Why Hammer Bullets Are Always Faster

Steve

This is my first post which I apologized for the tone. I aplogize again as it is not meaningless as whether we agree or not it spurned a discussion

"Absolutely 100 percent meaningless without pressure testing results. Not saying hammers do not get more velocity but this proves nothing. different bullets often get higher or lower velocity with same charge weights. Does not mean pressure is the same nor does "no pressure signs" means"

Other than the negativity, I do not have a different stance.

Lou
Even if you had pressure testing equipment , the answer would still be Yes , but you keep skirting around a simple question , so there is absolutely no answer that would put your mind at rest . Even if Hammer bullets had pressure testing equipment , there would be doubt because the data would be so far off conventional data , it would put doubt in your mind . If you loaded a Hammer bullet with a bearing surface of .5 compared too a bullet of .7 , everything else being equal including pressure the Hammer bullet would be faster , how you measure that pressure is another story.
 
What is a baring surface? I assume you mean bearing surface.
What is a baring surface? I assume you mean bearing surface.
That is a ridiculous question , unless you are trying to be funny , but I don't think that may be the case . My assumption would be Steve just misspelled bearing surface .
 
Even if you had pressure testing equipment , the answer would still be Yes , but you keep skirting around a simple question , so there is absolutely no answer that would put your mind at rest . Even if Hammer bullets had pressure testing equipment , there would be doubt because the data would be so far off conventional data , it would put doubt in your mind . If you loaded a Hammer bullet with a bearing surface of .5 compared too a bullet of .7 , everything else being equal including pressure the Hammer bullet would be faster , how you measure that pressure is another story.
^^^^^^^^^^^^^^^^ShoNuff^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
Well......you guys can keep discussing this. I'm going to keep stuffing powder into my brass and top them off with hammer bullets. I worked up loads the same way i do with everything. Found top end, BACKEd it off 1 grain. I dont really care what pressure is. Its safe. 143 hh in 7 rem mag at 3350. 3/8" group in a stock browning x bolt at 100. ButterBean.....thanks for your help. However....the two elk my wife and i shot hate you. Lol. The guides we used couldn't believe the results we got on those elk. You guy keep talking, im going out and shoot hammers in my model 94 356 and my whelen i built. Gotta see what they can do....it now an obsession. I have multiple people in the area that are now using the 35 whelen in iowa for deer. Want to know what i get for results. Not one asked for pressure. Just results. So....as soon as iowa weather clears up....im going to feed my new addiction. Lol. Thanks steve for making these bullets
 
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?

You can model this in Quickload. You have to back into a particular bullet's engraving pressure by comparing muzzle velocities at the same powder charge between that particular bullet and the reference bullet that you used to tune your powder burn rate to match Quickload projections.

It's engraving pressure that makes all of the difference from one bullet to another of the same weight. Max chamber pressure happens in the first few inches of bullet travel. If the bullet takes higher chamber pressure (and more powder burn time) to force it fully into the rifling, it will build a lot more chamber pressure before the bullet really gets moving. So you end up with higher average pressure working on the bullet as it travels through the first few inches of barrel, and you get more muzzle velocity.

Once a bullet is fully engraved, I can't imagine drag on the bullet has much effect on muzzle velocity. But a bullet with high engraving pressure will definitely have higher muzzle velocity (and higher chamber pressure) than a bullet with low engraving pressure (at the same powder charge.)

But! The bullet with low engraving pressure can take a lot more powder to reach the same max pressure, and that extra powder keeps the pressure behind the bullet higher for the entire time it's traveling down the barrel. So the bullet with the lowest engraving pressure ends up with higher muzzle velocity when loaded to the same max pressure.

To answer your question, in my rifles I get about 100 fps higher velocity from Absolute Hammers than I get with hard-to-engrave thick-jacketed hard-lead-alloy bullets such as Nosler Partition or Sierra Tipped Game Kings. This is with the same max chamber pressure calculated by Quickload with powder burn rate and bullet starting pressure tuned to reflect range data.

