Forums
New posts
Search forums
What's new
Articles
Latest reviews
Author list
Classifieds
Log in
Register
What's new
Search
Search
Search titles and first posts only
Search titles only
By:
New posts
Search forums
Menu
Log in
Register
Install the app
Install
Forums
Rifles, Reloading, Optics, Equipment
Rifles, Bullets, Barrels & Ballistics
Super Fast Twist Barrels for Hammer Bullets
JavaScript is disabled. For a better experience, please enable JavaScript in your browser before proceeding.
You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an
alternative browser
.
Reply to thread
Message
<blockquote data-quote="tacomHQ" data-source="post: 2890177" data-attributes="member: 67159"><p>Minor counters- no arguments:</p><p>I would agree ballistically a shape is a shape.</p><p>The question for me is to get the solid down the barrel 40-50 times without significant accuracy degradation (F1, PRS, Mil).</p><p>Lead is basically 1/2 the hardness of brass or copper. At room temp. At 500deg I would say it might be 1/8 as hard.</p><p>I would say that a copper jacketed lead conforms to the barrel.</p><p>Brass seems to act a bit like a button. It does not seem to conform but "wipes" to the nearest relief (observed in retrieved bullets) or off onto the boat tail. Edges to the grooving are like a hoe pulled thru soil- high edges are formed. Either to remain or wipe into the barrel. Barrels accuracy appears to reduce at a dramatically faster rate than copper jackets. They also appear to be harder to clean from the barrel. </p><p>Don't get me wrong... I believe in solids... and your success is outstanding. Outside of a precise shot- a fast kill should be a primary goal. Pencil holes aren't it. If your rounds are ever expected to go beyond 40shots- its godzilla. </p><p>My thought is a 5kfps round will not be a copper jacket bullet-- 200gr or more category. Solids have to be researched. </p><p>Perhaps it is time to run a small caliber test first- 6mm or 6.5- 50 rounds of copper jacket, retrieve the rounds and weigh them. 50 rounds of a solid- and repeat. We have retrieved a bunch of solids - at final velocities of <600fps in sand things stay pretty intact. Rather do water. </p><p>I believe the barrel interaction with the solid has several impacts on its success- including BC down range, maybe a bit further than a <em>typical</em> hunt LOL. However I think 55kpsi will "skid" a bunch of things. </p><p>We did a recent 300BO test: testing 4bullets, 4mfgs, and four different bullet weights starting at 16". Cut one inch, bevel the bore and shoot 4rounds each over a LabRadar. The fps dropped much slower than expected. Powder burn became the big issue/failure. We tested down to 7". Point being a huge amount of work is being done in the first 7-10 inches (this example). A potential is during the initial engagement of the lands, if the round is crooked - it remains crooked. Of course if it is crooked its area of contact is now greater than the base diameter of the bullet- where is the extra material going... deforming or in the barrel as a "wiped" component. </p><p>As a note on the 300BO - the heavier rounds are much more dependable than light grain rounds (gas gun). The heavy round seems to "force/effect" the burn rates during its initial acceleration event. Light rounds failed as the test progressed- which would, I believe, have an effect in cold weather.</p></blockquote><p></p>
[QUOTE="tacomHQ, post: 2890177, member: 67159"] Minor counters- no arguments: I would agree ballistically a shape is a shape. The question for me is to get the solid down the barrel 40-50 times without significant accuracy degradation (F1, PRS, Mil). Lead is basically 1/2 the hardness of brass or copper. At room temp. At 500deg I would say it might be 1/8 as hard. I would say that a copper jacketed lead conforms to the barrel. Brass seems to act a bit like a button. It does not seem to conform but "wipes" to the nearest relief (observed in retrieved bullets) or off onto the boat tail. Edges to the grooving are like a hoe pulled thru soil- high edges are formed. Either to remain or wipe into the barrel. Barrels accuracy appears to reduce at a dramatically faster rate than copper jackets. They also appear to be harder to clean from the barrel. Don't get me wrong... I believe in solids... and your success is outstanding. Outside of a precise shot- a fast kill should be a primary goal. Pencil holes aren't it. If your rounds are ever expected to go beyond 40shots- its godzilla. My thought is a 5kfps round will not be a copper jacket bullet-- 200gr or more category. Solids have to be researched. Perhaps it is time to run a small caliber test first- 6mm or 6.5- 50 rounds of copper jacket, retrieve the rounds and weigh them. 50 rounds of a solid- and repeat. We have retrieved a bunch of solids - at final velocities of <600fps in sand things stay pretty intact. Rather do water. I believe the barrel interaction with the solid has several impacts on its success- including BC down range, maybe a bit further than a [I]typical[/I] hunt LOL. However I think 55kpsi will "skid" a bunch of things. We did a recent 300BO test: testing 4bullets, 4mfgs, and four different bullet weights starting at 16". Cut one inch, bevel the bore and shoot 4rounds each over a LabRadar. The fps dropped much slower than expected. Powder burn became the big issue/failure. We tested down to 7". Point being a huge amount of work is being done in the first 7-10 inches (this example). A potential is during the initial engagement of the lands, if the round is crooked - it remains crooked. Of course if it is crooked its area of contact is now greater than the base diameter of the bullet- where is the extra material going... deforming or in the barrel as a "wiped" component. As a note on the 300BO - the heavier rounds are much more dependable than light grain rounds (gas gun). The heavy round seems to "force/effect" the burn rates during its initial acceleration event. Light rounds failed as the test progressed- which would, I believe, have an effect in cold weather. [/QUOTE]
Insert quotes…
Verification
Post reply
Forums
Rifles, Reloading, Optics, Equipment
Rifles, Bullets, Barrels & Ballistics
Super Fast Twist Barrels for Hammer Bullets
Top