How do you tell which jacket length to buy?

[barryjyoung]

So, there is a hydropress sitting in the basement. It wants to get to work. I went to buy bullet jackets and lo and behold, they come in different lengths. Unable to find a convenient chart on the internet that says for a 148 grain bullet use a jacket that is X long. So I turn to you. How do you know what length jacket to buy?
At more than $1000per case from Berger, I want to make sure I buy the right ones.

Thank you

Barry Young
Wanna be bullet maker

[Ajax111]

If you go on the Corbin web site, look up jackets. It will give you an idea of the jacket lengths for each weight of bullet.
It's only an idea, but it's a start.

Good Luck!

[MUSTANG]

Your Swaged Bullet will be a matching of Jacket Length and the Core you are using. The following table is from Corbin and lists the length of the core to the diameter and weight of the cast/swaged core.

http://www.corbins.com/corewts.htm


They (Corbin) used to have charts for what length Jacket for the desired weight range. Did not immediately find that; but perusing the Corbin Web pages would probably turn up those charts somewhere.

[Liseo]

For 155 grains ogive 7 bullets, I´m using J4 jackets 1.150" long

[475AR]

It will also depend on the nose shape of the bullet and also if it is a FP or HP with exposed lead or not. Corbins used to have a DOS program that you could input all of the data for a jacket, core and nose shape and it would give you a jacket length to start with.
What I have started doing is to order the longest jacket and make test bullet and see if it is what I want and if not trim the jacket and try again. I find I can get it figured out in a couple test bullets and once happy I record the information and I also do a core and trimmed jacket as well as a seated core in a jacket and keep them in a labled bag so later when I do another run I have them to set up the dies with.
It does speed up the future runs.

[barryjyoung]

Thank you Ajax111. I have been to the Corbin website, there is so much information there I sort of suffocate a little. Anyway after spending countless hours there, and an hour after your response, I still have not found a chart or anything telling me which jacket to buy for a given bullet weight. I cannot find it on Bergers site either. So I came here to ask.

Thank you
Barry

[barryjyoung]

Thank you Liseo. How did you determine which jacket to use?
Barry

[barryjyoung]

Hey 475AR:
That is helpful thanks. My plan was to buy long jackets, trim them to whatever length I need. Then buy appropriate jackets if they are available. That is a great tip keeping a core, trimmed jacket and seated core. I like that a lot.
Thank you
Barry

[Ajax111]

From Corbin web site for 30 caliber bullets.
Jackets------ Bullets
J-30-115=130-165grain bullets.
J-30-125=160-190 grain bullets
J-30-136=185-250grain bullets

There is no chart, that I could find. Each jacket gives you a range of the weight they are used for.

Good luck.

[barryjyoung]

From Corbin web site for 30 caliber bullets.
Jackets------ Bullets
J-30-115=130-165grain bullets.
J-30-125=160-190 grain bullets
J-30-136=185-250grain bullets

There is no chart, that I could find. Each jacket gives you a range of the weight they are used for.

Good luck.

Thanks Ajax111 I will go dig deeper.
Barry

[barryjyoung]

So, there is a hydropress sitting in the basement. It wants to get to work. I went to buy bullet jackets and lo and behold, they come in different lengths. Unable to find a convenient chart on the internet that says for a 148 grain bullet use a jacket that is X long. So I turn to you. How do you know what length jacket to buy?
At more than $1000per case from Berger, I want to make sure I buy the right ones.

Thank you

Barry Young
Wanna be bullet maker

It just seems like there should be information somewhere on which jacket to buy for a particular bullet, but I have been unable to find anything like it. This is amazing considering how many jackets are sold.

Wierd.

Barry

[garandsrus]

Each jacket length can produce a wide variety of bullet weights, depending on how much of the bullet nose you fill with the core while point forming the bullet.

Also, if you are making a flat point or lead tipped bullet, the jacket length will change. A flat point would normally take a shorter jacket since the lead fills the jacket and the jacket is not closed all the way.

Your best option might be to measure a bullet of the weight and design you want to make and then get jackets .1” shorter (I am guessing here) since the jacket will lengthen when it is point formed.

[barryjyoung]

Each jacket length can produce a wide variety of bullet weights, depending on how much of the bullet nose you fill with the core while point forming the bullet.

Also, if you are making a flat point or lead tipped bullet, the jacket length will change. A flat point would normally take a shorter jacket since the lead fills the jacket and the jacket is not closed all the way.

Your best option might be to measure a bullet of the weight and design you want to make and then get jackets .1” shorter (I am guessing here) since the jacket will lengthen when it is point formed.

Thank you so very much I will do just that.
Barry

[Ajax111]

Have you come up with a system on length yet?

[barryjyoung]

No sir, not yet.

[SSG_Reloader]

The ogive can dramatically change the weight windows of jackets. Jacket walk thickness of course too. What ogive and caliber are you Swaging and weight are you lookin for?

[barryjyoung]

I am currently set up to make .308 jacketted bullets with pure lead cores. I would like to start with 168 grain closed tip rebated boat tail base.

[SSG_Reloader]

What ogive?

I have some 308 variations, rebated boat tail setups and a tip closer too with an array of jacket lengths so as long as I know the ogive, I can dial in some tests for the length youd want.

[Gew]

1.150 inch rce jacket
Rce 8s point form
Rbt with open tip
Maximum weight with no lead pushing out the top is 175 grains for me. A 10s will be 167grains.

Don't get caught up in hitting an exact grain weight, focus on making every bullet in a batch exactly the same as the others. If the recipe you come up with makes a 166 or 171 grain bullet so be it, that's going to give the accuracy you may want.