Forming 25-06AI brass - better to start with 25-06 or 270 brass?

[Shinbone]

Thanks for everyone's input. This will be a hunting rifle, but I do like to mess around with fine tuning loads, and, once it is shooting good, I do like to have fun putting rounds downrange.

I was viewing fireforming as "wasted" barrel life. If barrel life will be 1000 rounds, then 200 rounds to fireform is not insignificant. If barrel life will be 1500 rounds, then 200 rounds is a littler easier to absorb.

 

[Brians356]

I do not believe firing 200 "bulletless" fireforming rounds will be nearly as deleterious to the barrel as full-charge loads pushing bullets through it. How could it be?
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[jepp2]

I was viewing fireforming as "wasted" barrel life. If barrel life will be 1000 rounds, then 200 rounds to fireform is not insignificant. If barrel life will be 1500 rounds, then 200 rounds is a littler easier to absorb.

You seem pretty intent on forming with pistol powder.

Using the barrel life calculator on this website, it predicts your accurate barrel life is 800 rounds. I would question the need for 200 cases for that kind of life. Cut it to 50, and have your load mostly developed by the time you have them done.

 

[Shinbone]

You seem pretty intent on forming with pistol powder.

Using the barrel life calculator on this website, it predicts your accurate barrel life is 800 rounds. I would question the need for 200 cases for that kind of life. Cut it to 50, and have your load mostly developed by the time you have them done.

I am not committed to any particular fire forming process. Just trying to get the most use out of the barrel before it goes kaput. And, since I have never done this, I am considering all options.

I am not understanding how using 25-06 loads to fire form helps me develop a 25-06AI load? I guess this is my sticking point. The case volumes and thus potential powder charges are different. Due to the difference in case volume, how does 25-06 load performance have any bearing on how a 25-06AI will shoot in the gun?

In other words, if I fire formed with 25-06 loads, the very next step would be to load a larger powder charge in the newly formed 25-06AI cases, which means the load data from the 25-06 shots would be of no use?

Maybe I am not understanding a critical step?

 

[jepp2]

When you fire the 25-06 parent case in your new rifle, it is like firing a 25-06 AI, since the case volume will take on the new chamber size during firing. I don't know how you load and therefore, don't know the nodes you seek. I tend to stay under the max pressure recommendation for the cartridge (65,000 for 25-06). When fireforming, I want the cartridge to take on a sharp shoulder as a minimum.

I shoot a lot of RL 19 in my 25-06 rifles. Looking at Sierra 6'th edition, for both 25-06 and 25-06 AI:
- using a 100 gr. Sierra bullet and RL 19 powder, the max load is listed as 57.5 gr and gives 3300 fps velocity (25-06) Quickload lists the WC of the case as 65.8 grains and the max pressure as 65,000 psi
- using a 100 gr. Sierra bullet and RL 19 powder, the max load is listed as 57.0 gr and gives 3400 fps velocity (25-06 AI) Quickload lists the WC of the case as 73.0 grains and the max pressure as 60,000 psi

From an accuracy standpoint, I would expect to see similar accuracy whether I fire that load from a 25-06 case, or a 25-06 AI case. Why does the load data seem to be conflicted? Different testing results like we always encounter and a different max pressure. But keep in mind that the 25-06 case has become a 25-06 AI case by the time the bullet has traveled 3.3 inches down the barrel.

I don't know what load of RL 19 will be required to have the cartridge form with a sharp shoulder. But that load is what I would use as the minimum load during fireforming. And depending, I would probably go higher watching for all the normal pressure signs. That is all part of having a wildcat.

I "hear" you continue to question the value of fireforming using a load vs. using pistol powder. I have just tried to share my view of what is the potential benefit of developing data while you are firing loads in your new rifle. And there is nothing that says that all 50 or 200 rounds (whatever you feel you need) have to be done using 1 method or the other. So you might try both.

 

[Shinbone]

Okay, so I think the part I wasn't understanding is running the 25-06AI at a lower max pressure than the 25-06?