Peterson Brass and 280ai neck bushing size

[CTK]

Hi,
I have come to believe that Peterson Brass is thicker and has less volume than Nosler. Have heard this on forums and found pressure signs at book max loads. I view this as a positive and am adjusting accordingly.

Question: I used a .308” Redding neck bushing for Nosler brass in my previous 280ai...... went up to my only other bushing for 7mm @309” on the Peterson brass. It seats the 175 Elite Hunter very smoothly and easily. A loaded case neck measures .313”. Do I have too much neck tension based on the subtract .002” method or am I okay due to the thicker brass? I do not own a micrometer to measure neck thickness. To the best of my knowledge the chamber is no turn. Jon Beanland built it and I assume he would have told me. He said was a tight Sammi 280ai chamber. I have no feeding issues. Time to buy a larger bushing?

Question 2:The pressure signs that I saw were a faint rectangular swipe and about 60 fps over Berger’s max load for RL 23. The swipe is a new mark for me. Have seen the Remington 700 oval/half moon swipes before but not this mark. The action is a Bighorn SR3. Know it has a form of controlled round feed. Would this explain the mark? My other Bighorn is a SR2 and does not have controlled round feed. I guess a swipe is a swipe. Just a new one for me. Could high neck tension cause spike in pressure.

thanks

 

[Ringostar]

I would consider getting a 310 and 311, then test them all.

 

[gman47564]

Couple things you might check.. first see if one of your bullets will fall down in a fired case.. it should.. then measure the neck on a sized case with your calipers.. then seat a bullet and measure neck again in the same place..

 

[john pruitt]

You should be fine .You are correct the peterson brass is thicker.

 

[RegionRat]

Your measurement over the seated bullet is giving you a good value for the brass thickness, so you can estimate your bushing choices based on your caliper measurements without having a tubing micrometer. Like Ringostar said, experimenting with the other bushing sizes is better than guesswork.

In my own work, I do load development on new situations with a similar starting view towards how to size down the neck, but... I prefer to develop the recipe using an in-line die and arbor press with a force gage. The “neck tension” value gives me a seating force range that is used to manage the whole set of issues including cleaning, chamfering, lube, annealing, etc. When the seating force changes, then I know I have to search for the reason.

On your second point, I know the use of a charge ladder test using a chronograph can start an infinite debate, but that is my advice. Exploring the hot end requires careful observation of the brass combined with homework to know when to expect pressure signs. I will add that getting a different answer driven by differences in brands of brass is possible.

If you are tipping over due to the differences in brand of brass, a fair question would be what was your margin using the other brand before seeing signs of pressure?

Your brass internal volume can be compared to your old recipe for a clue as to internal volume differences, and that measurement isn’t hard to learn using a fired case versus a virgin sized case and a spent primer for a plug. Check your old recipe against your new one. Using your scale and water makes this easy to try if you think you want to know the internal case volume. I don’t think this is as important as more direct testing of your load due to brass prep changes. In other words, even if you knew the case volume to the third decimal point, what would you do with the number? You will probably proceed to experiment with charge and neck tension anyway.... It is good to know if a new component is very different than an old one, but case internal volume would have to be significantly different to cause a load to tip over unless you were already on the hot end.

The internal volume, the chemistry and heat treat of the head, the heat treat of the neck, the cleaning and friction coefficient of the neck, and so forth, can all contribute to differences. By chance, did you do the exact same prep and recipe using your old brass at the same time as a side by side?

 

[CTK]

Your measurement over the seated bullet is giving you a good value for the brass thickness, so you can estimate your bushing choices based on your caliper measurements without having a tubing micrometer. Like Ringostar said, experimenting with the other bushing sizes is better than guesswork.

In my own work, I do load development on new situations with a similar starting view towards how to size down the neck, but... I prefer to develop the recipe using an in-line die and arbor press with a force gage. The “neck tension” value gives me a seating force range that is used to manage the whole set of issues including cleaning, chamfering, lube, annealing, etc. When the seating force changes, then I know I have to search for the reason.

