45 colt?

[tcrocker]

Does eny one think I could us 300 gr load data with a 315gr boolit. Right now I'm using ruger only loads and I like to load down to try to get tighter groups and save my powder/ hand.:cbpour:

[subsonic]

The 300gr boolit will **usually** use more powder than one that is heavier "with all things equal". Seating depth should be considered as your other important variable. Boolits that seat deeper have to use less powder to keep pressures in check. The short answer I will give is no. Use a little less powder to be on the safe side.

[HammerMTB]

Obviously you would need to load down and work up. 10% would be a reasonable figure to start. Thing is, I don't know what "Ruger loads" you may be using. I have a couple Redhawks, and some of the "Ruger Only" loads I have seen are well above known SAAMI spec loads. So 10% down from that is not enough, IMHO.
My experience with the 300+gr boolits in the .44 and .45 is they need to be shot hot to stabilize. If you load them light they may not stabilize for you and will be inaccurate at any distance at all. Yaw at 10-12 yards, and keyholes at 20 are not promising results.
Another way to load down is to use a lighter boolit.
I use 265's in my .44, and 255's in my .45.
They are a bit easier on the hands.

[Snyd]

Does eny one think I could us 300 gr load data with a 315gr boolit. Right now I'm using ruger only loads and I like to load down to try to get tighter groups and save my powder/ hand.:cbpour:

What powder?

[44man]

Sad to say you can NOT "load down" with heavy boolits and get accuracy. You NEED spin. Get a lighter boolit like a 255 gr so you can use Unique or 231.
One boolit does not work over the range of velocities.

[Char-Gar]

I find the old Keith 255-260 grain bullets to be just the ticket for me. I load them over 8.5 Unique and get factory/black powder velocities. Plenty of oomph and not hard on the hands.

[Whiterabbit]

One boolit does not work over the range of velocities.

This is also my experience given the same powder. Some bullet/powder combos are more sensitive than others.

To take it even further, by changing powder you CAN change velocity without a significant change in accuracy. Maybe.

As an example, I can load the same bullet in the same cartridge using H110 and trailboss and get the same groups at 25 yards (no big feat, but it's just an example). THe velocity differences are extreme. If took the time to figure out how to load an H110 round to shoot as slow as the TB loads coming out, I'm pretty sure the groups would open up.

So my suggestion besides the great recommendation to try a lighter bullet, is to switch powders, re-develop the load and see how you like it.


---------------

As a bonus, I should mention that you might not change the velocity at all by switching powders, but rather based on energy and/or burn rate just change the perceived recoil in a way that may feel more pleasant to you, accomplishing the same goal.

[Groo]

Groo here
$$man is correct-- heavy[long] bullets can't be loaded down as you will not get the spin[RPM's]
to make them fly true.
This shows up with the FA 454 revolver that has a slow twist and also the
marlin 44mag lever gun with a slow twist..
I even had this show up in a bench rifle--Boat tail bullets would keyhole
where the same weight flat base [shorter] would shoot into 3/8 in [ same load etc.]

[44man]

Groo is correct. I have worked many loads and the heavy boolit will always be slower then a lighter one of course. Yet it NEEDS a certain velocity that will be just over 1300 fps in the .44 and about 1160 fps in the .45. The .45 has a faster twist rate. As you slow it, groups open more and more. The same happens if you push more velocity, groups open.
The heavy boolit might be more touchy then lighter ones. I know I have shot a lot of light loads with good enough accuracy for anything as long as the boolit is not too heavy.
One of my favorites is a 240 gr with 7 gr of Unique in the .44. 231 works fine too.
I just can't make a heavy boolit shoot slow. Or too fast either. The sweet spot is narrow. A 300 to 330 gr boolit in the .44 can do under 1/2" at 50 yards but so can a 240 gr over a wider velocity range.
The .45 works great with a 250 to 255 gr boolit and 7 gr of Unique also. I have not found a reason to go to 10 gr for fun shooting.
The heavy boolits seem more spin sensitive.

