Testing the 30XCB

[Bjornb]

sometimes a powder just flatlines when it's near a peak.

I'd really like to see you go to a slower powder than 4350.
rl-19 is going to be my starting point, and rl-22 is on my second step list.

I have H4831SC, IMR 4831 and H-1000. I believe I saw both RL-19 and RL-22 at Bass Pro today, so that should be doable. Also IMR 4350, which lists as slightly slower than the Accurate version.
There's also the issue of when I'll need to anneal these cases. They now have 2 firings on a newly formed and turned neck. I have bought the Anneal Rite setup just for this purpose, and I'm getting ready to plunge into another unknown. Input would be appreciated as to when it's recommended to anneal.


Sarge, you're incorrigible.

[Bjornb]

Larry and Runfiverun,
duly noted. My next trials will concentrate on the slower powders. 4831, Hodgdon and IMR, plus RL 19 and 22 which I believe are both available locally here.

I shipped my chronograph off to Chrony today for an upgrade to the remote model. This is still an inexpensive chronograph (Chrony Beta Master), but it's what I have and it will be used exclusively for the remainder of the XCB testing. At the range where I shoot the chronograph setup is very consistent; it's set up at the end of the concrete that houses the covered shooting benches. My base is good and steady and the sky screen spacing is whatever the unit dictates.


I'll pick up a beam scale to use as a control against my ChargeMaster. It can't hurt to be more accurate.

I converted 20 virgin W-W 7x57 Mauser cases today; not sure if it will mean anything to the shooting trials, but neck wall thickness was thinner than the formed 30-06 W-W brass. Factory thickness (quite uneven) varied between .012-.013, I turned the necks to .012. With the bullets sized at .310 this should give a diameter as loaded of .334, a dummy round chambered easily with an OAL of 2.80, and no sign of rifling imprint on the bullet. Goodsteel has a case ready for my Stoney Point OAL gauge which will make it less of a guess to seat the bullets at different depths.

The rifle will get some rest while she travels with me to Arkansas for a possible fitting of a new extractor. Should be shooting middle of next week.
Bjorn

[Bjornb]

6 feet +- a few inches. This is on the short side, but again I'm limited by the layout of the county range. Setting up at 10-15 feet as recommended would place the Chrony in a swampy "dip" in the range and would not be feasible.

[RED333]

6 feet +- a few inches. This is on the short side, but again I'm limited by the layout of the county range. Setting up at 10-15 feet as recommended would place the Chrony in a swampy "dip" in the range and would not be feasible.

I do not have a chrony, but have read that might be a bit close, the blast could effect reading.
I have been wrong before and will be again.
I have got to get me a chrony.

[Bjornb]

That looks very doable. I'll have the remote version by next outing so this will work as you depicted. Thanks.

[Bjornb]

Took the 30XCB rifle to the range today, didn't really load up a lot of test loads; my chronograph is at the factory (Shooting Chrony) for an upgrade to remote display. Last time i shot the rifle I was getting some diagonal stringing; upon closer inspection the forearm was found to be binding on the barrel, starting about 6 inches back from the forearm tip.

This stringing seems to have been caused as the barrel warmed up, and repeated with 4 different jacketed loads. Cast loads were just shooting very poorly.
So off with the action, and after a little sanding with 120 grit the old dollar bill was sliding underneath the barrel again. Some Tru-Oil and back together she went.

A 10-shot group of jacketed just to make sure the problem was solved:

Then I shot the only cast bullet rounds i had loaded: 47 grs. RL22, a fairly stout load that filled the case nearly to the base of the bullet:

Not the worst result; I estimate the MV in the 2500 fps range.

However, during a visit to Goodsteel to have a new extractor installed, Tim discovered a small internal bulge in the barrel. That discovery, and coupled with the fact that the rifling is quite worn, led us to order a new Krieger barrel today, to be delivered within 6 months. 32 inches, 1-14 twist, 1.25 in. diameter.
Tim is only a few weeks from completing my second rifle in 30x57/XCB, so Big Bertha will be getting some rest while the new rifle (named Carmen Sandiego) gets broken in.

[Love Life]

Why thank you. I would enjoy that very much. I can bring milsurps and ammo and other cool stuff. You are welcome here any time, but prepare yourself for the gnats!!

[Bjornb]

I spend summers in Alaska so flying insects are considered companions.

[Bjornb]

Bjornb

"Then I shot the only cast bullet rounds i had loaded: 47 grs. RL22, a fairly stout load that filled the case nearly to the base of the bullet"

You need to get more RL22 in that 30x57 (30 XCB) case. I get 49 gr in my Winchester Palma .308W cases under that bullet. At 47 gr RL 22 my .308W Palma rifle ran 2400 fps at 35,400 psi. You're probably doing a bit less with the larger case. I suspect you should get 52 - 53 gr RL 22 in your 30 XCB cases. You should be doing a fast Quick Step with Big Bertha not a Viennese Waltz.........that group shows her potential......she wants to dance.........

Larry Gibson

True dat Larry.....but we've been stepping on each other's toes lately. Will shoot again Sunday and report back.

[lar45]

So who makes a good barrel, 14 or 16 twist, that you don't have to wait 6 months to get?

[Love Life]

I'd call Schneider. Last pair I ordered took less than 10 weeks. Their website sucks, but their phone works.

[tomme boy]

Call Benchmark also. Maybe Rock Creek.

[Love Life]

Maybe Hart might have one?

[Bjornb]

There are some barrels available at Brunos, he has a couple of Kriegers in 14 twist in stock. 28 inch barrels in Varmint profiles. About $335. I couldn't use them on Bertha since she requires a straight 1.25" barrel, but for a sporter-stocked rifle they should be perfect.

[MBTcustom]

Lothar Walther. It's no Krieger, but it scares the heck out of it. Very good quality barrels.
Check the supply houses online like Bruno's as has been mentioned.
Look for these brands:
Krieger
Bartlien
Schnieder
Brux
Lothar Walther
Broughton
Hart
Lilja
Pac Nor
Douglass
I don't really care for Shilen
Green Mountain will get you 3/4MOA eventually, 1.5 MOA out of the gate.
Steer clear of McGowen. I regret to say they have lost my business permanently, and I would rather use a factory Savage barrel. In fact, I would pay not to have to use that product. Nuf said. YMMV

[RED333]

What is that old saying, You get what you pay for.
One day I might get me a rifle built, but for now I am happy with what I have, and that is what counts.

[Love Life]

Dick I kinda figured you would pick this up and run with it.
Ohh well LOL

Did you do your rifle qual with a krag?

[MBTcustom]

Did you do your rifle qual with a krag?

What an insult! I thought the Sargent qualified with a Springfield? (Trapdoor​)

[Love Life]

BWB qualified with the spear!!

[MBTcustom]

BWB qualified with the spear!!

I've been meaning to ask him if he got to use the new tacticool bronze tip, or if he had to stick with mil-spec stone. Hmmm, I'll PM him.