450Bushmaster.net

pitted bore wrote:Barnes messed up their website listing of their 451 pointy bullets. This may perhaps be contributing to some confusion.

Here's an image that is a composite of the bullet images and information supplied for the TSX-450B bullet and for the XPB-460 S&W bullet.
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Notice that the Sectional Density (S.D.) is the same for the 275-grain TSX and the 200-grain XPB. This is incorrect. All 275-grain bullet of .451 diameter have the same sectional density. It appears that whoever inserted the data for the TSX bullet copied the S.D. and B.C. values from the 200-grain XPB bullet.

As a guess, the Ballistic Coefficient values for the 275-grain bullets will be almost identical.

A minor problem is that the S.D. and B.C. errors supplied by Barnes for the TSX bullet will propagate through product listings for vendors of the TSX bullet. This is already the case of the listing on Midway's website, which shows the TSX with the incorrect S.D. and B.C. values.
--Bob

pitted bore wrote:Barnes messed up their website listing of their 451 pointy bullets. This may perhaps be contributing to some confusion.

Here's an image that is a composite of the bullet images and information supplied for the TSX-450B bullet and for the XPB-460 S&W bullet.
.

.
Notice that the Sectional Density (S.D.) is the same for the 275-grain TSX and the 200-grain XPB. This is incorrect. --Bob

Chris P Bacon wrote:Hey Bob, yesterday I sent Barnes a quick link so they could see the mistake you pointed out here, two different people replied today, and it has been corrected.

Here is the new info;

Hoot wrote:

Chris P Bacon wrote:Hey Bob, yesterday I sent Barnes a quick link so they could see the mistake you pointed out here, two different people replied today, and it has been corrected.

Here is the new info;

Looking at two real specimens side by side, that makes more sense. All else being equal, you can seat one a little further than the other and still sink a taper crimp down into a driving band groove.
To me and depending upon your preferences, that gives the edgein an AR platform to the XPB when taper crimping. With the most forward driving band groove not quite below the mouth and taper crimped, that yields a COL of ~2.20. In the case of the TSX using the forward most groove yields a COl of around ~2.34 which may be too long to fit in most but not all AR magazines, depending upon the brand. In a bolt action, where there is more tolerance for COL (assumed) the edge goes to the TSX. That's assuming you want to cram as much powder in as possible. If you're using a faster powder like Lil Gun you couldn't put as much in as would fit without incurring excessive pressure, but with slower powders, things are different.
Just my humble opinion..

Hoot

Bmt85 wrote:I contacted Barnes a while ago about the difference between the 275's. They told me they were basically identical except the minimum velocities. The xpb requires 1400fps, while the TSX requires 1200fps. I also asked why they would make the TSX diameter .4505-.4510. They said it was to reduce pressure, but won't affect accuracy. One thing though, I found a load that showed very, very light pressure signs, then went hunting, and found the same load was WAY over pressure. Come to find out the barrel was horribly copper fouled! Worst I have ever dealt with, and that was only with about 30rds of Barnes through the barrel. So the bores squeaky clean and I'm going to try the same load again just to verify that was the issue. I used lilgun for it, but I'm going to crack open the 296 and work on that.

As far as load out length, I run the TSX around 2.34". I cut out part of the front on my 5rd mags. No problem feeding anything so far.

Chris P Bacon wrote: ... Hey Bob, yesterday I sent Barnes a quick link so they could see the mistake you pointed out here, two different people replied today, and it has been corrected. Here is the new info ...