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Post by rangeball on May 6, 2011 12:48:26 GMT -5
I have no idea, he offered to measure them. I can send him a sabot, .40 barnes and .40 xtp and have him match the xtp or the sabot, whatever we think is best. Savage Shooters initial guesstimates look like we can get between 2550-2700 without sabot stress pressure, but might as well optimize the base while we can.
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Post by Savage Shooter on May 6, 2011 12:51:43 GMT -5
I would match the Barnes 195 base. I have had really good accuracy from the new models. They can be "as" flat as the XTP and not be to sharp to cause problems.
Match XTP or Barnes flat base, either will be fine.
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Post by Savage Shooter on May 6, 2011 13:05:34 GMT -5
Savage Shooters initial guesstimates look like we can get between 2550-2700 without sabot stress pressure, but might as well optimize the base while we can. We need to make sure we have good twist stabilization to as low as 2500fps and up to 2700fps in the 1:22. This weight bullet will be real easy to get to the 2550fps range..... with BC of merely .30 a 240gr bullet at 2550 will keep terminal energy to nearly 500yds. Also keep in mind that there is a real good bullet for comparisons to what we are looking at. IMO the 240 - 260gr Dead Center is a good bullet to "benchmark" shape but without the boat tail. While not quite the BC as advertised is still up there.
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Post by rangeball on May 6, 2011 14:06:34 GMT -5
That dead center is what I had in mind to bore a mold out to and try a soft tip like Veral at LBT was proposing. May still be a way to go if this approach doesn't pan out.
I'll input the last specs I gave them and see what the program predicts for stability at 2500 fps. I initially calculated with 2700 fps and it predicted stability from 1:22.3.
Just ran it, at 2500 fps it predicts stability with 1:22.2.
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Post by edge on May 6, 2011 14:09:24 GMT -5
I just put a 40 caliber XTP on the comparator and the base is a truncated 0.021 radius.
The radius is full to the bearing surface but is about 0.003 short on the base intersection. I would assume that this is just manufacturing error.
For machining purposes you would want a radius to prevent any burr from forming as the tool loses contact. I would normally machine a sharp edge with a radius of 0.0002 to ensure the tool does not come off of the part.
edge.
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Post by rangeball on May 6, 2011 14:39:14 GMT -5
Thanks edge, I forwarded that to you. As soon as we know the finished weight, would you be willing to run some QL predictions based on some loads Savage Shooter is contemplating?
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Post by rangeball on May 6, 2011 15:13:02 GMT -5
Here's the response-
"We have our methods of cutting a corner radius to prevent mismatch so we will make sure there is a smooth blend to body and base. I will cut a .020 to .023” corner radius on the bullets."
Just waiting now for them to be produced and received, then will ship some to Savage Shooter for BC verification and TG for pressure trace data.
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Post by rangeball on May 18, 2011 11:43:59 GMT -5
100 of the prototype bullets are on their way to me today. Should have them by this weekend then will get them out to Savage Shooter for BC verification and TG for pressure tracing.
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Post by Savage Shooter on May 18, 2011 12:10:35 GMT -5
100 of the prototype bullets are on their way to me today. Should have them by this weekend then will get them out to Savage Shooter for BC verification and TG for pressure tracing. Any indication of exact weight yet.
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Post by rangeball on May 18, 2011 13:00:51 GMT -5
I forgot to ask. I'll find out.
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Post by rangeball on May 18, 2011 14:24:10 GMT -5
Here's the response- "We made them 240 grains. The length was 1.128”. I just plugged it into the excel program and it predicts- OAL- 1.128" Meplat diameter- .09" Ogive- T4 Weight- 240 SD- .214 BC- .312 Twist- 1:23.7 BS- 1.1 calibers I have my fingers crossed
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Post by Savage Shooter on May 18, 2011 14:38:45 GMT -5
Here's the response- "We made them 240 grains. The length was 1.128”. I just plugged it into the excel program and it predicts- OAL- 1.128" Meplat diameter- .09" Ogive- T4 Weight- 240 SD- .214 BC- .312 Twist- 1:23.7 BS- 1.1 calibers I have my fingers crossed Excellent
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Post by rangeball on May 18, 2011 15:12:20 GMT -5
I'm hoping TG has the powders in hand that you think will work best here, I know that was one of his concerns.
I'll put up pics of the bullets when I receive them.
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Post by Deleted on May 18, 2011 16:44:29 GMT -5
very interesting
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Post by deadon on May 18, 2011 17:52:42 GMT -5
Thanks Guys for all the effort that has gone into this new bullet!!!!!!! Rusty
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Post by dave d. on May 19, 2011 5:50:54 GMT -5
:)sounds great and thank-you for all your efforts I can't wait to hear how they fly.