[Whiterabbit]

Did you mean to reference bullet length to velocity vs group size (where weight in this case simply roughly though not always correlates to length)

Or did you mean to actually say the direct relationship to spin stability has nothing to do with length, only weight?

[44man]

Did you mean to reference bullet length to velocity vs group size (where weight in this case simply roughly though not always correlates to length)

Or did you mean to actually say the direct relationship to spin stability has nothing to do with length, only weight?
I would say both weight and drive length is important. I have WFN and WLN boolits that are the same weight but different overall lengths. Drive area is close and both use the exact same loads.
I have come to believe that the amount of the boolit in contact with the bore is more important then actual boolit length.
I just have not done much work in that regard. It would take too many molds.
Would I say the WLN shoots better because it is longer? No, I can't define that.
But boolit spin is important for stability and the heavier the boolit, the harder it is to add velocity to reach spin. I much prefer to over spin a boolit, any boolit.
I have found that faster twists can cover a larger range of weights and still be accurate with all of them. They favor more weight to start. Yet, use a lighter boolit and slow it, it will also do good. Slow the twist and you can speed up the lighter boolit. Take a .44 with a 1 in 20" rate. A 240 gr can be supreme yet the gun will shoot up to 330 gr. Each bullet, boolit has a sweet spot that can be reached. 180 to 200 gr bullets are sad unless shot very slow and anything over 330 will not be shot fast enough. So the range of the .44 can include 240 to 330 gr boolits. That is a wonderful range to play with.
Now take the Marlin .44 rifle with a 1 in 38" rate. I really think it is a round ball gun. Maybe a 180 or 200 shot to max would work. I sold mine, not wanting to shoot those light things for deer.

[Whiterabbit]

That's interesting. I'm no ballistician, but I've always read that for a given bullet flying through the air at a given rotation speed, the only thing that affects stability is the length, not the weight.

That the weight provides a secondary factor, like the ability for gun X with twist rate Y to have the capability to produce spin Z. But that the real stability factor is related to length.

Implying that if I have gun AA that can't shoot bullet BB because it's heavy and long and I can't stabilize it @ max pressure, the exact same bullet made out of zinc or aluminum or brass or copper might give me the ability to achieve a greater velocity/rotation speed.

Meaning that for weight to have an influence on stability (like all the AR-15 guys use as a standard for what bullets work or not), we have to assume bullet material is constant, right?

Or put another way, isn't it a misnomer to suggest bullet weight is the real factor in spin stability?

Just the musings of an engineer.

[subsonic]

Well Rabbit, something to consider here is that lead is relatively soft compared to copper and will strip (not take to the rifling) if you have A. not enough lead in contact with the rifling (bearing surface/driving length), or B. you are slamming too heavy a chunk of it into the rifling too fast (powder burn rate, etc). Objects at rest tend to.... you know the rest.

I think with cast there are more variables than most realize.

I've been recovering boolits from my sand bucket from my firelapping exercise and finding some interesting things - even when popped out with very light charges.

[Whiterabbit]

Sure, but if we want to obfuscate the issue, why not bring up additional powders as well?

I've got a bullet that will "never stabilize" no matter how fast or slow I push it. Bad combo for the gun right? Switch powders and it not only stabilizes but is accurate.

But that doesn't help us model bullet stabilization at all, right? The better way to think about it is to peel away the layers of complexity like an onion, model the core, then add on the rest of the stuff slowly. Otherwise we may as well throw our hands up.

We can probably think up some more variables to throw in there while we are at it. How about gas checks? how much farther till we lose sight of the original point?

[44man]

Sure, but if we want to obfuscate the issue, why not bring up additional powders as well?

I've got a bullet that will "never stabilize" no matter how fast or slow I push it. Bad combo for the gun right? Switch powders and it not only stabilizes but is accurate.

But that doesn't help us model bullet stabilization at all, right? The better way to think about it is to peel away the layers of complexity like an onion, model the core, then add on the rest of the stuff slowly. Otherwise we may as well throw our hands up.

