Any experience with max loads in 8mm06 Ackley

[shawnba67]

Any one ever play with this round. It's my first wildcat and I am gonna try and ask questions before I mess up. It's in a Mauser 98 gas a big 45 on the recieved and a step barrel. Using 200gr speer and imr4350 powder. I got to 2750 fps on my fire forming loads at 60gr and got what I thought were the starts of pressure sign. What fps have you worked to safely? I'm not looking to scorch the envelope but any advice on were the envelope is would be appreciated.

[koger]

I only shot 170gr JSP's in mine, and was getting right around 2980 average, will have to look up the data. No pressure signs, and no sticky bolt. I will get back to you.

[frnkeore]

What are you calling "pressure signs"? If the primer pocket is loose, that is defiantly a sign to back off.

Frank

[shawnba67]

121799
What are you calling "pressure signs"? If the primer pocket is loose, that is defiantly a sign to back off.

Frank
looked like brass flow back into ejector slot. well it looked like a scraped spot on brass 1/8''wide.primers were normal,but the scrape didnt start til right about max loading.

[UBER7MM]

Shawn,

You're two grains over what my ancient Speer manual records as the max load @2580 fps, (© 1979). Personally, I'd try a slower burning powder with a heavy 200 grain bullet, like H4831 or slower. I'd even start with 8x57 loads and work up from there.

I hope this helps,

[shawnba67]

Yes I worked up to the 60 gr, it's also in an Ackley improved chamber might explain why I got away with that 2 gr.

[shawnba67]

I just reread my last post and without proper punctuation it sounds close to snarky, it wasn't intended to be. I started at 54gr and went up. After I hit the speer max I made a third test round at .5gr intervals. My Ackley book listed 62 gr as max for 8mm06. I did not load past 60 and expected to need to stop short and take a few back a Apart. But other than brutal recoil all went well enough I don't currently have $$$ for new powders to try but do have 3 lbs of 4350 on hand so for moment that's my focus Thanks for anyadvice

[UBER7MM]

Shawn,

You have a wildcat of a wildcat, so load data will be extremely hard to find. 54.0 grains was a good place to start. The heavier the bullet, the more recoil. You can cure some of that with a 150 grain bullet, however, the 1:95 twist of your military barrel is well suited for 200 grains.

I've found that the most accurate load isn't necessarily the hottest load. I'd test loads for accuracy and stay with the tightest group. I'd also site in the first shot from a cold barrel, if your planning to hunt. I'm thinking that you've got an excellent gun for North American Elk or Moose or anything smaller.

[shawnba67]

That was my hope, and to get a good rifle as cheaply as possible. The 200gr was my hope at a one load rifle. My reloading experience isn't as extensive as I'd hope at least not for wildcat load development. I agree on the max load usually not being the most accurate, but the fastest accurate enough load will often be the best hunting load. The recoil isn't a big problem, it's not worse than my ML. If ain't fun though. My hope wS to glean some experience from the more experienced out there. I'm figuring since velocity and pressure are so tightly linked the max velocity some one has safely achieved in the AI version can be used as a do not surpass.
If this isn't available does any one know the general rule on grains of powder to drop back once pressure signs are reached? Is 1gr enough?

[fouronesix]

Given the variables of different powders, chamber specs, brass, bullets, bores, headspace, etc. it would be impossible to say what would be a "safe" reduction in charge once pressure signs are seen. Plus, without pressure testing equipment, who knows what the pressure really is when the pressure signs are noticed?

I owned, loaded for and shot AIs on both sides of the 8-06 AI. The 30-06 AI and a 35 Whelen AI-- but not the 8-06 AI. In both rifles, I could load very slightly larger charges before pressure signs started to show. But I don't think that means much. I did notice that the AIs generally favor a slightly slower powder than the powders favored by their non-AI "parent" cartridges.

IMO- just use published 8-06 load data and work up loads normally and don't believe or even pay attention to the often seen claims of "higher velocity at no cost" magic. I believe the biggest advantage to the AI cartridges is increased headspace control.

[frnkeore]

Your primers look fine and if you don't have any hard bolt lift problems, I wouldn't worry about it.

Your rifle is strong enough to withstand any pressure that the case will hold. Different cases will withstand different pressures as much as 2 gr. The hardness of the brass and how thick the case head is (front to back) will determine how much pressure it will take.

I use two standards to determine maximum loads:

1. If I pierce a primer or it opens a primer pocket, I cut back 2 gr on a hot day and maybe 2.5 gr if it's in the 60's or colder.

