Author Topic: How To???? (Read 1029 times)

JPH45 · « **on:** May 12, 2005, 10:03:13 AM »

.379 bullets are difficult to find at best. What would a fella need to bump factory 375 bullets for the 375 Winchester (200-220 grainers) up from 375? Any good reason this couldn't be done?

talon · « **Reply #1 on:** May 12, 2005, 11:35:59 AM »

I believe the diameter of the .375 Winchester is .376. But, in any case, you could probably 'bump-up' jacketed flat nose .375s up .006"d without loosening the core-jacket bond. If you are going to bump up lead .375s to .379"d for a tight barrel fit, fine, but you may have an accident if you run a jacketed bullet that size thru the bore.

riverjackal · « **Reply #2 on:** May 13, 2005, 07:35:03 AM »

Talon,
What would a man need to put a hornady 220 grain bullet of .375 diameter into a rcbs press and bump it up to .377 or .378 ? That is my question.
I think it is a good idea but the price of hornady 220's would probably go up.
JPH45, I think you have hit on an idea that will work for 38-55 reloaders to tinker with. All I can come up with off the top of my head is a modified die set of some smaller diameter to run the bullet into and then push it back out with reasonable ease. I appreciate it and I will pursue it with vigor.

jcunclejoe · « **Reply #3 on:** May 13, 2005, 08:08:36 AM »

Accuracy wise you are always better off to bump something up than to reduce the diameter. We are of course talking jacketed bullets. If you can push on the lead tip and base and make the bullet larger you will actually increase the "grip" of the jacket on the core.

If you draw the bullet down to a smaller size by even .001 you will loosen the grip of the jacket. This happens because the lead has very little spring back and the copper has much more. So when it goes through the die the lead will stay the smallest it gets and the copper will spring back some from the smallest it gets, going through the die.

The finest bullet making dies in the world are designed to grow the bullet ever so slightly at each stage of the forming. That ensures that the copper jacket is stretched tightly over the lead.

Talk to the people at CH4D or RCE or Corbin and they can make you a die to bump your .375 bullets up to .379 They will not be too cheap but you can make what you need.
Good luck
Joe

talon · « **Reply #4 on:** May 13, 2005, 09:17:20 AM »

I've never bumped up a bullet, I've always reduced them when I had to. As to how much you can reduce them, it depends upon the shape of the bullet, and the thickness and material of the jacket. If it's core bonded, there's no problem at all. I'm not sure, but I believe a "bump up" die will cost as much as a PF die as they are basically the same thing ( about $175)) And, I don't believe you can find one for a reloading press, but I've never tried.
I make .377"d 255 grain jacketed bullets for 38-55 work. I also have ring dies to reduce these puppies down to .376"d. Again, the reduction dies have to be built for the thickness and type material of the jackets you work with.