Some success....more work to do

[bcp477]

Now I am finally getting some good results with my paper-patching project. I am trying to find a paper-patch load with a plain-base 170 grain, BHN 15, flat-nose bullet....that will give me good accuracy and about 2000- 2100 fps. The bullets are cheap....no gas-checks required....and a load like that will be a good light deer load (approx. on par with a 30/30 load). I have settled on re-sizing the the .324" diameter bullets to .314"....then patching with ordinary lined notebook paper....to a final (dry) diameter of between .324" and .325". This, with a charge of 24 grains of IMR-3031, plus about 0.5 grains of cotton wool, seems to be accurate in my newly - rebarreled M48 (8mm Mauser). I have more testing to do, but so far, so good. I also need to chrono my load, once I settle on the best charge weight. I also have found that powders like 2400 and Unique are simply too fast to get the results I need with this bullet, in my rifle anyway. But, I am seeing some positive results.... which is encouraging.

[leftiye]

coool! Thanks for the overview. Is there any chance that harder boolits might help? I've read here that 50/50 WW/Pure which heat treats to about BHN 23 expands controllably at that 2000-2100 fps. velocity. Surprisingly, the low antimony lead is malleable, and expands but isn't brittle even though it's hard.

[bcp477]

Harder bullets might help...or not, I can't say. I am not having any problems that would indicate that the bullets are too soft, anyway...so that seems not an issue of consequence at the moment. As it is, I have to do more testing to find the best powder and charge weight....and then chrono the load to see if I am getting the results (velocity) I need for hunting, while getting acceptable accuracy. The whole point of the exercise is to make use of these cheap plain-base bullets....not to modify the bullet "formula". I do not cast my own bullets and I cannot do so - so that is not an option for discussion here.
I made a mistake when I listed the charge weight, in my first post (of this thread). I stated 24 grains of 3031......actually it was 30.0 grains of 3031. So, I should be fairly near the velocity I need....I just need to refine the charge weight, to find the "sweet spot". There is no sign of any problems - the paper patches are definitely shredding and falling away as the bullets exit the barrel - and the barrel is remarkably clean after shooting these. Accuracy is actually quite good....4 of 6 shots in the last string grouped within 1.5" (the other two were not so close, but that MIGHT only be due to the fact that I am using iron sights - they were still all in the "black" on a standard SR-1 target, at 50 yards). My calculations indicate that I shouldn't have to exceed about 32 grains (of 3031), in order to get to about 2100 fps. As for the bullet hardness, I have no doubt that a BHN- 15 bullet will expand at these velocities (better than a harder one) ...so why re-invent the wheel ? If I get the velocity I need, with acceptable accuracy, then I will have a viable load (for my purposes).