Crimping hammer bullets

[Goose71]

Not to start a debate. I'm thinking of getting some hammers for a 7-08. Is it necessary to crimp them. I've been reading all hammer posts and seems there's a bunch of crimping I've never crimped. Just trying to get my ducks in a row.
Thanks BRUCE.

 

[Laelkhunter]

I'm not familiar with them, but is there a crimp groove or cannelure on them? I do not crimp any bullets that do not have a crimp groove.

 

[JTH]

Not necessary but will likely improve your groups if done correctly. I'm shooting sub 1/2 moa right now, waiting for Lee FCD to arrive. I expect to see even tighter groups after crimping.

 

[Varmint Hunter]

Not to start a debate. I'm thinking of getting some hammers for a 7-08. Is it necessary to crimp them. I've been reading all hammer posts and seems there's a bunch of crimping I've never crimped. Just trying to get my ducks in a row.
Thanks BRUCE.

While using a Lee FCD seems trendy with Hammer bullets; I've had mixed results with it. I originally tuned a few very accurate loads before I even considered crimping. Later, based on the many posts here, I bought several FCD dies and tried them out. Some loads had erratic velocity while others tightened up a bit. I think it's just something you've got to try on your own but crimping isn't necessarily "needed" with Hammer bullets.

Some of the very light for caliber Hammers have VERY little bearing surface in the case neck. They would likely benefit the most from crimping. Some posters here crimp on the full diameter shank while others crimp in one of the parabolic grooves. It only makes sense to me to crimp in the grooves if you want the crimp to have the greatest effect. The last few loads I've worked up are crimped that way and have performed well at distance.

 

[Seabeeken]

I tried crimping and my groups and numbers opened up. Went back to .004 neck tension and bearing surface fully in the neck. My groups in several rifles are .5 or less without crimps

 

[Huntnful]

I saw no benefits from crimping my already tuned hammer loads. I tried it on several different bullets. But they were already shooting extremely well. I'd say, load without crimping first and use crimping as a tuning tool if it's necessary. But mine have all shot great with no crimp and .002 neck tension.

 

[DoneNOut]

I fully intended to crimp the 120HH in my 7-08 loads, except all the PDR grooves are in the case neck. My rifle has a shorter throat which leaves the "just of the lands" at 2.700" COAL. Dang, I was so excited to have a magazine length of 2.825 too, but them bummed when I discovered the short throat. I wanted to load them longer. They are printing MOA and sub minute with a few powders, so I'm not complaining.

Don't know what my neck tension is, but sizing down 308 Lapua brass to 7-08, and alcohol swabbing inside the necks, the HH seat tighter than any other bullet I've seated to date.

As it was explained to me and made sense, the tight neck tension and crimp is to give the powder more burn/dwell time for all the powder to get ignited and none wasted out the tube.

 

[Laelkhunter]

Not necessary but will likely improve your groups if done correctly. I'm shooting sub 1/2 moa right now, waiting for Lee FCD to arrive. I expect to see even tighter groups after crimping.

A Lee Factory crimp die is a lot more forgiving than just setting your seating die to crimp.

 

[Hard rock]

I fully intended to crimp the 120HH in my 7-08 loads, except all the PDR grooves are in the case neck. My rifle has a shorter throat which leaves the "just of the lands" at 2.700" COAL. Dang, I was so excited to have a magazine length of 2.825 too, but them bummed when I discovered the short throat. I wanted to load them longer. They are printing MOA and sub minute with a few powders, so I'm not complaining.

Don't know what my neck tension is, but sizing down 308 Lapua brass to 7-08, and alcohol swabbing inside the necks, the HH seat tighter than any other bullet I've seated to date.

As it was explained to me and made sense, the tight neck tension and crimp is to give the powder more burn/dwell time for all the powder to get ignited and none wasted out the tube.

Sizing down may be making the necks thicker causing a tighter neck I'm sure your aware but might keep a eye on that and mic it out that can cause pressure problems too might run a bullet in the fired case too check clearance no matter how experienced a reloader we may be sometimes we over look things

 

[FEENIX]

Not to start a debate. I'm thinking of getting some hammers for a 7-08. Is it necessary to crimp them. I've been reading all hammer posts and seems there's a bunch of crimping I've never crimped. Just trying to get my ducks in a row.
Thanks BRUCE.

No!

 

[asd9055]

I am an observer here. I will enjoy this one!

 

[lancetkenyon]

I don't crimp any of my Hammer loads.
They all shoot extremely well.

 

[DoneNOut]

Sizing down may be making the necks thicker causing a tighter neck I'm sure your aware but might keep a eye on that and mic it out that can cause pressure problems too might run a bullet in the fired case too check clearance no matter how experienced a reloader we may be sometimes we over look things

Very good point, my man! I mic'd the brass in 308 form and in 7mm form. The 7mm form was only .001" thicker.

 

[QuietTexan]

Necessary no, an option yes.