Question about an old powder

[MarineTech]

First, a little back story is in order.

Recently, a close friend inherited one of his grandfather's rifles. This was a custom rifle built from a Mauser action in .257 Roberts back in the late 40's. It's a beautiful job with Lyman peep sights and a quick throw side scope mount with an "Alaskan" scope. Apparently, this rifle was the envy of many in the area. A beautiful job and a great rifle. We were up helping my friend's parent clean out some of his grandfather's old things and we came across his old reloading notebook. Now this is where things got really interesting. It had his complete load development for that rifle including data and the targets he tested them on. It appears that he settled on 2 loads for the rifle. 1 load is legible and intact and was labeled "Deer Load". It consisted of a 117gr. JSP bullet in a Remington-UMC case with a Winchester large rifle primer and 43gr. of 4320. The corresponding target was labeled "100 yrds" and has a 3 shot group that can be covered by a nickel. Unfortunately the second load is partially obscured by water damage, but is labeled "Crow/woodchuck load". That's unfortunate because the target shows an even tighter group that can be covered with a dime. It was using a Winchester case with a Winchester large rifle primer, an 87gr. JSP bullet, but the powder is difficult to make out. Looking at it, it appears to say "43gr. of 435 C".

So, here's the deal. I've got a Yugo Mauser that's being rebarrelled to .257 Roberts to use as a varmint rifle. I was planning on doing some load development for it, and, at the same time, work up some loads for my friends rifle. From what we can tell, this notebook dates back to the late 60's or early 70's. While I know that powder formulations have changed a bit since then and I'd have to start about 10% low and work back up to be safe, the notebook does give me a good starting point for that rifle. I'm assuming that the 4320 mentioned in the 1st load is IMR 4320 which is still available and is shown in a number manuals that I have for the .257 Roberts. The 435 C has me stumped though. I'm thinking that it may be a 4350 as this powder is currently shown as suitable for the .257 Roberts, but the "C" is away from the rest of the 435, so I'm not sure.

Does anybody know if there was a powder called 435 C, and if there was such a powder, what is the modern equivalent?

 

[Mike Irwin]

Well, this is nothing more than a guess, but the only powder that I can really match that was fairly close to the numbers that you've got there is what you proposed, IMR-4350.

Here's a thought on the C...

When you shake the case, can you hear anything rattle?

4350 is a pretty slow powder, so the charge may be compressed, and that was Grandpa's way of telling that...

 

[C.R.Sam]

By my early 50s data for 257 Roberts

That load for the 117 gr bullet looks to be bout 10 percent OVER max.

43 gr of 4350 under a 87gr jacketed should be mild and produce around 3,000 fps.

Above info is from early 50s and pertains to powders available then.

Sam

Added, think would have to go to 48gr 4350 under the 87 to start getting compression....again....50s powder.

 

[Johnny Guest]

The Superb .257 Roberts - - -

CURRENT information on IMR website, at http://www.imrpowder.com/pdf/IMR_rifle.pdf
Unfortunately, no data shown for 87 gr bullets.

I agree, the old notes must refer to 4350 powder, but C.R.Sam’s comment that 43 gr of 4350 and an 87 gr bullet being pretty mild is spot on. My personal experimentation with 4350 in .257R (limited to two rifles) has been with the 100 to 120 gr. Bullets. My own Ruger 77S really shoots well with 43 to 44 gr of 4350 and a 100 gr bullet, and this is not max.

MarineTech , Very interesting story. I respect your quest for information on friend’s granddad’s loading data. HOWEVER, the point bears repeating: CURRENT powder different from that of the 50s and 60s. Even if all the notes were clearly readable, your thoughts about backing off and re-developing the loads are exactly correct.

Sounds like you contemplate a wonderful project. For what it’s worth, my favorite load: R-P cases, Rem 9-/12 primer, Sierra flat base Spitzer bullet, and 44 gr. IMR 4350. About half a grain under max, but standard cautions apply. My early 1970s Ruger has not been babied at all, but this is the only deer hunting combo I have that gives sub-MOA groups on demand. It was the “First deer taken†rifle for both my sons and several other friends and relatives.

My kindest wish to you: May your association with the .257 rifle be as long and rewarding as mine has been.

Best,
Johnny

 

[MarineTech]

Thanks for the answers folks, I appreciate it. 4350 was pretty much what I thought it was, but I just wanted to verify. I know that there used to be a couple other powder companies around that are gone today. Figured that I better make sure.

Johnny, I fully expect that my .257 experience will be just as rewarding as your own.

 

[Paul "Fitz" Jones]

4350 powder loads

My load for my 50's .257 Roberts load was 43 grains with the 87 grain hornaday bullet for 3,000fps.

My Hornaday #3 manual shows varous weight bullets and powder charges of 4350 and the amount of powder that can be used is based on the length of the bullet compressing the powder. With the 60 grain bullet max is 51.5 for 3600 fps and as the bullets get longer for 75 graains, 87 grains, 100 grains, 117 grainsand 120 grains the max was 42 grains for 2700fps.

I liked the 87 grain load for crows or ravens I forget the difference and still have some brass left in my extensive lifetime collection of brass and ammo.

My oldest is a 50 caliber rimfire dud from the civil war and my most interesting is a Korean war triplex bullet of three parts held by a plastic sleeve for charging Chinese.

John Paul