Home Forums Reloading Big Game Rifles Powder choice for 21 inch 257 Roberts

My barrel is a 21 inch 1:10 twist and all of the reload books test with 24" to 26" barrels.

Generally speaking would you want to use a faster or slower powder with the shorter barrel, or does this not apply. I was always under the impression to use the slower powders with the heavier bullets in a caliber???

I have IMR 4064, IMR 4350, and H-335, although I see no data for H-335.

I tried 39.5 gns of IMR 4350, CCI-200 primer, WW Super and Nosler 100 gn Ballistic Tips. The groups were 3/4 inch @ 100 yds with crappy mil 2-stage trigger, but the velocity was 2606 fps, which is well below the 2820 fps in the book with the 24" tube.

I would not worry about the shorter tube at all...I would just run the working max of IMR4350 (or H4350) with the 100 gr.It is not true that faster powders need to be used in shorter barrels to get the velocity...H4350, IMR 4350,or some other slow burner (IMR4831,RL22) will get you as much velocity as the 21" barrel is capable of giving.

Don't be afraid to work up a good bit. Check out Hodgdon's data online to see what I mean. 3000 fps is likely within reach.

What rifle are you going to us this in? You have to be careful
about what load you use in what gun?

I always start out with 4064 or IMR 4895 in a caliber less than a 270 in length and bore...both just seem to work real well for accuracy... slower powders are hit and miss until the bullet weights get heavier like a 140 in a 6.5 bore if you are wanting max velocity...

those two, RL 15 and a few more in that mid burn rate, always give great velocity...and superb accuracy...

Wow, yes, I guess I should have mentioned the firearm. It is a 1939 Turk action, large ring 98 with the longer front receiver ring and small ring thread. I shot factory Win +P loads in it and was not thinking it was not a candidate for +P reloads. I sure wish that I had chronoed those factory 117 +P's. I was sighting in at a different rifle range than I tested my reloads; the sight-in range is indoors shooting through a baffled indoor section then going outside in a fence protrected area.

I was under the impression that the reload manuals, Nosler and Sierra, were +P loads. I had a few Roberts before but all were 24 inch and I don't remember my IMR 4064 data anyway. I know I used IMR 4350 in my 257 Rob AI's but that is a whole different animal. No way that I would Improve a 21 incher.

46 grains of either 4350 with a 100-grain bullet is NOT a +P load--and even +P .257 loads are only 60,000 psi, which is by no means warm.

The slow velocity is a little puzzling, since I've owned several 22"-barreled .257's and that load generally gets right around 3000, give or take 50 fps. You're not going to lose 400 fps due 1" of barrel. Oh, and that load almost always shoots great.

You might have a slow barrel, in which case it wouldn't hurt anything to add some powder. (Or maybe your chronograph was slow!) Another possibility: Does your barrel have a longer than standard throat, so bullets can be seated out further in the 98 magazine? A longer throat would result in less velocity with bullets seated to standard OAL.

My to the lands is 2.932"; my initial seating depth for work up is 2.915" or .017" off of the lands.

I am guessing I can heat these loads up quite a bit.

i have a ruger #1 in 7/57 can not get too shoot the way i think it should have used 4350 and 4831 the 4350 does the best but room for improvement any help will be good have tried 139 to 150 bullets thank MOOSE

sbrmike,

Yeah, the throat in your rifle is around .1" longer than SAAMI standard, which probably accounts for most of the low velocity. I'd just start adding powder to the load, a grain at a time, and watching the chronograph. You should be able to get 3000 easily.

OK here are some more results; remember that the crappy, heavy 2-stage military trigger is installed. I don't put a whole lot of weight in the groups sizes. Numerous loads were tested and all put 2 within 3/4" with a third a little over an inch from the other two. The F14 contour barrel is very light and is hot after three rounds. This is a no frills hunting rig and 3 shot groups are realistic for the field.

I am thinking that 44.0 gns of IMR 4350 is the upper limit as far as pressure. 44.5 gns only yielded 9 fps more than 44.0 gns.

Here are 44.0 gns results: Velocity 2930 fps, ES 17.02, SD 8.48; 2 shots 1/2" apart the third about 1-1/4 to the left of these two.

Tightest group was a solid 3/4" group with 43.0 gns of IMR 4350; Velocity 2835 fps, ES 35.16, SD 17.77.

I am going to use one of these two loads. What are your opinions. Go with the Chrono or go with the group? Go with higher velocity???

Are your groups and velocity readings all based on 3-shot strings?

I use H414 in my 22" model 77 ruger.

Flip a coin. 100fps ain't gonna kill stuff deader nor is .75" versus 1.75" groups. Which load puts your first shot from a cold, fouled barrel closes to the POA?

3 shot groups work for my purposes. The barrel gets too hot for longer strings anyhow.

I guess my real question is would you trust the smaller ES and SD or go with the actual group size on paper?

This is not a bench gun, nor is it a match grade barrel. I am going to put a Timney trigger in it eventually. I know the groups will shrink. The 2-stage trigger doesn't bother me, but the pull weight on the second stage is probably 8 or 9 pounds. I know a lighter trigger will tighten the groups up.

One other thing that I want to clarify is that it is not always the last shot that is wide; two are closer and one is wider on most groups. It is the 2d or 3d shot that is wide in the various test groups. One of them will match the first and one doesn't. The heavy trigger pull is undoubtedly the culprit.

The only load that is out is 44.5 gns of 4350. I could live with any of the others.

FWIW-
I recently worked up a load for my Ruger #1-A, in .257 Roberts, with a 22" barrel.
At the same time, I was also trying to improve the overall accuracy of the rifle. I ended up free floating the barrel, installing a Hicks Accurizer, and taking a small amount of wood off the rear of the forend so it was not in contact with the receiver. It's now producing MOA groups, so I'm happy.

Anyway- I settled on a load of 43.0 gr. of Big Game powder, behind a 100 gr. Nosler Ballistic Tip, for a chronoed MV of 3080 fps. It seems to be a little more accurate and consistent than 46 gr. of IMR 4350, and meters beautifully. Big Game is also a very clean-burning powder.

sbrmike,

It seems to me that all of your data is pretty much worthless. ES and SD need a LOT more input than 3 shots to be valid, and the bad trigger has to be affecting your groups. In fact it might be the major cause of the fliers.

Concluding that a 9 fps difference between 44 and 44.5 grains means the load is nearing top pressure is invalid as well. That's both because half a grain of single-based powder would only result in about a 30 fps change anyway, and your data is based on 3-shot strings. It's common to see a 25-300 fps difference between 3-shot strings of the same load.

Plus, Hodgdon's maximum listed load with a 100-grain bullet is 47.7 grains--at only 47,000 CUP. The velocities you're seeing also indicate relatively low pressures.

My advice would be to do yourself a favor and either get the trigger worked over or buy a better one, and then start adding powder to your loads again. You're not anywhere near maximum, and that may also be the reason for the fliers. Slow-burning powders burn more consistently the closer the pressure gets to the level they're designed to operate at, and you're nowhere near that.

My first load for a 257 Roberts was 43.5gr of IMR 4350, for
2935FPS in my model 70, with 24 in barrel. For 100gr bullets
I the best speed I got was from IMR 4064 or W760. For
Heavier 115 to 120gr bullets I used H4831SC or RL22. Also
the W760 Worked good with 110gr Accubonds.