Home Forums Hunting & Shooting Ask The Gunwriters 51gr H4350 in Roberts AI with 100gr TTSX?

Three grain backdown for a Model 70, unless you like gas in the face.

As long as one is wearing eye protection, gas in the face is like a nice warm breeze. Complete with the occasional metal particle.

I just noticed this post and I decided to look to see what I have written down on my reloads with my 257 Improved I built quite a few years ago on a commercial Mauser 98 action with a 24" ER Shaw barrel. I use 51 gr. of IMR 4350 with a Hornady 100 gr. Spire Pt. I see than when I chronographed it, it averaged 3200 FPS. I get no pressure signs and it is one of the most accurate rifles I own. Over the last 10 or so years, I have shot some very nice Mule deer bucks and none have required a second shot!! I have quite a few other rifles, but I always grab the 257 AI when I leave the house.
Just wanted to contribute,
Ken

Kenny my Dad's was on a 1908 Mauser and he shot the 117gr Hornady BTSP at about 3100fps w/52.5gr of RL19. Killed a lot of big west Texas whitetails w/that load. He loved the load. powdr

powdr,
I just edited my post--again! I looked again, and I used IMR 4350 not H4350!! I also found a sample of the group I shot with it when I reloaded the last time (2007). It is a very nice 1/2" 5 shot group!!
I am guessing that with approx 40 rounds left loaded for this rifle, I will never have to reload for it again!! I'm 68

Ken

It becomes less amazing when you note his method was remarkably similar to yours, "based on all the usual signs". He stated using the same method. This is probably more significant than comparing 6mm, 25-06 etc. If we have no way of determining between the calibers chamber being identically proportionate to scale, the comparison becomes less meaningful if not meaningless. I suspect it more important to limit pressure to the weakest link of the equation, be it the action, brass, chamber of each. It is for this reason I would suggest double checking a load before accepting a maximum as ok. I certainly could have said it better, and should have. As to Ackley's book, I mostly only refer to it when he's the A in AI due to the before mentioned varied results.

My old friend, One-thumb Walter, has always maintained that cases are their size, because they're meant to be filled to the top with powder...any powder.

It's difficult to pay much heed to P.O. Ackley's velocities. IIRC, some of the loads in his books weren't even chronographed, velocities being estimated from trajectory.

Some other loads weren't even from his own tests, but from other guys who provided him with info. God knows how these sources came up with their velocities. Pulling in ballistic data from less than reputable sources reminds of the fellow who once told me "I know my 204 is shooting 4000 fps with 39 grain bullets, because it's louder than factory ammo".

Richard,

Apparently you chose to ignore the other part of what I plainly stated about the loads in my rifle, about figuring what velocity should be safely possible from the pressure-tested results from other cartridges around the .257 AI in size.

I don't base ANY of my handloads merely on "all the usual pressure signs." If specific, trusted data isn't available, I also look at similar rounds and use proven formulas to calculate what velocity should be safe. I have used this method for years, and when the .300 WSM first appeared, used it to produce the first published loading data. When pressure-tested data came out within the next year, my loads (based on comparison with .300 Winchester Magnum data) were all within a grain, and the vast majority were dead on or within a half grain. That is not the way things work when somebody depends TOTALLY on all the usual signs.

Never got a load from John that was even remotely unsafe. Matter of fact one can usually add a grain or two safely. powdr

John, I would have thought the comparison to Ackley would have been more of a compliment. I feel certain Ackley had access to Remington's and Winchester's pressure data and devised formulas as well. To that end I have used the standard round plus 5% for improved rounds before access to information was widely available. Would appreciate you comments on that method. I do try to keep my loading current. I have Lyman 49th Edition, Nosler 7, Speer 14, none of which include 257AI. Sierra 5th Ed. lists 48gr. of IMR 4350 as a maximum charge (pg. 346), and Hornady 8th Ed. lists 45.3gr. of IMR 4350 as max. (pg. 301) These listed charges stay pretty close to the method of plus 5% I have previously used. So my question is, given that your max. is roughly an additional 5% of the published info I have available, is there a formula simple enough to share that can be used, and if so, would you care to share it? I have to emphasis simple, if you are willing to share that info, (I understand if you're not, I'm sure you worked hard to get it). I would not use anything to complicated at the reloading bench. Thanks in advance, Richard

Can't help with pressures but i use 50.0 of H-4350 with the same bullet.
3200=- in my rifle.

Thanks guys

I appreciate your viewpoints, knowledge, common sense, experiences and reminder of a very basic reloading factor. Load for reasonable velocity.

If I load for 3100 the pressures should be just fine. 3200 plus is possible but 3100fps is all the get up and go I'll need.

Thanks
Jim