Fireball out the barrel of my modern Trapdoor carbine

[LouB]

I checked the Hodgdon data for trapdoor rifles and 57 gr H335 with 300 gr SRA HP jacketed bullet is correct on 5/22/2021 data. 17,700 psi.

Lou

 

[Charlie98]

Charlie88, based on your advice and Hodgdon data, I'm about to try 30gr of IMR4198 pushing a cast 405 which should travel at about 1300fps out of my Pedersoli carbine.

That will be a good load to check your rifle with... by that I mean the load is below 1500fps, where overly soft, or improperly lubed bullets can start to lead, and is a known quantity. If you get leading with that load, we would have to look at a bigger bullet. The recoil is such that you shouldn't be fighting the recoil... you can concentrate on shooting, not finding your detached retinas.

Let us know how it goes!

 

[jval]

Tried out the 30gr of IMR4198 pushing a cast 405. Very comfortable to shoot. Thanks for the advice. By the way, no more fireball like I experienced when shooting 300 gr with H335.

 

[jval]

I did not use a Chrono, but I will assume the fps is close to the advertised 1,300. Also, the lead I used was 405 hard cast with copper gas check and three lube rings.

 

[GHinNH]

I know nothing about .45-70 this is just a quick and dirty model result, and in no way should be taken as gospel or viewed as acceptable data. These are SAMMI specs for cartridge and do not represent your particular firearm, case capacity, seating depth, etc...etc...

What it does show, even with a 26" barrel using H335 the burned propellant is only 73.3% so the rest goes out the end of the barrel (fireball) with resulting high error rates. Powder should be within 90% or better burn rate to get consistent FPS, SD/ES numbers, all major factors in a accuracy.

 

[GHinNH]

IMR4198

 

[Charlie98]

What it does show, even with a 26" barrel using H335 the burnt propellant is only 73.3% so the rest goes out the end of the barrel (fireball) with resulting high error rates. Powder should be within 90% or better burn rate to get consistent FPS, SD/ES numbers, all major factors in a accuracy.

That's all quite true. I have a friend that has QuickLoad and he runs stuff off for me. When I was researching loads for my 1885, I was very interested to see the case fill on different powders, and the projected burn efficiency. My IMR4198 load with a particular 385grn cast bullet in my 32" barrel had a burn right at 90% and swapping in AA5744, right at 91% It's one of the reasons I recommend those powders for lower velocity cast loads in something like the .45-70. Conversely, to get good burn efficiency out of slower powders... like H335, you have to ramp up the powder charge, which translates into more energy, yes, but also recoil and blast. It all depends on what you want.

Many people will also recommend slow (and not so slow) pistol powders... like Unique, 2400, IMR4227, even something like RedDot. Those powders all burn almost at 100% but you trade very poor case fill, and in some cases a very sharp pressure peak, depending on the particular load and powder. I'm not necessarily a big fan of those powders in the .45-70, although I've tried them, and they work.

 

[GHinNH]

That's all quite true. I have a friend that has QuickLoad and he runs stuff off for me.

Having ballistic software is something of a rabbit hole, at least for me. I can easily spend way too much time with it. It took my stubborn brain about a year to give up on many commonly accepted "norms" like trying to make a particular powder work for multiple calibers. It can of course be done, if the results are acceptable to the user.

As you know burn rate and case fill are especially important, some powders very suddenly react violently to under and over charge thresholds and I suspect a lot of accidents are because of it. If a lighter load is desired often a different powder is needed.

There are many very good reasons to model a powder for a particular firearm before trying it.

 

[GeoDudeFlorida]

Having ballistic software is something of a rabbit hole, at least for me. I can easily spend way too much time with it. It took my stubborn brain about a year to give up on many commonly accepted "norms" like trying to make a particular powder work for multiple calibers. It can of course be done, if the results are acceptable to the user.

I'm the opposite. I do the research and reading, loading and testing, developing loads so a wide variety of powders can be used with a particular bullet weight and style. I have recipes for almost every pistol powder in a given set of pressure ranges that produce very similar results with very similar bullets and mixed cases. I have probably a dozen variations of the old 2.5gr. Bullseye with a 148gr. LWC load - using Red Dot, AA No.5, IMR 700X, Titegroup, and recently added Ramshot Competition to the list. They all produce the same result: good solid hits on paper from a .38Spl revolver at 25 yards.

My "recipe book" is for feeding the belly, not delighting the pallet of an epicurean.

 

[Charlie98]

If a lighter load is desired often a different powder is needed.

Lighter or heavier. In these days of empty shelves, I'm constantly seeing posts about using this or that powder in a...uh... not so optimal load. It makes me cringe a bit, sometimes.

 

[Charlie98]

Having ballistic software is something of a rabbit hole, at least for me. I can easily spend way too much time with it.

A few years ago I started loading cast bullets for rifle in earnest... these days it's about all I load, outside of the generic AR/M1a/Garand loads, of course. I really had to take a step back and look at my reloading process and selections. Initially, I use H4831 to load cast for my .348WCF... boy, what a train wreck that was, but... it's what I had always used for jacketed bullets. Wrong answer. Same same with the .45-70... using slower powders. Duh. Looking at the data my friend provided via QB, it wasn't so much a rabbit hole, maybe just a really bright lightbulb going off in my head.... it's lead me in a very different direction, a much better direction. Information is power.

