Testing the 30XCB

[RED333]

It will come back as soon as you post some more targets.

[tomme boy]

I would skip the Richards Microfit stocks unless you like to finish everything on the whole stock. They are not user friendly.

[MBTcustom]

I would skip the Richards Microfit stocks unless you like to finish everything on the whole stock. They are not user friendly.

This is true, however, I don't know where else you can get a finished stock in some of their more practical target styles. That, and for many people who are truely interested in accuracy, the barrel is not where they are going to cut cost. The stock? Well, it beats the alternative. Lot's of folks are on a very tight budget.

[RED333]

I would skip the Richards Microfit stocks unless you like to finish everything on the whole stock. They are not user friendly.

I picked up one for my Browning A bolt, Had the action fitted in a few hours.
The rest took a few more hours, all in all, about 8 hours of work and I am very happy with the way it came out.
The good thing about a "ruff" after market stock, you can make it "yours", the bad, it takes some time.
I had the time, the basic know how, so it was good for me.

[Doc Highwall]

RED333, Nice job and I see you are in your right mind as the bolt is on the left side of the gun, same as mine.

I am thinking of getting some of Richards stock blanks for a winter project.

[MBTcustom]

I have often considered learning to shoot left handed. I'm left eye dominant you see. When I shoot a rifle left handed, it feels like riding a horse facing backwards, but my brain is at piece. Just never could bring myself to learn to shoot left.

[Bjornb]

Another range trip today, sunny South Florida, 85 degrees, no wind. Had a borrowed chronograph set up at a measured 11 feet from the muzzle. No other variables have been changed, case prep, primers, gas checks and lube remains the same. Tried 5 different loads of Alliant RL22. I'll let the pictures speak for themselves. All loads were fired in 10-shot strings, from front rest and rear sandbag at 100 yards. Muzzle velocities are averaged, there were no dramatic extreme spreads.


I also took pictures of a couple of sample cases to show the necks and primers after firing. Case on left is 47 gr. charge, case on right is 51 grs.:


I did not measure the groups as I just wanted to show the trend with progressively higher charges. Target dots are 1 inch if anyone really cares.

[Love Life]

Is that horizontal dispersion at 51 gr shooter error? A serious question with no malice or offense intended.

That 47 gr case neck is what all of my .243 necks looked like using Retumbo, even with annealing. Even with necks like that the bullet was traveling 3200 FPS (jacketed) and sub MOA at 1,000 yds. I'd continue to play with variables with the 47 gr load and reshoot the 51 gr load on it's own to see if the dispersion was caused by shooter fatigue after firing the 1st 40 shots.

[Bjornb]

LL, it's not a tiring rifle to shoot. She's so heavy that she just sits there on the front rest, not moving much. And no offense is taken (even though my kids think I'm infallible). The 47 gr. load was very encouraging, and I was planning to continue loading all the way to a compressed load for the next outing. Also got H-1000, I'll try that just to see what she does with a super-slow powder.

[RED333]

Cleaning between groups?
Time between shoots and groups?
The lower charge does show promise.
I do not shoot that good on a good day.

[Love Life]

Which shots were the high and low outers in the 48, 49, and 51gr groups? Were they random?

[Bjornb]

LL, the flyers in each group were random. However, as an RO buddy commented (he's an F class shooter), in his opinion I was shooting my various loads too rapidly, risking poor accuracy from an overheated barrel. I admit to being under a time constraint; that's not good but such is my schedule sometimes. I will make time for slower fire, and rather do my shooting over several sessions.
Red, there was no cleaning between strings. There was no leading observed after the range session and the rifle cleaned up with one wet patch and 2 dry patches.
Larry, I think it's also time to change some other variables. I'm doing as best as I can with the casting and sorting, even though there are most likely many casters out there that can do a better job. Lee pot and Lyman Ladle, plus a PID from Goodsteel, that's what I've got. I've been reading one of Joe Brennan's texts today, where he describes a primer test using velocities vs. pressures as variables. The WLR primer that I've bee using came out as the primer creating the highest pressure, CCI 200 the lowest. Pressure difference was over 10K psi. Cartridge was 300 Win Mag. Interestingly enough, velocities were nearly identical. I can reference this text if any of you wish.
Another variable is of course lube. I know that this is a very delicate subject on this forum, but other lubes should possibly be tried. I have no favorites, since before I started shooting the XCB, Lars BAC was my favorite and only lube. I'm wide open to suggestions.
From the parallel XCB thread it appears that 1 or more of the other XCB rifles will not be made available for testing, and that's too bad. Btrojs rifle is an absolute beauty (I held her in my hands) and would probably outshoot Bertha, giving valuable info to the rest of the forum.
I'll keep shooting as long as it's fun.
Bjorn

[roadie]

Ok guys, it's a free country. I sure wish you both luck with your XCB rifles. And I mean that.

