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bjornborud
I shot 160 rounds loaded with the XCB bullet today, giving my XCB rifle a good workout. What I was doing was in no way a TEST, in fact I won’t be using that word much anymore, since a test implies laying down baselines, using a comparison protocol, a minimum amount of shots, etc. etc.
Rather than getting all complicated I’ll be doing some shooting, explaining and observing over the next few months, and I invite you shooters out there to share your comments and critiques here on the board. No “rights” or “wrongs”, I’ll be trying out a multitude of variables in my quest to make my rifle shoot as well as she is capable of.
When I did my “HV lube test” the other day, Geargnasher commented that I hadn’t shot sufficiently large strings for the bore to get conditioned with the lube. I have to admit that he most likely is right, and today I wanted to give this famous lube a fair shake. At the end of the day a hundred rounds lubed with FWFL had gone down the bore, and here are some of the highlights:
First I shot a few mild loads – 13 grains of Unique. After the first group of 6 I went directly into 3 strings loaded with 28 grains of Varget. The first 2 groups, 15 shots each, were filled with 3/4 gr. Dacron, with the third group (10 shots) I used Puff-Lon as a filler. This is a powdery substance that is compressed (by 20%) between powder and bullet base. I could not detect much difference in accuracy between the two methods.Then I went straight into some High Velocity stuff. The lube held up very well as the target pictures show. I didn’t set up my chronograph; I have ordered this contraption and it’s being delivered Wednesday:
It should make documentation much easier, since I like to gather data from all my shooting.
The numbers in parenthesis next to the HV groups are MVs chronographed with the identical loads earlier, when the rifle’s barrel was 3 1/2″ shorter. It should give a good reference.Here are the targets from several of the strings shot with Felix lube:
At this point I scrubbed the bore thoroughly, and changed over to a lube I hadn’t tried before: White Label 2700+, from Lars’ Lubes. I had loaded several strings from mild to wild, and to say that I was impressed with this lube would be an understatement. In earlier conversations with Larry Gibson it was mentioned that this lube could be too stiff and possibly leave lube in the grooves upon muzzle exit. Because of the XCB bullet’s shallow grooves I decided to give it a go and it appears the lube performs as advertised.
With this lube I also mixed it up and loaded several bullets cast from pure linotype. Those are indicated in the target photos.
All in all I was very pleased with the way both rifle and loads performed. Not pictured are several groups shot with experimental powders, that didn’t work out well. These loads bombed with both lubes, so no fault there. Hodgdon Superformance just doesn’t shoot well at the velocities we were trying to attain, and more experimenting is needed in this area.
bjornborud-
Replies
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timmalcolm
daveridenour
johnblackwell
I went to the range today; been in bed with the flu since Christmas Eve and getting a little antsy. I have set as a goal to re-shoot every load I shot with my XCB rifle before I had it re-barreled, since the rifle clearly shoots much better with the new barrel. So today I shot a final 3 strings using the MBT breech seater, just to see if the accuracy would improve much beyond the previously attained 2 MOA+-. I also loaded 40 rounds with Alliant RL19 and 30 rounds with Milsurp WC867. The strings with the breech seater were loaded with Hodgdon LeveRevolution. I won’t bore you with photos of every group, but here are the 3 High Speed groups with data included:
So, it appears that I’m able to shoot sustained 2 MOA groups at 3000 fps, but nothing better. Since the breech seater will now be fitted to Larry Gibson’s new 30×60 rifle, I’ll be waiting to see if Larry can improve on my results. He probably can.
The 4 loads of RL19 were nothing to get excited about. I have the photos and data, but I don’t see any reason to waste the bandwidth. Suffice to say that the groups were between 1.69 and 2.35 inches, and the MVs ranged from 2222 to 2455 fps. A waste of resources. However, I would like to share 2 pictures. I learnt something very valuable from Larry’s lube test: the often large number of shots needed to re-condition the bore when changing lubes. I had been shooting Lars 2700+, and because I had a number of leftover bullets with 2500+ lube when loading the RL19 rounds, I decided to use these. I also loaded up 10 extra rounds with the starting charge (45 grains) to shoot from a clean bore. The following pictures show 2 groups shot with identical ammo, the first group from a clean bore.
Lastly, I shot 3 groups loaded with WC867. This is the third time I try this powder, and 52 grains continue to shoot well. No screamer, but it is starting to look like a reliable hunting load at 2300 fps. I’ll definitely be testing this load at longer distances.
Again, nothing to brag about here, but I wanted to share both progress and lack of same. More rounds are loaded and more shooting will be forthcoming.sgt.mike
darrinwright
Good Heavens!
Group #3 with the WC867. That is hitting a deer in the eyeball 8 of 10 times if said hunter is comfortable taking such a shot. No screamer/nothing to brag about? Egad! I know jacketed bullet shooters that only DREAM of such consistency!
Again, you may not be seeking accalades, but you certainly deserve them. 10 shot groups DO NOT LIE.
Awesome. Simply awesome.I went to the range today; been in bed with the flu since Christmas Eve and getting a little antsy. I have set as a goal to re-shoot every load I shot with my XCB rifle before I had it re-barreled, since the rifle clearly shoots much better with the new barrel. So today I shot a final 3 strings using the MBT breech seater, just to see if the accuracy would improve much beyond the previously attained 2 MOA+-. I also loaded 40 rounds with Alliant RL19 and 30 rounds with Milsurp WC867. The strings with the breech seater were loaded with Hodgdon LeveRevolution. I won’t bore you with photos of every group, but here are the 3 High Speed groups with data included:
So, it appears that I’m able to shoot sustained 2 MOA groups at 3000 fps, but nothing better. Since the breech seater will now be fitted to Larry Gibson’s new 30×60 rifle, I’ll be waiting to see if Larry can improve on my results. He probably can.
