Rum and coke here.
Increasing the diameter of a copper bullet
- Thread starter BJung
- Start date
BigGame
Silver $$ Contributor
You’re looking to build a CA hunting round, you’ve said. Peregrine are non-expanding dangerous game bullets. I don’t think anything in your region requires this. Buy 50 of these Hammer bullets and try them. They are suitable for any game animal in CA and will work with twist rates as slow as 1:13.5
.312 Cal-150gr Stone Hammer™ - Hammer Bullets
The 303 British now has a Hammer! This Stone Hammer™ design with a 2.5mm hollow point will be perfect for the old war horse to do some table fare work. This pure copper projectile should run close to 2800 fps and do a great job on big game.
hammerbullets.com
Buy some Hornady 150 gr or 174 gr .312 diameter and see if they help your accuracy problem. Or knurled the diameter up in a lathe in a collet and a knurling tool. Or buy 8mm Barns copper bullets and turn them down to any diameter you desire. Without a lathe the larger diameter Hornady bullet would be the choice or change the barrel. Swaging up bullets take a lot of pressure plus special dies and cost a lot, and all copper bullets would be next to impossible for the average hobbyists, plating up would be an option.
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hogpatrol
Gold $$ Contributor
A die can be bought that the smokeless muzzleloader guys use to size down bullets for sabotless shooting. I have one that's made for reducing the diameter of jacketed bullets. Hankins may be able to make one for the size desired. A friend has an SML land rider shooter and he sizes his bullets to .456 which leaves .002 on the diameter, .001 on the side of no contact with the grooves. If .3115 isn't working, there's something else going on, the load, the twist, the crown or other variable. A half a thousandth small shouldn't mean squat in a hunting rifle.. For measuring, the only thing calipers are good for in a reloading room is measuring the length of your cases, CTBO and CTOL. If one has a good set of eyes, case lengths could be measured with a six inch scale graduated in 100ths. OT, In my reloading room, I have calipers scattered around like cheater glasses, there's always one at hand to make quick use of.
hanksprecisiongunparts.com
Bullet Resizing Dies - Hanks Precision Gun Parts
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bozo699
Gold $$ Contributor
Erik Cortina did something similar and 1 hole groups at 1000 yards
Wayne
dhagerty40
Gold $$ Contributor
Ca you are limited to solid copper bullets for hunting. But have you read the warning from Barnes that the bullets prefer a large muzzle jump? I copied it here:
When loading a Barnes TSX, Tipped TSX or LRX bullet, your rifle may prefer a bullet jump of anywhere between .050” up to .250” or more. This distance off the lands (rifling), aka “jump” may be limited to the rifles throat length, magazine length and bullet length.
When selecting the cartridge overall length (COAL) we recommend starting with a minimum “jump” of .050” off of the lands. You can test different seating depths and find a “sweet spot” that your particular firearm prefers. We suggest working in at least .025” increments as follows seating the bullet deeper to allow a further jump. Your test plan could look something like this:
1st group- .050” jump
2nd group- .075” jump
3rd group- .100” jump
4th group- .125” jump
5th group- .150“ jump
6th group- * see below
This length can be determined by using a “Stoney Point Gauge” or other methods. You do not have to seat the bullet at, or on one of the cannelure rings. Remember there are many factors that may control or limit the seating depth for your application. You may find that you need to start at around 0.150” off the lands and are not able to get any closer due to limiting factors including proper neck tension and magazine length.
*In rifles that have long throats you may be limited on how close you are able to get the bullet to the lands. In these instances, it is not uncommon to find the best accuracy with a jump of .200” or more.
This jump may possibly stay the same regardless of powder or charge weight within a given rifle. If preferred accuracy is not obtained, we certainly recommend trying another powder, for the powder type and charge greatly affects the overall accuracy of each individual firearm.
FYI- An accurate load requires a bullet with the proper consistent case neck tension which leads to more constant pressures and velocities.
A die can be bought that the smokeless muzzleloader guys use to size down bullets for sabotless shooting. I have one that's made for reducing the diameter of jacketed bullets. Hankins may be able to make one for the size desired. A friend has an SML land rider shooter and he sizes his bullets to .456 which leaves .002 on the diameter, .001 on the side of no contact with the grooves. If .3115 isn't working, there's something else going on, the load, the twist, the crown or other variable. A half a thousandth small shouldn't mean squat in a hunting rifle.. For measuring, the only thing calipers are good for in a reloading room is measuring the length of your cases, CTBO and CTOL. If one has a good set of eyes, case lengths could be measured with a six inch scale graduated in 100ths. OT, In my reloading room, I have calipers scattered around like cheater glasses, there's always one at hand to make quick use of.
Bullet Resizing Dies - Hanks Precision Gun Parts
Lee will do that too. I had one made to size .224 bullets to .223 for an old 22K Hornet. Works great.
Yeah, and of course we all have the tooling in the kitchen to make it happen. @jackieschmidt, you are something seriously special. Always love the insight you bring.
dellet
Gold $$ Contributor
I have had a lot of accuracy problems with solid copper bullets and subsonic loads. The problem was stability that was not caused by bullet length, but diameter, similar to what might be happening here.
Because of not sealing the bore completely, the base of the bullets were being gas cut and along with a poor exit from the muzzle, stability was effected.
The solution was to crank up the pressure using faster powders, from the high 20k to the mid 40,000 psi range. Memory says that 44,000 was a number actually suggested by Barnes, but since I can not find that in writing, I might have called, or be confused.
If you look up pressures needed to deform metals, most copper alloys will be above 40,000 psi.
Flat base bullets were easier to get good obturation than boat tails, and hollow bases would expand and seal the bore at much lower pressures.
This would align with the “Barnes bullets need to be pushed hard comments”
Because of not sealing the bore completely, the base of the bullets were being gas cut and along with a poor exit from the muzzle, stability was effected.
The solution was to crank up the pressure using faster powders, from the high 20k to the mid 40,000 psi range. Memory says that 44,000 was a number actually suggested by Barnes, but since I can not find that in writing, I might have called, or be confused.
If you look up pressures needed to deform metals, most copper alloys will be above 40,000 psi.
Flat base bullets were easier to get good obturation than boat tails, and hollow bases would expand and seal the bore at much lower pressures.
This would align with the “Barnes bullets need to be pushed hard comments”
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divingin
Gold $$ Contributor
May not apply here, but when the CA lead ammo ban for hunting came out, there was a lot of talk about needing to scrub the bores clean of the gilding metal used for jackets from lead bullets prior to trying to get the monolithics to shoot well. Apparently the leftover jacket metal played hell with the copper used for the non-lead bullets.
Haven't heard a lot about that recently though (I'm not a hunter, though, so I don't go looking for it, either.)
Haven't heard a lot about that recently though (I'm not a hunter, though, so I don't go looking for it, either.)
The T99 already has a large bullet jump. I can barely seat the bullet in the case when the longest bullet touches the rifling.
rockhound78
Silver $$ Contributor
I have read of suggestions to take two new clean files and put a bullet flat on one and put the other on top and just move the file back and forth, parallel with the first. Won't take long to "knurl" the bullet. Or, you could powder coat the bullet to increase the diameter.
Knurling? I have heard people are using this process on muzzleloading bullets
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