.257 STW question - crimping

[Rum River]

Question:
How often are you other loaders having to crimp a high-pressure caliber such as this?

Background:
I am load developing for a friend's Rem. 700 with a 26" stainless sporter-contour barrel. It began life as Remington Custom Shop item in .257 Wby. When my buddy (a huge STW fan) heard there was one in .257, he immediately had the rifle rechambered without even having fired a shot.

He wants to use 115gr Trophy Bonded Bear Claws. As they're a bit spendy, I'm starting with 115gr Nosler Ballistic Tips. Beginning with virgin Winchester 7mm STW brass, Fed. 215 primers and Retumbo powder I shot a series from 75grs. charge to 82grs. The 82.0 charge chrono'd 3627fps average for 5 rounds, and is as high as I wish to go.

I am now establishing the COL for the Trophy Bonded Bear Claws, and the neck tension is so low I'm going to have to crimp. Anybody run into this before?



Rum River

 

[pjracer]

crimping is not a common practice. if you think neck tension isnt enough then you call whoever makes your dies and see if they make an undersized decap assembly

 

[Rum River]

Based on pjracer's reply, and the comments on other threads I found while searching, I opted not to crimp.

The expander ball miked .255", and the bullets were averaging .256". The owner had purchased 200 rounds of unfired Winchester brass. Miking case thickness at the case mouth revealed inconsistencies that aggravated the case neck tension issue.

I removed the expander ball, chucked it in the drill and used polishing stones to remove just over .001".

I pulled down one of the cartridges I knew to have too-little case neck tension, resized it with the modified expander ball in place (after removing the decapping pin) and reassembled the cartridge.

Now I can feel tension when seating the bullet, before there was no resistance at all.

Now I have to back up and re-shoot the last series of test loads to make sure my pressures are okay.

 

[dirtball]

If you continue to have problems, may I suggest you buy a 7mm STW Type-S Neck sizing die and the appropriate bushing/s for the 257. Most expander balls tend to pull the case necks out of concentricity any ways and that is not good for accuracy.
Dave

 

[Rum River]

I only now realized what's REALLY going on.

When miking the Trophy Bonded bullets, I didn't pay that much attention where on the bullet I took the measurement.

Turns out at the very base, they mike .257". Move up the shank maybe 1/4", and they mike .256", move further towards the tip, they mike .255".

I went through a whole box of 25, they were all the same. Opened another box, miked half of them, they also varied .002" from the heel forward.

I have a call into customer support, we'll see what they say.

 

[Rum River]

The plot thickens..........

Turns out there's a review on Midway USA from 3/12/2008 describing the identical problem.

Trophy Bonded has discontinued this bullet.

It's too early for a response to the message I left for customer service (the greeting gave hours for Monday through Thursday).

Just out of curiosity, anyone out there have any experience with Trophy Bonded customer service?

 

[oldfamily]

try the 110 accubond, they work good in my stw