The .45-70 Gap

[3Crows]

Why the gap between Trapdoor top end and Marlin (Lever) loads?

An example is that H4198 tops out at 31.0 gr for 405 HCLFP and then does not pick up again at all until in Marlin loads where the 400 SPRJFP begins at 46 grains! What happened somewhere between 31 grains and 46 grains? Why do not the Marlin loads begin where the trapdoor leaves off and give data for 405 grain HCL on upwards to 1500 fps or so give or take where leading might become an issue of concern?

The 31.0 grains of H4198 in my GBL and two SBLs gives 1280 fps with the MBC Large Buffalo 405 HCL and I would like to drive that bullet on up to 1350 to 1400 fps.

 

[GeoDudeFlorida]

That’s definitely a question for the people who write manuals. Only the people who do the separating know why they do it.
Which manuals, specifically?

 

[3Crows]

I have non-published load data that gives 43.5 gr of H4198 for 1750 fps and that from the Marlin SBL (18.5 inch barrel) which seems out of line if I do straight line calculations and then yet another showing 35 grains at 1500 fps, both with a 405 HCL. In the Gap, it is the wild wild west . All sorts of magic stuff goes on there.

I am loaded up at 32.0 grains H4198, see what happens. Maybe I can get a chrono out tomorrow or so.

All I want to do is to shoot a Large Buffalo into a big fat pig and watch him drop DRT.

 

[ArchAngelCD]

GAP??? I'm at a loss there, what is that?

 

[3Crows]

GAP??? I'm at a loss there, what is that?

I thought I had explained what I mean. If not I mean the Gap (not GAP) that exists in data between where the trapdoor loads leave off and the Marlin loads begin and in particular for the commonly loaded 405 grain lead cast bullets. For example, I am loading 32.0 grains of H4198 for 1420 FPS with a 405 grain lead bullet (Marlin 19 inch GBL) but the max load given in my few books and several manuals is 31.0 grains of H4198 for trapdoor and the 405 grain lead bullet is not even accounted for in the Marlin loads that are principally heavy bullets or jacketed. Real, imagined, whatever, I find there is a gap in the published data it seems for that middle ground, too heavy for trapdoor load listings and not mentioned for Marlin (Lever gun) at all.

Yes, I do find some data, particularly home brew loads all over the www but they are not in a book and some of us beginner sorts are kind of squeamish about loads that are not listed in a published and therefore thinking vetted and proven manual/data. So therefore my load above is in the gap.

 

[ArchAngelCD]

I got you now, you ment the gap they leave in the data between the 2 load classes. Now that I read you post again you did explain it, sorry.
Yeah, I always wondered about that too.

 

[db_tanker]

okay so I knew I had seen three different levels of pain available for the 45-70.

My Lyman #50 has three levels - Springfield trapdoor (what I use for my TC single shot), those max out at 16-18k CUP. Then you have loads for Model 86 Winchester and 95 Marlins - those roll at around 27k CUP. Then you have Ruger #1 and #3 (they also say these could be used for 98 Mausers) Those loads roll up to just under 40k CUP.

As an aside - the next loading listed is for the 450 Marlin - those don't break 43k CUP.

 

[eastbank]

my load for a ruger #3 is 50 grs h-4198 with a 300 gr hornady J bullet at 1950-2000 fps, i could load heavier but that load shoots lights out. i worked up to that load by starting at 44 grs. this load gives no pressure sings at all and the cases last., and as i only load J bullets in my rughr#3 and only lead in my other 45-70 the loaded the loads never get mixed up. three shot group at 100 yards, ray charles is my tracker.

 

[3Crows]

okay so I knew I had seen three different levels of pain available for the 45-70.

My Lyman #50 has three levels - Springfield trapdoor (what I use for my TC single shot), those max out at 16-18k CUP. Then you have loads for Model 86 Winchester and 95 Marlins - those roll at around 27k CUP. Then you have Ruger #1 and #3 (they also say these could be used for 98 Mausers) Those loads roll up to just under 40k CUP.

