Long Range Hunting Online Magazine


Go Back   Long Range Hunting Online Magazine > Rifles, Reloading, Optics, Equipment > Reloading

Reloading Techniques For Reloading


Reply

280AI Necked to 338 Neck Length Question

 
LinkBack Thread Tools Display Modes
  #8  
Old 06-07-2013, 08:00 AM
Edd Edd is offline
Gold Member
 
Join Date: Jan 2011
Location: Tulsa
Posts: 870
Re: 280AI Necked to 338 Neck Length Question

The neck will be about .032" longer when necked up to a .338.

Necks get shorter when the diameter is decreased and longer when it is increased.
Reply With Quote
  #9  
Old 06-07-2013, 08:41 AM
Gold Member
 
Join Date: Dec 2009
Posts: 746
Re: 280AI Necked to 338 Neck Length Question

Quote:
Originally Posted by Edd View Post
The neck will be about .032" longer when necked up to a .338.

Necks get shorter when the diameter is decreased and longer when it is increased.
OK, looks like my understanding of the process is bass ackwards. Thanks for the help! Would the neck need to be trimmed to obtain the proper 2.54" case length following being necked up?

Last edited by benchracer; 06-07-2013 at 09:05 AM. Reason: added a question
Reply With Quote
  #10  
Old 06-07-2013, 08:58 AM
Gold Member
 
Join Date: Dec 2001
Posts: 787
Re: 280AI Necked to 338 Neck Length Question

Quote:
Originally Posted by benchracer View Post
Here is the thinking behind what I want this wildcat to do:

1. I am looking for approximately the following performance levels from a 26" barrel @ 63k-65k psi:

3050-3100 fps with a Barnes 185g TTSX

2800-2850 fps with a CE 225g D62

2600-2650 fps with a Berger 250g Hunting Hybrid

2. I want to keep the case capacity to a level that favors powders in the 4350 burn rate range. I am hoping that if I do that, RL-17 will work well in my wildcat and provide a velocity advantage that cannot be had in a case capacity that favors the 4831/RL-19 burn rate range. I am probably going to need QL to help me get an idea what case capacity I am really after. That will probably be one of the first items on my shopping list as I plan and research this.

3. I want to retain the option of using Nosler 280AI brass without fireforming. I might still end up going with Norma 280 brass and fireforming, but it would be nice to be able to skip that step, if desired.

Here are my questions/concerns with the information regarding using the Sherman reamer:

Would the .300 Sherman reamer simply need to be fitted with a .338 pilot to produce the desired chamber?

From what I have been able to find out, the 30-06 and .280 case each have a capacity in the neighborhood of 68 grains, the 280AI capacity is around 73 grains, and the Sherman is around 76 grains. By comparison, the .338WM has a capacity of about 86 grains. As mentioned above, I am interested in bumping capacity enough to gain some velocity, but I want to be careful not to bump it so far that I have to use H4831/RL-19 burn rate powders. I believe that would end up costing me performance, rather than enhance it. My problem is that I don't know where the cutoff in case volume is.

I assume that going with the .300 Sherman would require me to fireform my brass. Is that correct? Would I need to use the false shoulder technique to do this?

Where the dies are concerned, I have used a micrometer seater die in the past and never felt that it offered much advantage over my standard Redding dies. Where the bushing die is concerned, I have always been leery about using one because I have read that the bushing dies tend to cause a "doughnut to build up in the case neck. Once again, I have always had excellent results with my standard dies and have never felt the need to manipulate neck tension like the benchrest guys do.

My bottom line, where dies are concerned, is that I would like to stay with standard type Redding dies. What would I need to do to make that happen? If I stayed with the Nosler 280AI case, would that allow me to use off-the-shelf dies like the ones I mentioned previously?


If you took 280AI neck it up to 338 that case would hold app 71gr/R-17 to the top of the case mouth and if you filled to the start of the neck it be appr 65.5gr/R-17. The 35 WhelenAI to the top of the case mouth it hold appr 72.gr/R-17 and do same to 30x280AI it hold appr 70.5gr/R-17. A new 280AI case filler to case mouth hold appr 70gr/R-17.

You going to run pretty close to 338-06AI velocity and I would use 338-06 data as start loads.
__________________
Semper Fi
Reply With Quote
  #11  
Old 06-07-2013, 09:00 AM
Edd Edd is offline
Gold Member
 
Join Date: Jan 2011
Location: Tulsa
Posts: 870
Re: 280AI Necked to 338 Neck Length Question

When you decrease the diameter of the neck, the shoulder becomes longer.

It becomes longer because it is extended farther forward.

