Shooters Forum banner
1 - 20 of 20 Posts

·
Registered
Joined
·
2 Posts
Discussion Starter · #1 ·
I notice that load data specifies the manufacture of the bullet along with the weight. What is the difference between a Speer 160g and a Nosler 160g bullet with regards to charge? Is it OK to use load data for a Speer 160g for a Nosler 160g bullet?
 

·
The Shadow (Moderator)
Joined
·
8,964 Posts
Yes, and no.
Assuming the same construction, then you can interchange data; but ONLY if it's the same construction.

So don't use Cup-N-Core data for a Barnes, or something like the Speer Deep Curl bullets. Pressures can change dramatically with different cores and jacket materials.
 

·
Super Moderator
Joined
·
13,768 Posts
But Hodgdon does list the specific bullet, it's COL and the case and primer used. So they are saying they only know the data they got was good for that specific combination in their test barrel. What you can infer is that if you use a bullet with the same weight and of the same type of construction, the starting load will be fine. Higher loads will probably not make very different pressures, but you need to work up to them in steps of no more than 2% of the maximum charge value while watching for pressure signs to be sure of it.

Things that can make a difference, even when the bullet construction is the same include: distance of the bullet jump to the lands and difference in seating depth due to shape. For example, a boattail VLD vs. a flat base round nose bullet of the same weight will have the former eating up more space in the case when the COL matches. That tends to increase pressure unless the amount of gas bypass around the pointed shape into the bore is enough greater to neutralize the effect. Hard to predict and varies by gun. So use the starting (lowest) load, always, and work up.
 

·
Registered
Joined
·
51 Posts
And the length of the bullet's engagement in the rifling will produce different results within the same brand and same weight of bullet. A boattail will be different than a flatbase in that length, two differently constructed flatbases may have different lengths within the same weight and same brand, and as Nick said, develop pressures differently. If one bullet shows a lower start point, go with that. Had to do that sort of thing with a couple of cartridges that have very little data around for given bullets and work thru what I could find and calculate from there, European cartridges with no N. American data, European bullets with no N. American data. Take your time and find all the info you can. Sure is a lot easier now with the internet, but, need to be careful with what you do find.
 

·
The Shadow (Moderator)
Joined
·
8,964 Posts
My pressure tests are certainly not exhaustive, but comparing a flat base Pro-Hunter, to a VLD I couldn't find a major statistic difference in pressures.
Which is only to say, that relatively speaking, bearing surface differences alone aren't a significant difference. I would have needed to shoot a box of each and get averages for anything tighter. So while I wouldn't disagree that any change can lead to differences, with the same core and jacket construction, bearing surface alone likely won't give drastic differences.
But always err on the side of safety of you can't measure differences.
 

·
Registered
Joined
·
2,523 Posts
Eddy,

This comes to the a place where it is wise to have loading data from several sources.

Read and compare, taking into account as has been stated above the construction of the bullet.

Then if a person is starting a load development any place but at or near recommended starting loads, you may already be in trouble.

Unless your are well acquainted with a given rifle and how it reacts to pressures you may well be in trouble taking load data for a relatively soft bullet and substituting a bullet of higher integrity, heavier construction, EVEN starting at "starting" load data for the softer bullet.

Be wise, be safe, start at starting powder charge levels and do a load work up never increasing powder charges beyond .5gr as you approach the maximum listed loads.

As you work up toward the maximum load levels, not only might a full grain increase put you over the top pressure wise, but full grain increases may well mean you have just gone right past the sweet spot for your rifle hidden 1/2 grain back.

Crusty Deary Ol'Coot
 

·
Registered
Joined
·
2,255 Posts
Although I have data for numerous different bullet manufacturer's, I still use data for bullets of like construction if I'm unable to locate data that's specific to that bullet. As long as a hand loader performs a proper development, matches data with construction characteristics and weight, starts the development at a reasonable place in the table, and works up in reasonable increments, it's pretty difficult to go wrong IME.

Regarding Speer plated bullets, which by definition is really just a type of bonded bullet, such as Gold Dots, Deep Curls, as per Speer, I have treated them as I would a cup & core for as long as those products have been on the market. The only other added recommendation Speer offered, was to not run short barrel Gold Dots at full tilt velocities. As explained to me by their tech adviser, it's not really a pressure related issue, but more so about bullet integrity, in that SB bullets are designed to perform best when maintained within recommended reduced velocities.