As an aside - the next loading listed is for the 450 Marlin - those don't break 43k CUP.

That is true, there are three load levels and above trapdoor loads I do not find loads for non-gas checked 405 grain pills as I used in my example. Sure we can extrapolate that if 31.0 grains is max for said bullet in a trapdoor and in the Marlin loads it shows perhaps a 325 grain copper jacketed bullet at 40 grains of H4198, then we are probably safe to load an easily pushed cast lead bullet above 31.0 grains. But, the whole point of published load data is to be able to use proven, vetted, repeatable loads with specific bullets, primers and cases.

Do you see a published load for a Marlin class load using a lead, non-gas checked bullet of 405 grains with H/IMR-4198 or similar? I do not have all of the latest books nor some of the golden oldies so I admit I am probably far from complete on what has been published.

 

[GeoDudeFlorida]

This is the part where you start getting nothing but bone-shattering artillery load posts.
The “gap” is where you’re over what most ballisticians consider safe for an original, 120+ year old trapdoor and under the minimum accuracy load for a modern lever action. It kinda depends on who did the lab work - which is why I said to ask one of the manual editors.

 

[Jim Watson]

What happened somewhere between 31 grains and 46 grains?

Interpolation happens. If 46 is safe in your gun and you know that 31 is not going to stick a bullet or "detonate" then is should be clear upon inspection that 40 will work.

 

[3Crows]

This is the part where you start getting nothing but bone-shattering artillery load posts.
The “gap” is where you’re over what most ballisticians consider safe for an original, 120+ year old trapdoor and under the minimum accuracy load for a modern lever action. It kinda depends on who did the lab work - which is why I said to ask one of the manual editors.

Yes, I guess I will need to do that. The 32.0 grains of H4198, and I may up it a little yet, is giving me exactly what I wanted, 1420 fps with a 405 grain lead bullet. The recoil is powder puff level, much less than Hornady LR 325 and Federal Hammer Down 300 jacketed bullets. I know that the load is safe for the rifle and will not hurt it or myself, but still, interpolating across the Gap and not even using the same bullet types even if the same powder seems a little odd.

Maybe I call Hogden when I get an opportunity and ask them why there is no load data, as in my example, for a 405 grain HCL bullet in the Marlin section as clearly a lot of folks are loading in the 1300 to 1500 fps range, in the Gap, with H4198 and the 405 lead bullets above the max trapdoor load of 31.0 grains, why make loaders interpolate between bullets of different type to guess it is okay---? Oh, well, dang.

Is there a chart comparing the barrel drag/pressure of a copper plated bullet to a lead bullet. With a copper jacketed bullet, friction in the barrel would increase at the square of velocity which means pressure would not be a straight line, or what exactly is the relationship of pressure and velocity for a jacketed bullet. What is the equation? Hmm, off to the books again I guess.

 

[Jim Watson]

First, consider the .45-70 Trapdoor and Marlin as two different cartridges.
Next, Hodgdon set the maximum load for each one separately based on industry standards and their company notions.
Then, the usual manual "starting load" is 90% of the maximum, they don't take the trouble to back it down to a real minimum.

If you can find direct mathematical calculations for in-barrel behavior, good for you.
All I know of is buried in the software for Quickload and the real pro stuff.

 

[GooseGestapo]

Simple!
Pressure doesn’t build in a linear fashion.
Most Trap Doors are over 100yrs old and in, unknown to the publisher, condition.

It’s near impossible to interpolate the weight/velocity pressure/velocity gain between two charge levels. Too many variables.

 

[GeoDudeFlorida]

Yes, I guess I will need to do that. The 32.0 grains of H4198, and I may up it a little yet, is giving me exactly what I wanted, 1420 fps with a 405 grain lead bullet. The recoil is powder puff level, much less than Hornady LR 325 and Federal Hammer Down 300 jacketed bullets. I know that the load is safe for the rifle and will not hurt it or myself, but still, interpolating across the Gap and not even using the same bullet types even if the same powder seems a little odd.

