Question about Max load data with Trailboss

[Knebel]

I am aiming to load some 440 grain 500 s&w to archieve at leats 1000 to 1100fps. That would give me roughly 1000footpounds. The projectiles I have have a gas seal..

So I found this load data and I am curious... why is the MAX so low when its around 20000psi? The 500 can handle 50k psi!?

I have loaded 400 grain projectiles with 9 grains of Trailboss and they show 0 pressure signs and are very accurate, but I am looking to bump up the energy a bit on the 440s. 350grains are good with 12grains of Trailboss.

I use a lot of alliant 2400 and have interpolated some load data while always staying on the low side. 28grains of 2400 with the 400grain is not very accurate but still manageable to get followup shots done. However, recoil is substentially more with this powder.

The question is, i cant find much data on the 440 grain 500s&w that will produce a lower recoil. How safe would it be to bump up the max charge of trailboss 1 or 2 grains?

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[gmerkt]

To your original question, why does Hodgdon top out Trail Boss at 21,200 # pressure. I cannot say for certain but here are my thoughts. Trail Boss is a kind of specialty powder. It may have burning qualities that change to explosive qualities after a certain load level is reached. I don't know for sure but Hodgdon must have a good reason for their recommendations, being as it is so starkly different from other recommended loadings. In the way of max. pressure, that is.
SR4759 (now obsolete) was another sort of specialty powder, often used for reduced loads. Once you hit a max load in 4759, it would quickly lead you into over-pressure territory if exceeded. I'm not a scientist, I can't adequately explain it, but propellants have different qualities as to how they burn. Some are more forgiving than others.

I wouldn't go down the road of comparing Trail Boss with 2400 for any purposes of extrapolation. Trail Boss is much faster than 2400, not similar in properties. My guess is that Hodgdon offers data for Trail Boss in .500 S&W so shooters can have a kind of plinking load for such a powerful cartridge. If you're looking for a round the produces less recoil, then go for a lower charge of a more appropriate powder. Which no doubt you've already considered but I'd say this would be the path to follow.

 

[Knebel]

Thank you. I'm not comparing Trailboss to 2400. I was just saying I load with 2400 too and got a decent enough downloaded load with it, however that load is not very accurate. 20 yards has a 1 to 2 feet spread. With trailboss I get 5 shots into a 5" group quickly.

Trailboss is a nice powder for reduced loads thats why I was wondering. I have no problems with it in the lighter projectiles and can go just over max a little with no real pressure signs to be concerned about (If I compare the looks of the casings to loads with W296...which btw knocks your socks off even at starting loads lol)

My main concern is, I am taking the gun for bear defense on a trip soon and looking for a load that will be managable in recoil and no ear pro. There is no way I can shoot a full power 440grain load rated at 1800fps out of a 2.5" 500 magnum without braking my ears or wrist lol.

 

[The Heretic]

Is the 500 one of the snubbies?

I have no problems with recoil in my 460V (5" barrel with comp) with full power loads. Between the weight and the comp, it is a pussycat compared to my 329PD and any .44 mag loads; the lightweight of the 329PD makes it a real handful.

My guess is that the character of TB changes above a particular pressure. Combustion/etc. will do that - above a certain pressure the character can change by order of magnitude and you get above a safe level much faster - non-linearly - and KABOOM!

 

[Knebel]

Maybe I gotta source some CFE BLK. I see starting loads at 1400fps and 28000psi. That might be good for a lower recoil load?

