Proper neck tension on 45acp?


PDA






m0par
May 16, 2010, 11:34 PM
Is there a standard measure for neck tension to prevent bullet set back in 45acp?

Do the ammo manufacturers test for it during QC? If so, does anyone know what their specs are?

If you enjoyed reading about "Proper neck tension on 45acp?" here in TheHighRoad.org archive, you'll LOVE our community. Come join TheHighRoad.org today for the full version!
Steve C
May 17, 2010, 12:04 AM
Best guess would be that the allowable neck tension depends upon the manufacturer and what they deem as necessary for their product. Some factory ammo will set back in some pistols when chambered while other ammo from different manufacturers will not.

Every manufacturer crimps their ammo and doesn't rely on neck tension only to keep the bullet in place, esp with pistol ammo. They sometimes even put a heavy cannelure in the case below the bullet base to prevent any set back. Military ammo is usually heavily crimped into the bullet cannelure.

For handgun ammo I generally just test the bullet tension by pushing the nose of the bullet against the edge of the bench top using thumb pressure. If it holds in place then there's enough tension, if not it needs more crimp.

pcwirepro
May 17, 2010, 12:16 AM
This is something I check on most factory ammo I buy. Blazer is the only manufacturer that I have found to have poor neck tension. I use the same method Steve has suggested.

LightningMan
May 17, 2010, 12:34 AM
I can't help with an answer on factory ammo, but I do know that all brass is not made equal, as some case walls are thicker than others. When I reload, I set my crimp according to what brass I am reloading. The thinner types like Winchester need a little more crimp to hold the bullet and thicker types need a tad less. Like Steve C stated; For handgun ammo I generally just test the bullet tension by pushing the nose of the bullet against the edge of the bench top using thumb pressure. If it holds in place then there's enough tension, if not it needs more crimp.
Another test would be to use a set of calipers & check you OAL after (Safely) sling-shoting a few test rounds through the gun. If they maintain at, or are within a couple thousands (.002) you should be good. LM

m0par
May 17, 2010, 06:59 AM
Thanks all for the input.

I think the thumb-press is a decent test, and the slingshotting would be a more practical test of actual forces encountered (minus recoil, of course). I was just wondering if there were specifications the industry used. Besides, I like specs :)

I vaguely recall reading either someone's personal test or some sort of spec using 40lbs, but can't find anything on it now.

NuJudge
May 17, 2010, 07:02 AM
Pay attention to what LightningMan said about different case wall thickness. The thinest I have encountered was some Remington brass, that was old when it gave me problems in 1980.

For all cases, I use dies that probably size down a case's OD more than necessary for most brass. Especially for semi-autos, cartridges I've loaded have this "wasp waist" look, and I don't have any trouble with bullets telescoping into cases.

CDD

EddieNFL
May 17, 2010, 08:20 AM
My spec is .469 -.470 case mouth after crimping.

ranger335v
May 17, 2010, 08:24 AM
I've only loaded and shot a few thousand .45 ACP in the last 40 years but the question of how to specify/qualify bullet set-back resistance has never occured to me. It has never been a problem either and my crimping has always been the minimum required to remove any case flare.

Visionairy
May 17, 2010, 10:02 AM
I just started loading .45 with a LEE LOADER the other day and I had some issues with "smushed" bullets cycling through my Glock. About 1 in 10 rounds smushed and FTF and were a pain in the a!! to remove. The lee loader process doesn't use any crimping operation whatsoever so i'm sure that doesn't help.

I wasn't sure if it was the bullets or brass but I noticed that 100% of them were the S&B brass. Now I check EVERY round with finger pressure before measuring OAL.

I need to get a real press, these 45's are HARD as hell to resize with a hammer!!! Plus I've wacked my hand a few times pretty good, soft mallets don't feel any better than hard ones on your fingers

The Bushmaster
May 17, 2010, 10:56 AM
Testing for neck tension on a .45 ACP? Never gave it a thought...Why? If your reloading procedures are proper you should have no problems with neck tension.