Maybe I call Hogden when I get an opportunity and ask them why there is no load data, as in my example, for a 405 grain HCL bullet in the Marlin section as clearly a lot of folks are loading in the 1300 to 1500 fps range, in the Gap, with H4198 and the 405 lead bullets above the max trapdoor load of 31.0 grains, why make loaders interpolate between bullets of different type to guess it is okay---? Oh, well, dang.

Is there a chart comparing the barrel drag/pressure of a copper plated bullet to a lead bullet. With a copper jacketed bullet, friction in the barrel would increase at the square of velocity which means pressure would not be a straight line, or what exactly is the relationship of pressure and velocity for a jacketed bullet. What is the equation? Hmm, off to the books again I guess.

I guess in a way we all have to look at things from the other guy’s point of view: testing is expensive; every new published load is a potential liability time bomb; the point of testing and publishing is to sell something - a book (fewer people are buying), powders or projectiles - and, there aren’t any firearms in “the gap” between existing data sets. There’s really no incentive for the labs to test and publish new data on a 150 year old cartridge.

 

[db_tanker]

That is true, there are three load levels and above trapdoor loads I do not find loads for non-gas checked 405 grain pills as I used in my example. Sure we can extrapolate that if 31.0 grains is max for said bullet in a trapdoor and in the Marlin loads it shows perhaps a 325 grain copper jacketed bullet at 40 grains of H4198, then we are probably safe to load an easily pushed cast lead bullet above 31.0 grains. But, the whole point of published load data is to be able to use proven, vetted, repeatable loads with specific bullets, primers and cases.

Do you see a published load for a Marlin class load using a lead, non-gas checked bullet of 405 grains with H/IMR-4198 or similar? I do not have all of the latest books nor some of the golden oldies so I admit I am probably far from complete on what has been published.

3Crows,

I have the following in my Lyman #50 -

#457643 400 gr. with wide nose for lever rifles - 2.530 COAL
IMR 4198 - 35.5 gr @ 1535 fps - MAX - 39.5 gr @ 1699 fps

#457193 405 gr - 2.550 COAL
IMR 4198 - 36.5 gr @1533 fps - MAX - 40.5 gr @ 1717 fps

tests were done with a test receiver and a 24" barrel

They also mention that if you are using a micro grove barrel to keep velocities below 1600 fps and bullets at 15 brinell or harder.

Wanted to add - these bullets are NOT gas-checked. Lyman manual does differentiate on that with other loads and load data.


Hope this helps!

D

 

[Varminterror]

Don’t overthink it.

Driving out of town, a 20mph school zone street turns into a 40mph thoroughfare, which turns a mile later into a 65mph state highway. There are not signs for every 5mph in between, but since the road and travel are continuous, the legal speed allowance below the posted limit are implied.

The Bible didn’t catalog every meal He ate…

 

[jmorris]

Why the gap between Trapdoor top end and Marlin (Lever) loads?

Same reason there is a difference in the fuel that is acceptable to run in a 1948 Ford 8N tractor and a 2022 GT 500, they are built different.

Of course you must understand that any load that is safe for an antique trap door is also safe in a new Marlin but not the other way around.

 

[GooseGestapo]

Lyman is notorious for using undersized bullets and excessively hard lead. Sure fire way to ensure poor accuracy and excessive leading.

I’ve run my.45/70’s up to 2,100fps using 12-14bhn “soft” lead but at .460” sizing.
One has Microgroove rifling, other has Ballard (REMLIN).

This is three shots from the “REMLIN” at 50yds with a Lee 400gr RFN over 20gr of #2400 for about 1,500fps.
Bore fit trumps alloy hardness every time.
Lube was SPG.

(2-covered were previous shots zeroing in the scope...)