 

[jval]

So, let me repeat what I understand. H335 does not completely burn, so a lot is going out of the barrel. That would explain my occasional fireball using 57 grn of H335 pushing a 300 grn Hornady HP. Sounds like I could do better with IMR4198 and it's higher burn rate. Using Hodgdon data, IMR4198 produces 23,500 CUP at recommended load for a 300 grn bullet. Lyman suggests 36 grn with a lower CUP of 17,000. I'll try that one and may even boost the powder to 40 grn. At the range yesterday, I was coming "close" to hitting that 16" square plate at 150 yds downrange off-hand, iron sights using H335 and a 300 grn Hornady HP.

 

[GHinNH]

My "recipe book" is for feeding the belly, not delighting the pallet of an epicurean.

I lol'd over that!

Lots of folks love the process of developing with paper and pencil and I do too...to an extent... but I can shorten it considerably which is fine by me, especially for large consumables like 9MM. Heck it WAS the only way when I reloaded years ago, computers were not even mainstream then. But since I got back into it a few years now I find it very helpful and reassuring that I know what to expect.

Personal preference and to each their own. I'm not much on saying my way is the only way, plenty of others insist on doing that.

 

[Charlie98]

That would explain my occasional fireball using 57 grn of H335 pushing a 300 grn Hornady HP.

Part of it is the powder itself... H335 is a flashy powder, pun intended. BL-C(2), is, too, for example. Part of it is the burn %, among other things, including the length of your barrel, and your bullet weight.

Faster powders work well for lower velocity loads... but understand, as I mentioned, they will have a sharper pressure spike... the bigger the charge weight, the higher you push the pressure peak. There is a point, chasing higher velocities for example, that it makes sense to switch to a slower powder to achieve the same velocity without going into the danger zone, pressure-wise.

1400'ish FPS out of a 405grn cast bullet is what I consider ideal for general shooting. I'm not a hunter, but even at such 'low' velocity, there isn't much that would get in the way of that. For taking down things like paper and steel... I can't think of anything better.

 

[GeoDudeFlorida]

I lol'd over that!

Lots of folks love the process of developing with paper and pencil and I do too...to an extent... but I can shorten it considerably which is fine by me, especially for large consumables like 9MM. Heck it WAS the only way when I reloaded years ago, computers were not even mainstream then. But since I got back into it a few years now I find it very helpful and reassuring that I know what to expect.

Personal preference and to each their own. I'm not much on saying my way is the only way, plenty of others insist on doing that.

Oh, I still use a computer, load books, software I wrote myself - it's what I do, mostly - but I look for terminal performance w/ Loads A-[...] @ Velocity X using Bullet Y w/ Powders A-[...]...etc.

What I'm saying is, if the only powder I can get is Titegroup - or AA No.5 or 700X or Red Dot or... - and I still want to shoot my Model 15-3 .38Spl with Speer 148gr. HBWC, I have loads already tested and written down for it which delivers the same performance as my preferred load, the infamous tried-and-true 2.5gr of Bullseye. I don't have to adjust my hold, the sights, or anything. And I don't have to do any last minute load development when supplies might be scarce for a powder I typically don't have.

 

[GHinNH]

Sounds like I could do better with IMR4198 and it's higher burn rate. Using Hodgdon data, IMR4198 produces 23,500 CUP at recommended load for a 300 grn bullet. Lyman suggests 36 grn with a lower CUP of 17,000. I'll try that one and may even boost the powder to 40 grn.

Again I do not know your measured specifics or anything about 45-70, just sharing quick results so....yeah

At 40gr IMR 4198 and 300gr Hornady .458dia 26in barrel at least you should break slightly over at 81.8% with very acceptable pressure. At 36gr the burn drops lower to 78.8% I might go ahead if were me, while I try to source a more appropriate powder, but that's just me.

 

[GHinNH]

Oh, I still use a computer, load books, software I wrote myself - it's what I do, mostly - but I look for terminal performance w/ Loads A-[...] @ Velocity X using Bullet Y w/ Powders A-[...]...etc.

What I'm saying is, if the only powder I can get is Titegroup - or AA No.5 or 700X or Red Dot or... - and I still want to shoot my Model 15-3 .38Spl with Speer 148gr. HBWC, I have loads already tested and written down for it which delivers the same performance as my preferred load, the infamous tried-and-true 2.5gr of Bullseye. I don't have to adjust my hold, the sights, or anything. And I don't have to do any last minute load development when supplies might be scarce for a powder I typically don't have.

I gotcha,
I just bought two pounds of Win244/WinClean from Midsouth while the getting was good for .45ACP since my other choices are non-existant. It's not in the powder database yet so when it gets here I'll be hoofin' it old school and hoping for good results.

 

[Charlie98]

I just bought two pounds of Win244/WinClean from Midsouth while the getting was good for .45ACP

I've got a bit of data for it... PM me if you are interested.