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

I was about to load some 100 grain TTSX for my Roberts AI so I read my record of the work up with 100 grain TSX. I had recorded 51grains H4350 with 100TSX. That seems like a HOT load.
Chronographed; 3201, 3225, 3209 3216 3221. 22 inch barrel.

Can someone tell me what pressures that is producing. CUP or PSI will be OK.

I like my Roberts AI. I like my face. I like my life. I like keeping them all intact!

Thanks
Jim

sounds like a max load for a 25-06AI, don't think I'd be stuffing that much in a Roberts. Can you even fit that much in a Roberts case?

Sounds like Dick Austin is being an idiot again.

I think you are likely right at the edge with that load. 3200 or so FPS is what I'd be looking for with that powder.

Steelhead I welcome you to stuff 51 gr. into a 257ai; I hear blue dot will go 3200. Try it.

To OP, steelhead's an idiot. Don't load anything he says until you've double checked it someplace valid, like a Hornady or Nosler reloading book. In fact IMR/Hogdon has their info online which is where you should check. Repeat, steelhead - big mouthed idiot - IMR info good.

Scott

Thanks for weighing in. Any idea how I could find the pressures produced here?

Thanks
Jim

hang in there, scottie will be right back with the pressure.

MAX load for a 25-06AI is 5 to six grains MORE, three grains more for the std. 25/06 in Sierra's latest.

3,100 from a 22" std. 257 is about it. Going to 3,200 in a 22" 257 AI is also going to be about it, since the 25/06 will get 3,330-3,400 depending on barrel length.
(Nosler lists a 100 BT from a 24" barreled 257AI with I4350 at 3,208 with 56.6gr water capacity)

51 grains is at max or a little over, I wouldn't start there but I wouldn't be scared to work up to that starting out at maybe 48 grains.

Pressure is found in a pressure barrel, no real way for you to find pressure without one. All you can do is rely on the data provided in your reloading manuals, and check your brass for signs of pressure.

RichardAustin

I don't have the Hornady book at hand but I do have the Nosler book here. Could you give me the page number that addresses H4350 in 257 RobertsAI? I would like to read their commentary.

The Roberts case easily contained 52gr of H4350with 100gr TSX when I was reloading them. They trickled in just fine. I shot some but I was not pleased with pressure signs. So I expect I'll not need to "stuff" 51 grains. Just want to know the pressures.

Steelhead may be a hardhead but he has weighed in on several questions I've had in the past and has been accurate and helpful. He, too, can probably read the books.

Thanks
Jim

Well Jim, you do seem to have computer access, so why not check the IMR /Hogdon site if you really want that info? I have no problem with you doing as steelhead would, have at it.

As I said, I think 51 would be about max. Once I hit 3200fps I'd stop and not be skeered to drop it a grain.

I know we've run 51-52 with the XLC, it was a Barnes listed load in an older manual. TSX and XLC tend to be kinda close in my experience.

Just checked and they showed 48.5 of H4350 with the 100gr X, which tends to be more sticky a bullet and I'd expect to get a few more grains in.

Load to velocity is how I'd roll and be content to stop at 3200. What's it doing at 50?

My Nosler manual shows several propellants topping out at or just above 3200, including the IMR version of 4350. Seems like a reasonable ceiling to me.

I took my 24" Nula Bob AI to 3309 with 51/H4350 and the Nos 100 BT as well as the XLC. I would NOT go any higher.
But for an everyday load I switched to R19.

I use 46.5 grains of H4350 under a 100TSX from a Kimber roberts, no pressure signs

Looking at Hodgdon's site shows the 6mm Rem. producing better than 3100 fps with 100 grain bullets and both H and IMR 4350.

That's a smaller diameter neck on the "non-Ackleyed" version of the case.

As has been pointed out, based upon my experience (which is admittedly limited) that is likely a hot load I'd not make hotter.

Check out the Nosler data online; IIRC (please check this) they list 51 gr IMR-4350 as max w/ 100 gr Noslers which would include the ETip which is stickier than the TSX.

Scott is right on when he suggests letting your chronograph be your guide.

If its any consolation I've been getting 3330 fps from 50.5 gr IMR-4350 & 100 gr Speer HPs for several loadings (>3) without any sign of issues w/ the RP brass in my 24" barreled 257 AI.

Along with the chronograph I like to reload 3 cases and fire them first each time I visit the range just to see how many firings I get before issues arise. Probably overthinking things, but as you say my rifle and especially my face are worth it.

3152

"My Nosler manual shows several propellants topping out at or just above 3200, including the IMR version of 4350. Seems like a reasonable ceiling to me."

Thanks
I have some IMR 4350 but I have a lot more Hodgdon 4350. So...... Lookin to use the Hodgdon.

Thanks
Jim

Brilliant. Check velocity at a pre determined speed and forget pressure. Just bloody brilliant.

I wasn't suggesting the IMR, just commenting on the nature of a reasonable max speed with that class of propellant.

Based on MAX's/pressure tested data between the std. 257 and the std. 25/06 with like barrel lengths using H4350, checking the speed IS checking the pressure.
Of course having the cases and primers not showing any flags, 3,200 IS about it.

