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Re: hour glass ammo???

PostPosted: Sun Feb 11, 2018 7:08 am
by Al in Mi
My 500AIMM (Ultramag case cut back to 1.800) I have to do the same to get a tighter fit especially on the .500 Barnes bullets.

It does look they are sized down a good bit more than needed, but one theory might be to eliminate bullet set back if one were to hang up feeding.

the current 275gr Banes I have on hand mic .4504-.4506 at the base on the half dozen I just checked.

Re: hour glass ammo???

PostPosted: Sun Feb 11, 2018 8:04 am
by Robert FL
I put the brass in its own bag to keep them separate from my other spent rounds. I will throw them away.

Re: hour glass ammo???

PostPosted: Sun Feb 11, 2018 8:33 am
by Al in Mi
Robert, what's the length of those fired cases?

Re: hour glass ammo???

PostPosted: Sun Feb 11, 2018 12:24 pm
by Robert FL
1.694"

Re: hour glass ammo???

PostPosted: Sun Feb 11, 2018 9:55 pm
by Hoot
Robert FL wrote:1.694"


Was that before or after resizing? Actually, it doesn't matter. Either way should be good to go. That allays concerns about them shrinking back once expanded to their normal diameter! There's that Theory vs Practice conundrum biting me in the butt again. ;) Do you have any of them left with the hour glass profile that haven't been fired? It would be interesting to know how long they started out at. Its a little harder getting the caliper jaws on just the lip and rim edge but it can be done.

Hoot

Re: hour glass ammo???

PostPosted: Mon Feb 12, 2018 6:40 am
by Robert FL
I only bought a sample pack of 5. I test shot 3 to see how they would group at 100 yards. They shot same as the 250 Hornady FTX..I still have 2 unfired rounds, I was trying to take a hog with those 2 to see how they preformed. The 3 groups of hogs that I had at my hunting spot moved on..that happens when you start shooting some of the group..so I have to get over and find them or another new group. I plan on throwing the brass in a recycling bin, I would think the brass is stressed from the agressive crimp. In my non reloading mind I think it could split due to metal fatigue?? I can measure the 2 unfired rounds later today(brass), they did not fit in a Sig poly mag due to the bullet length.

Re: hour glass ammo???

PostPosted: Mon Feb 12, 2018 7:44 am
by jphillips0422
I purchased a 20 pack of the Black Butterfly 275 XPB (I miss typed in earlier post and stated XTP) a little over a month ago. When they arrived I pulled one of the bullets and used an OAL gauge to see how much extra room could be had in the case. I kept the piece of unfired brass. Its Starline and measured at 1.701. I did notice the bolt on my rifle was tough to close with a few of their rounds, but not horrible.

My fired brass is the same as Robert FL: 1.693-1.694 (6 pieces). In contrast I measured 20 pieces of fired Hornady Black factory ammo brass and they ranged 1.686 to 1.695.

Re: hour glass ammo???

PostPosted: Mon Feb 12, 2018 8:05 am
by Hoot
Robert FL wrote:...snip... I plan on throwing the brass in a recycling bin, I would think the brass is stressed from the agressive crimp. In my non reloading mind I think it could split due to metal fatigue?? I can measure the 2 unfired rounds later today(brass), they did not fit in a Sig poly mag due to the bullet length.


One trip through that downsizing die will not shorten their lifespan significantly. Repeated trips would take their toll more so than a regular sizing die.

So are you saying that some of the 5 fit your Sig poly mag and some didn't, or were you using a different mag for the first 3? I would expect that the vendor would check COL on his rounds for consistency. BTW, I'm not trying to crap on this vendor's products. All new offerings get close scrutiny around here. ;)

Jphillips: Thicker walled brass like Hornady's will behave differently than thinner walled like the Starline, in terms of shortening from expansion. Usually, resizing them grows them back a little.

Hoot

Re: hour glass ammo???

PostPosted: Mon Feb 12, 2018 8:37 am
by Robert FL
Hoot, I have only used Bushmaster and the ASC? Stainless magazines. I have 2 Sig Poly mags but have not used them. After reading another thread about bullet length I tried to load the 2 BB Barnes into the poly mag..they were a little long..no problem with the 2 stainless steel mags.

Re: hour glass ammo???

PostPosted: Tue Feb 13, 2018 6:05 am
by Robert FL
The unfired BB with 275 Barnes measured 1.715". I measured a new Hornady and it was 1.691"