More thoughts on A-Square .450-.400 data. Danger!?

[1886]

We were discussing the old .450-400 several days ago. I now have all of my reloading components for this oldie. I reviewed the A-Square data and got started. The data calls for a max charge of 87grs of H-4831 with their 400gr triad of bullets. 87grs? Seems a little light for such a large case. My Hornady cases hold an average of 116grs of water. By comparison Federal .416 Rigby cases hold an average of 129grs of water. According to A Square 87grs of H-4831 will produce 2150fps for an average pressure of 31,500 psi out of a 26" barrel. I weighted out 87grs of powder and dumped it into the case. Well my hunch was correct, not nearly enough powder to properly fill the case. Unused case capacity with slow burning powder is a text book recipe for detonation. A large amount of unused case capacity only heightens this dangerous condition. I discussed this with Mic and he whole heartedly agrees and is working out some data. I will share if anyone is interested. I mention this because some forum members have or had a rifle chambered for this interesting round. Certainly if one wishes to push a 400gr bullet a good deal faster at a pressure level appropriate for a slow burning powder H-4831 or RL-22 are good choices. Do with these observations what you will. Regards, 1886.

[Leverluver]

It's pretty universally known in the "doubles" crowd that a filler is to be used with the old Nitro cases. The are usually too voluminous for modern powders. In general, when one of the 4831s are used in the 450-400 a filler isn't necessary but most definitely with the medium burners like Re15, H4895 or Varget. The filler of choice is a foam cylinder such as supplied by Kynoch.

[HollicaSnooze]

Much appreciated, 1886. I went back and reviewed my loads and see where I have been using 68.0 gr. of RL-15, as published in the Barnes #3 Manual. Interestingly, this powder is not included in the Barnes #4. Should I have cause for concern? As mentioned, I am using Woodleighs at present, with the intent to go to Hornady's when the .410"s are available.
I didn't think this would be a problem in switching from Barnes as the pressures should be less with Woodleighs', I would expect.

[1886]

Mic actually thought RL-15 might be best. He is working out the calculations this evening. 1886.

[Doc Hudson]

Parson my ignorance, but which of the .450/400 cartridges are you talking about?

The .450/400 Blackpowder Express 2 3/8" Bottlenecked case?

The .450/400 Nitro Express 3" Straight case?

Or the .450/400 Magnum Nitro Express 3 1/4" Straight case?

[Leverluver]

Doc

Both the 3" and the 3 1/4" are both bottle neck cases. The 3 1/4 started out as a black powder express round but transitioned into the smokeless era with "Nitro for black" loadings. The 3" was always a smokeless round. The 3" is what is being resurrected. Currently Ruger chambers it in the #1 and Searcy and Heym along with a few others make doubles in that chambering.

[1886]

Yes we were discussing the .450 .400 3" smokeless. As lever stated it has seen some renewed interest with the collaboration between Hornady and Ruger. 1886.

[HollicaSnooze]

Any word from Mic on his findings with RL-15? I haven't had any troubles with the loads I have shot with it, but certainly don't want even an inkling of a chance, given the implications of detonation!

[Leverluver]

There are two schools of thought on loading the large volume Nitro cases. The first is to use a slow bulky powder that will fill the case capacity to 95%+; preferably 100%. The second is to load with a faster powder that more closely duplicates the burn profile of cordite. Ther are positives and negatives to both methods. With the slow powders, it is a little less likely that older double rifles will regulate with such a load. Also, the slower powders have higher residual pressure further down the barrel that can put the barrel solder joints in jeopardy. Neither of these is a concern with a single shot, especially a Ruger #1. One other negative is that the larger quantity of slower powder will have a greater "rocket" effect and some say that it will generate greater recoil. The positive part of the slower powder is that it most certainly will develop the desired veolcity at a lower chamber pressure than with a fast powder.

The positives of the second method using the faster powder is that if the burn profile is closer to cordite, it will more likely regulate in older rifles that were regulated with cordite. Again, no concern with a single shot. Probably 98% of those that do use one of the faster powders such as RE15 DO use a filler to take up the empty space, either kapok or foam cylinders expressly made for the purpose. This concept of using fast powders in the large cases while using a filler goes way back but was championed in this country by tests and writings done by Ross Seyfried. BTW, his favorite for virtually all the Nitro cases is Re15 but he is using a filler. Whether or not the powder used is linked with SEE or not is not the only focus of those that use fillers. They are also looking to have a load with 100% reliability of ignition. Remember, most that have loaded these cartridges are using them to killl things that could kill them right back. Reliability is king.

[1886]

A single base, read nitrocellulose only, deterred, slow burning powder like H 4831 does pose a potentially huge hazzard when loaded at reduced levels. This a function of ignition or more accurately inadequate ignition. In simple terms powder begins to burn, bullet is moved and then the powder stops or burns much more slowly, gases condense and cool. At this point bullet travel essentially stops. At some point powder ignition resumes and this causes a wave. This wave can be clearly demonstrated by running a high pressure hose into a calm, still pool of water. This is what creates detonation. Fillers are not mentioned in any manual I have read and are not to be recommended with smokeless powder. Fillers add yet another variable in a variable laden process. This condition is not as apt with a double base powder, nitrocellulose/nitroglycerin, powder like RL-22 all else being equal because it is easier to ignite. All else being equal, how does one quantify that statement? The hottest primer commonly available to the average handloader is the Win. large rifle magnum primer not the Fed. 215. The Fed. 216 is hotter still but not available as an over the counter item. A faster burning powder double base powder like RL-15 is to be preferred when loading large capacity cases at reduced levels. One should still employ the hottest primer available. 5744 will also work well. If you need a load to hammer the Buff. that are trampling the onions then a load that provides 5-10% powder compression with H4831 and a 400gr bullet is entirely appropriate in the bank vault strong Ruger #1. Recoil quickly becomes the limiting factor with the Ruger #1 not action strength. Double rifles are another matter entirely and require a different approach. Be safe. Do not load slow burning powders at reduced levels. Review the manuals and the manufactures warnings. This is clearly stated. 1886.

[Hobie]

I've been watching this topic, of course, but every time I see the title my first thought is...

"Standing in front of it."

I don't know why.

[1886]

Any word from Mic on his findings with RL-15? I haven't had any troubles with the loads I have shot with it, but certainly don't want even an inkling of a chance, given the implications of detonation!

Sent you a P.M. sir. 1886.