You may be surprised how small this Absolute Hammer advantage is in my rifles. Some folks claim that they get 300 fps higher velocity with Absolute Hammers. The reason I only get 100 fps is that I don't load up to sticky bolt lift. I work up loads using ejector print on soft-headed Nosler or Norma cases, with Quickload (tuned to a published Hodgdon powder charge, bullet type, and chamber pressure) as an extrapolation tool.

My own view is that sticky bolt lift is not a reliable indicator of safe working pressure limit. For example, given the tenon diameter in my rifles I estimate that a standard-diameter case (e.g. 30-06) will take 30% more pressure to hit sticky bolt lift than does an ultra-magnum diameter (e.g. 28 Nosler) case. That may be why the folks claiming the highest increase in muzzle velocity for Absolute Hammers are the folks shooting standard-diameter cases. But they may be running VERY high pressure to get that uplift.
 
You can model this in Quickload. You have to back into a particular bullet's engraving pressure by comparing muzzle velocities at the same powder charge between that particular bullet and the reference bullet that you used to tune your powder burn rate to match Quickload projections.

It's engraving pressure that makes all of the difference from one bullet to another of the same weight. Max chamber pressure happens in the first few inches of bullet travel. If the bullet takes higher chamber pressure (and more powder burn time) to force it fully into the rifling, it will build a lot more chamber pressure before the bullet really gets moving. So you end up with higher average pressure working on the bullet as it travels through the first few inches of barrel, and you get more muzzle velocity.

Once a bullet is fully engraved, I can't imagine drag on the bullet has much effect on muzzle velocity. But a bullet with high engraving pressure will definitely have higher muzzle velocity (and higher chamber pressure) than a bullet with low engraving pressure (at the same powder charge.)

But! The bullet with low engraving pressure can take a lot more powder to reach the same max pressure, and that extra powder keeps the pressure behind the bullet higher for the entire time it's traveling down the barrel. So the bullet with the lowest engraving pressure ends up with higher muzzle velocity when loaded to the same max pressure.

To answer your question, in my rifles I get about 100 fps higher velocity from Absolute Hammers than I get with hard-to-engrave thick-jacketed hard-lead-alloy bullets such as Nosler Partition or Sierra Tipped Game Kings. This is with the same max chamber pressure calculated by Quickload with powder burn rate and bullet starting pressure tuned to reflect range data.

You may be surprised how small this Absolute Hammer advantage is in my rifles. Some folks claim that they get 300 fps higher velocity with Absolute Hammers. The reason I only get 100 fps is that I don't load up to sticky bolt lift. I work up loads using ejector print on soft-headed Nosler or Norma cases, with Quickload (tuned to a published Hodgdon powder charge, bullet type, and chamber pressure) as an extrapolation tool.

My own view is that sticky bolt lift is not a reliable indicator of safe working pressure limit. For example, given the tenon diameter in my rifles I estimate that a standard-diameter case (e.g. 30-06) will take 30% more pressure to hit sticky bolt lift than does an ultra-magnum diameter (e.g. 28 Nosler) case. That may be why the folks claiming the highest increase in muzzle velocity for Absolute Hammers are the folks shooting standard-diameter cases. But they may be running VERY high pressure to get that uplift.
Velocity potential with the Absolute Hammers has a lot to do with the efficiency of the cartridge and the size of the cartridge. The more efficient the cartridge is the less gain we see and the larger the volume is the case the less gain we see.

QL is difficult to make match field data from bullet to bullet. They profiled our bullets only by dimension but did not take into account the drive band design. At this point as it sits it is not a good predictor. The best method is good old fashioned load development. Use start loads for similar weight conventional lead core bullets and work up your load from there watching for all the traditional pressure signs. Hammers will show less pressure than conventional lead core bullets, so those listed start loads will be very mild to work up from.
 