On your second point, I know the use of a charge ladder test using a chronograph can start an infinite debate, but that is my advice. Exploring the hot end requires careful observation of the brass combined with homework to know when to expect pressure signs. I will add that getting a different answer driven by differences in brands of brass is possible.

If you are tipping over due to the differences in brand of brass, a fair question would be what was your margin using the other brand before seeing signs of pressure?

Your brass internal volume can be compared to your old recipe for a clue as to internal volume differences, and that measurement isn’t hard to learn using a fired case versus a virgin sized case and a spent primer for a plug. Check your old recipe against your new one. Using your scale and water makes this easy to try if you think you want to know the internal case volume. I don’t think this is as important as more direct testing of your load due to brass prep changes. In other words, even if you knew the case volume to the third decimal point, what would you do with the number? You will probably proceed to experiment with charge and neck tension anyway.... It is good to know if a new component is very different than an old one, but case internal volume would have to be significantly different to cause a load to tip over unless you were already on the hot end.

The internal volume, the chemistry and heat treat of the head, the heat treat of the neck, the cleaning and friction coefficient of the neck, and so forth, can all contribute to differences. By chance, did you do the exact same prep and recipe using your old brass at the same time as a side by side?

I just ordered 310 and 311 bushings. Spoke to Redding and somewhat gathered that my Continuing using the expander somewhat negates the increased neck tension from the thicker brass and the 309 bushing. Also figured out that I am probably needlessly overworking the brass by the combo of too small bushing and use of the expander. Do most people remove the expander on Redding competition dies? If so I may have completely missed the point of the bushing dies. Or is the idea to properly size the neck and then have a light touch with the expander? I got rid of my Nosler brass and decided to start new with the Peterson so have not done a side by side comparison. I am going out today in the heat to try a reduced load and some seating depth experimentation. Using RL 23 which should not be greatly impacted by the 90 degree temps but will give me an upper range for temp impacts on pressure. This is a custom hunting rifle. I would stay home before I deer hunted in 90 degree temps. I continue to learn so much from the experts on these specialty sites. I appreciate the responses from all.

 

[nmkid]

You would probably do well not using the expander.

 

[oldroper]

I just ordered 310 and 311 bushings. Spoke to Redding and somewhat gathered that my Continuing using the expander somewhat negates the increased neck tension from the thicker brass and the 309 bushing. Also figured out that I am probably needlessly overworking the brass by the combo of too small bushing and use of the expander. Do most people remove the expander on Redding competition dies? If so I may have completely missed the point of the bushing dies. Or is the idea to properly size the neck and then have a light touch with the expander? I got rid of my Nosler brass and decided to start new with the Peterson so have not done a side by side comparison. I am going out today in the heat to try a reduced load and some seating depth experimentation. Using RL 23 which should not be greatly impacted by the 90 degree temps but will give me an upper range for temp impacts on pressure. This is a custom hunting rifle. I would stay home before I deer hunted in 90 degree temps. I continue to learn so much from the experts on these specialty sites. I appreciate the responses from all.

As mentioned you do well not to use expander. I just got 100rd Peterson 280AI brass. I have 2-280AI and 280AI I'm working on one has 26" Kreiger barrel and been fire form 280 brass. My other one has 27" Lilja barrel and using Nosler brass for that one. I used IMR-7828ssc to measure case capacity and that powder is what I'm using. Their was appr 1gr more using Rem case and Peterson case weight 4gr more.

I have Redding body die and use that then neck die with bushing (no expander). I also have set of Wilson neck die and seater made from chamber reamer. I drew 1st elk rifle season here in Co and won't have 280AI ready and give me more winter to play with it. Good luck

 

[CTK]

My 310 and 311 bushings showed up today. I should remove the expander, use .002" neck tension first, and experiment later?

 

[Ringostar]

I would size a small batch of cases with each bushing. Keep them separate from each other. The load some test ammo keeping everything else equal. Shoot them and see if one groups better than the other. Yes, remove the expander.

 

[oldroper]

My 310 and 311 bushings showed up today. I should remove the expander, use .002" neck tension first, and experiment later?