SMOA
 

·
Registered
Joined
·
5,330 Posts
What is the difference between a Speer 160g and a Nosler 160g bullet with regards to charge?
The differences are not really the issue,core hardness, jacket composition, bearing length, seating depth, etc. the point is they are different. If none of those factors, (and several others), have meaning, stay with a recipe for every factor. Each one is a book of their own.
 

·
Registered
Joined
·
3,006 Posts
It surprises me how much difference there is in velocity in similar weight bullets .
Hornady seems to have the quickest most of the time.
I figure some bullets must be a lot harder to push down a barrel than others.
Although I wonder some times because I use ADI load data and there powders ,some of ther max loads stop when they lose accuracy not because of presure.
I think the mix the different companies use as a jacket must have different friction ratings.
 

·
The Hog Whisperer (Administrator)
Joined
·
37,456 Posts
I'm on the side of 'similar bullets will do similar things.' I've loaded MANY cup and core bullets of the same weight and similar shape, with load data for other cup and core bullets .... and rarely find the least bit of velocity difference over the chronograph (or downrange performance, either). E.g., 100gr. long sleek Nolser Solid Base bullets (sadly no longer available) shoot just like the stubby (original) 100gr. Remington Core-Lokt bullets in my .257 Roberts, and group together at 100 yards. Once the bullet engraves to the rifling, don't think that jacket friction is the most important factor in pressure. How much of the available case volume (powder space) is taken up seems to be much more important in terms of velocity and pressure, as long as two bullets have similar engraving force and jump to the lands. Is there a measurable difference? Surely there is, if one has the ability to measure to the nth degree. Is it the most important factor, or even something that will show up on target? Probably not.

Remember, it takes a lot of data to prove slight differences, as there is a range of results that can happen with each individual shot (both pressure and velocity), even if all the components are the 'same' and previously measured out to the gnat's backside to be the 'same.' The closer the two bell curve distributions are to each other, the more shots it takes to statistically prove the difference. Most people would probably run out of patience, money, and ambition before being able to prove that a boat-tailed spitzer from one company was substantially different than a flat-based spitzer from another company, in terms of friction down the bore, with similar jacket and core material. Note, too, that our load books generally give us one range of charge weights for ALL the bullets that a company produces. That tells me that the differences in the friction between one length of bearing surface and another are pretty low on the list of things I need to worry about.
 

·
The Shadow (Moderator)
Joined
·
8,964 Posts
.

Regarding Speer plated bullets, which by definition is really just a type of bonded bullet, such as Gold Dots, Deep Curls, as per Speer, I have treated them as I would a cup & core for as long as those products have been on the market. The only other added recommendation Speer offered, was to not run short barrel Gold Dots at full tilt velocities..

SMOA
They do (maybe did, since I haven't bought the brand new manual) caution about deep curls producing different pressures than their other bullets; and needing different data. I did a post showing how dangerously things can get with them.
308, 150gr bullets, win 748 with a "middle of the book" charge, produces what you'd expect from a hot-Cor, et Al. Substitute in a deep curl:




Recoil, report, all nonsense "signs", and the velocity feel perfectly in line with what someone would think was happening. Only when you can measure pressure would you realize that is trying to blow up.
 
  • Like
Reactions: MusgraveMan

·
Registered
Joined
·
1,047 Posts
In everyday practical loading, you can use the same weight, basic configuration/style bullet data from different manufacturers. But, begin the load work up with starting loads and make sure OAL is workable...

One "problem" when a newer reloader asks a question on a forum, one with many well experienced members, the answers will morph/drift into advanced reloading techniques and theory. Not all bad but sometimes a flood of information can be confusing to a new reloader...
 

·
Registered
Joined
·
2,255 Posts
They do (maybe did, since I haven't bought the brand new manual) caution about deep curls producing different pressures than their other bullets; and needing different data. I did a post showing how dangerously things can get with them.
308, 150gr bullets, win 748 with a "middle of the book" charge, produces what you'd expect from a hot-Cor, et Al. Substitute in a deep curl:




Recoil, report, all nonsense "signs", and the velocity feel perfectly in line with what someone would think was happening. Only when you can measure pressure would you realize that is trying to blow up.
Looking at the chart I'm trying to discern which pressure curve is for which bullet? It looks like the chart may not have fully loaded on my computer. I seem to remember something about this, wasn't it in reference to the DC rifle bullets. I think it had something to do with bearing surface if I recall. Didn't Speer discontinue those DC rifle bullets?

What I was referring to is the Gold Dot handgun projectiles, which really doesn't appear to match the specifics the OP was inquiring about, but he really didn't provide the specifics either. I regularly load the Deep Curl handgun bullets and have been using data for C&C bullets since they hit the shelves. But not having a way to test pressures, I really don't know, therefore my observations are based entirely on pressure signs related to brass, primers, extraction characteristics, velocity comparisons with jacketed bullets, all of which can be significantly flawed.

