, 2015 7:33:42 GMT -5
Great results with very little testing so far. Cant wait for more!
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Post by keith on Sept 29, 2015 8:21:34 GMT -5
Like I said above, that BC is hard to believe. I just tried to figure out what it was so that I could calculate the form factor so I could get BC's for the 340gn and 412gn when I test them. It seems way too high for how light the bullet is. When I ran the numbers I had to use the no wad velocity to even get into the .4s because the no wad velocity required a BC that is is unbelievably high. My thought is that the wad should not drop velocity by 40fps, if anything I would have thought it would create a better seal and thus higher velocity. I wonder if the wad passing the chrono was causing poor reads. I am going to repeat this test by dialing on a 300 yard zero and and shooting it at 100yds and seeing if I can measure this better but with only .62" of vertical at 300yds I was able to find absolute center. I need to link up with Rob and see if we can shoot some at 500yds and see if this holds water. I don't think it will because having played with truing functions at short range they almost always come up with extremely optimistic BC's. It's generally more accurate to make small MV adjustments since it is more likely that your chrono is off than the bullet is way more efficient than you think. Here's the drop chart that matches:  |
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Post by Deleted on Sept 29, 2015 8:33:33 GMT -5
I have always wondered if the wad going across the chrono caused issues. Been thinking about moving the chrono to 100 yards and trying to shoot over it there. Only issue I have is I'm afraid I'll hit the chrono. Our rifles shoot well enough I shouldn't worry about it but the worry is still there. I might try 50 yards then 100 yards next time out to see what kind of results I get.
It's neat to see ask the stuff your going through to figure your bullets out. Great job on all the work your doing with these bullets.
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Post by keith on Sept 29, 2015 9:18:19 GMT -5
I don't know if it will work with the SML wads (no reason it shouldn't) but when I was loading a lot of shotgun slugs (both sabot and full bore with wad, cork, and gas seal) and shooting sabot ML I placed a shield with a small loophole in front of my chrono to protect it from all the ejecta while just the bullet passed through; sabots will definitely embed in 3/4" ply at 10ft. I have never shot wads over the chrono with the sabotless until yesterday so I didn't think of using a shield. Dave said he gets lower MV from felt wads (which I used) than from fiber wads.
I thought about putting my chrono right there infront of the 300yds target. Like you, I should be able to thread the sky screens but it would be my luck that I'd center punch the chrono.
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Post by keith on Sept 29, 2015 10:10:56 GMT -5
IF I use a G1 BC of .480 since it matches at 300yds and do the backwards math I get a form factor of .439 so IF .480 is a good BC then the form factor says the 340gn bullet will have a .543 BC G1 and the 412gn bullet will have a .659 BC G1. By no means am I saying this is gospel and will need to shoot them quite a bit further to see. After I get some of the heavies made I will link up with Rob and Carlos to see if we can push some to 600 since my home range is only out to 300 since the 1000m KD is down for maintenance.
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Post by Deleted on Sept 29, 2015 10:51:37 GMT -5
Those BC's are crazy. If they turn out that well that would be amazing.
I'll look at your chart more in depth but did you post altitude also? Where I'm at is around 1200' and after talking it over and research I believe I found that Parker test his at higher elevation. Which I believe affects the BC also.
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Post by Deleted on Sept 29, 2015 10:54:11 GMT -5
Out of curiosity how did you get all that information on your chart? I did see altitude which was around 200'. All the BC talk confuses me to a point and still trying to understand everything.
Excited to see how well they perform on game.
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Post by keith on Sept 29, 2015 12:09:44 GMT -5
I pulled my altitude from my Garmin 401 and Kestrel on the range then double tapped it on Google Earth when I got home. I only put it into JBM because it was available and for transparency since so many BC's are posted without how they were obtained. I generally run my solver using Temperature, Barometric Pressure, and Humidity which I pull from my Kestrel or if I have good service my phone pulls from the nearest airfield and inputs into my solver. I have found temperature has a larger effect than humidity on air density and you can always just run 50% humidity without ill effect. Altitude is almost irrelevant when you consider that it is cancelled by temp and barometric pressure.
Hopefully, you smoke a Mule with one and can tell me how they do. I know they react violently to dirt berms...
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Post by keith on Sept 29, 2015 14:43:21 GMT -5
Edge ran the numbers in his ballistic lab software and predicts .318 G1 at 2500fps and .334 G1 at 3000fps which sounds WAY more reasonable than what I got from my drops. Like I said, determining BC from short range trajectory is a dangerous thing and I need to shoot them at least 500 yds before I say I'm confident in a number.
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Post by rojo23 on Sept 29, 2015 15:37:44 GMT -5
Keith, I know I am getting a little off target but do you ever use the density altitude from your Kestrel? Is that as accurate has putting in everything individually?
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Post by Deleted on Sept 29, 2015 20:19:19 GMT -5
Edge ran the numbers in his ballistic lab software and predicts .318 G1 at 2500fps and .334 G1 at 3000fps which sounds WAY more reasonable than what I got from my drops. Like I said, determining BC from short range trajectory is a dangerous thing and I need to shoot them at least 500 yds before I say I'm confident in a number. I wonder why your formulation of bc and his have such a large difference...? There must be a constant variable difference between the two formulas imo....Interesting....thanks for all of your work and sharing .... |
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Post by keith on Sept 29, 2015 20:21:20 GMT -5
Keith, I know I am getting a little off target but do you ever use the density altitude from your Kestrel? Is that as accurate has putting in everything individually? No, I do not. We run our solvers on TBH. |
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Post by keith on Sept 29, 2015 20:26:12 GMT -5
SML,
My guess is that their BC is calculated and mine is using gun data. I know for a fact that short range truing tends to predict high BC or MV (depending on which you choose to work with ) because you are trying to make small adjustments in drop with big changes in BC or MV. It needs to be done around transonic to work properly. They may also not have all the dimensions they need from my bullets.
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Post by Richard on Sept 29, 2015 20:47:45 GMT -5
Here is my $0.02 when it comes to the chronograph and the dangers of wad/sabots destroying the photo cells.
When I was shooting sabots, I had built a box and set my PACT chrono cells down inside the box. (plywood box). I had to attach rubber reinforced conveyor belting to the front as the sabots were beating the hell out of the plywood.
Now that I am shooting sabot less, I have retired that unit to my basement for air rifle chronographing. I am now using another PACT chronograph with absolutely no protection to the plastic photo cells. I never use the sky defusers. Its been a couple of years now and I have encountered no damage to the photo cells. My light weight aluminum tripod has sustained a few dents from the veggie wads but I have since shielded them. So, what I am saying is I doubt the wads are going over the top of the photo cells and causing any erratic readings. My PACT is set 10' from the muzzle.
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