Tight Neck

[simpleman]

I am curious about the "Tight Neck" process. Read some about it here and wanted to know what the latest was on sizing the 450 brass with the 45 ACP or 45 dies.
What are the results? Is it worth the extra step and the price of the die?

[Hoot]

I am curious about the "Tight Neck" process. Read some about it here and wanted to know what the latest was on sizing the 450 brass with the 45 ACP or 45 dies.
What are the results? Is it worth the extra step and the price of the die?

Yes, it is applying an additional couple of mils sizing down the case from the mouth, the depth that the bullet will be seated, to pre-load some neck tension since there never seems to be enough. I didn't buy a die to try it out. The member who pioneered the method used a .45 Long Colt die. While I didn't have one of them, I did have a .45 ACP die set, so I used it.

Right now, I haven't been pursuing it, mainly because of symmetry of the sizing being a bit of a challenge. Without any method to register the case squarely in the center of the die, or holding the base any firmer than a standard shell holder as it constricts, the case can sometimes constrict more on one side than the other. When you seat the bullet, though it's lined up straight to that shifted neck, the entire length can sometimes be a little off center. a little ingenuity and experimentation could fix that. It did not turn out to be the manna from heaven for tightening up the velocity SD or significantly improve accuracy outside the normal variations I see, so while it has promise, I have not pursued it. That and being in the midst of a busy summer, has left me with less shop time that I'd like.

If the process can be tuned a little better, it will buy you some additional neck tension, but the jury it out on whether it's worth the extra effort. At least that's been my experience so far. Not a lot, but enough to develop an understanding of it.

Hoot

[simpleman]

Thanks for the info. I was trying to get sd and es down.
Off the top of yor head what is a good or decent sd or es to shoot for?

[Hoot]

Thanks for the info. I was trying to get sd and es down.
Off the top of yor head what is a good or decent sd or es to shoot for?

From my experience with this caliber for the bullets I have shot, anything below a velocity SD of 20 would be great. 20-30 would be more typical and 30-40 not unheard of. Here's the kicker. My best 5 shot 100 yard group was with an SD of 41. I have seen little correlation to meticulous case preparation and attention to detail while reloading as having any significant impact upon velocity SD. This is the only caliber where I've seen that. Then again it's hard to throw a wild pitch when throwing a shotput. Also, I have applied some God awful heavy stab crimps and gotten velocity SDs in the single digits, but the groups were worse than the same bullet with a lighter crimp and velocity running all over the place.

As far as the issue of velocity SD and vertical stringing goes. Again from my experience. Figure on inserting "From my experience" in front of every statement here and save me the trouble. Anyway, velocity variation seems to impact vertical dispersion more as the bullet weight goes up. In other words, a 50 fps change in velocity seems to manifest in more vertical POI change with the 300 grainers I've shot, as opposed to say the 225 grainers at 100 yards. I do not know if it continues to get worse the higher you go as 300gr bullets are the heaviest I have dabbled with, since the heavyweights do not figure into my particular hunting opportunities up here in MN.

Hoot