Either way, you're certainly right about making sure bullet construction and profile is compatible before deciding which data should be applied. But this is also why I made a point of addressing proper load development any time we start a cold development with new to us components. Even two C&C's can produce significant;y different pressure characteristics.

SMOA
 

·
The Shadow (Moderator)
Joined
·
8,964 Posts
Those traces are all from the Deep Squirrels, but some ran away.

I don't know if they are actually discontinued, or just not currently being made. The sporting public found out about the Got Dot rifle bullets recently, but they've been out in government and contractors hands for many years.
 
  • Like
Reactions: MZ5

·
Elk Whisperer (Super Moderator)
Joined
·
11,600 Posts
I notice that load data specifies the manufacture of the bullet along with the weight. What is the difference between a Speer 160g and a Nosler 160g bullet with regards to charge? Is it OK to use load data for a Speer 160g for a Nosler 160g bullet?

To keep it simple, yes, but as was stated earlier , start at the low end (starting or minimum charge) and work up to what's the most accurate. I always go for "most accurate" never mind what the speedometer says.

Except Barnes, I don't "do" Barnes so I can't say what they do without using their data.

RJ
 

·
Registered
Joined
·
1,839 Posts
In everyday practical loading, you can use the same weight, basic configuration/style bullet data from different manufacturers. But, begin the load work up with starting loads and make sure OAL is workable...

One "problem" when a newer reloader asks a question on a forum, one with many well experienced members, the answers will morph/drift into advanced reloading techniques and theory. Not all bad but sometimes a flood of information can be confusing to a new reloader...
Very true. That's probably why Hornady lists all their bullets of the same weight and caliber together with one load table. Always liked that feature of their manuals. Some others are doing that now, but I think Hornady was the first of the majors to do it right from the beginning.
 

·
Registered
Joined
·
1,839 Posts
Looking at the chart I'm trying to discern which pressure curve is for which bullet? It looks like the chart may not have fully loaded on my computer. I seem to remember something about this, wasn't it in reference to the DC rifle bullets. I think it had something to do with bearing surface if I recall. Didn't Speer discontinue those DC rifle bullets?

What I was referring to is the Gold Dot handgun projectiles, which really doesn't appear to match the specifics the OP was inquiring about, but he really didn't provide the specifics either. I regularly load the Deep Curl handgun bullets and have been using data for C&C bullets since they hit the shelves. But not having a way to test pressures, I really don't know, therefore my observations are based entirely on pressure signs related to brass, primers, extraction characteristics, velocity comparisons with jacketed bullets, all of which can be significantly flawed.

Either way, you're certainly right about making sure bullet construction and profile is compatible before deciding which data should be applied. But this is also why I made a point of addressing proper load development any time we start a cold development with new to us components. Even two C&C's can produce significant;y different pressure characteristics.

SMOA
The old saying 'ignorance is bliss' applies here. For decades we got along with no chronographs or trace data, chalking up weird failures and anomalies as just that - 'weird stuff'. What we didn't know didn't hurt us, right?

Well, when chronys became commonplace, we found out that a lot of the loads we'd been using were on the ragged edge of dangerous, and in some cases, near proof load levels. More data is a good thing, and current load data is safer than it was before. Same thing is going on with trace data.

Since trace equipment has become more affordable for the home user, we've found a way to ferret out the bad load combinations. For example, in the trace pic above, #1 not only is over pressure, but is a 'double hump' trace. That secondary pressure spike is dangerous, and can lead to a blown up rifle. At the very least, it tells you that the powder used is not compatible with the bullet being tested. Such traces are also associated with the phenomenon of the ends of barrels falling off as if they were cut by a plasma torch.

The point is that there is more to be considered than just max pressure and velocity, and chronographs and trace equipment can provide the extra data points to keep things safe and right side up.
 
  • Like
Reactions: Submoa and Darkker

·
Registered
Joined
·
2,899 Posts
I notice that load data specifies the manufacture of the bullet along with the weight. What is the difference between a Speer 160g and a Nosler 160g bullet with regards to charge? Is it OK to use load data for a Speer 160g for a Nosler 160g bullet?

It is a very complex issue. Much (most, from my direct pressure work and also reading previously-published work on the topic) of the difference is in the exact materials composition and hardness within the bullets. Some of the specific factors cited by others here may theoretically make a difference, but in practice the differences cannot be detected above normal shot-to-shot variation, even with extremely precise and careful handloading and measurement practices.


