38/55, 1:20 twist.

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  • Last Post 07 October 2015
Singleshot S.A. posted this 31 August 2015

Hi guys, I bought a rebarelled Pedersoli Sharps a while back, It was a reasonably cheap buy and I'd wanted one for a while. I don't have photos yet but will try to get one up later. It has a single trigger, and a straight stock (not pistol grip), and a “safety” that automatically engages as the breech is opened. This “safety” merely puts a spacer between the hammer and firing mechanism. It works. Has caught me out a few times thinking I'd had a miss fire. Would this be a Cavalry carbine. ? Anyhow, The barrel that was fitted has a 1 in 20 inch twist, and my question is,.... what will be the heaviest, or, longest projectile that is likely to stabilise. I did a silly thing and went out and  bought a mold (325g) before checking the bore, and unfortunately, they didn't stabilize, went through at about 45 degrees. haha. Anyway, I did have a pretty heavy load, (breech seated) of drop tubed, slightly compressed, 57 grains of Wano 'P' with a lubed wad. Could it have over stabilized, or am I up for a lighter mold. Obviously I have loaded some lighter loads and will be trying again, but would like to hear your thoughts. PS, I'v had mild success with the Lee 250g  with the 57g load, so that's why I started with 54g, 55g, 56g and 57grain loads for the heavier projectile. Perhaps they stripped, (30:1 lead tin), which dropped out of the mold at .381, and the barrel is .380. All ideas and advice is appreciated, cheers, S/S from S.A.

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Ken Campbell Iowa posted this 31 August 2015

the lee 250 gr is the best of my 3 or 5 377-8-9 molds in a win. 94 38-55 i recently put together .

velocities between 1200 and 4000 fps don't have much effect on stabilization ... so it is primarily your twist that is too slow for that long bullet ... the good news is that lee molds are priced such that it hopefully won't be a financial disaster .

also you could mill off the base of the mold and make a shorter bullet, with a plain base ...or dial it in in a lathe 4-jaw and while you are at it bore the base section to fit your chamber ... my lee 250 casts the largest bullet and fits my sloppy m94 chamber best of my molds .

of course you should do a cast or lead upset image of your chamber and throat to get the best idea of what your bullet should look like . that procedure is probably rule one for shooting our mushy lead bullets .

just some thoughts . ken

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onondaga posted this 31 August 2015

http://castbulletassoc.org/view_user.php?id=9226>Singleshot S.A.

Try one of the recommended loads from Hodgdon for 38-55 Winchester. Hodgdon recommends a 250 or a 255 gr bullet and a reasonable variety of powders:

http://www.hodgdonreloading.com/>http://www.hodgdonreloading.com/

Lymann #4 handbook only recommends 225 -335 gr cast bullets. Lee only recommends 200- 255 gr bullets. Your mold at 325 gr would not have been my first choice due to lack of recommended loads..

Twist charts will tell you what is ideal for your bullet but be advised that rifles shooting cast bullets are way less sensitive to bullet weight.

Your keyholing on paper could also be due to velocity, load pressure, barrel length and alloy choice related to your load level.

Common twist rates for the 38-55 are 1:12 , TC carbine and rifle and 1:18, Ruger and Marlin 336 Cowboy. The faster twist is for heavier bullets in the Marlin Cowboy but your 1:20 twist is for even heavier bullets and close enough for your 325 Gr cast bullet in my opinion.

I don't think your twist rate is the problem.

Gary

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Ken Campbell Iowa posted this 31 August 2015

berger bullet's online calculator thinks ::

.4 dia bullet, 0.3 bc, at 1600 fps; length 1.2 is stable

at length 1.3 inches it is slightly unstable .

oh, except in denver, where it is stable again ( g ) ...

these calculators are fun to play with, at least they are valuable at showing there is some range in the proper twist ..

ken

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Singleshot S.A. posted this 31 August 2015

Thanks Ken, I hadn't thought of shortening the mold, so if all else fails, all is not lost.

onondaga, I will continue to try different loads, I have only just started really, yes it is a tad heavy,for some, but I think the heavier bullets do help with powder burn. It will only ever shoot black powder, light plinking type loads are of no interest for this rifle, I use my 32/40 for that to a maximum 200 yds. I'm glad to here you think the 1:20 might still work. Thanks again, S/S S.A.

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onondaga posted this 31 August 2015

http://castbulletassoc.org/view_user.php?id=9226>Singleshot S.A.