We can probably think up some more variables to throw in there while we are at it. How about gas checks? how much farther till we lose sight of the original point?
I can't solve it at all. I have two pistols, both 10" that I used for IHMSA with heavy bullets because of the twist that is fast. I wanted deer loads with 120 gr SSP bullets but NOTHING would group. Then I decided to try Varget and called Hodgden for loads. They said NO in no uncertain words, too slow. Guess what, I got less then 1/2" at 50 yards with 2175 fps from the 7BR ( This gun LOVES 160 to 175 gr bullets.) and super accuracy from the 7R but I did not chrono it. The 7R uses 2 more gr of powder so it should be near the same. NO OTHER POWDER WORKED!
I had no place to start with Varget and might be lucky. Pressures seem very low but it burns clean too. Yet bullets are fast.
Now why does it burn? Why is it fast? why is it clean? How in the world does it shoot light bullets? Why is it so accurate? I was so far out of the box that no one would touch it yet the powder works.

[T-Bird]

I feel elevated any time I can be in a group that is discussing obfuscation. T-Bird

[tacklebury]

Personally the only issue with hardness is obturation of the round to the rifling. ;) The lighter the load, the softer the alloy... ;)

[Whiterabbit]

I'd love to talk about that, totally isolated from everything else. Because that can't be true just at face value, can it?

It would mean that we can't over obturate, right? That once we obturate, we obturate, and pushing harder doesn't hurt. Right? But that's not the case, is it? What is the mechanism for leading at high velocity with soft metal? Shear strength of the lead not capable of containing the pressure despite being fully obturated? That implies we can use a soft lead but find an alloy element that increases strength and be good to go. So surely it can't be that?

Furthermore, physics isn't different for copper vs lead. Copper rounds are typically .001 smaller than lead ones, but shoot very well that way. Does that mean obturation is a non-issue with jacketed and copper rounds? Or do hey obturate easier? I'm not really interested in addressing this, just making sure a discussion about lead hardness and pressure and obturation would be able to apply to other materials, too. :)

So really, if obturation is the issue with lead hardness at a low load, what is the issue at high loads?

[tacklebury]

Friction from faster moving objects... The reason jacketed bullets don't care is that they don't shed at the speeds we shoot them... If you throw a copper slug at 5000 fps guess what, it sheds. ;)

[Whiterabbit]

So you are suggesting my theory (theory because I really don't know and am just trying to rationalize it, anyone chime in here) that it's shear strength of the bullet material that defines when it deposits in the barrel?

In other words, that it is not related to hardness?

[tacklebury]

Shear strength of the material is in direct proportion to hardnes would be my thought. Typically any material softer than a second material will also shear easier, ie. aluminum is softer than steel and will shear easier. Some materials are better at avoiding shear pressures, but overall this will not hold true. Obturation of the bullet deforms it and causes the sides to press harder into the rifling and thus grip better avoiding the shear point of lead directly. If you harden lead, but no obturation can happen, then you get jetting of hot gases along the sides of the bullet causing increased temperature and thus reducing the shear pressures needed at that point and the bullet deposits this into your rifling's leading edge of the lands. The reason that it decreases accuracy is that now there is a sloping piece of softer material leading up to the land and thus subsequent bullets cannot grip the rifling as well...

[Whiterabbit]

I hold a degree in materials engineering. Shear strength and hardness are sometimes correlated but not always. As an example, water quenched steel is REALLY REALLY hard! but snaps like a twig, and doesn't take much force to do it. Anneal that same steel and now it's tempered. It becomes really really tough with only a small loss in hardness.

Of course, lead is not steel, and I haven't really studied its mechanical properties like steel or aluminum. Hang on, I need to do some reading. Thanks, you've given me a direction to look in.

[tacklebury]

Yep, brittleness is one thing I didn't include. If you get to a point of brittleness, obviously, there's a threshold there. hehe