My first 45/70 gas check loads

[ACES&8S]

Done lots of revolver lead & gas check loads in 44 mag 45 colt & 357 mag.
Never done a rifle before, my Marlin 1895 45/70 - 22"bbl is the one here.
I got 200 Cast Performance heat treated solids Gas Check F/P .458 - 300 grain
bullets/ also says LBT style as well as lFNGC.
You can tell I am no expert on gas checks.
I have searched with no results on possible starting loads for Gas Checks.
I know they have to be hotter than common lead bullets but less
than brass, that's all I know & maybe that is wrong.
Powders I have found which I have lots of are H4198 // H335 // IMR3031
& IMR4198 //H4895 // H-Varget, got other powder of course.
Any ideas of info location or personal testing?

 

[adcoch1]

Done lots of revolver lead & gas check loads in 44 mag 45 colt & 357 mag.
Never done a rifle before, my Marlin 1895 45/70 - 22"bbl is the one here.
I got 200 Cast Performance heat treated solids Gas Check F/P .458 - 300 grain
bullets/ also says LBT style as well as lFNGC.
You can tell I am no expert on gas checks.
I have searched with no results on possible starting loads for Gas Checks.
I know they have to be hotter than common lead bullets but less
than brass, that's all I know & maybe that is wrong.
Powders I have found which I have lots of are H4198 // H335 // IMR3031
& IMR4198 //H4895 // H-Varget, got other powder of course.
Any ideas of info location or personal testing?

Start with trapdoor starting loads and work up. The 45-70 has a lot of capacity and a gas check bullet will probably let you use all of it you can stand. A gas check should allow for 2000fps without batting an eye, can your gun handle throwing them that fast?

 

[25-20 WCF]

In the OP’s rifle, GC bullets will not produce enough extra pressure to worry about with any moderate pressure load. The maximum bullet velocity isn’t limited by the absence of a gas check, but instead by bullet hardness, bullet design, rifling type and the powder used. I’ve pushed 300-grain plain-based bullets to over 1900 fps, just not in a Marlin. As suggested, begin with Trapdoor loads but you don’t have to use the Trapdoor starting loads - they are the same pressures as the lever-action starting loads. Hodgdon TD data shows close to 2000 fps with 300-grain cast bullets, they will be low enough in pressure to not have to worry about.


.

 

[ArchAngelCD]

I used to use mostly 4198 in my 45-70 ammo until I tried AA5744, now I use nothing else.
3031 works well with ja we wcketed bullets.

 

[ACES&8S]

Thanks for the info so far.
I don't make our lead bullets, my son does all that & taking a look all he has made me
are g/c cast bullets for S&W 25-5 and S&W 29-10 plus 3 model 19's which run them really
well accurate & clean.
These 45/70, as I said are factory g/c to keep from having to buy factory ammo, it is
the only caliber I haven't found a reloaded medium load for in brass bullets.
Maximum loads yes, the 325 grain flex tips but to much recoil for fun shooting and
accuracy.
Got way ahead on reload material for every other caliber except this one.

 

[MEHavey]

Gas checks -- per se -- do not affect pressure over that of a plain-base cast bullet.
The driving factor for working pressure will be bullet alloy/hardness and match up w/ groove diameter..

You neither need/nor want anything over BN-15 (Lyman #2) for pressures/velocities well in excess of your comfort level.
And with the advertised Cast Perf hardness of 18-21, you may have to drive them hard to get them to obdurate/make up for them being slightly undersize at 0.458
(the `85 Marlin likes 459+/460 best)

 

[Charlie98]

Gas checks -- per se -- do not affect pressure over that of a plain-base cast bullet.
The driving factor for working pressure will be bullet alloy/hardness and match up w/ groove diameter..

You neither need/nor want anything over BN-15 (Lyman #2) for pressures/velocities well in excess of your comfort level.
And with the advertised Cast Perf hardness of 18-21, you may have to drive them hard to get them to obdurate/make up for them being slightly undersize at 0.458
(the `85 Marlin likes 459+/460 best)

All that... ^^^ ... right there.

I use both Cast Performance and Montana Bullet Works bullets, there is nothing magical about the load data for them because the overall velocity is low enough, cast or jacketed, that you shouldn't have problems. Based on experience, this with a nice Marlin 1895 LTD V I had, I would start with Trapdoor loads generating around 1500fps, and proceed forward. I started with 'modern lever-action loads' and they were far too much for what I wanted... and I wound up pulling almost 100 cartridges.



ME is right, however... you may or may not have problems with the bullet diameter. I would load 20 or so test loads and see what you find, first, before getting too excited and loading up a bunch.

IMR4198 is the first powder I reach for with cast .45-70 bullets, H4198 or AA5744 being alternates. Stepping up to jacketed, assuming you want hunting velocity, I reach for IMR3031... but understand, the further you climb the velocity ladder, the more that rifle will tell you who is in charge... both at the target, and the buttpad.

My actual data from my 1895 LTD with 350grn non-GC bullets...


28grn AA5744, 1400fps
28grn IMR4198, 1425fps
45grn IMR3031, 1600fps

Looking at Hodgdon's online data for the 300grn cast bullet, I would start with their starting load of 33.8grn IMR4198 and work forward. Their starting load for IMR3031 and the 300grn, showing a velocity of 1839fps, is beyond my threshold of pain, but if you wanted all that velocity, that would be a good place to start.

 

[ACES&8S]

and I wound up pulling almost 100 cartridges.

Been there & stared in that movie with the 45/70.
I would think a gas check at .458" would be diameter enough but the hardness must matter. I have the hardness
tester here, will try it on the new bullets.
I went thru 2 boxes of brass jacketed 300 gr hp hornady thinking I could find, as you say where I was in charge, with
accuracy & recoil. Only to find that maximum load was the only truly accurate load I could maintain.
During that 100, I tried SEVERAL that looked good with 5 shots, only to make 5 more & they would string a
line of impacts or scatter all over. Ended up knocking out 20 rounds at one time.
Again as you said the rifle was in charge with about 24 pounds of recoil it feels like MORE than my
50 bmg which puts out about 75 pounds of recoil with 750 grain Hornady Match Ammo.
Don't get me wrong, I don't fear or flinch recoil, if I did then the round is wasted & the info
is worthless. I just want the 45/70 to be almost fun to shoot or at least reasonable. I gave up on the
T/C 45/70 barrel, time wont allow me to cover all of the 45/70 loads.
PS= the break in lapping ammo was very accurate, Hornady Flex Tip 325gr.
45/70 = be ware what you want lest you get it > My Grandmother always said.

 

[Charlie98]

I just want the 45/70 to be almost fun to shoot or at least reasonable.

Then a 300grn cast bullet and IMR4198 should do you well, with the caveat that you don't really need the premium bullet or the gas check at anything below 1500-1600fps. Those 350's I was shooting were just the cheapo LaserCast FP plain base bullets.

 

[ACES&8S]

Wow did I hit a roadblock.
I have had these old WOLF PRIMERS since 2009 during a previous 2'nd amendment scare.
Just been using them for some testing then never use them as the final formula, but I made 5 of
the 45/70 with imr4198 & they were like black powder, slow to ignite & then one didn't fire
at all.
Looked into the problem, WOLF of course, the primers were silver in this box, the rest are
bronze which is what Wolf is supposed to be, thank goodness I never made any boxes of them
or anything else of any number. A total of 5 rounds are all that were around.
None of the other Wolf are silver but half of them have the same lot #.
So even in the days of primers at a desired level= 1,100 of them are hitting the water jug.
Never cared for them anyhow.
Got 5 more loaded with CCI, ready to test when it cools off outside.