retread
04-19-2014, 06:39 PM
I only started casting about 2-1/2 years ago. I read as much as I could on the subject, I was particularly paying close attention to bore vs boolit diameter. I slugged the barrels of all my handguns and rifles in order to determine the boolit diameter needed for each. Then of course I cast my and sized accordingly (generally slightly over the slugged diameter).
I load on a Dillon RL550B for my handguns and was not happy with the results. Accuracy was not what I expected and some leading was present especially on lighter load that failed to obturate sufficiently to "fill" the bore. After some head scratching I loaded some dummy rounds on the 550 with properly sized and lubed boolits, then pulled them with an inertia puller and found that they had been swagged down to a smaller diameter by the case.
In my quest for answers, I noticed many folks were using "M" dies to cure this problem in rifle calibers. I decided to machine some new powder funnels for the RL550B. I list here two illustrations of my modifications:
Dillon 9mm funnel - .354
New funnel - .357
Dillon 45 Colt funnel - .448
New funnel - .450
Cases generally spring back about .001. I machined the new funnels to suit the bores of my handguns ( I load .358 in 9mm and .452 in 45 Colt).
I have had great results in all calibers after making the new funnels, not only at the range but in the loading process. I used 304 SS for my funnels mainly because I had some 5/8" bar stock on hand. For greater wear resistance you might want to go to 4140 heat treaded but I think the SS ones will last a long time.
102715
I load on a Dillon RL550B for my handguns and was not happy with the results. Accuracy was not what I expected and some leading was present especially on lighter load that failed to obturate sufficiently to "fill" the bore. After some head scratching I loaded some dummy rounds on the 550 with properly sized and lubed boolits, then pulled them with an inertia puller and found that they had been swagged down to a smaller diameter by the case.
In my quest for answers, I noticed many folks were using "M" dies to cure this problem in rifle calibers. I decided to machine some new powder funnels for the RL550B. I list here two illustrations of my modifications:
Dillon 9mm funnel - .354
New funnel - .357
Dillon 45 Colt funnel - .448
New funnel - .450
Cases generally spring back about .001. I machined the new funnels to suit the bores of my handguns ( I load .358 in 9mm and .452 in 45 Colt).
I have had great results in all calibers after making the new funnels, not only at the range but in the loading process. I used 304 SS for my funnels mainly because I had some 5/8" bar stock on hand. For greater wear resistance you might want to go to 4140 heat treaded but I think the SS ones will last a long time.
102715