sghart3578
12-27-2013, 01:10 PM
I started on my current project many months ago but work and family demands are delaying progress. Thanks to everyone who have answered questions in the past.
I have a VZ24 carbine in 7X57. I really like this little rifle. The bore slugs at .276 X .287 with a throat of .290. Excellent rifling, etc. It shoots heavy jacketed .284 bullets extremely well. My son with his young eyes can routinely hit clay pigeons at 125-150 yards. That was good enough for many years but recently I decided to try to cast bullets for it. I cast for all of my handguns and all of my 30 cal rifles with great success. So I figured that this 7X57 would be easy also. Then I discovered the whole oversized bore issue with milsurp 7mm's compared with domestic 7mm's and their bullet molds cut for .284.
I bought a Lyman 287641 mold and beagled it. It drops the bullets at .289. After lubing and gas-checking they shoot pretty well over 16 gr of 2400 and 10 gr of Unique. I have double beagled some bullets also. They drop at .293 with the nose at .282. I ran these through a custom Lee sizer at .289" but haven't shot them yet.
Then last night I was reading a section in Sharpe's "Complete Guide to Reloading". It was on page 62 of the supplement, not the original text. He discusses the proper sizing of cast bullets. He states that with plain based bullets sizing them .002 - .003" over groove diameter works best. But what caught my attention was his testing with gas checked bullets. His testing showed that cast bullets, gas-checked and sized .001-.002" UNDER the groove diameter consistently grouped better than conventional over-sized cast bullets.
My question is: Do any of you guys have any experience with this? I am greatly interested. I am going to do my own testing as currently my combination of equipment and rifle is perfect to test this theory. My rifle has a groove diameter of .287 and my Lyman mold, unbeagled, drops a bullet at .285 with my alloy. I will post my test results next week but I was wondering if anyone here has already been down that path.
As always I thank you guys in advance for your time and expertise.
I have a VZ24 carbine in 7X57. I really like this little rifle. The bore slugs at .276 X .287 with a throat of .290. Excellent rifling, etc. It shoots heavy jacketed .284 bullets extremely well. My son with his young eyes can routinely hit clay pigeons at 125-150 yards. That was good enough for many years but recently I decided to try to cast bullets for it. I cast for all of my handguns and all of my 30 cal rifles with great success. So I figured that this 7X57 would be easy also. Then I discovered the whole oversized bore issue with milsurp 7mm's compared with domestic 7mm's and their bullet molds cut for .284.
I bought a Lyman 287641 mold and beagled it. It drops the bullets at .289. After lubing and gas-checking they shoot pretty well over 16 gr of 2400 and 10 gr of Unique. I have double beagled some bullets also. They drop at .293 with the nose at .282. I ran these through a custom Lee sizer at .289" but haven't shot them yet.
Then last night I was reading a section in Sharpe's "Complete Guide to Reloading". It was on page 62 of the supplement, not the original text. He discusses the proper sizing of cast bullets. He states that with plain based bullets sizing them .002 - .003" over groove diameter works best. But what caught my attention was his testing with gas checked bullets. His testing showed that cast bullets, gas-checked and sized .001-.002" UNDER the groove diameter consistently grouped better than conventional over-sized cast bullets.
My question is: Do any of you guys have any experience with this? I am greatly interested. I am going to do my own testing as currently my combination of equipment and rifle is perfect to test this theory. My rifle has a groove diameter of .287 and my Lyman mold, unbeagled, drops a bullet at .285 with my alloy. I will post my test results next week but I was wondering if anyone here has already been down that path.
As always I thank you guys in advance for your time and expertise.