Bullet company VS Powder company max load

[gsparesa]

Here I go again. I'm new at reloading and these "sticklers" take the "safety" out of reloading in my mind. I want to load 10mm ammunition with IMR SR4756 powder and a 155gr Hornady HP-XTP bullet (#40000) and WLP primers and Starline brass.

Hornady's loading manual (8th edition) for 155 gr HP-XTP has a start load of 8.8gr (1150 fps) and a max load of 11.4gr (1400 fps) with WLP primers. The handgun for Hornady's data was taken with a Colt Delta Elite, 5" barrel with a 1:16" twist.

The Hodgdon/IMR web site only lists a max load of 8.5gr (1310 fps) using a 155 gr HDY XTP bullet with WLP primers. The test barrel was at 5" with a 1:16" twist.

So, I have the bullet companies starting load (8.8 gr) going over the maximum load (8.5 gr) from the powder company. The bullet companies 8.8gr load at 1150 fps and the powder companies 8.5 gr load at 1310 fps. That's 160 fps more in a load with 0.3 grains less. I should have bought a Colt with all that extra horse power.

So, what does an experienced reloader do in this situation?

 

[BoDog]

Start low and work up, watch primers for pressure signs, but remember they are only a partial indicator. Remember some hot loads will just beat your gun to death. If a load doesn't shoot well why bother with it.
Only hits count.
Just because a load is safe in one gun doesn't make it safe in all. I have even had loads that were safe in winter that weren't in the summer.
My advice to you is find a load that you and your gun shoot well and stay with it. A good hit with a 44 special is better than a poor one with a 44 mag. and your gun will last longer.
Hot loads are a gunsmiths best friend. Practice with an accurate load is your best friend, it will do the job when you neeed it.

 

[Snapdragon]

I would look at several different data sources to see what they say. I don't load 10mm and have no pet loads for it. If I started loading 10mm I would go to the powder company data, to the bullet company data, and to any other data I could find to try to get a good idea of what a safe load should be. I would be looking specifically at what powders are most frequently used and what powders seem to have about the same data among the various sources. If all sources agree on data for powder "A" but disagree significantly on data for powder "B", I would tend to want to start out with Powder "A" and work up a load that shoots well in my handgun.

Just because data are given for a certain powder with a certain bullet does not mean that that powder is the best choice or even a good choice for use with that bullet.

You might want to consider other powders.

 

[OKFC05]

I'd use HS6.
I'm rather skittish about the steepness of the SR4756 pressure curve in similar cartridges, such as the .41 magnum. I don't load 10mm.

 

[Culina]

Go with the data from the powder company. The bullet makers data is based on their results with a specific lot of powder and they have no idea what the high and low end or acceptible standard is from the powder manufacturer

 

[arjay]

I would agree with snapdragon and use a powder that different sources agree on or at least overlap.The one you're looking at would have me flinching every time I pulled the trigger.

 

[fredj338]

Every data source is diff because they do NOT use the identical components or test platforms. Even identical laods in several diff test platofrms will yield diff results. So averaging data is a good way to find realistic starting points. Matching components as close to possible w/ the data will get you closer still. OAL matters, bullet type matters, when getting close to max, everything matters.

 

[Steve C]

When I have found this situation I will start witht he powder companies data and work up if needed.

Had a similar situation with the .41 mag and Hornady 210 gr XTP's using 2400. Data from sources whas all over the place with max loads from 17.5gr (Alliant) to 20.0 grs (Hornady). Went with the powder company and Used Alliants 17.5grs which chrono'd at 1,413 fps out of my 6" S&W 57, a few fps less than Alliant said it would and over the 1,350 fps that Hornady said you needed 20.0grs to get. No pressure signs, no case sticking and accurate to boot so that's where I stopped. Since that time published loads have got a bit more conservative regarding the .41 mag but its still my favorite .41 mag full power loading.

 

[TSQUARED]

I always use the powder manufacturers pressure tested data.

 

[Titegroups]

I would reduce by 10% and work my way up. Start with 8g and go from there. Watch the COAL. Others will argue but starting with a reduced charge of almost anything is the safe way to go. There are some instances where reduced charges are warned against by the manufacture and you may want to heed those warnings. I would go with powder manufactures numbers first but check around. Also a chronograph comes in handy as you can see. I load 10 with Power Pistol, many like blue dot for max performance.

 

[amazingflapjack]

I appreciate much of what has been said. I do load the 10mm, for both revolver and pistol, and I use the same powder and bullets-a couple different weights-for both. In general, I do a survey of what different sources say about this loading-get an apx average-and back off at least a full 1/2 gr from the high average or moore, depending on the round. I like my stuff loaded toward the "warm" end of the spectrum, but as has been said, I don't like edgey loads. Just relax-back off a little to be safe, and enjoy-take your time. Go safely, Flapjack.

 

[sps282]

I recommend the powder manufactures data as the best place to start you can always carefully work the load up if you feel it's necessary. Most often the real hot loads don't shoot as well as some of the lighter loads and if you can't hit the target high velocity is a mute point.

 

[H Richard]

I usually rely more on the bullet mfg data. My reasoning is the difference on crimp groove location, ogive design, bearing surface, all contribute to the eventual pressure & velocity. Start at the lower to mid loading data, then work your way up. Some powders get to max pressure suddenly, so be aware of what powder you are using and it's characteristics.

 

[johngalt]

I suppose there isn't any hard rule about powder co. vs bullet co. It depends on which company and how much you trust their data.

For example, I don't use Hogden data at all. Their data is quite safe, but very low. It wildly exaggerates the velocities you will get for a given charge. My favorite manual is Hornady, I believe their data more closely matches reality because they test in real guns.

Alliant uses Speer data, since they are the same company. I consider either is a good choice. Speer data seems to run a little warmer than Hornady for the cartridges I load (.38 and .45 auto), so I am a little hesitant to use Speer's max loads.

Lee is just a compilation of other's data, they don't do any load development or testing. It is sometimes a bit vague which bullets is for which data. I would rather get original data, not Lee's "intrepretation" of it.

 

[Roadranger]

I use BlueDot in my 10mm loads. It runs the full gamet of bullet weights. I believe it is one of the most tested powders for the 10mm. I found it's data to overlap more from all of the sources I have looked at and be more consistent between the sources. If one finds the same load listed in mulitple sources, it's usually a good place to start. IMR 4756 is a very energetic powder, as is BlueDot. As stated, it's always best to start low and work your way up. A Colt or Glock does not have the margin for error like a M700 Remington or M70 Winchester. Bob!!

 

[ILLWIND]

I chronograph most if not all loads I shoot. I once read in a manual years ago that never add more powder than the max load AND never surpass the max listed velocity for a given bullet/powder/primer/casing combo. It sure beats pulling bullets.