Personally, I'd knock it back a grain too......

You are a [bleep] idiot, and that's the best part of you.

Yep, I'd personally run it at 50grs and call it a day.

I agree with the 3,150-3,200fps notion or thereabouts. 3,300-3,325 is about comfortable with 100's in my 23" 25-284 and it's got a bit more room in the case. RL17 seemed to be the ticket there, when comparing with H4350. I want to say I hit pressure around 3,250 with the 4350.

Just loaded
5 @ 48
5 @ 49
5 @ 50
5 @ 51
TTSX
Hodgded 4350
257 RobertsAI
Goal - 3150fps

I'll be at the range next week.

Thanks for the help, men. Appreciated.

Jim

I've loaded 100-grain bullets of various sorts to 3200 fps in the standard Roberts with IMR4350, and had the pressure checked. It was fine, as it should be, since by the basic rules of interior ballistics the .257 Roberts should be capable of more velocity than the 6mm Remington with a 100-grain at the same pressure. There are a bunch of published loads at around 3200 or even higher for the 6mm. Nosler, for instance, lists a top velocity of 3261 fps for 100-grain bullets in the 6mm from a 24" barrel.

Consequently, when I was running a .257 AI (which was a few years ago) I expected a little more velocity than from the standard cartridge. The only accurate Barnes bullet in that rifle (a NULA Model 24) at that time was the 100 XLC, and I used 52.0 grains of H4350 for a little over 3300 fps. Dunno what the pressure was but based on all the usual signs, plus the results safely possible from the 6mm Remington and standard .257 Roberts I had no worries.

Rug I've run a 257AI for 25years and used only 51.0gr IMR 4350 and 52.0gr of RL19 from a slow can of powder...both reaching 3050fps from a 21in barrel. You'll be fine. powdr

Some more data:

Since the powder capacity of the .257 AI is about halfway between the standard Roberts and the .25-06, we'd expect potential velocity to be about halfway between them. We've already seen that the standard .257 should easily be capable of 3200 or so with 100's from a 24" barrel. .25-06 data from manufacturers who use the same barrel to work up loads and chronograph them indicates 3350-3400 fps is possible. Thus we come up with about 3300 fps in the .257 AI.

Also, the data for Accurate 4350 (which I've found similar to IMR and H4350) shows 52 grains as maximum with the 100 TSX from a 24" barrel, for a velocity of 3293 fps at 61,100 PSI.

Ackley published one load for 100 gr. bullet of 50gr./ 4350 for 3,257/fs. I've had varied experience using his published maximum loads.


ETA: rug/Jim Vol. 1, page 336/337 of P. O. Ackley's HANDBOOK FOR SHOOTERS & RELOADERS , apologies for not knowing which edition.

I am always amazed that people still considered Ackley's book a source of reliable data. A lot of the loads were a grab-bag from "various sources" (I believe that's the phrase used in the book), and some he acknowledged were estimated by the wildcatters who developed pet cartridges.

A few of the loads he personally tested were probably OK, but the more I learn about pressure-testing the less I trust any data from that era. A lot of people simply didn't know how to conduct repeatable and controlled pressure tests, which is why Speer used case-head expansion as their method, after nobody working there could figure out out to work copper-crusher equipment.

There are also two other factors: Nobody knows what bullet was used in most of the data in his book, or the primer, case, etc. And the powders used not only aren't exactly the same anymore, but the storage conditions are unknown.

There are a bunch of other errors in that book, which I won't go into since they're too numerous. It's an interesting slice of history, but not a trustworthy source of loading data.

I picked up an almost full box of 117gr 25 caliber Remington roundnose bullets at a gunshow a few years ago. Inside cover of the box had some load data scribbled in pencil for the 257AI. That's what I use.

I usually make up my own speeds, that way the cartridge can be what I want it to be....

The K Hornet can be amazing in that regard.

I've heard that if you "short-cut" mil-surp H4831 in a Cuisinart, then fill up a K-Hornet case to the brim and seat a 40-grain bullet on top, the velocity is close to 4000 fps.

I haven't "heard" that one...

Ackley "data" was filled with a lot of "I heard" and speculative, optimistic craziness.

In this case, having a lot of std. Roberts data and std. 25/06 data with H4350 and a chronograph is about ten thousand times more reputable, and repeatable, than anything original Ackley data could dream up.

I believe Ackley data had 3,450 with a 45 gr. bullet in the K-Hornet....just because it was "improved". Ouch!

Maybe it WAS chronographed somehow, but they used an old rimfire barrel?

The .223AI REALLY shines in that light. Especisally compared to the deuce mag.

Now you're typing like Elmer Fudd, you wascawy Ackleyite....

Sounds like the result of too much fiber.

His real handle is "Granola".....

Just add powder until you have to beat the bolt open with a hammer, then back down 1 grain. Back down 2 grains on a Remington 700, as the bolt handles fall off with minimal beating or prying so you want a proper safety margin.

I've found that it grinds better if you toast it in a cast iron skillet over an open fire first.

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