Neck Tension

slimjim · Posted: Sat May 11, 2013 8:20 pm Post subject: Re: Neck Tension

Found something interesting today as I prepared to do some more terminal performance testing with my six8. I had some 115gr Federal Fusion MSR and pulled the bullet to get a picture. It took 38 pounds of force to extract it. My six8 loads average 9 pounds of pull force without a crimp and 11 pounds of pull force with a crimp. The Fusion bullet had adhesive on it. You can see it in the image below, its on the right. Has anyone else heard of this?

English Mike · Posted: Sat May 11, 2013 9:22 pm Post subject: Re: Neck Tension

It's sealant rather than adhesive.
I've seen it fairly frequently on milsurp but never before on commercial ammunition.
Did the primer have sealant too (usually red or green laquer)?

slimjim · Posted: Sat May 11, 2013 9:26 pm Post subject: Re: Neck Tension

I'll check the primer tomorrow. This may be a sealant but it also acts as an adhesive. The sealants are applied after the bullet is inserted and only cover the case/neck opening and bullet interface/juntion.

Vince · Posted: Sat May 11, 2013 11:28 pm Post subject: Re: Neck Tension

All military ammo has a sealant applied to the projectile, and primer I believe, when manufactured. This ensure viability in any climate when on operations.

To be honest, I have never pulled any factory loaded civilian sporting rounds, so I don't really know if they all do use sealant. Maybe it is part of their procedures to assist in a more consistent burn and consistent pressure. Could also be a way of saving on a little powder...more for less. However, it doesn't surprise me that they are using sealant to cover their butts in this litigation crazy world.

slimjim · Posted: Sun May 12, 2013 6:07 am Post subject: Re: Neck Tension

There is no evidence of sealant on the primer, then again, it could be internal like on the bullet. I'll have to check it further after I shoot some.

Hornady factory ammo comes with fully crimped primers that have been a bugger to get out. Not sure why they have to do that because they loads are not high pressure.

MacD · Posted: Sun May 12, 2013 12:05 pm Post subject: Re: Neck Tension

I used to buy a lot of American Eagle. 223 FMJ and all primers were crimped in. I had a few boxes of 45ACP S&B with sealed primers. I found one reference to bulk Federal Fusiom MSR in. 223 that refered to sealed pimers not bullets. I thought crimped primers wre only for rounds that may be used in fully automatic firearms and sealing of primers and bullets was for service ammo that may be subjected to wet conditions. I wonder if Slim has it right. If you want to use a slower single base powder in a round that usually needs a faster one sealing the bullet to raise peak pressure will increase burn rate.