45-70 and IMR-4198. Powder position sensitive?

[Gone_rabid]

Looking to load for a subsonic round for my CVA Elite Stalker that’s been cut down to 16” and features a suppressor. Had a great load with trailboss but like everything else, it’s no where to be found.

Stumbled upon IMR-4198 at the LGS and bought a couple of LBS to try to use. Lyman shows a load for a 24” barrel with 420gr cast bullet w/IMR-4198.. min of 21.5gr/952fps to 28.5/1267fps. With that said they used a fiber wad. I do not want to do this due to the suppressor.

Quick load shows with a 25.5gr/1049fps with a 16” barrel. This is calculates to 56.6% case fill.

Thoughts on this load without fiber wad?

291758

[hawkenhunter50]

I just got back inside from firing a 1895 Marlin 45-70 using 34 grains of 4198. This is a Trapdoor starting load. It isn't position sensitive, but does leave a few unburned kernels in the barrel.

[Gone_rabid]

Here’s some more information pertaining to these loads I’m pondering.

291762
291763

[Targa]

I’m using 31 grains of 4198 with a 405 grain bullet out of my Pedersoli carbine trapdoor, excellent load with good accuracy and a average of 1360 fps through the chronograph with a ten shot string. I have not noticed any position sensitivity.

[725]

I use 30.0 gr's with either a Dacron pinch or discs cut from LDPE to take up the air space. Fine load on the mild side. My concerns with these light loads are the possibility of ringing the chamber. I'd stay within recommended manual loads.

[Gone_rabid]

Here’s the thing. It is a Lyman created load for a trapdoor.

I’ll have to google what ringing the chamber is.

[Larry Gibson]

With that suppressor I do not recommend the use of a filler. 4198 w/o a filler in the 45-70 loaded to subsonic levels is indeed, position sensitive. I suggest using Unique instead, w/o a filler,. Start at 8 or 9 gr and work up in 1/2 gr increments until you just start hearing a "snap" in front of the barrel. The 'snap" indicates the the bullet is just barely breaking the sound barrier right in front of the suppressor and then slowing down to sub-sonic within a few feet. Thus you don't hear a "crack". Then back off 1/2 gr of Unique and you'll have the optimum sub-sonic load for your rifle/suppressor/bullet.

[Rapidrob]

For what it is worth, I have found the hard way, the slower powders in a large bore rifle will have the unburnt powder grains strike the suppressor baffles and over a few hundred shots, damage them where they needed to be replaced.
I went back to and now stay with the faster burning powders to prevent this from happening.

[Hootmix]

I have been loading by taking " Larry's" advise, never have had a problem, and i thank folks like him & others who'v been their, done the work.
coffee's ready,, Hootmix.

[Skipper]

Rabid, Lyman no longer uses wads in their data. Take a look at Lyman #50 manual.

[dale2242]

I use 30gr of IMR4198 in my TD with a 400gr bullet.
I use 1 gr of dacron with this load.
No unburned kernels of powder.