I’ve got a Lee 405gr RFN-HB that cast HARD and undersized at .457” shoots better the harder you push it. At 1,200fps over 13.0gr of Green dot it shoots “patterns”, but at 2,000fps over a full compressed case of IMR4064, shoots under 2moa at 100yds.

It’s all about Bore fit! And enough pressure to obturate the skirt. My buddy shoots 600yd silhouette shoots with his Sharps reproduction using this bullet in his .45/90 over 90gr of BP w/SPG and pure lead! Watching from beside him, you can see the bullet in flight with a spotting scope before the smoke obscures it, and then several seconds after hear the “Clang”.... makes you realize how deadly these antiques are!

 

[MEHavey]

I’ve run my.45/70’s up to 2,100fps...

You're a better man than I, Gunga Din...
Yesterday's Ruger#1 45-70 , , ,
. . . . . . . 405gr Lym457193(#2)_PC'd / 0.459" / IMR-4759 / 35.0gr / 1,775fps (~42,000CUP Spockian estimate)
. . . begins to leave that realm of "not uncomfortable" when shot off the bench



... spotless bore afterwards tho'
(now if I could only find more RL-7 for my 330 Goulds)

.

 

[AJC1]

This is exactly the reason quickloads and grt is so valuable. Testing is expensive and they won't do more than what they feel is nessary. Same bullet same powder I wouldn't be at all worried loading and testing the middle ground "gap". This senerio happens a lot, and I do it all the time in 38/357 which realistically is just a smaller stragitwall. Mind the minimums in the case as powder burn becomes erratic below start in a lot of cases.

 

[3Crows]

It is apparent that I have been misunderstood. I am not interested in loading for anything other than a Marlin 1895 rifle between Trapdoor and the beginning of Lever loads. The problem that began this thread is that there seems to be a dirth of "same bullet and same powder" loads across the Gap.

I - and, there aren’t any firearms in “the gap” between existing data sets. There’s really no incentive for the labs to test and publish new data on a 150 year old cartridge.

1. Yes there are, any Marlin or Henry rifle for which the rifleman does not want to detach a retina but wants loads above trapdoor level.

2. The .45-70 cartridge is quite popular, 150 years old or not. But good point.

Moving on, I understand now. I got it figured out and I will call Hogden and speak with them on, as in my example, for intermediate loads for 405 grain HCL bullets beyond trapdoor level. It is pretty clear now that loads between 32 and 36 grains of H4198 behind a 405 HCL bullet are safe and relatively mild and effective for game even if they are not published. I like to stick to published data but in this case, in the Gap, I cannot.

I went up to 33 grains this morning and that is right at 1500 fps. The 32 grains was 1420 fps. Both shoot clean, Pb does not seem to be accumulating, accuracy is decent.

So y'all can call it good. Thanks to all for responding .

James

 

[3Crows]

It’s all about Bore fit! And enough pressure to obturate the skirt. My buddy shoots 600yd silhouette shoots with his Sharps reproduction using this bullet in his .45/90 over 90gr of BP w/SPG and pure lead! Watching from beside him, you can see the bullet in flight with a spotting scope before the smoke obscures it, and then several seconds after hear the “Clang”.... makes you realize how deadly these antiques are!

Pretty cool that Wikipedia has Billy Dixon as #15 on the sniper list for distance using a Sharps .50! That is pretty rarified company when you look at the rifles used by the snipers both above him and below him and there he is and a Sharps!

 

[Soonerpesek]

I use AA5744 in my loadings, and I will have to check in Lyman #50 and #51 when I get home, but am pretty sure that the 3 levels overlap with that powder.
I will see if they list H4198.........
I am interested in your findings with Hodgden....

 

[GooseGestapo]

If you like 5744, get some ShootersWorld “Buffalo Rifle”.
Same thing, just 2/3rds as expensive!
I too have used some 5744.
Great powder for application. My container only held 14oz IIRC. Not 1lb.!