Why Hammer Bullets Are Always Faster

Yes. With the same powder charge. But what about with the same amount of "pressure " behind it.
Like a molly bullet or ct? Not enough to make a difference usually. I never played that game with a strain gauge, but I've run plenty of molly on other rifles when it was new. Roughly the same pressure at a slightly heavier charge and possibly 20 to 50 fps more at peak pressure. Not enough difference to write home about as far as I was concerned.
I toss this stuff in the same camp as AI cartridges and GS customs bullets. You can play with things all you want. Throating changes can help with speed (longer), reduced bearing surface can help with drag but may be poorer for accuracy, especially in looser factory bores.
A powder switch may get you a few more fps without pressure signs, but must guys here are using single base powder (for temp. stability) which actually has somewhat poor energy density compared to double based powder. Most single base powder has roughly the same energy per grain (all the IMR ones used to be the same energy per grain- size and coating controlled speed) so to do any more work without extra pressure you needed more case capacity and slower powder. It makes for a longer peak without excessive pressure.
 
Lefty7mmstw ,

I don't understand. Are you saying all the anecdotal information is not real?

By the way, I used GSCustom bullets about ten years ago. They were the most accurate bullets through my rifles. In fact the most impressive group I fired was with the 265 grain from my .375. The first three shots made a hole 1/16" taller than it was wide. I put another down range. It opened up the group to 5/16" so I fired another. The final five shot group was 9/16" with a average velocity of 3,055 feet per second. I fired ten 85 grainers in my .257SLR with a average velocity of 3,919 feet per second. The group measured 11/16". The 7STW did many 1" groups at 300 yards.
 
Lefty7mmstw ,

I don't understand. Are you saying all the anecdotal information is not real?

By the way, I used GSCustom bullets about ten years ago. They were the most accurate bullets through my rifles. In fact the most impressive group I fired was with the 265 grain from my .375. The first three shots made a hole 1/16" taller than it was wide. I put another down range. It opened up the group to 5/16" so I fired another. The final five shot group was 9/16" with a average velocity of 3,055 feet per second. I fired ten 85 grainers in my .257SLR with a average velocity of 3,919 feet per second. The group measured 11/16". The 7STW did many 1" groups at 300 yards.
I think it's a bit more like the guys tearing it up with their 300rums and 220-230 grain bullets with rl33 running over 100grains powder and doing 3200 fps without pressure signs a few years back. I stopped at 3,000 fps with 95grains and made mention of it to others that they were treading on thin ice. Most of them didn't care but started having pressure signs and other issues. I'm still shooting 95gr rl33 with 225 Hornady pills- my kid took his buck with that load this year.

there is no such thing as a free lunch.... from high school econ. but a very important thing to remember with velocity generation in rifles too... Unless you have pressure tested data you have no business at all breaking the velocity "speed limit" of what the cartridge is usually capable of.
 
I think it's a bit more like the guys tearing it up with their 300rums and 220-230 grain bullets with rl33 running over 100grains powder and doing 3200 fps without pressure signs a few years back. I stopped at 3,000 fps with 95grains and made mention of it to others that they were treading on thin ice. Most of them didn't care but started having pressure signs and other issues. I'm still shooting 95gr rl33 with 225 Hornady pills- my kid took his buck with that load this year.

there is no such thing as a free lunch.... from high school econ. but a very important thing to remember with velocity generation in rifles too... Unless you have pressure tested data you have no business at all breaking the velocity "speed limit" of what the cartridge is usually capable of.
Did you see my post showing the Hodgdon data for the 257 Roberts comparing the Sierra and the GMX with 300 fps diff in velocity with the higher velocity bullet showing 500 cup less pressure? Who paid for that lunch?
 
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Did you see my post showing the Hodgdon data for the 257 Roberts comparing the Sierra and the GMX with 300 fps did in velocity with the higher velocity bullet showing 500 cup less pressure? Who paid for that lunch?
post number?
500 cup isn't much either. I've seen more variance shot to shot with some ammo
 
I think it's a bit more like the guys tearing it up with their 300rums and 220-230 grain bullets with rl33 running over 100grains powder and doing 3200 fps without pressure signs a few years back. I stopped at 3,000 fps with 95grains and made mention of it to others that they were treading on thin ice. Most of them didn't care but started having pressure signs and other issues. I'm still shooting 95gr rl33 with 225 Hornady pills- my kid took his buck with that load this year.

there is no such thing as a free lunch.... from high school econ. but a very important thing to remember with velocity generation in rifles too... Unless you have pressure tested data you have no business at all breaking the velocity "speed limit" of what the cartridge is usually capable of.
Once again since you mentioned it, Do you drive the posted speed limits ?
 
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I think it's a bit more like the guys tearing it up with their 300rums and 220-230 grain bullets with rl33 running over 100grains powder and doing 3200 fps without pressure signs a few years back. I stopped at 3,000 fps with 95grains and made mention of it to others that they were treading on thin ice. Most of them didn't care but started having pressure signs and other issues. I'm still shooting 95gr rl33 with 225 Hornady pills- my kid took his buck with that load this year.

there is no such thing as a free lunch.... from high school econ. but a very important thing to remember with velocity generation in rifles too... Unless you have pressure tested data you have no business at all breaking the velocity "speed limit" of what the cartridge is usually capable of.

Should we then, stop doing things the way we have been doing them for three or four generations? You are bringing economics to a reloading thread and expect to be accepted?
 
Here is head scratcher to "decide" which highly respected load manual to use based on their pressure testing.

Nosler shows for .243 Winchester H380 at max load for 55BT at 47.5 grains at 3951fps. That's smoking!

Hodgdon shows same bullet with H380 at 51.0 grains at 4010 fps! Laser!!!

But wait!!! How can this be?Hmmm 3.5 grain differential in maximum load based off their pressure testing.

I guess you better be well versed in pressure observations with a 3.5 grain differential from two HIGHLY RESPECTED RELOADING DATA MANUALS.

There is also a 0.040 differential on OAL but cannot be reason for 3.5 grain differential which is very SIGNIFICANT in potential pressure effects.

So who do you believe? Bullet manufacturer or powder manufacturer? They both have pressure testing capability. Where do I start for 55HH ladder?

What a conundrum! Sure glad I have 40 years of reloading to make appropriate VISUAL pressure observations. Just sayin...

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