Resizing jacketed bullets

[cooper]

Does anyone have any experience using jacketed bullets which have been resized?

It's getting hard to find surplus 147 or 150 gr 30 cal bullets at a decent price (I shoot a Garand).  Some of the military surplus sites sell .312" 147 gr FMJ bullets which have been resized to .308".  I was thinking that the "rebound" of the lead core after sizing might not be the same as the rebound of the copper jacket, if you know what I mean, possibly resulting in a lead core which is loose in the jacket.

Does this affect accuracy?  Has anyone actually shot bullets like these, and how accurate are they?

[wncchester]

Yeah, know what you mean and question the accuracy with any such down sized bullets too. 

The problem is the core does not "rebound" but the jackets do.  It might work if the bullets were first formed down to say, .284" or so, and then back up to .308.  That's normal, and the core would be locked tight, but not if it is just down in a single step process.

[talon]

As I usually swage bullets from raw jackets and lead cores, I rarely have a need to resize existing bullet to a smaller diameter. I do sometimes repoint Spitzer bullets to RN, and it doesn't overly affect accuracy. ( this repointing doesn't work in all circumstances. A lot depends on the caliber, the origenal ogive, and the final ogive.) Some who have studied resizing bullets, and making reduction dies, state that under the majority of cases, a reduction of up to .005" is quite OK. If the jacket has been annealed there will be less springback. of course, and some jacket metals spring back more than others, but as a general rule, a .005 reduction is a "safe bet". Remember, even if a bullet is being reduced .005"d, the 'squeezed' core material has to go somewhere, so you'll get a deformed nose. Lead doesn't 'spring back', but it flows . It may need repointed.

[jager]

I've been resizing .323 diameter jacketed bullets through a .318 resizing die (made for me by a fellow in Montana) for a couple of decades. The maker of the die recommended I use Speer bullets that were "flat based"; however, I have used other brands with limited success. I only drive them to about 2350fps, which must not cause any undo stress on the jacket or cores. I first lube the bullet, then drive them through the die.  It is slow, but they are as accurate as any of the special .318 bullets I have from Norma or RWS.

[Hank08]

Jager, have you miked the inside of your die.  I'd be interested to know how small it has to be sized to allow it to spring back to .318.  It has to be smaller .317, .316?  I'd appreciate that # if you could find out.  Or if your die is .318 what size are your bullets after sizing? .319, .320?
H08

[jager]

Hank - I am now unable to "mike" the inside of may die since I have J.B. wlded it to a wooden block so I would have a "platform" to drive the bullets through. I did go back and measure many of the bullets I resized over the years (I've had the die some 15 years).
   The 175gr. FB Sierra's I resized were .3185 to .319. The 200gr. Speer were .318 "on the nose". The "maker of the die" indicated that some brands, other than Speer, had a tendency to "shift their cores" and were less accurate; and that I should not resize any "boat tailed" designs. While I realized the "squeezed" lead has to go somewhere, I believed the open end would accept the "flow".  I had not considered "spring back" to be a "significant" problem until I read it here. While a .001 may increase the amount of pressure of any given load, I don't think it will effect it any more than a bullet with a "harder" or "softer" jactet material at comparable speeds.
   I tend to agree with Talon, that .005 is acceptable for bullet reduction. A chronograph usually points to "anomalies" when using components that have been "modified" and appropriate cautions should be taken. (Many variables = many results!)
   Before I purchased the die and found a person who sold me some Norma .318 bullets, I tried some "old" Cor-lock Remington 170gr. RN .32 cal bullets that miked .320. They shot and performed well out my "Drilling" with loads in the 2500fps range at an estimated 40,000CUP range (not measured). My Drilling does "slug" .318 precisely. I believe this is the bullet Remington used in ther factory 8MM loads for many years.
   Thanks to all for the usefull info.

[Hank08]

Thanks, Jager, I've tried sizing down and I've also shot the Speer .32 special bullets.  I have 2, at present, .318 bore rifles and I've started  low with .323 bullets and worked up and found that nothing bad happened.  One of the most accurate loads in my combo gun is the 175 gr. .323 Sierra Spitzer loaded to 2500 fps.  No signs of pressure of any sort, primer pockets never get loose, cases last a long time, I don't remember ever throwing any out.
I was thinking that a heavy jacket would size down different than a light jacket, maybe not spring back as much or what about a partition would the partition be a different size than the rest? Just thinking.
H08