But you can push the cartridge nose first into the bench and see how much pressure it takes to push the bullet into the case. If you wish. Other then that. Load'em. Shoot'em. Load'em again.

SlamFire1
May 17, 2010, 11:18 AM
Wilson Combat recommended taper crimping to 0.469", and that is what I do.

Works fine for me.

Robert101
May 17, 2010, 06:59 PM
I've not been concerned about a specification for neck tension either. The die manufacturer is really setting the tension by the diameter of the expanding die. Removal of the taper crimp is just that - just remove the crimp to a measurement of .469 to .471 (for me). The taper crimp contributes minimally to the bullet retention. Beyond that just described, if you are getting a smashing of the rounds in your gun, then it seems you have a feeding issue.

Check the diameter of your bullets. They should measure at least .451

243winxb
May 17, 2010, 07:10 PM
I vaguely recall reading either someone's personal test or some sort of spec using 40lbs, but can't find anything on it now. 5.56mm ammo test at 35 to 45lbs bullet pull. This can be gotten by the bullet expanding the brass .002" or more on loading. Measure you sized & expanded* 45acp case. Now seat a bullet, did it get larger in diameter by .002" ? Some Rem. brass can have thin walls. The bullet will fall into the case on seating.

243winxb
May 17, 2010, 07:16 PM
I need to get a real press, these 45's are HARD as hell to resize with a hammer!!! Plus I've wacked my hand a few times pretty good, soft mallets don't feel any better than hard ones on your fingers Many years ago i started with > The Lee Hammer loader works but the bullets got deformed on seating for me. Took way to many hits to seat a bullet. I did buy an expander to open the case, worked much better that way.

243winxb
May 18, 2010, 09:31 PM
corrected post 13 above to read Measure you sized & expanded* 45acp case.

sophijo
May 18, 2010, 10:18 PM
Get one of these;

http://www.lewilson.com/casegage.html

Drail
May 19, 2010, 10:14 AM
To test for sufficient neck tension seat a bullet and then press it against the edge of the bench before you crimp. Push hard. If the bullet moves into the case you need more tension and applying heavy crimp will not stop the movement. The crimp serves only to remove the flare, it does almost nothing to hold the bullet in place. (unless you have crimped it into a deep groove in a cast bullet) On a jacketed round the neck tension is really the only thing holding the bullet (assisted by the tar like adhesive used on military rounds in full auto guns). If you can push the bullet into the case remove the expander plug from the die and mike it. If it is not 4 or 5 thous. under the bullet's dia. it needs to be turned down in a drill or drill press until it is. When a bullet is seated you should be able to see the outline of the bullet and its base through the brass. The bullet has to have tension on its full length and not just at the mouth of the case. Trying to anchor it using only a crimp on the mouth will not keep it in place from setting back or pulling forward in a revolver and will cause the case to crack from overworking the brass. Crimp only enough to remove the flare so the cartridge will chamber smoothly. By using this method your cases will last much longer than they will if you over flare and over crimp the mouth of the case and the bullets will be held tightly. I learned this from one of Elmer Keiths books and it has worked for me for many years. I have .41 and .44 Mag brass that I have been using since the 1980s and have never had a bullet pull forward or had a case split. I also have .45 ACP brass dated 1985 in continous use and never had a single round set back.

stork
May 19, 2010, 12:03 PM
As an avid Bullseye shooter I have loaded & tested over 40,000 rounds of 45ACP over the last 10 years. I also own a Ransom Rest that gets used a lot. My first Kart barrel liked a hard crimp (.463-.465) to shoot at 50 yards. My current Kart barrel likes a much more standard crimp of .470 and shoots much better that way.

The only way to tell is load them up and shoot them. A couple of excellent 1911 gunsmiths, Roddy Toyota and John Giles both set their custom Bullseye guns up to shoot the best with a .463-.465 crimp.

YMMV
Stork

If you enjoyed reading about "Proper neck tension on 45acp?" here in TheHighRoad.org archive, you'll LOVE our community. Come join TheHighRoad.org today for the full version!