There is an article on this exact topic in a book called "Handloading," by Wm. C. Davis, Jr., published by the NRA. The copyright date is 1981. The article appears on pp. 133 - 137 of that book, if you can find a copy. The article contains both info from work published from 1955 through then-current (about 1980-ish, I expect) work measuring pressures and speeds in the 30-06 while changing individual components.


**I dearly wish the NRA still engaged in this kind of genuinely useful work for the shooting-sports community in general, and its members in particular.**


There is a table in that article that shows 10 different 150-grain bullets, their lengths, diameters (to 0.0005 inch), core weight, jacket weight, bearing surface length, pressure, speed, and speed-pressure ratio. For the test, all cartridges were fired with a constant charge of a single lot of IMR-3031 over a Federal #210 primer in a Western case. A pressure barrel on a universal receiver was used, and temperature ranged only 2 degrees Fahrenheit throughout the test. RH did vary across a 15 percentage point range.


One of the things that table shows is that pressure does not correlate very well with bearing surface. One way to _try_ to keep materials properties the same is to compare bullets from the same manufacturer. Only 2 manufacturers had 2 different bullets in the test summarized in that table, and I'm not convinced the materials characteristics would have been designed to be the same between those pairs. Nonetheless, one of those pairs shows a positive correlation between pressure and bearing surface, whereas the other shows a slight negative correlation. However, the second pair's bearing lengths are not very different, and their average pressures are _probably_ within the statistical 'noise' limit, so therefore one might reject that comparison or deem there to be no correlation. Again, I'm not convinced the bullet pairs from those manufacturers would have the same materials characteristics, but it's all there is in that data.



There are other tables that show the effect of changing nothing but the primer, and separately the case, on bullet speed (velocity for those that like that term).



There is also a table shows speed vs. bullet (but not pressure) for 21 different 150-grain bullets.



I will quote below more than a sentence or two, but I believe it is justified and legally acceptable use in this context. If a moderator disagrees, I'm sure they'll let me know or change the post(s).


"These investigations provide a useful insight into the effects of component switching on ballistics. They prove that the effect is real, and large enough to demand caution when near-maximum loads are being used. They do not, unfortunately, provide a simple set of rules by which the effects of component switching can be accurately predicted, even in the .30-06 cartridge which was used for the investigations. The complexity of the problem, as revealed by these investigations, indicates that there are no simple rules. A fair question is, 'What should the handloader's position be on the practice of component switching?'


A safe and obvious answer is that the practice of component switching must be completely avoided, and that is undoubtedly the best course where it is practicable..."

The article goes on to add that there may be instances where switching cannot be practicably avoided (market-limited component availability, etc.), or one is loading for a gun with special requirements such as loading for commercial versions of (or surplus) military semi-auto rifles that function better with ex-military cartridge cases.
 

·
Registered
Joined
·
2,899 Posts
Here is a bit more from that article:


"The general rules that emerge are these:


1. Do not load maximum charges when moderate loads will suffice as well. With charges 10 per cent less than the maximum charges listed in reliable data sources, there is little danger that a change in the type of primer, bullet or case will raise the pressures excessively. For most purposes, loads 5 to 10 per cent below maximum are completely adequate, and may even be preferable to maximum loads.


2. When substituting any metal component (primer, bullet or case) for one of another brand or type in a near-maximum load, _always_ reduce the charge weight by about 10 per cent, as is recommended by most powder manufacturers and reloading manuals. The one exception to this rule is in the use of certain powders such as Winchester-Western 296 in handguns...for which the manufacturer specifically warns...
{I've deleted a bit here, as indicated by the 3 dots}


3. If the reduced charge shows none of the characteristic signs of excessive chamber pressure, and it is desired to increase it, limit the increments of increase to about 1 per cent of the charge weight, and test-fire each incremental increase before proceeding to fire the next higher one.


4. If any sign of excessive pressure is encountered...reduce the charge that produced the symptom by 5 per cent, and regard that as the maximum charge.


5. If no sign of excessive pressure is encountered before the charge weight has reached the maximum charge listed in a reliable source of reloading data, stop at the maximum charge listed...


Handloaders should be awsare that component switching is not without some risk, even if these rules are heeded, and it should not be done without some compelling reason. If it must be done, following these rules provides the best chance of avoiding any serious consequences.

Personally, I would modify #5, above, to read:


If no sign of excessive pressure is encountered before this point, stop when you reach the first of either the maximum charge or the maximum speed (velocity if you like) listed in a reliable source of reloading data
 
1 - 20 of 20 Posts
Top