2. I determine how long I want the brass to last, 5 loads per case is minimum but, 10 is more economical. When the primer pocket loosens the brass is done!

Finding Max loads isn't dangerous if you use the proper powder for the starting charge and work up in 1 gr increments at first and then .5 gr as you see the primer loose it rounded edge. 1 gr WILL NOT blow your gun up, it may well pierce a primer or open a primer pocket and you'll feel a little gas in your face (never shoot w/o glasses).

If you have good brass, reaching Ackely top loads, can be possible but, be cautious near the top. I had no trouble getting max charges of 3031 with a 140 gr bullet in my 7mm AI Mauser, using Norma brass.

People that have blown guns up, have almost always grabed the wrong powder for the loading data or not checked the powder charge with a powder scale. There are other reasons, too but, not by exceeding max load data by by 1 gr.

Like I said, the brass will tell you what is max if your using the right powder.

Frank

PS
There is one more indicator with your cartridge, your shoulder :) 200+ gr bullets will tell you when to stop if your going to shoot it much!

[EDG]

Shawn
I found some data in my old 1970s Pacific Manual. If you want to look for this manual it was copyright 1967 and my copy is dated as the 5th printing in 1971.

It has data for the 8mm-06. Then it says boost the data 5% for the 8mm-06 AI.

The 4350 data for the 225 grain bullet is 57 grains max.
Boost it 5% and you get 59.85 grains of 4350.
I think your loads are safe but you can be sure by shooting 10 to 20 more rounds.
Case capacity and hardness, primers, seating depth and even ambient temperature might affect your results.

[GabbyM]

Given the variables of different powders, chamber specs, brass, bullets, bores, headspace, etc. it would be impossible to say what would be a "safe" reduction in charge once pressure signs are seen. Plus, without pressure testing equipment, who knows what the pressure really is when the pressure signs are noticed?

I owned, loaded for and shot AIs on both sides of the 8-06 AI. The 30-06 AI and a 35 Whelen AI-- but not the 8-06 AI. In both rifles, I could load very slightly larger charges before pressure signs started to show. But I don't think that means much. I did notice that the AIs generally favor a slightly slower powder than the powders favored by their non-AI "parent" cartridges.

IMO- just use published 8-06 load data and work up loads normally and don't believe or even pay attention to the often seen claims of "higher velocity at no cost" magic. I believe the biggest advantage to the AI cartridges is increased headspace control.

243 A.I. may not be a close comparison to a big bore 8mm-06 AI but. My experience with it gives me reason to agree with everything fouronesix posted above.

[shawnba67]

Thanks much for the advice and help. Trying to keep sight on that fine line between safe maximum and not leaving to much on the table. May only be a 5% capacity increase for a2% velocity gain, but it's there why not grab it by the tail? I already paid for it!

[Hang Fire]

Very true, I had a 8mm-06 made up in early 1960s when such was common, it was a deer killer for sure with jacketed ammo.


Shawn,

You have a wildcat of a wildcat, so load data will be extremely hard to find. 54.0 grains was a good place to start. The heavier the bullet, the more recoil. You can cure some of that with a 150 grain bullet, however, the 1:95 twist of your military barrel is well suited for 200 grains.

I've found that the most accurate load isn't necessarily the hottest load. I'd test loads for accuracy and stay with the tightest group. I'd also site in the first shot from a cold barrel, if your planning to hunt. I'm thinking that you've got an excellent gun for North American Elk or Moose or anything smaller.

[fouronesix]

shawnba67,
The compilations by Loadbooks USA are very good. They incorporate published data from available sources into a single, easy to use reference. And, they are very inexpensive. Here's a link for the 8-06 and 338-06 compilation.
http://www.midwayusa.com/product/794498/loadbooks-usa-8mm-06-springfield-and-338-06-a-square-reloading-manual?cm_vc=ProductFinding

[shawnba67]

Thanks much. I've got a couple of those already in other cAlibers , also got a subscription to loaddata( which I love) but they a only use Ackleys rather optimistic data.

[fouronesix]

Thanks much. I've got a couple of those already in other cAlibers , also got a subscription to loaddata( which I love) but they a only use Ackleys rather optimistic data.

You have that right about Ackley's data being optimistic. He was "selling" his improved cartridge idea when he developed a lot of that data. He was known to push actions to the limit and also kaboomed a few. His data usually pushes the upper limit (and exceeds standardized limits once in a while) and leaves no margin for error for either the brass case or the gun. Most of his data does show the recognizable increase in velocity…. but that comes at a price. And to this day…. velocity sells :)