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Post by 7mmfreak on Sept 28, 2015 19:10:21 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 schunter on Sept 29, 2015 7:02:05 GMT -5
Great to see you are back in business Keith. Look forward to see more testing. If that BC is indeed that high the BOMBs will be a big hit!
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Post by Dave W on Sept 29, 2015 7:29:49 GMT -5
Definitely showing some promise, keep us posted.
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Post by edge on Sept 29, 2015 7:31:23 GMT -5
That is a great BC from that light of a bullet and a great group at 300 too  edge. |
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Post by 7mmfreak on Sept 29, 2015 7:35:57 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. Here's the drop chart that matches:  |
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Post by Dave W on Sept 29, 2015 7:46:58 GMT -5
Usually, I have found felt wads decrease velocity, veggies increase velocity.
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Post by 7mmfreak on Sept 29, 2015 7:59:22 GMT -5
Mine are felt so maybe that explains the loss of 40fps. Either way 40fps makes a bigger difference over the short range than a jump in BC because it takes a huge jump in BC to match the curve at 2440fps. My chrono could be off by 40fps also. It was extremely cloudy and windy yesterday with intermittent rain.
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Post by 7mmfreak on Sept 29, 2015 10:10:07 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 rangeball on Sept 29, 2015 11:00:09 GMT -5
Sweet.
Remind me again what jacket thickness and diameter you decided on?
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Post by edge on Sept 29, 2015 11:33:16 GMT -5
Just curious how that compares to BC estimation based on dimensions?
( Meplat diameter, ogive radius and length )
edge.
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Post by 7mmfreak on Sept 29, 2015 12:11:30 GMT -5
Sweet. Remind me again what jacket thickness and diameter you decided on? Jackets are tapered from .030" at base to .019" at nose and I can provide them at .458" or .452" |
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Post by rangeball on Sept 29, 2015 12:13:21 GMT -5
Sweet. Remind me again what jacket thickness and diameter you decided on? Jackets are tapered from .030" at base to .019" at nose and I can provide them at .458" or .452" Nice. Thanks. |
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Post by 7mmfreak on Sept 29, 2015 12:14:28 GMT -5
Just curious how that compares to BC estimation based on dimensions? ( Meplat diameter, ogive radius and length ) edge. I don't know how to do that. I know how to get a form factor if you know the BC so I just plugged in all the hard data I had and ran the BC until it matched my drop then used that BC to get form so that I could estimate for the heavier bullets. Like I said, I want to shoot them to 500-600yds and see how they marry up with that BC before I say that is DEFINITELY the BC of this bullet. I'm betting I find it is a little lower than that. |
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Post by rangeball on Sept 29, 2015 12:28:17 GMT -5
I have Edge's excel program saved, if you can give me the following data I can run it through to see what it predicts-
Weight
Overall length
Secant or Tangent ogive
Ogive radius #
Caliber
Meplat diameter
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Post by 7mmfreak on Sept 29, 2015 13:32:40 GMT -5
Weight: 300gn
Length: 1.020"
Ogive: Secant
Radius: 14 calibers offset .040"
Meplat: .120"
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Post by lwh723 on Sept 29, 2015 13:53:58 GMT -5
Looks promising. Will be interested to see where your BC settles at. Not sure how it could be that much higher than a Parker MH or a 335APB.
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Post by rangeball on Sept 29, 2015 14:29:37 GMT -5
Weight: 300gn Length: 1.020" Ogive: Secant Radius: 14 calibers offset .040" Meplat: .120" Something weird going on. Inputting the above and using a specific gravity of 10 and the MV posted above, the program predicts a bullet that weighs 216gr with a bc of .248, stabilizing up to 1:40 tr. It also has almost no bearing surface. Somethings out of whack. Even bumping the specific gravity up to 11.35 for pure lead only gets total weight up to 246 gr. |
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Post by 7mmfreak on Sept 29, 2015 14:40:43 GMT -5
Edge ran the numbers too 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 7mmfreak on Sept 29, 2015 14:42:13 GMT -5
Looks promising. Will be interested to see where your BC settles at. Not sure how it could be that much higher than a Parker MH or a 335APB. I'm not at all sure that it is higher than an MH or APB. Short range truing is dangerous, I just haven't had a chance to shoot these further. |
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Post by rangeball on Sept 29, 2015 15:32:11 GMT -5
Edge ran the numbers too 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. Good. It's been awhile since I've messed with the program, so who knows what I missed. Edge, what did I do wrong? |
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Post by edge on Sept 29, 2015 16:36:02 GMT -5
I actually did it on my RSI Shooting Lab.
edge.
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Post by cowhunter on Oct 1, 2015 12:35:35 GMT -5
I can believe the BC. Let us know when you make some to sell.
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Post by 7mmfreak on Oct 1, 2015 20:12:44 GMT -5
I'm taking a short break from a hurricane but head back out in the AM and work through the weekend. I'm supposed to be off next weekend and will make a batch of 340gn bullets to mail out for testing. After that I leave for another 3 weeks. Hopefully, when I get back I have some feedback on these bullets and can start offering them to board members.
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Post by 7mmfreak on Oct 3, 2015 8:27:07 GMT -5
I came in from the hurricane recon last night and passed out on the couch, where my wife left me, and I woke up at 5:30 this morning. I took and degreased all the bullets about to go out for testing. Here is a pic of the first 75 I cleaned this morning and boxed up:  |
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Post by Dave W on Oct 3, 2015 9:30:32 GMT -5
Sure would look good with some of those pointy tips on top of them.  Look great, sure there will be some nice results gathered from the testing. |
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Post by rambler on Oct 3, 2015 10:20:54 GMT -5
I came in from the hurricane recon last night and passed out on the couch, where my wife left me, and I work up at 5:30 this morning. I took and degreased all the bullets about to go out for testing. Here is a pic of the first 75 I cleaned this morning and boxed up: How bout I pm you my address and you can send 'em on.....i'll field test them and get back to you |
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Post by 7mmfreak on Oct 3, 2015 12:32:17 GMT -5
Sure would look good with some of those pointy tips on top of them. Look great, sure there will be some nice results gathered from the testing. Edge turned some points for me. After the initial testing I'll put points in some to see how it affects BC. As, it stands no point is helping keep these at an advantageous price point. I just need to compare the tip to non-tip to see if the juice is worth the squeeze. |
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Post by 7mmfreak on Oct 3, 2015 12:34:26 GMT -5
Rambler,
I almost kept them all because it's hard to look at bullets and not shoot them.
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Post by rambler on Oct 3, 2015 13:36:08 GMT -5
Rambler, I almost kept them all because it's hard to look at bullets and not shoot them. No kidding.....they look vicious! |
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Post by kash913 on Oct 3, 2015 13:58:46 GMT -5
You need my address I put them to the test. Lol
Looking good
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