.38-55 duplex load questions

[nitroproof]

I'm wanting to try some duplex loads in my .38-55 Whitney R.B.

Q. #1: I want to try Unique... My old red Lee scoop (#20) is throwing about 2.6 grains. Enough or should I try a more? (Also have 4227, RedDot, 700X, 2400, 4227, 4198, etc...)

Q. #2: Lee red scoop # 141 throws around 35 gns FFFg by weight, Lee red scoop #167 throws around 40 gns FFFg by weight but fills the case to within 3/16" of the top requiring way too much compression (seating depth: 0.6" (long 310 grain bullet).

Q. #3: Should I still drop tube?

Q: #4 Sound like a reasonable starting point?

Thanks, Craig (NRA Lifer) :holysheep

[twotrees]

Nitro,

I have been using 4,7 gr of a faster powder than Unique, but the same amount of Unique should do you well.

I load 40 gr of 3 F Goex and use the expanding plug to compress the powder and a 36 cal wonder wad (lubed) to bullet seating depth.

It has shot well for me and 50 rounds shot in less that a hour didn't crud up the bore.

Be careful the reduced load of 40 gr and the fast powder can be trouble if you double charge the fast stuff.

Good Shooting,

TwoTrees

[nitroproof]

Took a Bic Stic ball point pen (type with the removable cap) and dropped in a case charged with the 2.6 grs of Unique. Marked it with a red pencil at the case mouth. Dropped it in each case to check for missing/double charges. Double charged one on purpose to check the "checker".

Works great.

Will shoot some duplex loads Saturday :holysheep

[Dale53]

I have no experience with the 38/55 but I have shot a truck load of duplex 40/65's and have shot with MANY who did the same with 40/65 and 45/70.

Work up a load with your choice of Black Powder. Reduce that "proven" load by 10% (by weight)and replace that with 10% by weight of your choice of powder. I have always used and preferred RL-7 but 4227 works very well also. I don't care to use the faster powders to duplex. It is too easy to drop a double charge. Rl-7 measures well and the results are excellent.

The Lyman cast bullet handbook has actual pressure data using 4759 in a 45/70.

If you don't exceed 10% (using a relatively slow powder such as 4227 or RL-7) you should not have pressure problems.

Good advice would have you starting with 5% and working toward 10% smokeless. Use as little as it takes to get the performance that you desire. With a good duplex load, you can literally shoot all day. I had several 100 shots and over days with NO problems. Just shoot as if you had smokeless powder in the gun (no blow tube, no wiping, etc. just shoot). The clean up should be just as thorough as if you had used all Black Powder. I use a good black powder solvent then dry patches, then a good preservative.

I built a duplex powder measure from a broken Mec shotshell reloader. It helps to prevent a double charge (just like it does with powder and shot in the shotshell loader). I drop from the measure, then use a compression die. As the British say, "It works a treat".

NOTE; I recommend that you use a good black powder bullet lubricant like SPG (I use Emmert's Home Mix).

Good luck and shoot center!
Dale53

[omgb]

I shoot a lot of duplex in both 45-90 and 38-55. My personal choice is RL 7 and then 2400 in that order. They work, produce excellent accuracy and have some margin of error built into them. They are fast enough to get the job done but not so fast that a full grain one way or the other makes any difference.

I have found that unless stepped up velocity over straight BP is your goal, sticking to about 6% of the charge by weight is a better deal than 10%. It burns as clean as the heavier charge but does not raise pressures much over BP.

The lube issue is a big one. Use a good BP lube like SPG. Others designed for smokeless are going to fail big time.

[woody1]

From Ideal Handbook No. 38 for the 38-55: 255 grain cast + 5.5 gr. 4759+38 gr. FFg. They don't list any velocity. FWIW Regards, Woody