I don't take all the measurements you guys play with, and when I do -- like when throating out a rifle -- I never remember the numbers.
But in general: The throat for the 187 BIBs is just about the same as for the 240 Sierras when you keep the boattail of the latter in the neck. But the twist needed for the 240s is about 1:10, the optimum twist for the 187's is 1:12, or even 1:13. If you aren't driving them that fast, 1:10 will work, it just isn't optimum. I shot the "prototype" 187, which was a 190 with a 7.5 tangent ogive in a 1:10 barrel that had been throated out for the 240s.
I shot these for six matches from June to October. A variety of conditions. They shot well and I had a couple wins, but felt the low (for 1,000 yards) ogive was costing me some. That's where the 10-ogive came from. The 10-caliber tangent ogive was still easy enough to manufacture to get consistent bullets, and was ballistically superior to the 7.5-ogive. Would a 12 ogive be better? Who knows. The BC would be higher, but what about the consistency in manufacture? Not tried, so we don't know.
I have never tried the BIBs when pushing the bullet base beyond the neck. In times past, I would have said this is a no-no, for the reasons Lynn gave. But Al's success with the Wolf Pup should lead us to question that. Apparently he uses a lot of neck tension, anneals the cases to preserve the tension, and has great success.
As to the success of the BIBs: They hold three single-group records at 1,000 yards. NBRSA HG, IBS HG, and the Austrailian HG. There was a year when Joel Pendergraft, using BIBs, won about half the HG matches he shot in at Hawks Ridge. That is a phenomenal performance.
As to measuring, I don't bother. At first I did. But I bore easily, and when bullet after bullet measured the same, I quit. The most important "spin test" is downrange anyway, and if I have several years data, I trust that.
The downsides: (1) Randy only makes one run of the bullets per year, usually around December. (2) For optimum performance, you have to set the rifle up for them. There aren't any fall-back bullets.
There is a (3) as expressed by Lynn. I don't hold to it, but some do. The BC numbers aren't as good as with other bullets. Still, from the real world, Joel shot 210 Bergers and 187 BIBs at the same match. Essentially the same performance. The BIBs might have been marginally better, but "sample size one" says that's too big a stretch.
As to Lynn's comment, I find it hard to believe the winds in California are more switchy than at the old Hawks Ridge, or Pennsylvania.
Lastly, what I believe wins matches is bullets and barrels. Over time, what counts is consistency. It may be that Berger has solved the issues of manufacturing a 15-caliber secant ogive with consistency, but that wasn't always the case. There have been, what, "inconsistent" lots of Bergers. Another shooter who went to the BIBs was Charles Bailey. When he shot Bergers back in the late 1990s, he needed 2,500 bullets to sort to get down to the 500 he needed for a year's competition. When he went to BIBs, he too quit measuring.
From a narrow personal point of view, I hope the 187s don't catch on. That way, I can be pretty sure I can get them.
You might want to ignore me. I know of no way to insure a superior barrel every time. Over 10 years of shooting the 187s has lead me to believe I do know a way to get a superior bullet every time. I believe new shooters have a conundrum: If they shoot well, they don't realize that a large part of their performance was they caught a good barrel & good bullets. They think their beliefs about what makes a good 1K -- or any distance -- rifle has been validated. If they don't shoot well, they go off looking for other theories. Very few buy up 10 barrels, have them chambered and test for the best. Very few go on a search for consistent bullets. Just another difference between 1000 yard and point-blank benchrest.
FWIW
