AlphaSeeker Posted April 30, 2014 Share Posted April 30, 2014 Using Xtreme 200 gr FP heads, the lands are contacted At an COL of 1.315. The mag can fit 1.18 Do I have a defective chamber? Link to comment Share on other sites More sharing options...
kneelingatlas Posted April 30, 2014 Share Posted April 30, 2014 Do you mean 1.1315"? Link to comment Share on other sites More sharing options...
AlphaSeeker Posted April 30, 2014 Author Share Posted April 30, 2014 No. I inverted a bullet into an empty shell and dropped it into the chamber. Pushed in until case mouth made contact, then measured. Loaded another dummy to 1.275 - drops in and spins freely. Link to comment Share on other sites More sharing options...
kneelingatlas Posted April 30, 2014 Share Posted April 30, 2014 That's really long! How does it shoot? I would just load at 1.165" and call it good as It groups well. Link to comment Share on other sites More sharing options...
AlphaSeeker Posted May 1, 2014 Author Share Posted May 1, 2014 Thanks. I'll load to max magazine length and try to find someone with a 40 sw to compare chrono results. If I am unlucky enough to get a bad barrel, it will show up in the chrono data. I just wish I could get some measurements for standard chamber so I would know for sure. For a premium prices gun, I would hate to have a botched example. Link to comment Share on other sites More sharing options...
jmbaccolyte Posted May 1, 2014 Share Posted May 1, 2014 Seeker- Please turn the bullet around and see how long the cartridge can be before it it hits the throat/rifling. Also you might consider using 10mm magazines; it works for me. But 1.23" O.A.L. has fed perfectly for me with 180 grain Bayou and BBIs, so I didn't try any other length. Link to comment Share on other sites More sharing options...
AlphaSeeker Posted May 1, 2014 Author Share Posted May 1, 2014 Thank you for the suggestion - 10mm mags sounds great, will try it tonight. Too bad I can not use them for 40 production. Link to comment Share on other sites More sharing options...
CHA-LEE Posted May 1, 2014 Share Posted May 1, 2014 On my Limited .40 pistol I use 1.225 OAL ammo and its still no where close to hitting the lands. I think that EAA/Tanfo may set the lands depth of the .40 & 10mm barrels the same. That way all they have to do is ream the chamber deeper for the 10mm setups. Verses manufacturing two different rifling configuration barrels for .40 and 10mm. Externally, the .40 and 10mm barrels are identical so my money is on them using the same rifling depth for both calibers. Link to comment Share on other sites More sharing options...
AlphaSeeker Posted May 1, 2014 Author Share Posted May 1, 2014 You have a very good point. Not what I want to see in a "premium" gun model but probably true. Link to comment Share on other sites More sharing options...
CHA-LEE Posted May 1, 2014 Share Posted May 1, 2014 Realistically though, Who cares how deep the lands are? The EAA/Tanfo guns have a long standing reputation of excellent accuracy. If the bullets go exactly where you want them to when you shoot it, does it matter if the lands are 1mm away or 1 mile away? The answer is NO. Link to comment Share on other sites More sharing options...
AlphaSeeker Posted May 1, 2014 Author Share Posted May 1, 2014 Actually, it does matter. On guns with a longer bullet to lands gap, velocity tends to be lower. Had an opportunity to chrono a couple of guns some years back and the looser spacing also gave lower fps results - 40 to 60fps difference if I recall correctly. Not a big deal unless you happen to fall bellow the required PF or need to use more powder to maintain PF. Nothing earth shattering. I still love the brand and will adjust my loads to suit. Link to comment Share on other sites More sharing options...
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