The 4 loads of RL19 were nothing to get excited about. I have the photos and data, but I don’t see any reason to waste the bandwidth. Suffice to say that the groups were between 1.69 and 2.35 inches, and the MVs ranged from 2222 to 2455 fps. A waste of resources. However, I would like to share 2 pictures. I learnt something very valuable from Larry’s lube test: the often large number of shots needed to re-condition the bore when changing lubes. I had been shooting Lars 2700+, and because I had a number of leftover bullets with 2500+ lube when loading the RL19 rounds, I decided to use these. I also loaded up 10 extra rounds with the starting charge (45 grains) to shoot from a clean bore. The following pictures show 2 groups shot with identical ammo, the first group from a clean bore.
Lastly, I shot 3 groups loaded with WC867. This is the third time I try this powder, and 52 grains continue to shoot well. No screamer, but it is starting to look like a reliable hunting load at 2300 fps. I’ll definitely be testing this load at longer distances.
Again, nothing to brag about here, but I wanted to share both progress and lack of same. More rounds are loaded and more shooting will be forthcoming.Bjorn,
Wow!!! That 52gr WC867 group is most impressive!! Thanks for posting that!
Dave
michaelburns
Wow, some super impressive results right there, bjorn!
Silly question – the XCB bullet – how does it compare to the Lyman 160gn Silhouette bullet, 311672? I have a custom 7.62x39mm with a .308 barrel and the leade profile of a .308 Palma Match, and the Lyman fits and does well. For comparison, the Lee Harris mould does not fit at all because it’s too fat on the nose. And the Lapua 123gn hollow base spitzers also do not fit, since they’re also too fat on the nose. (The rifle shoots sub half-MOA with 135gn Matchkings, which pleases me greatly).
But frankly NOE moulds are better than Lyman, and 5 cavities are better than 2 and I’d like to go over to an NOE mould for this rifle rather than struggle away with the vastly out of round nonsense that the Lyman mould produces.
I haven’t yet done a lot of comparing between specific bullets. I have the Lyman SIL mould and I’m sure a comparison is in the cards at some time in the future. The only bullet I have compared the NOE 165 XCB bullet to is the Mihec 30 SIL. I shot several strings with both bullets last Wednesday night, and the shooting will be posted here as soon as I can find some time to take pictures. Spoiler alert: The NOE bullet edged the 30 SIL when loaded to the same levels. Velocities were in the 2300-2400 fps range as I was looking for a consistent hunting load with WC867 milsurp powder.
Larry Gibson
Thanks for the replies.
I dug out the reamer drawing, and remembering that it did in fact cut .0015″ looser than the drawing (grrrrrrr) I reckon it’ll fit with the case mouth somewhere on the front band.
Also, I noticed that the XCB has a proper front band rather than the rather weedy one that isn’t even really a full band on the Lyman Sil. I like that, since as a general rule I like to have some full diameter driving band ahead of the case mouth. It doesn’t always seem necessary, but doing so has solved a few problems I had with particular rifles a few years back.
At what nominal diameter do the XCB’s drop? The lyman drops at .3105 perpendicular to the seam (the narrowest bit of the oval) in hard-ish alloy @ about 18BHN, which is .0005″ over throat. I gas check & lube them at .312, and they go quite well (but of course I want more performance!).
It took a few days to get pictures taken. On top of that I had some issues with the MagnetoSpeed (it wouldn’t export data correctly into Excel), so all chronograph data had to be copied longhand onto the targets.
Some of you guys may be asking why I’m posting all this shooting, and here’s why: At some point, when I feel there have been enough loads shot and recorded by the XCB rifles, I’ll be posting everything in an “illustrated handbook” format on Castpics, so others who may want to shoot similar loads can look them up and see what worked and didn’t work in my rifles, and what velocities they can expect to get with the various loads.I started off with 6 strings all loaded with 52 grains WC867 milsurp powder, since this powder has shown promise as a medium velocity producer for hunting loads. This load shoots right at 2300 fps, with near MOA accuracy. This time I had also loaded 2 strings with the MP Molds 30 SIL bullet, just to see how that bullet would do with the same load. I also loaded 3 of the 6 strings with compressed BPI Original shot buffer, since this has been reported by some shooters to give improved accuracy.
Here are the targets from the WC867 shooting:
As you can see, the buffer didn’t do much for me. As for the performance of the 30 SIL bullet, no particular load workup was tried, I just wanted to see how it shot with a known good load.
I then shot several strings with Hodgdon H4831SC and IMR 4831. The H4831SC groups stayed together reasonably well, but the 4 strings shot with IMR 4831 clearly show how the groups are opening up as the charge increases.
Next up is AA4350, which has given fine accuracy and speed for Larry. Then I’ll get into the ball powders to see if the groups will stay together around 2800 fps. I also have a new XCB rifle I’ll be trying out, it’s a hunting version built on a small ring Mauser. Stay tuned.
timmalcolm
daveridenour
johnblackwell
sgt.mike
darrinwright
michaelburns
Larry Gibson
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