Recent content by afmelo

Well done! It's a shame that the sole MKIII "steel" that I own is a cavalry carbine and I do not expecte such short barrell to give good accuracy! All my other Sniders are conversions with - maybe- an exception of an artillery carbine built by the Portuguse arsenal "FA" on 1878 with barrels...

Indeed! I gave a look to the JBM site and was surprised with the handfull information contained therein! Will take time to absorb... Many thanks!

As previously mentioned, I am by no means educated on BP rifle loads! I am just starting with older BP rifles and trying to learn as much as possible. This is why I am abusing your knowledge, trying to understand the main differences of the game! Being a competition benchrest shooter where we...

Many thanks, I was surprised as well! Found this. Do you know? http://kwk.us/ibsw.html

The site for the BP calculations is: https://www.p-max.uk/cgi-bin/black_powder.cgi

Found a software for black powder calculation. Input Snider data for your 520gr bullet and 70 gr black powder. Here is the result! Noticed that the pressure curve is faster growing than with your test with 30gr of 5744 !

These are the bullets I have ready available here, made by ARES, a company from Slovakia (https://www.ares-gun.sk/perkusne-ares.html ) . They produce lubricated lead bullets and powder coated. I am trying the powder coated for the time being for as long as I do not have an appropriate bullet...

Here photos of the HMCC and Snider cartridge page. Notice that the proposed donor cartridge to convert to Snider .577 was the .577 NE (BELL) - an expensive rarity nowadays!

I have the 13th edition, same loads! Also, although restricted to 30gr of 4198, in "The Handloader's Manual of Cartridge Conversions", one of my mail tools for old guns...

Many thanks for the prudent advice on the WR... Point taken! I was impressed with your graphic - will look closer to the pressure building timing for the future and compare the various similar loads on such particular point.

Yes, single and double base powders really have a different behavior - I use a lot N140 and N540 in my 6Norma BR benchrest loads. They are very different in reaction to weather conditions, namely heat and humidity. After a few years I prefer single base powders - more stability and less barrel...

New calculation with a slightly faster powder - Vihtavuori N105 It is incredible that this software forecasts 1210 fps with a such low chamber pressure producing 8378 PSI only! Does this make sense to you?

Now the calculation of a similar load using Vihtavuori N110 - sightly lower pressure and more 87fps speed!

Calculations for 5744 28gr which seems to be a very good load!

Test with TrailBoss - for the average speed of 1200 fps, need to load 21.5gr, which will produce a chamber pressure of 21.148 PSI, a clear no-go load!