Personally, I think it's a good thing that btroj and geargnasher are running their own tests, their own way. That's how new things are discovered, rather than sticking to the old, only way to do things. They might well branch off to something that could leave the old, only ways in the dust. Might be hard for those with huge egos to accept, but, that's life.

I also believe that their findings will be shared with the forum at some point, I don't think that anyone can say that either geargnasher or btroj have been unwilling to help others in the past.....I sure haven't seen that. And I can well understand their hesitation in posting results now. It's been well demonstrated that those results will be attacked.

BTW: Were it me, I'd play around with the 49 gr. load.....it has a nice core group. It might also stop that soot that the 47 gr. has.....but that's just me.

[Bjornb]

Bjornb

I think we should compare bullets. There is no reason you shouldn't push 2600+ fps with accuracy with that 14" twist rifle. I'm casting some more NOE 310-165s this week. I see we are casting the bullets quite a bit differently. How about I send you some when I get them cast, GC'd and lubed? Maybe you can send me some? Besides the differences in casting the bullet I think we should change one variable at a time. Do you have any H4831SC or RL19?

As to Brennan's tests; I've no disagreement with them. As long as the same load is used primers do make a difference in pressure. However, if you are working up a load the primers (as long as ignition is consistent) do not make a difference in accuracy because it be at most likely the same pressure. The biggest difference I found so far is with powders. Even those of the same type and close to the same burning range make the biggest difference IF the cast bullet can take the acceleration. As with you I have not had as good accuracy with RL22 at the same psi's and velocities as with AA4350, RL19 and H4831SC.

Larry Gibson

Good idea, PM with shipping address sent.

[geargnasher]

Ok guys, it's a free country. I sure wish you both luck with your XCB rifles. And I mean that.

This will probably come as a shocker to you and a lot of people, but I wish you, Tim, and Larry success with this project, too. Wishing it won't make it happen, but with the slower twists and tight chambers this should be a slam-dunk for all of you.

Gear

[MBTcustom]

This thread has been cleaned up and superfluous posts have been deleted, and infractions given.
Further attempts to troll will be dealt with.

[Bjornb]

Sarge I doubt you need my help with your groups but thanks for the compliment (I've seen your shooting).
As for Hodgdon Superformance, it is listed directly underneath H4831 (slower) on the burn rate chart. That should make it a candidate for testing; especially since it is a ball powder and therefore may behave differently than the other powder types.

At the local BassPro today (looking for RL19), the powders in stock were IMR4320, Leverevolution, RL7 and 17, and H414. A sad state of affairs.

[runfiverun]

your primers WILL definitely affect the powders you use.
with rl-19 I have found that the federal large rifle [210] or the rem 9-1/2 to be the primer of choice in almost all of my rifles I use it in. [with one exception the mag-tech 9-1/2 in my 257 bob]
the 25-06's both like the fed, my 7x57 Ackley likes the 9-1/2, the 7x57 likes the fed, but all the rifles shrunk groups by about 25% just through this one change.
H-414 might be worth looking at too, we have to balance out the pressure rise with the boolits
mush-ability.
backing the boolit out of the rifling is also something that may help too. [especially when switching to a faster powder]
jamming the boolit in the throat can cause the slower powder to increase it's burn rate, something I learned the hard way [using 7828 in the 0-6 with an oversized 314299]

[DR Owl Creek]

FWIW. I haven't tried using Hodgdon Superformance with cast bullets yet, but it works very well for me with jacketed bullets in 243 WSSM, 270 WSM, and 300 WSM loads, giving very good accuracy and high velocities.

Dave

[Bjornb]

Bjornb

The Super Performance powder made to produce a bit different time/pressure curve than regular powders as is LeveRevolution. While the peak psi's may be close to the same as H4831 how the pressure curve gets there is different.........slower in the "rise" basically. I'm trying to get some to test also. Sending NOE XCB bullets (80) out today. They are sized (.311....as cast basically), GC'd with Hornady GCs and lubed with 2500+. Suggest you load them as is over 46, 47, 48 and 49 gr of H4831SC.

Larry Gibson

Good. I'm loading my few remaining bullets for shooting Thursday, will try to duplicate Sunday's loads with CCI primers. Yours will be loaded as suggested.