So in my testing with Hammer bullets my test procedures went as follows. These tests were done in my 257 Allen Magnum, 270 Allen Magnum and 7mm Allen Magnum.

i would take freshly formed brass, using a corn meal forming method. With a batch of test brass prepped and ready to load, i would enter the test with full expectation to destroy this brass in the testing process. The reason is because my goal was to find the absolute max velocity for my wildcats using one uniform source of brass for whatever bullet tested.

would start with a very safe starting load and then increase powder charge 0.5 grains at a time shooting each load over the chronograph and recording velocity readings. I would continue increasing powder charge until i went from the primer pocket on the once fired case being tight to the first hint of primer pocket loosening with a simple 0.5 gr increase in powder charge.

once i reached this point i would take the last four powder charges and repeat at least three times to make sure the results were the same in that the primer pockets would show first hint of loosening at that same 0.5 gr increase point, if it was different, i would repeat an additional two times to get a good average.

with this point found, i would record the data and velocity results.

then would repeat with a slightly slower powder. repeat the entire test process and get the same data to the same point in brass strength. If max velocity was higher with the slower powder, i would then test an even slower powder and repeat the process until i reached a point where the maximum velocity started to drop off telling me i was out of the useful burn rate for that wildcat.

i found quickly with the hammer bullets that a slower powder rarely increased this maximum velocity so i would step down to a slightly faster powder repeating this same test procedure to find max velocity. usually finding that velocity would increase significantly as the powder burn rate increased. Something not common with my large capacity magnums using lead core/cup jacketed bullets.

This was the common result with every test i performed with the hammer bullets, in every single test, using faster the conventional powder, velocity was significantly faster then with same weight lead core bullets when loaded to that same primer pocket fail point.

not only that but with the lighter bullet weights, velocity spreads were tighter then with conventional bullets with slower powders. Now these tests were not designed to find top USABLE velocities out of my rifles, it was to compare bullets loaded to their max limits in chamber pressure determined by same brass tested in same barrel. Certainly a pressure barrel would be more accurate finding exact pressure levels but this is more then accurate enough to compare how bullets compare to each other as far as max pressures are concerned.

to find my max usable load for my customers rifles, i use a load that offers a minimum of 8 firings per case. Using lapua or peterson brass, this is consistently a similar percentage off this absolute max velocity limit. At this point, i could care less if the pressure is 75,000 psi as long as the brass will offer a minimum of 8 firings per case but i know my pressures are well south of 70k.

in every one of these tests, the Hammer bullets were significantly faster then any lead core bullet design of same or similar (+/- 5 grains) weights. To that point, they were also faster then the barnes tsx or lrx when tested the same way with a variety of powders tested.

i also tested some conventional chamberings with the Hammer bullets and in my testing, the velocity advantages increased as the case capacity of the round tested decreased. By that i mean, a 284 with the 177 gr hammer would show more of a velocity advantage over conventional bullets then the in my 7mm AM testing the 177 gr hammer would over conventional bullet weights. My big 7mm would certainly still have a 75-100 fps velocity advantage but the smaller round would be in the 150+ fps range compared to conventional bullets.

one can not say these results are meaningless when all bullet designs are tested to the same exact case failure point, in repeated tests to confirm that failure point. Then all bullets would be retested with a variety of powders, some faster, some slower, all to the same case failure point.

again, i was not testing for usable velocities and pressures, i was loading to the same pressure failure point and comparing the results bullet to bullet so as close to apples to apples as possible.

once again, please to not read this as me saying i recommend loading to this level of pressure. This was simply for testing purposes in EXTREMELY strong rifles, those being my Raptor LRSS platform which has a receiver strength on par with most cheytac class receivers. Still, my recommended loads to customers are far lower then the test results obtained during these tests.

and i repeat, in every test, the Hammers produced the highest velocity levels ranging from 75-150+ fps velocity advantages over conventional lead core bullets of same or similar weight and on average 50-100 fps gains over barnes tsx and lrx bullets.

all that said, i use hammer bullets, i use nosler bullets, i use hornady bullets, i use berger bullets. All have pros and cons, all have situations they may or may not be the best choice. Point being, if you need a hard fast bullet option, give the Hammers a try and see what they do out of your rifle. If your not happy, dont use them, if you are happy, great!!

Kirby, thank you, this is very informative. I really like the systematic experimentation.

I will preface my question with - I am a novice reloader, started about 4 years ago and moving forward slowly. However, I've been driving over 40 years so I'm much more comfortable with pushing 5mph over the highway speed limits than I am pushing past factory load data with or without pressure testing data.

My reloading has focused on T/TSX and AccuBond and I'm starting to experiment with Hammer Hunters. I'll probably be dead and buried before I feel confident enough to try Absolute Hammers.