Extending it forward makes the neck shorter.
Reply With Quote
  #12  
Old 06-07-2013, 10:35 AM
Platinum Member
 
Join Date: Dec 2008
Location: Northern Id.
Posts: 3,103
Re: 280AI Necked to 338 Neck Length Question

Quote:
Originally Posted by benchracer View Post
OK, looks like my understanding of the process is bass ackwards. Thanks for the help! Would the neck need to be trimmed to obtain the proper 2.54" case length following being necked up?
Benchracer....I think what is confusing you is you have two different things going on. When you increase the neck size on a case from .284 to .338 the the point of the shoulder/neck junction moves back giving you a longer neck by .040 plus thousandths. On the other hand, necking a case up shortens the OAL a little (.005-.010") and it is all in the neck so you have a net gain of .035", plus or minus, in the neck but the oal is slightly less. Does this make sense? You would not have to trim, in fact, the case oal would be slightly shorter......Rich
Reply With Quote
  #13  
Old 06-07-2013, 10:45 AM
Platinum Member
 
Join Date: Dec 2008
Location: Northern Id.
Posts: 3,103
Re: 280AI Necked to 338 Neck Length Question

Quote:
Originally Posted by benchracer View Post
Here is the thinking behind what I want this wildcat to do:

1. I am looking for approximately the following performance levels from a 26" barrel @ 63k-65k psi:

3050-3100 fps with a Barnes 185g TTSX

2800-2850 fps with a CE 225g D62

2600-2650 fps with a Berger 250g Hunting Hybrid

2. I want to keep the case capacity to a level that favors powders in the 4350 burn rate range. I am hoping that if I do that, RL-17 will work well in my wildcat and provide a velocity advantage that cannot be had in a case capacity that favors the 4831/RL-19 burn rate range. I am probably going to need QL to help me get an idea what case capacity I am really after. That will probably be one of the first items on my shopping list as I plan and research this.

3. I want to retain the option of using Nosler 280AI brass without fireforming. I might still end up going with Norma 280 brass and fireforming, but it would be nice to be able to skip that step, if desired.

Here are my questions/concerns with the information regarding using the Sherman reamer:

Would the .300 Sherman reamer simply need to be fitted with a .338 pilot to produce the desired chamber?

From what I have been able to find out, the 30-06 and .280 case each have a capacity in the neighborhood of 68 grains, the 280AI capacity is around 73 grains, and the Sherman is around 76 grains. By comparison, the .338WM has a capacity of about 86 grains. As mentioned above, I am interested in bumping capacity enough to gain some velocity, but I want to be careful not to bump it so far that I have to use H4831/RL-19 burn rate powders. I believe that would end up costing me performance, rather than enhance it. My problem is that I don't know where the cutoff in case volume is.

I assume that going with the .300 Sherman would require me to fireform my brass. Is that correct? Would I need to use the false shoulder technique to do this?

Where the dies are concerned, I have used a micrometer seater die in the past and never felt that it offered much advantage over my standard Redding dies. Where the bushing die is concerned, I have always been leery about using one because I have read that the bushing dies tend to cause a "doughnut to build up in the case neck. Once again, I have always had excellent results with my standard dies and have never felt the need to manipulate neck tension like the benchrest guys do.

My bottom line, where dies are concerned, is that I would like to stay with standard type Redding dies. What would I need to do to make that happen? If I stayed with the Nosler 280AI case, would that allow me to use off-the-shelf dies like the ones I mentioned previously?
You should have no problem getting the velocities that you are looking for. The .338 Sherman would probably hold approx. two more grains than a .300 Sherman which would put it near 79 grains. IMR 4831 would work well as would H4350, RL17 and even up to RL22 with the heavier bullets. You would have to fire form the Sherman by using a false shoulder. If you wanted MAXIMUM velocity gain, the Sherman would do it but if the extra hassle is not worth it to you, the gain would not be that much.......Rich
Reply With Quote
  #14  
Old 06-07-2013, 11:22 AM
Gold Member
 
Join Date: Dec 2009
Posts: 746
Re: 280AI Necked to 338 Neck Length Question

Quote:
Originally Posted by elkaholic View Post
Benchracer....I think what is confusing you is you have two different things going on. When you increase the neck size on a case from .284 to .338 the the point of the shoulder/neck junction moves back giving you a longer neck by .040 plus thousandths. On the other hand, necking a case up shortens the OAL a little (.005-.010") and it is all in the neck so you have a net gain of .035", plus or minus, in the neck but the oal is slightly less. Does this make sense? You would not have to trim, in fact, the case oal would be slightly shorter......Rich
Thank you. Your explanation clears things up for me! I was thinking about neck length in isolation and trying to relate that to case OAL, which was screwing me up. I knew I needed a conceptual adjustment somewhere, I just couldn't figure out where I was going wrong.
Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes


Current Poll
Do you plan to buy a new custom rifle in the next 12 months?
YES - Of course - 73.10%
1,549 Vote
NO - wife/girlfriend won't let me. - 26.90%
570 Votes
Total Votes: 2,119
You may not vote on this poll.

All times are GMT -5. The time now is 05:51 AM.


Powered by vBulletin ©2000 - 2014, Jelsoft Enterprises Ltd.
Content Management Powered by vBadvanced CMPS
All content ©2010-2014 Long Range Hunting, LLC