TightNeck

[commander faschisto]

Hey, Hootster...did you get a chance to check tightneck process on the 250 FTXs yet?

[Hoot]

Hey, Hootster...did you get a chance to check tightneck process on the 250 FTXs yet?

Yes. Composing post right now.

[Hoot]

Well, what's good for the goose may not necessarily be good for the gander.

I set out on a brief experiment to compare the impact of the TightNeck process upon the Hornady 250gr FTX, using my gold standard load of 38gr Lil Gun and a COL of 2.26". It has performed admirably in the past from my rifle, but then all the FTX's and the XTP Mags like 38gr of Lil Gun from my experience.

With the standard resized case and taper crimp as my control group, I shot 5-shots at 100 yards, along with 5-shot using just the TightNeck pre-treatment to the case, 5-shots using both the TightNeck Plus .475 Taper crimp (275 Barnes seemed to like this) and lastly, because I TightNecked more cases than I needed, I ran a 5-shot run with 40gr of W296 using both the TightNeck Plus Taper. That's the second time QuickLoad let me down WRT W296. What's worst, I knew the corrective setting in QL to get it right and in my haste forgot to apply it to the W296 charge, yielding a low velocity, albeit fairly accurate string.

Here's the actuals:



Here's the resulting Groups:



I was surprised that the TightNeck Plus Taper was not the most accurate. I was equally surprised that the regular process case plus taper crimp yielded the greatest velocity. I would have suspected that with the added tension from the TighNeck, or Plus Taper, would have jacked up the pressure and hence the velocity a little more. The W296 was clearly 2 grains short and you can see the POI dropped as a function of the reduced velocity.

This is a very limited run at a conclusion, but it sure looked like the undisturbed cases with just a taper crimp had the advantage in terms of velocity, but the TightNeck without the taper crimp had the edge on best 3-shot string, among the Lil Gun entrants. All in all, a general head scratcher and IMHO, the argument for the TightNeck is still unsettled. In retrospect, I should have run a control group for the 275 XPBs as well. Such a small sampling is just a glimpse into the long term benefit for this approach. More folks have to give it a try and report back.

All four loads were shot round robin to randomize any hot streaks. I averaged one shot every 3 minutes, due to trying to be a good neighbor timing wise, to the fellow shooting a match muzzle loader a few positions away. Chrony was set up at 15 feet.

I'll be going to bed with a head full of quandary, which happens to be right now.

Hoot

[BayouBob]

To further answer Alaskabushmaster's question. You can get tree pruning gum in a spray can at most good sized hardware stores. It is used to seal the wound and keep bugs out when you trim limbs off of a tree, particularyly an ornamental or fruit tree. It may not be as easy to find in your neck of the woods as it is in the lower 48 where we have lots of boring bugs and fungus.

[Hoot]

A brief followup to the 250 FTX. Their performance being different than the 275 XPB may be as much caused by the fact that they run a little wider. I did notice that even without having the wide spot at the heal like the 275XPB, the 250 FTX was considerably harder to start in the TightNeck. With a good chamfer on the inside of the mouth and persistence, they did start however and had strong, consistent tension as they were seated. That having been said, they is a good argument that the TightNeck process may better serve .451 bullets as opposed to .452 bullets. Tolerances do vary and my experience has been that what a manufacturer calls .452 may wind up being in reality, .451 or .4515. Ditto on .451's running .450 or .4505.

I am conflicted on whether I want to subject my brass to the shrink and stretch process as it may lead to premature case deterioration from work hardening.

Hoot

[Jim in Houston]

Many thanks to Hoot for his testing on the different crimp options.

I tend to agree from the data Hoot posted (with his reservations about the sample size) that the "standard" process to seat the .452 250 gr FTX appears to be at least as good as and better in terms of velocity as is achieved with the more complex TightNeck process. I am also much relieved by these results, since I am reluctant to venture into "experimental" territory of reforming the case for the TightNeck, having just "mastered" the taper crimp.

However, the point about the .451 diameter bullets is an interesting one - looking forward to a similar comparison for the 275 XPB.

[Siringo]

In order to achieve consistent neck tension, my thought has been to have the cases as close to factory new as possible. Meaning clean. I purchased a Ultra Sonic case cleaner and whow!!!! I have always tumbled my 450 brass, but this machine really gets the insides clean. It took several cycles and the solution was so dirty, you would have thought I had fired black powder in these cases. Now the inside necks are nice and clean and not imbedded with burned on carbon (which can function as a lube).

[wildcatter]

In order to achieve consistent neck tension, my thought has been to have the cases as close to factory new as possible. Meaning clean. I purchased a Ultra Sonic case cleaner and whow!!!! I have always tumbled my 450 brass, but this machine really gets the insides clean. It took several cycles and the solution was so dirty, you would have thought I had fired black powder in these cases. Now the inside necks are nice and clean and not imbedded with burned on carbon (which can function as a lube).

Yeah! Good Stuff Ain't it!!

I've been using ultrasonics for 20+ years and wont be without it.

http://www.brownells.com/.aspx/lid=1070 ... eaning#top

..or of course if ya got a spare 8+ grand hanging around..

http://www.brownells.com/.aspx/lid=1519 ... NIC-SYSTEM ..

..t

[Hoot]

The discourse on neck tension begs yet another question though. For those who stab crimp their loads and in the case of different bullets, those internal stab crimp scar rings can be of differing degree and in different locations up and down the case. How do you maintain consistency of tension with them added to the equation? Especially when sharing load data from one user to the next. My experience pushing bullets past those internal stab scar rings has been that the neck tension impact of old powder residue pales in comparison to those rings. They are in effect, short TightNeck zones of differing degrees.

I never noticed this as much with the lighter bullets, but as I've been experimenting with the heavier ones recently, the velocity has a greater impact upon vertical stringing and that's only at 100 yards. With the slower powders, I've seen velocities vary by 150-200 fps in the same load run. The only thing I can attribute that to was the difference in neck tension I perceived when seating the .451 class of bullets. Not so much with the .452's.

Hoot

[wildcatter]

A brief followup to the 250 FTX. Their performance being different than the 275 XPB may be as much caused by the fact that they run a little wider. I did notice that even without having the wide spot at the heal like the 275XPB, the 250 FTX was considerably harder to start in the TightNeck. With a good chamfer on the inside of the mouth and persistence, they did start however and had strong, consistent tension as they were seated. That having been said, they is a good argument that the TightNeck process may better serve .451 bullets as opposed to .452 bullets. Tolerances do vary and my experience has been that what a manufacturer calls .452 may wind up being in reality, .451 or .4515. Ditto on .451's running .450 or .4505.

I am conflicted on whether I want to subject my brass to the shrink and stretch process as it may lead to premature case deterioration from work hardening.

Hoot

Hoot my-man,

FYI guys,

Today, I split a case, due to the side-crimp. It split at 22 loadings (I do not anneal, if I did, they'd load many more times). My thought is, don't over crimp and count your loadings, you'll be surprised..

..t