MJR Posted December 28, 2011 Report Share Posted December 28, 2011 I have been shooting out to 800yds today and tried some rounds i'd trimmed the meplat on. it was quite windy and to be honest I couldn't tell if there was any benefit or not. my drops were the same for rounds that were or weren't trimmed although again I was getting knocked about a bit by the wind which was also pushing poi down by up to a minute and a quarter. Does trimming reduce BC and if so by how much? Link to comment Share on other sites More sharing options...
Chris-NZ Posted December 28, 2011 Report Share Posted December 28, 2011 Were the projectiles just trimmed or (re)pointed as well? In less-than-good conditions, you probably may not be able to tell any difference in group size. The object of "pointing" is to improve BC but equally, to reduce BC variance among individual projectiles, the hope being tighter elevation at longs. Chris-NZ Link to comment Share on other sites More sharing options...
MJR Posted December 28, 2011 Author Report Share Posted December 28, 2011 Chris, just trimmed to make them flat and square to the centre line of the bullet. Link to comment Share on other sites More sharing options...
Chris-NZ Posted December 29, 2011 Report Share Posted December 29, 2011 Well, in fact you've just gone backwards in BC but least it's more consistent Funniest thing- just been down to visit my main gunsmith and his business partner/fellow gunsmith was actually playing with a custom pointing die! The projectile in question was the 155 Berger .308 which he will be shooting in F-TR at the Nationals in two weeks time. He'd bought a die, ie http://www.bullettipping.com/bullettippingdie_detail.asp and had made up a finer pointer for it which achieves a 0.9mm diam tip, which translates to .035 sq inch tip area. Anyway, it is a noticeably finer tip than the one that came with it. Excuse the rough pics off the iPhone: Using the info off Bryan Litz's website, the interpolated G7 is now 0.240 as opposed to the std BC of 0.228. We ran this through the ballistics prog and it translates to 12.2" less elevation at 1000 (rel to 300yds). Big deal you might say, and you'd be right, but the real gain is in 7 inches less wind drift at 1000 compared to the std version. I could live with that Chris-NZ Link to comment Share on other sites More sharing options...
MJR Posted December 29, 2011 Author Report Share Posted December 29, 2011 Chris, thanks for that. I realisethe tipping reduces bc but was hoping for more consistency. Like the idea of gaining 7" less drift. Whats the angle of the tip on those pointed rounds? It looks to be around a 60' taper? Makes me wonder if a bullet seating die could be converted.... Link to comment Share on other sites More sharing options...
Chris-NZ Posted December 30, 2011 Report Share Posted December 30, 2011 Have a look at the ammo specs on this article: http://www.6mmbr.com/gunweek100.html Relevant to the discussion I think plus some other interesting stuff. Chris-NZ PS. I'll ask John about the angle Link to comment Share on other sites More sharing options...
zulu_dawn Posted January 27, 2012 Report Share Posted January 27, 2012 Funniest thing- just been down to visit my main gunsmith and his business partner/fellow gunsmith was actually playing with a custom pointing die! The projectile in question was the 155 Berger .308 which he will be shooting in F-TR at the Nationals in two weeks time. Chris-NZ well chris, interested to hear how your mate did in the nationals with the pointed ones? Link to comment Share on other sites More sharing options...
taylor Posted January 27, 2012 Report Share Posted January 27, 2012 i been pointing bullets for a few years now and i am convinced it makes a differnce ,i did trim but dont now just point and shoot ,i was getting 3/4 moa flatter with vlds and 1 moa with the hybrids at 1000yds so if its flatter then its got to be cutting out some wind and tips are more uniform vertical is better Link to comment Share on other sites More sharing options...
That bald headed Geordie Posted January 27, 2012 Report Share Posted January 27, 2012 Hi, I used to trim the meplats, but now cannot be bothered, and just use the Whidden bullet pointer to do my Berger 180gr VLDs. I am sure that trimming and pointing may give me a slight improvement over just pointing, but life is too short. But if it makes you feel good then do it. Link to comment Share on other sites More sharing options...
Chris-NZ Posted January 30, 2012 Report Share Posted January 30, 2012 well chris, interested to hear how your mate did in the nationals with the pointed ones? He had some very good shoots (incl a 50.10) and was quite happy with how the rifle was shooting, esp the group elevation holding, but got some "treatment" in the conditions. This is the first year he's got back into shooting (after failing eyesight) but managed fourth in F-TR. He's a top shooter historically having won the National title in TR once but took a long time to realise his eyesight isn't up to TR now. Trentham was also at its worst this year- ask any GB team member what Trentham wind can be like.. They didn't finish shooting one day in the qualifying til 7pm such were the stoppages from rain and extreme wind. He's about to do some systematic testing of projectiles at 1000. He tells me the current load with pointed projs produced ".. a 10 shot group at 600 for a vertical of 45mm with 7 in 18mm." I'll keep you informed as to what his testing shows Chris-NZ Link to comment Share on other sites More sharing options...
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