Is this load data to HOT?

[Water_Gremlin]

I received some load data from Cast Performance for their 405gr. WLNGC for the 45-70 today. I need to call them and find out the COL, primer, pressure's, and what brass they used. Anyways they recommended a minimum charge of 46gr H4198 @ 1700fps and a max of 51gr. H4198 @ 2000fps both out of a GG.

Looking at my manuals and loaddata.com that load seems a little hot, especially for a cast bullet. I don't trust this data so far. Am I just over cautious or is this data way too hot for the 45-70 out of a GG with an 18.5" barrel?

[ADfields]

I'm no 45-70 guy but the 5 books I have all match very close to those numbers. I did see that 2 of my books have notes about high power loads in older guns and some lever action guns. They don’t say just what a "high power" load is, but this is the fastest 405 gr. load they show so I would say it is high power.

I would also think it is also gonna pinch the shoulder just a little bit.

Andy

[BrownBear]

I received some load data from Cast Performance for their 405gr. WLNGC for the 45-70 today. I need to call them and find out the COL, primer, pressure's, and what brass they used. Anyways they recommended a minimum charge of 46gr H4198 @ 1700fps and a max of 51gr. H4198 @ 2000fps both out of a GG.

Looking at my manuals and loaddata.com that load seems a little hot, especially for a cast bullet. I don't trust this data so far. Am I just over cautious or is this data way too hot for the 45-70 out of a GG with an 18.5" barrel?

Good idea to double check any data, then as a policy to work up to max from a lower level, no matter which authority you get the data from.

I'm in a small group of skeptics about the strength of the Marlin and the wisdom of using really hot loads in them. I've seen three now that had been "ringed" by high pressures in the chamber area, ruining both the barrel and the action. Yeah, throw them in the dumpster when that happens. All three owners are good and cautious reloaders and swear they had been using published max data. Argue the point back and forth all you want, but at least three guns that I know of (and there are almost certainly more) have hit the dumpsters for pushing that little action just a wee bit too far.

Be careful out there.

[Vance in AK]

For what it's worth, you can generally push cast (with gas checks) harder than jacketed because they have a lower level of friction & give lower pressures.
I think I would consider CP a reliable source as long as the data was intended for your gun (sometimes they give a little hotter loads for Ruger #1s & Mauser 98s).
I will tell you that it will probably hurt at the upper end!!!

[Murphy]

Generally the 400 grain cast bullet can reach 2000 fps but I'm not sure that velocity from an 18" barrel would be a good idea. From my 22" barrel I stop with 2000 fps and since there is no reason to shoot 400 grain cast at that velocity I use 1800 fps for a top and find it is all I need in the iron sight realm of the 45-70. Giving real moose mashing, bear bashing power from the muzzle to my limit of open aperature shots.

I agree with Vance and BrownBear. The Marlin is strong but why push things when you get nothing but recoil and gun wear and tear from it. It does not kill any more deader. (is that a word) And a cast bullet will deliver higher velocity at same pressure of JSP or same velocity at lower pressure. H4895 is such a good powder for cast bullets for this caliber and has a mild, predictable curve. I really like it with 400 to 450 grain cast bullets.

[Vance in AK]

So Murphy, for moose mashing & bear bashing do you prefer cast?
By the way, I agree with the 1800 fps thing.

Here's an interesting study by Randy Garrett (Garrette Cartridges) on penetration in the .458 dia cartridges. His findings are interesting to say the least. Sorry if this has already been posted & I missed it.

http://www.garrettcartridges.com/Penetration.htm

The conclusions I draw from them are that the only thing speeds above 1800fps will gain you is a flatter traectory.
I'm just starting to play with a guide gun again in 450 & looking forward to load development. Right now I've just been shooting up some stuff I had loaded for my 15" (counting the muzzle brake) Encore pistol barrell. 405 Rem jacketed that were doing an avg of around 1670 from the Encore. I haven't chronographed them in the GG yet but with a useable length gain of about 5" I'm guessing 1850-1875ish. The little testing I have done so far the load seems accurate. Powder is H-322. Had good luck with Reloader-7 & 420 cast in the Encore barrel.