Why Hammer Bullets Are Always Faster

[Lou270]

Have you founded a bullet company from the ground up and done all the research and trial and error field testing that goes into that? If not maybe consider that it looks kinda silly to be condescendingly asking @RockyMtnMT if he knows how this stuff actually works. At this point this is just becoming embarrassing.

I wasn't asking Steve, I was asking the group. I have debated with others more than Steve but if he is willing and wants to jump in, I will not use kid gloves. Steve is a big boy and one of the reasons I respect him is he has the cajones to participate on a forum like this. I am assuming other companies lurk here or even participate with some avatar. I am not putting anybody down nor do I think Hammers need to run faster than other bullets to justify using them.

Lou

 

[RockyMtnMT]

What is a baring surface? I assume you mean bearing surface.

Is that how you spell it?

 

[HARPERC]

Which is why there is a standardized pressure testing procedure that is descibed by saami including reference ammo.

I keep hearing hammers get xfps more. If that is only in your gun then it should not be a claim that gets repeated as it may not in next gun given this rationale

Lou

.....and yet factory ammo comes out the other end hundreds of FPS lower than advertised.

Reference ammo in hand loading books?

The caveat repeated near daily in this and most forums is "this worked in my rifle, your mileage may vary, start low proceed with caution".

 

[HARPERC]

Dear God is there a moderator who can put this thread out of its misery at this point???

I don't think its got to that point. Bumpy at points, but not to where I've hit ignore.

 

[Calvin45]

I wasn't asking Steve, I was asking the group. I have debated with others more than Steve but if he is willing and wants to jump in, I will not use kid gloves. Steve is a big boy and one of the reasons I respect him is he has the cajones to participate on a forum like this. I am assuming other companies lurk here or even participate with some avatar. I am not putting anybody down nor do I think Hammers need to run faster than other bullets to justify using them.

Lou

Okay fair enough. Maybe I'm getting a little too combative as well here haha. Gonna step out I think

 

[ButterBean]

Well to get back to the OP, Yes Ed you are correct, Hammer's are always faster and thank you for the video

 

[Lou270]

Yeah, post ran its course while ago with nobody convincing nobody. Surprise! My excuse is I am at my ranch this week and no entertainment but phone once gets dark. Too tempting to jump back when see notifications. I will try not to post back so can move on

Lou

PS. BB…better gifs next time

 

[RockyMtnMT]

Do you gents know what a pressure / time curve is, how it impacts velocity, and how engraving pressure affects things? If so you know that engraving pressure is typically 3-4k for say a lead/copper rifle bullet. An unbanded mono is 5-6k. So by reducing engraving pressure you are dealing with couple k psi total as it is not gonna be zero. That is not gonna change velocity a whole lot. Part of my skepticism but again if somebody thinks my numbers off lmk.

BB - need better gifs

Lou

This is interesting. How do you determine the amount of reduction in engraving pressure by design? How many fps are gained per thousand pounds of pressure reduction? I don't know, I'm guessing you do?

 

[cajun]

Someone earlier mentioned moly coated bullets. Back in the day one of my reloading mentors was big in moly coating. What we found with moly coating is it reduced the friction in the barrel. Much like reducing the bearing surface. What we found was when we were at max book loads the velocity was less because the pressure was less due to the lower friction. We had to run higher powder charges to get the same velocity. Pressure and velocity are related and go hand in hand. What changed was the amount of powder to get there. Now the other benefit of moly coating was less fouling in the barrel. But the point is less friction meant less velocity and less pressure. In short we got the same velocity with coated and uncoated bullets. What changed was the amount of powder required to get there.

 

[cajun]

If you look at Noslers load data they list the same data for all their bullets of similar weight. Obviously the engraving pressure of the bullets are different but the max velocity they list is the same. They do however note that with their solid copper bullets you should start at minimum charge weights because the engraving pressure is higher and it will take less powder to get to max velocity. This is why a chronograph is invaluable in reloading. Charge weights may vary due to bullet engraving, chamber tolerances and barrel freebore. But max velocity is consistent with max pressure.

 

[Calvin45]

I don't think its got to that point. Bumpy at points, but not to where I've hit ignore.

Yeah I think you're right. Sorry about that. My excuse is I've been at a family gathering that's wonderful but also frying my brain…a tad on edge I realize. Again, sorry fellas, was being a touch dramatic here

 

[fordy]

Gday
I'm real dumb on some of the stuff you guys are talking about & to me it's pretty simple I'm staying that way so I hope I don't inflame the wonderful moments everyone is having lol

One question Steve how'd weatherby find the hammer hunters
I know they were the easiest bullet they have tuned across the board but how about the other stuff that's on the table in this thread
Only expect a response if it dosent go against privileged information between you 2

Simple sole is off to stir muddy & then bring on 2023
Happy new year to all
Cheers

 

[nralifer]

OP, Thank you for the data, I have been very happy with my limited experience with the Hammers so far.

Please allow me to re-iterate some of the feedback discussed above ... I prefer to not push velocity without published load that includes measured chamber pressures. It is just not safe enough for my taste. Are there any plans to start collecting such data, maybe in collaboration with folks like Weatherby?

A lot of things in a rifle influence velocity. I will mention a few:
Caliber
Barrel length
Throat design
Steel alloy used
Rifling twist rate
Rifling design
Bore tolerances of barrels
Rifling uniformity
Quality of chambering
Chamber design and volume
And we haven't got to the cartridge, powder, primer , brass alloy, bullet design, etc.
Frictional forces between the bullet and barrel are of a finite influence on bullet speed. Increased MV due to reduction in bearing surface contact often come at the expense of increased bullet drag at supersonic speeds because of changes in the surface curvature of the bullet shank creating a shock wave at every change in surface curvature. In the long run, increasing muzzle velocity at the expense of increased drag is a losing proposition because the higher drag forces the bullet to lose energy at a faster rate though out it's entire supersonic flight. Ever wonder why Berger and Sierra have no groves at all on their shanks? Ever wonder why Barnes has gone to putting grooves on their all copper bullets? The reasons have little to do with MV, and have everything to do with flight drag (in the case of Berger and Sierra) and barrel copper fouling and consistency in accuracy in the case of Barnes. The original Barnes X bullet had no groves but shot terribly out of some barrels and well out of others. The groves reduced copper fouling and improved more consistent accuracy from barrel to barrel but at the expense of drag.

We all should remember that any mechanical design is a compromise of many smaller design features built in to the final design. That is an engineering truth as applicable to bullets as it is to bridge building. It is up to the end user who buys a design for a specific purpose to live with the advantages and compromises of that design he/she bought into.

As shooters and reloaders armed with chronographs, bullet speed takes on a large significance because it is so visible. We, myself included, attach a large significance to that measurement, but the significance of bullet speed needs to be judged in the larger context of what the shooter is trying to accomplish.

 

[HammerBullets]

Since this post isn't long enough thought I'd throw in Ron Spomers load development review before going to Mozambique.

Key words: "more muzzle velocities," "didn't show… pressure," "unusual speed," "minimal bearing surface."