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Post by pposey on May 19, 2011 8:01:48 GMT -5
Sure sounds like a sharp looking eye catching bullet for sure!
You guys have gone above and beyond in effort on this thanks for all you efforts,,
If this bullet flies as good as it sounds it could really be something
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Post by rangeball on May 19, 2011 8:46:54 GMT -5
If this bullet flies as good as it sounds it could really be something I was thinking more about this, and I agree. If the BC pans out, not only will it be better for those wanting to shoot long range, but even the guys only wanting to shoot 150-200 yards will get a step up in performance with less wind drift, point and shoot hold, less fps/recoil for the same performance, etc.
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Post by GMB54-120 on May 19, 2011 9:05:43 GMT -5
I was hoping for one that would also work in sub guns but im sure that can be accomplished with a more conventional lead/copper version later. Not many have faster than a 1-28 twist and 2500fps is pretty much a no go with subs.
The same weight however in a conventional style SST type bullet should easily stabilize at slower speeds or slower twists since it will be shorter. I realize at this point, that is not the goal until you see how well the project progresses. Trying the 240gr you have coming in a Knight or other 1-20 45cal sub gun might provide some useful info for later design work.
I would love to try some in a 220gr copper version for use in sub guns. If the price isnt insane i would gladly pay for them to make me 100 in 215-220gr also. I can test them in a 1-20, 1-28 and a 1-30 twist 45s using BH209 but only for accuracy and fps.
I know this is about smokeless but a bullet that works well in both, or two weight options might very well bring back interest in inline 45s from major manufacturers who have the money to spend on more 45cal R&D.
Thank you again for all your efforts. Ive been a big supporter of a better 40cal option since i got my first inline 45cal. IMO the right bullet can make the modern 45cals into what they should have been instead of using 155gr bullets and hyped advertisement claims. IMO that is what basically killed further 45cal development and basically no further R&D.
I also think you a spot on about the slight radius on a monolithic bullet. IMO that might be why the Lehighs are not performing as well in smokeless and i will talk to Dave or Grouse if i can about adding the recommended radius to a few IF he has the time. The bottom edge is so sharp, im betting it is causing most of the issues with smokeless speeds.
Great work guys and i cant wait to see it.
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Post by rangeball on May 19, 2011 9:28:46 GMT -5
gmb, the problem with one bullet to fit all is that it isn't really the best for any one certain use. Once we work out this bullet for smokeless, I'm confident Dan would be more than willing to work with you on a bullet similar to what you are describing. One thing nice about the way he produces bullets on a swiss lathe, he can draw them up on the computer and spit them out, no need for having new molds cut, swaging dies, etc.
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Post by Richard on May 19, 2011 10:01:53 GMT -5
Rangeball..............I had started following your initial post but lost track as the pages increased Sorry! I just had some more time and reviewed the last two and caught the e-mail "back and forth" between you and the perspective bullet company. Very interesting. Nothing much I can offer than has not already been presented by several of our knowledgeable members. The concept of the base not being TOO sharp is well noted. I had a Barnes that I machined flat that still blew a sabot. Possibly because it was not slightly radius-ed. It sounds like you and the other contributors are on the right path. Hopefully they will work and not be overly expensive. Let me note that there will still be a problem that Edge and I had discussed concerning getting the bullet properly centered in the sabot/bore which would still be a problem even with the most perfect bullet. A QLA or very close tolerance bore guide along with a starter who's interior is an exact (or at least has a centering ability) match for the bullet would seem to be warranted to get the best results. I thank you for your efforts as this is definitely one of the weak links in our quest for maximum accuracy. Richard
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Post by rangeball on May 19, 2011 10:05:33 GMT -5
Richard, keeping the bullet centered has been in the back of my mind. Based on the specs they gave me, the bearing surface should match the sabot petal length, which hopefully will give us a good start to work with. Hopefully this will be one thing that just works
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Post by spaniel on May 20, 2011 8:59:09 GMT -5
I go away for awhile on other activities and come back to find you troubelmakers innovating in my absence. Shame on you! I'll take 100 of them if they are anywhere close to design specs.
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Post by rangeball on May 20, 2011 9:23:36 GMT -5
Just for clarification, this original run is just for testing to see where we're at and will be refined as necessary. Once it's perfected, they will be available for sell direct from the maker.
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Post by rangeball on May 20, 2011 12:48:34 GMT -5
Bullets just arrived. I started a new thread.
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