Neck tension

[foxwhistler]

Reading a few of the older posts on this forum,i noticed a lot of members use bushing neck sizer dies.A couple of posters even said that you can vary the neck tension on your loads.My question is that in"Modern Reloading",by Richard Lee,he states that the most neck tension you can place on a bullet is .001 of an inch.I just wanted to know if people agree with this?Also has anyone ever tried to get cases with different neck tensions ,seat the bullets and then pull the bullets and measure the internal diameter of the necks?
The reason i`m asking this is because i`m wondering what is the most neck tension i could get?

[acloco]

Good question. Let me toss a wrench in as well. CRIMP THE NECKS!

[Rick in Oregon]

From what I've learned over the years of handloading, varying the amount of neck tension is not only possible, but different tension is practical for differing needs.

(Not to disparage Richard Lee, a good fellow and dedicated to our sport..... but he's incorrect saying only .001" of "press fit" is possible or needed so to speak.)

For proper ignition, some neck tension is required, but you don't want so much as to raise pressure prior to bullet release. On the other hand, you need enough tension so the bullet does not fall out of or back into the case. Crimping is one way to ensure proper ignition, but we don't want to crimp precision handloads intended for small targets in small calibers; it's just not needed or required.

Most "experts" agree that tension from .001" to .003" is about right for most uses. If you've neck turned a batch of cases too thin, and have a SAMMI factory chamber, chances are once you've sized in a standard neck or F/L die, the bullet will not have enough tension and probably fall back into the case (been there). The only way to cure this is with neck bushings smaller than the existing neck diameter.

For varmint shooting single shot, not much tension is required. I usually use about .002". Some of my cases that lack "spring back" that have been shot many times and reloaded, only have about .001" of neck tension, but still enough for my needs. When needed, I'll anneal them, resize them with a small bushing, and problem solved. Rifle calibers for big game are a different matter, as recoil will set bullets back into cases still in the magazine if not enough tension has been applied. But we're only talking about varmint/target use here.

So for most purposes we'd use for our varmint rifles, I'd opine that from .001" to .003" press fit or tension is really needed. This is the advantage of using bushing neck dies, and I highly recommend using them. Hope this helps.

[foxwhistler]

Thanks a lot Rick.I haven`t been reloading very long and it`s nice to have experienced people to learn from.

[Njanear]

Good question. Let me toss a wrench in as well. CRIMP THE NECKS!

Is that 'tossing in a wrench' or 'pulling the pin out of the grenade'?

[homefront]

I only crimp my levergun loads.

[Rick in Oregon]

The only loads that come out of my gun room crimped are all my .45 ACP's with a taper crimp, and all my various revolver loads with a roll crimp.

The exception is for my Marlin .44 Magnum 1894 rifle, which also gets a roll crimp - all other rifle fodder is not crimped....no reason, not even my 330 Dakota or .338-06 Ackley, on those two I use .004" of neck tension so the bullets will not back into the case under recoil, or set back on the trip up the feed ramp from the magazine.

[jo191145]

Different neck tensions make a big impact on load requirements. Last summer I ran two side by side Audette ladders with Benchmark and cases using the expander ball and without the expander. W/O expander creates much more tension.
The two tests hinted the best accuracy would be found with the tighter neck tension.
Subsequent group tests did not work out that way. Maybe I didn't try hard enough. I was pressed for time.

The most accurate load I found was with the expander just under max charge.
Still pretty slow with a 40gn bullet.
As I went over max the accuracy was much better with tighter neck tension. I plan on revisiting this entire test before this season begins.
I'm willing to give up a touch of short range accuracy if I can boost the velocity enough to help battle the wind.

When BR shooters switched to Viht 133 they quickly found they needed to increase neck tension and jam deeper in the lands than with previous powders.
Its pretty much a given that Viht powders like a hard start and perform best when pressures are maxed. Or maybe over maxed. Thats been my experience anyway.