If you can consider a replica powder instead of real BP, consider Alliant Black MZ. It is the cleanest burning replica powder, the easiest to ignite and it has the lowest ES by chronograph of any replica or black powder.

It is inexpensive $21.85/lb and in stock at: http://www.powdervalleyinc.com/index.html

Here is a good general description of Alliant BMZ: http://www.alliantpowder.com/products/powder/blackmz.aspx

Gary

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Singleshot S.A. posted this 01 September 2015

Thanks Gary, Jeez, I wish I lived in the U.S.A haha, Alliant MZ, at my local South Australian seller, $57.80. Remembering we only get about .75c per dollar at the moment. I hadn't actually heard of MZ, ( pretty much an ADI man or a bit of WIN 760 and some old SR4759), checked my LGS and blow me down they have some. That price is about the going rate for most non Aust made powders, Win @ $59.00, ADI (Aust) $48.00. I sometimes shoot a Duplex load in the 32/40, mainly because it's on a Martini Cadet action and the duplex helps with the residue. Would the MZ work as the primer load. ? Cheers S/S S.A. http://s1090.photobucket.com/user/AussieCombat/media/Black%20powder%20stuff/DSC02501.jpg.html>

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onondaga posted this 01 September 2015

http://www.castbulletassoc.org/view_user.php?id=9226>Singleshot S.A.

The BMZ would work as well as black Powder in a cartridge application for duplex loads. BMZ is a direct volume substitute for 2F Black Powder.

The BMZ alone would be a fine load also and very clean. The little fouling that BMZ leaves is non-corrosive and actually a dry lubricant that does not attract moisture. BMZ is a citrus based propellant and a true innovation in clean replica powder shooting.

I routinely shoot BMZ in a flintlock main charge with a .3 gr BP primer pan charge and shoot 30 times a range trip with no cleaning or patch running between shots shooting the 50 caliber  250 gr Lee R.E.A.L. bullet cast in pure lead  with 75 gr BMZ. I use this powder in percussion rifles also. It puts fun back into muzzle loading it is so clean.

In America, BMZ is priced a few dollars less per pound than real BP and is also the lowest priced BP substitute available that I know of. It is economical to shoot here and I think it is the best we have to offer. I earned two second places in Postal matches on this forum with BMZ. So, I really like it.

Gary

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Singleshot S.A. posted this 02 September 2015

Good info,thanks.

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onondaga posted this 02 September 2015

The Alliant instructions for BMZ state that BMZ ignites best and burns most completely when compressed. Re-read the general info on the product and keep that in mind. You can work around that with a recommended ballistic filler like BPI Original ballistic filler or Precision Reloading PRPSB spherical filler if you need a reduced load of less powder than a normal compressed 105% load of BMZ powder in a cartridge by using a safe and recommended filler to achieve 105% density with a reduced load.

Gary

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Singleshot S.A. posted this 05 September 2015

Just regarding a shorter bullet,

I was given a tip yesterday,...... seat the projectile in a sizing die to the required length, cut it off with a hacksaw, then file it square against the hardened die body.

Tried this, seems to be a good way to get a rough idea. Will shoot them tomorrow. THEN I can shorten the mold. My 325g is now 265g, that is, about 8mm shorter. Cheers S/S.

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Mal posted this 07 September 2015

Hi SS,        If you need to mill the base off that mould bring it over and I can do it for you.                                     Cheers Mal.

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beltfed posted this 07 October 2015

Onondaga,

Beg to differ with your comments on twist vs bullet length/wt. --that the “20 twist” is for even heavier bullets"

Just the Opposite: Its the Faster twists that stabilize longer bullets.

as in the 12 twist t/cs will stabilize the longer bullets. The 20 needs shorter bullets.etc

beltfed/arnie

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onondaga posted this 07 October 2015

http://www.castbulletassoc.org/view_user.php?id=1981>beltfed

You are correct, I dyslexicated. 1:20 is slower than 1:12 or 1:18.

Gary

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Brodie posted this 07 October 2015

The 255 gr. Lee bullet stabilizes quite well in my Stevens m44 38-55 with eight to ten gr. of Unique.  I haven't used black powder or any substitute yet, but Unique, Red Dot, IMR 4227 all work well.  I might note that my rifle and perhaps yours seem to prefer softer bullets.  1:1 pig lead to WW is the hardest alloy that shoots well for me. Your mileage may vary. Brodie

B.E.Brickey

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beltfed posted this 07 October 2015

Gary,

Understand, I am not trying to be a smart a#$. I figured you knew better

beltfed/arnie

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