BP loading in a 8x58RD cartridge for a 1872 Rem. RB made in Sweden???

[Smokepole50]

I have done a lot of pressure testing with the 8x58RD cartridge fired in a 1872 CG Swedish RB rifle re-built/converted to 8x58RD in the 1890's. All my testing was done with modern smokeless powders to try and provide safe loads for the shooting public/world to use in this old rifle and cartridge.

The pressure limit for this rifle set by Carl Gustaf was 28,000 psi. I was recently asked by a forum member if I had done any testing with BP in this cartridge and I have not. I actually was rather taken back by the question and thought why would anyone want to try such a thing with such an old and potentially weaker action.

After a bit of reading here in some older posts I find myself asking some questions I thought I would never ask.

Does anyone have any pressure data with BP cartridge rifles that could be used for comparision? I did see one reference to 18K psi but that was a bigger bore cartridge.

In reading I see that shoulder angle or lack there of is thought to be benificial in BP cartridge powder burn rates as well as lessening the potential for pressure spikes. The 8x58RD cartridge has the longest shoulder taper of any cartidge I have seen so this is a good thing, I think.

The 1.5 X caliber equation might be an issue as .326 x1.5 only equals roughly 49 grains of powder and the case will hold close to 70gr of powder.

So does anyone have any thoughts on the subject or references I could look at to help me make a wise decision about any future testing I might do with this cartridge and BP?

If you desire you can see some of my Pressure Trace work on Gunbosrds under the Swedish Rifle Forum and the 1872 Swedish RB relaoding thread.

Thanks, Smokepole50

[bigted]

smokepole ... the recipe for BP loading is the same ... no matter which cartridge you desire to use. the preassure is going to be within the real of "can do" for any action as the blackpowder will not develope the preassure that any smokeless powder will develope.

the recipe is as follows ...

1- make a 'dummy' cartridge with your boolit seated to depth desired in a case with no primer.
2- now mark the boolit and meassure the distance from the case mouth to the bottom of the boolit.
3- fill your case with your blackpowder to just about 1/32 inch above this distance.
4- now pour out the powder into your scale and weigh it to see what grainage is desired for your beginning.
5- load 10 or 15 of these with blackpowder lube on the boolit.
6- take em out and sight it in with your new BP load ... now do a clean of the bore and proceed to do an accuracy test.
7- take and add 1 grain to this amount and load 5 ... add another grain and load 5 ... so on and so forth.
8- the results will tell you which load is the best for accuracy ... now load 20 and go shoot two 10 shot groups.
9- now the play is in action ... try ... just try ... to wipe that silly grin off your face.

have fun and report back with results and more questions. most impotently tho ... have fun. [smilie=s:

[Boz330]

I don't have any pressure info but that case will hold more than 70gr. I tried BP and the fouling was horrendous in that small boolit diameter. I figured it was worse than I wanted to deal with and went back to smokeless.

Bob

[Boz330]

smokepole ... the recipe for BP loading is the same ... no matter which cartridge you desire to use. the preassure is going to be within the real of "can do" for any action as the blackpowder will not develope the preassure that any smokeless powder will develope.

[smilie=s:

While you may not be able to develop the pressure with BP that you can with smokeless, you can develop enough to cause problems. I was trying to develop a LR load for my 40-65 and managed to pull the ends off of several cases and the ones that didn't separate were stretched .100" and pretty much scrap. The cases had the same pressure indicators you would expect of smokeless. That was done with a case full of 2F Swiss and .250" of the boolit in the case.

Bob

[Smokepole50]

Thanks Bob.

After reading around that is pretty much what I thought the case was and wanted to here from someone else. The 70gr number was just a number I repeated from the guy who questioned me about experiments using BP. I have held my breath and turned my face away from that RB enough times breaking new ground with loads/powders that have never been tested and documented. I think I'll refer my friend to this thread.....IMO, it just is not worth the danger using BP in those early RB rifles in 8x58RD. Maybe a #5 Remington in 7mm Mauser would be fine but that is another rifle and cartridge from a litttle later on down the metalurgy trail.

[Boz330]

I don't believe the BP will give any problems but the fouling is really bad with that weight of boolit. My point was that you can have problems from BP.

Bob

[Smokepole50]

Exactly.........and I don't want any issues with a rifle design from 1867, built as a 44 caliber BP cartridge rifle in 1872 and then converted to a over powered 8x58RD cartridge in 1893 that was intended to be used as home guard last defense rifle.

I am not a BP cartridge expert but from what I have read about BN cartridges .326 is small and thus higher pressures. If the barrel gets fouled and the 224gr bullet encounters additional resistance the pressure curve could easily rise well above 28,000 psi and that is a bad thing in this rifle. From my experiments with the Pressure Trace II system I have noticed significant pressure increases just from firing shot strings of no more then 5 rounds in a row with smokeless powders that leave little to know residue. Based on my experience with this old rifle, that is in very good to excellent original condition, I would not want to shoot an extended session with loads that made 25,000 psi. After about 3 shots the pressure starts rising every shot down the bore until she cools down.

[bigted]

i guess i didnt read the "converted" portion of your origanal post.

i have loaded the 375 H&H with compressed loads of 2F goex and other then having a grand blast with it ... no problems at all. i have played with the 43 spanish as well in an old roller and it just eats my loads of 79 grains powder with so much pomp n circumstance. never had preassure problems with these two bottle neck cases when loaded to the nuts with black powder.

i would hesitate tho with the small bore combined with an old roller that was not built around the cartridge.

i believe i would stand by my post tho in a rifle that is in good shape and remains chambered in the origanal chamber. black powder is great stuff and ever so much fun ... the only times i ever had what i considered a specially high preassure load was in a 45-70 that hadnt been cleaned properly and what i figure happened was that the fouling inside the case grabbed the boolit upon ignition and held it just a fraction of time allowing the preassure to rise a bit past normal.

i have never had any special problems tho when used in a clean rifle and loaded in clean and scrubbed cases. course i been unhappilly surprised with some smokeless loads that i had thought were good as well in the past so ... shows that i still dont know all about this game. all i do is recomend what works for me.