Why Hammer Bullets Are Always Faster

[RockyMtnMT]

Gday Steve
Just wondering if you were eating your sandwich & the bread in it was so lovely that you typed that in & it should have been brass not bread

I also don't mind eating my words so if it is bread I'll happily eat my bread comment but @ this hour here I'll put it in the toaster first
So why it's cooking please explain the bread part
Cheers

Stupid phone!

 

[RockyMtnMT]

If you are not using a chronograph then should stop and back off. Assume using a chronograph, then you should be paying attention to velocity adjusted for barrel length and ambient conditions (ie temp). If you hit expected velocity before max charge you should stop there. Used to not happen much, but not uncommon with all the custom, semi-custom, and factory guns with "match" chambers these days.

However, I am assuming you mean a case where velocity is significantly low (say 100 fps less than expected) and still getting some pressure signs. The first thing I would do is check with factory loads to see velocity and if has same pressure signs. I would also try different brand of brass. If get expected results with those I would keep paying attention to it but assume it is a bad lot of brass though I would keep loads on mild side until do not see signs again after more shooting

If do see pressure signs even on factory loads or other brass (again assuming significantly lower than expected velocity) then I would look for a mechanical cause of the pressure signs (web search is friend here). If cant figure it out then would just live with "slow gun" or send it on its way

Lou

I believe what you are saying is the only thing that matters is the weight of the bullet and the vel. All bullets, of equal weight, are at the same pressure at the same velocity? Regardless of form, or material?

 

[RockyMtnMT]

Ok, I'll add a little more food for thought. Is a 30 cal 100g bullet with a muzzle velocity of 3000 fps exhibiting the same pressure as a 100g 7mm bullet at 3000 fps?

 

[Calvin45]

Ok, I'll add a little more food for thought. Is a 30 cal 100g bullet with a muzzle velocity of 3000 fps exhibiting the same pressure as a 100g 7mm bullet at 3000 fps?

Not if the barrel lengths and case capacities are equal

 

[RockyMtnMT]

Ok, I'll add a little more food for thought. Is a 200g 30 cal bullet with a .7" baring surface with a muzzle velocity of 3000 fps exhibiting the same pressure as a 200g 30 cal bullet with my a .5" baring surface with a muzzle velocity of 3000 fps? Both bullets of the same physical property and design other than the dimensions.

 

[RockyMtnMT]

Not if the barrel lengths and case capacities are equal

Ok. Shot from the same rifle. I'm my last post.

 

[Hard rock]

Ok, I'll add a little more food for thought. Is a 200g 30 cal bullet with a .7" baring surface with a muzzle velocity of 3000 fps exhibiting the same pressure as a 200g 30 cal bullet with my a .5" baring surface with a muzzle velocity of 3000 fps? Both bullets of the same physical property and design other than the dimensions.

No

 

[adam32+P]

Ok, I'll add a little more food for thought. Is a 200g 30 cal bullet with a .7" baring surface with a muzzle velocity of 3000 fps exhibiting the same pressure as a 200g 30 cal bullet with my a .5" baring surface with a muzzle velocity of 3000 fps? Both bullets of the same physical property and design other than the dimensions.

Depends on the bolt face diameter.

 

[Calvin45]

Ok, I'll add a little more food for thought. Is a 200g 30 cal bullet with a .7" baring surface with a muzzle velocity of 3000 fps exhibiting the same pressure as a 200g 30 cal bullet with my a .5" baring surface with a muzzle velocity of 3000 fps? Both bullets of the same physical property and design other than the dimensions.

My experience tells me no, but Im pretty sure this question ain't for me haha. Butting out

 

[RockyMtnMT]

Not if the barrel lengths and case capacities are equal

If I am understanding the arguments that Hammers can not have more velocity without more pressure then I'm not sure that barrel length could be an issue?

 

[RockyMtnMT]

Depends on the bolt face diameter.

Shot from the same rifle?

 

[Calvin45]

If I am understanding the arguments that Hammers can not have more velocity without more pressure then I'm not sure that barrel length could be an issue?

No no man I'm on the side that says they can!!! . I just received my first order of hammers in the mail.

I'm saying if you're shooting a 7 and a 30 out of equal barrel lengths and equal powder charges at equal pressure the 30
Will be going faster as the total volume from chamber to muzzle for gas to expand is greater.

 

[RockyMtnMT]

Depends on the bolt face diameter.

What does bolt face diameter have to do with chamber pressure?

 

[K.E.C. Darkside]

Ok, I'll add a little more food for thought. Is a 200g 30 cal bullet with a .7" baring surface with a muzzle velocity of 3000 fps exhibiting the same pressure as a 200g 30 cal bullet with my a .5" baring surface with a muzzle velocity of 3000 fps? Both bullets of the same physical property and design other than the dimensions.

This... Is where you need to be. Compare same weight same caliber with different bullets. Sorry if I am repeating what other have said.