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Velocity issue with my new build 6XC

Thanks again guys for all the responses! I tried N550 as per reply #12 in this thread and it produced 3155 fps with a SD of 13 and 40.5 grains. No pressure what so ever. Weird how one rifle/chamber combo can shoot one powder with no pressure issues, and mine with 8208 was at the upper limits right off the bat. I did order Quickload today and will pursue N204 when i receive it. For now back to the ole reliable H4350.

Anybody ever mess with Ramshot Hunter in the XC case?

Frank
 
40X Guy said:
Anybody ever mess with Ramshot Hunter in the XC case?

Frank

Yep. Well, at least in the form of Data 85, which was an "off" lot of Hunter. I use it for practice, so am not going for speed (dont really do that in match loads either) and at 36.4grs with a 107 class bullet, it shoots really well, and at a slow poke speed. Allows me to get a lot more life out of a bbl than running warm match loads. The stuff meters great as well. If you want speed, I imagine you will get it out of Hunter, but maybe not what you are seeing with N550.

John
 
Mudcat said:
40X Guy said:
Anybody ever mess with Ramshot Hunter in the XC case?

Frank

Yep. Well, at least in the form of Data 85, which was an "off" lot of Hunter. I use it for practice, so am not going for speed (dont really do that in match loads either) and at 36.4grs with a 107 class bullet, it shoots really well, and at a slow poke speed. Allows me to get a lot more life out of a bbl than running warm match loads. The stuff meters great as well. If you want speed, I imagine you will get it out of Hunter, but maybe not what you are seeing with N550.

John

Thanks John, I have a pound of Hunter in my cabinet and looking at burn rate chart seems like it might work well. Basically i am looking for ~3050-3100 fps with good accuracy, and maybe Hunter or N204 will get it done. Quickload should help. Looking forward to putting this rifle thru its paces.

Frank
 
40X Guy said:
Weird how one rifle/chamber combo can shoot one powder with no pressure issues, and mine with 8208 was at the upper limits right off the bat.

Ain't it though!

I guess that's why it's a really good idea to be real prudent when searching for suggested loads on the 'Net & elsewhere, then take a conservative approach to initial testing with one's own equipment & conditions.
 
Frank, how good were the groups you shot with the '550 when you tried it a few weeks ago? Anywhere near as good as the best ones you shot with the 4350 a week or so ago? WD
 
WD, groups were nothing to write home about, smallest group was in the 4's at 3,079 fps with a sd of 22 and that was with 40.0 grains of N550. I am going to revisit that this holiday weekend and play with seating depth. The velocity is there with the N550.

Frank
 
37.5 grains N550 (2990 fps, SD 5) or 40.5 grains RL-17 (3180 fps SD 12) gave me half MOA vertical at 600 yards last year.

37.0 grains 8208XBR (3140 fps SD 4) or 39.4 grains H4350 (2985 fps, SD 10) showed quarter MOA vertical, all with hBN-coated Berger 105VLD & Norma brass.
 
Wayne, 73 rounds thru the tube, just got back from range and tested 5 rounds with 40.2 grains of H4350. Decent group but nowhere as good as 39.0. I just got done pressing the 107's over 39.0 grains as per my first target pic in this thread for match tomorrow. This rifle is a test mule and it is turning out to be fun. Will keep everyone posted up.

Frank
 
I revisited N550 last nite and also tried some Norma N204 powder based upon my new Quickload software.

N550: 39.8 avg. speed 3084 sd of 6
40.0 avg. speed 3101 sd of 7
40.2 avg. speed 3132 sd of 21

groups in 4's and 5's, may be able to shrink with seating depth changes.

N204: 40.8 avg speed 3098 sd of 17
41.0 avg speed 3116 sd of 19
41.2 avg speed 3139 sd of 14 bolt lift a tad sticky.

The N204 shot very good groups in the 2's and 3's and is clean burning. The velocity is there also. This is with once fired brass neck sized only. For now I will retry the N204 load of 40.8 and bump up the charge of H4350. According to Quickload H4350 starts to get hairy around 42.0 grains. I will start at 39.9 and work my way up from there.

Frank
 
How'd the match go over the weekend?

Also, did you ever try increasing the neck tension a couple thousandths or so on the 550 (or any of the other loads for that matter)? Just curious. WD
 
WD, I took the load of H4350 @ 39.0 grains to the match and shot a 140 out of 150, with a 50, 45 and 45 at 1, 2, and 300. I had never shot the rifle over 100 yards until last saturday and went in blind. Rifle shot good, but velocity of that load was only 2888. I was actually tickled it shot that good, after all this I may just stick with the H4350 and go up in charge and retry the N204 with different seating depths. I have not increased the neck tension as of yet. About .001 with new brass, and .002 with the once fired.

Frank
 
Update, After playing with the 6XC for a few weeks after my last post, I was checking headspace measurements on fired brass and found it was .012 over new brass, so my chamber is waay too long and i feel the .237 bore bartlein barrel may be hindering me velocity wise also. Its back at the smiths and will get a correct chamber with a new reamer from Kiff, I will probably have about a 26.5 inch barrel after setback. The reamer used was based on formed 22-250 brass and reamer was probably 10 years old. Plus chamber had to be polished in the case head area just so a round would chamber. Thats what happens when i decided i wanted something new and wanted it quickly. :(
Smith suggested BiB bullets as they are fatter at base of bullet and will work good in the .237 bore.

Frank
 
Frank - In looking at your last 2 posts it looks like you are pretty close to Dave Tubb's load and results mentioned here

http://www.accurateshooter.com/cartridge-guides/6xc/

Another interesting article here also (I'm guessing that you have already read these but just in case :-)

http://www.accurateshooter.com/cartridge-guides/6xc-for-competitive-shooting/

and here

http://www.accurateshooter.com/technical-articles/reloading/alliant-reloder-17/
 
The long headspace is no problem if you adjust your dies accordingly. If you are near the 150 round mark, you are probably nearing the stage where the barrel might jump up a step in velocity.
 
cr500 said:
The long headspace is no problem if you adjust your dies accordingly. If you are near the 150 round mark, you are probably nearing the stage where the barrel might jump up a step in velocity.

Agreed with your statement, but i feel i should not have to "fireform" cases to fit the chamber and it was taking at least 2 times fired to get them up to snuff to where they were tite enough to have something to work with. And also agree with 150-200 rounds that barrel is broke in and velocities are good. New reamer on order, probably won't see until Jan. or so.

Frank
 
Frank,
I don't think you will be sorry for rechambering, .012 is a lot of stretch, you would probably encounter early case head separation anyway, I like my chambers tight.
Wayne.
 
I to was disappointed with 4350, tried varget 38 gr gave me 3250. Varget works well, just work up with your gun. Won last 600 match with this combo.
Paul Larson Long range-Mid range HM
 

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