Would you follow the same procedure if you were not using your extremely strong rifles? e.g., most of mine are Remington 700 actions along with one-offs of M70 CRPF (7WSM), Barrett Fieldcraft (6.5CM), Kimber 84L (280ai) and a cheap Thompson Venture (243).

Based on that, I don't think that trying a set of experiments like you outlined is advisable ... is that correct?
 
I have a note into the head ballistician at Wby to confirm what I can or cannot say. They do not share their data on anything.

Steve, thanks for that ... I'm assuming that they might have pressure testing systems and so I'm wondering if there is any hope that you all might get any insight that you could share with us. I'm guessing not ... but if they do and if you could share, I would be grateful if we could get a sense of where their factory Hammer Hunter loads might be with respect to SAAMI pressure specifications.

In lieu of such data ... I believe that you have recommended to start loading Hammer Hunters with Nosler load data.

Could you share any information about your testing results that might give one a sense of how that might intersect with SAAMI pressure specs? Something like the detailed experiments Kirby outlined comparing the point at which brass failed for HH vs. AB or TSX or ??? ...

Thanks.
 
Velocity potential with the Absolute Hammers has a lot to do with the efficiency of the cartridge and the size of the cartridge. The more efficient the cartridge is the less gain we see and the larger the volume is the case the less gain we see.

QL is difficult to make match field data from bullet to bullet. They profiled our bullets only by dimension but did not take into account the drive band design. At this point as it sits it is not a good predictor. The best method is good old fashioned load development. Use start loads for similar weight conventional lead core bullets and work up your load from there watching for all the traditional pressure signs. Hammers will show less pressure than conventional lead core bullets, so those listed start loads will be very mild to work up from.
Agreed the 6.5 prc with the 124 gr versus the 123 gr absolute I see a 100 fps gain with the absolute 3400 and 3500 fps . The difference of 200 plus fps with comparing a cup and core too the absolute.That is taking in consideration of a efficient cartridge , there may even be more vel gain in other cartridges.
 
Compared 69gr Sierra bullet to a 71gr Hammer Hunter with same load data. Done this with different calibers. Same results. Hammers are always faster. This time I recorded it.


This has to be the most mind spinning post/thread I've ever read through on this forum and I respect everyone's opinions. I've loaded Hammers in over fifty rifles now and some things can't be explained without extensive/expensive testing. However, one thing I've learned from this thread is that I now want a rifle built by Kirby and hope to make that happen soon.
 
Steve, thanks for that ... I'm assuming that they might have pressure testing systems and so I'm wondering if there is any hope that you all might get any insight that you could share with us. I'm guessing not ... but if they do and if you could share, I would be grateful if we could get a sense of where their factory Hammer Hunter loads might be with respect to SAAMI pressure specifications.

In lieu of such data ... I believe that you have recommended to start loading Hammer Hunters with Nosler load data.

Could you share any information about your testing results that might give one a sense of how that might intersect with SAAMI pressure specs? Something like the detailed experiments Kirby outlined comparing the point at which brass failed for HH vs. AB or TSX or ??? ...

Thanks.
It has been a long time since I loaded anything other than a Hammer. Some experiments with other bullets but nothing to compare loads sxs with Hammers. Our loading and testing process has been very much the same as what Kirby outlined. We try not to go to the point of failing the brass. We do pay attention to case head expansion and primer pocket longevity.

So you know. SAAMI pressure specs are not set by any kind of testing by a governing body to see where the failure of any components or rifles is with a specific cartridge. My understanding is that the designer of a cartridge will pick a number and call it the SAAMI spec. Nothing more than that is required. Maybe @elkaholic, Rich Sherman can give some light to this subject. By the way his cartridges are extremely efficient. They tend to hide pressure and do the same thing no matter what you stuff in them!
 
I have been spelling bearing surface wrong for as long as I can remember. I can't believe none of you knuckle heads has never corrected me before. Thanks a lot! :rolleyes: :)
It's all good Steve. I've seen muzzle breaks and brakes more times than I can count. Thanks for making a great product and for the outstanding customer service. Stay humble and hungry and please keep up the good work, pushing the limits and enjoy the journey!
 

Recent Posts

Top