 

[thorborg]

My angst in loading, for many different cartridges experimenting with many different powders and projectile weights did not moderate until I got my first reasonably reliable chronograph. Albeit only 20 bucks, (a long time ago) and it was definitely persnickety, but with much practice you find that once you figure the right light conditions it likes, and always provide that, I was reasonably assured the accuracy of the unit and could rely on it. I now use a radar but frankly the old cheapo worked just fine if you forget the many times I left home with perfect lighting only to get to the mountain with crappy lighting.
I have nearly a dozen different loading books from most the major sources covering a wide range of years and was constantly perplexed when finding a max load spread of 10 to 15 grains or more (rifle loads). Until the chronograph, I sallied fourth with some trepidation and stayed on the safe side by starting near the bottom and averaging the middle loads as a max when different books were in conflict, then used that as a start to working up loads. Without a way to measure pressure, reading primer and case condition can only go so far when loading, especially for guns that due to age, may require loads of different pressure than modern versions. My BFR 45-70 revolver would withstand 60,000psi , miles above old trap door and some lever rifles of sometimes just 30k+psi
With the chronograph, I can add speed to the comparison and my comfort. My books list pressure along with the speed so if books claim 2500 fps is what you get with their max load and one book says 39.5 grains and another claims 44 grains for the same powder, and I went to 44 grains because the brass and primer looked OK but the speed was nearly 2800, I could now with the chrono, assume I'm over the listed pressure and may want to back off if pushing the firearms strength.
Lots of things besides powder and bullet weight can increase pressure ranging from a greased case to crimping so the more you can know about your handloads the more confidant and assured you'll be of your loads if only for safety's sake.

 

[Knebel]

Its pretty interesting actually. Even the low velocity trailboss loads are more accurate than anything I just tested with alliant 2400. Interesting, i loaded 5 each from 24 to 27grain of 2400 and only the 26 and 27 grain charge was somewhat more accurate. Still, with trailboss I can shoot a pretty small group. Maybe the faster powder works better in the snubnose? I have 0 signs of high pressure and can probably go up with the alliant and the trailboss.

 

[dave peoples]

there are lots of other powders and loads that will do what you want., hs-6 and Universal wil put you in the 900- 1100 fps range in a 4" barrel. Longshot is another good performer in that range. Even Tite Group will do it. Trail boss is ok for plinkers but for anything else you need to build some pressure. the 500 doesn't even start to breathe until you hit 30kpsi. You can pm me if you need more info.

 

[Knebel]

Good info, thank you! I'm wondering if there is anyone who loaded the 500 mg with cfe pistol?

Anyway I just got a chrono and can do some more serious testing. I'm aiming for 1000 to 1500ft/lb with the 440 grains and that will start at about 1100...1200fps. Enough to give a bear a hard time but not enough to hurt my wrist too much. Aiming at 1300fpf with my 335grain lead bullets.

I can find no powders anywhere so I'll have to use what I currently have.

 

[dave peoples]

Gavintube on youtube has a video in which he uses Cfepistol in the 500. have fun

 

[red442joe]

I love light loads of TrailBoss!
Mine is a 200 grain lead semi wadcutter in 45 WinMag for 800 fps. Won't cycle the Automag IV but very accurate and shoot to same poa as 230 grain XTP at 1600 fps at 25 yards.
Mike at Hodgdons says DO NOT compress TrailBoss-scary erratic things start to happen.
I make dummy rounds with drilled primer pockets for the col and bullet I want. Back fill with TrailBoss to get your max load of TRAILBOSS.

Joe

 

[Knebel]

Yeah my trailboss loads go only 700fps with a 400grain. Feels like a toy compared to 1300 with the same bullet...

I use trailboss a lot in 38 spl for plinking, i just chronographed them and they go 450fps haha. Shoots like a pelletgun.

 

[saxon]

trailboss has compression issues based on the powder design, that is what i learned when loading for 45 colt ruger loads


an explanation appearing in the June 2016 issue of Handloader magazine appears to provide the answer. In the article, Hodgdon's Ron Reiber is credited with the following: "Reiber cautions that Trail Boss does not respond well to compression and becomes erratic in its performance--not dangerous, just erratic." The article identifies a starting load of TB as 70% of the powder weight to the base of the bullet (which is the usual definition of a starting load) and then working up from there to max at the base of the bullet.

Shape and size have a profound effect on the burning rate and power generation of a powder (Meyer 1987).