6Arc 20" from Brownells ---- :D
#1
Big Grin 
So, just finished assembling a 20" faxon into some parts I already have, and took it to the range. 
First off the 105 factory loads drop in and out with no problem, so that was the first test.
This is the nitrided barrel, rifle gas, 5R rifling,
This baby has some good stuff I will say.

Using the Hornady 105 Bthp's factory.
I topped it off with a 4-12x40 Vortex diamondback tactical I have, on paper at 15 yds, 2 holes touching at 25, and 3 shots, 0.919 CTC, and mind you these were the first 7 shots down the pipe. I think some of that wideness is a bit of woggle that hit me on shot #2 of 3.

Switched over to using my magnetospeed, shots 8-11, 3 were at 0.2" and the entire 4-group, 1.06" CTC (#4 was the flyer).
Speeds and pics posted (I hope).
2665, 2674, 2676, 2643.  Avg 2664, SD 15.

I was using a CPD mag, one already broken in for my grendels, worked 100% but I didn't push it, most were 1 or 2-shot mag loads.
Recoil is light, with the VG65 gamma I have on there, it is basically like a 223 in feel.  Rifle is probably 9 lb give or take (I haven't found my weght scale from our move yet.  Sad  ).

the other pic.


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#2
Sounds like you're off to a good start. Plugged 2664 fps into JBM ballistics. It shows the 105 BTHP at 1389 fps (1.2 Mach) at 800 yards and 1135 fps (1.017 Mach) at 1,000 yards at standard pressure. Not too shabby!
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#3
Yeah with the current scope I couldn’t see that far. I’m thinking of putting either a 3-18 strike eagle or 4-14 PA scope on it, I have both in standby and I like their reticles. Probably the PA. I was thinking today, on the way back home, hornady took a slightly shorter case for the creedmoor vice just using the 308 , this seems analogous in that it’s slightly shorter than the new “308” of the Ar15 frame (ie, the Grendel)...
with my 103 eldx’s I feel good about getting 2700 give or take. My die set came today. I need more brass!!!
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#4
Those velocities were very similar to what I was seeing today with the 108's out of an 18" barrel, and I mean very close with the factory load. SD 9, sub MOA @100. I think the rifle +2 gas puts a little more pressure behind the bullet. The 105's pushed into the lands shot better on the first outing. Scratching my head on that one.

The 25 gn. 8208XBR load topped with a 108 pill netted in the range of 2440, but showed some drop and the group opened up. SD 15, I think they need to be pushed a little more. But I need to measure the chamber a figure bullet jump first. But the numbers matched what Hornady said they would per the load data.
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#5
Range trip today hoping to accomplish several things,
1. First shoot some more 105 to get 1x brass. Check groupings
2. 2 ladder tests of 103 Eldx, with CFE and with 2520.
3. I had some time left so did some "load-'em, measure, auto-feed, measure, and shoot... looking to measure any set-forward of a chg handle- chambering, and of a full cycle load after firing- chambering.

Got all of these done!
1. More shooting, I use 3-shot groups, those groups ranged from 0.73" to 1.4" ctc, average of 5, 3-shot groups 1.075". Now as I watched POA and POI during the shots I can say most of the wider strays were my own wiggle, or tiring eye. This barrel is a definite 1"/100 yd shooter as long as I can keep steady. That's with these factory 105's. So now I have some 1x, and 2x, brass. I will attach a pic, groups 2-3 on top, 4-6 in middle, left to right: #2-3: 1.031, 1.404. #4-6, 1.133, 0.732, 1.076

2. Ladders: I loaded 103 Eldx to 2.260 with CFE223 and AA2520, both at 0.5 gr steps. The Cfe went 27.0-29.5, the 2520 went 26.5-28.5

27.0 - 2469
27.5 - 2522
28.0 - 2552
28.5 - 2609
29.0 - 2657
29.5 - 2701

2520:
26.5 - 2509
27.0 - 2549
27.5 - 2607
28.0 - 2633
28.5 - 2678

All brass looked good, primers a little flattened but nothing I haven't seen before. Like I posted earlier none of these loads were compressed, they were all at or above the shoulder line but none into the neck.

Finally, I took 3 105 rounds at random and measured them at 3 stages: out of box,
after a chg-handle load (like the first one would be), then extract and measure. Last, fire one, let the second load, then extract and measure (this step only for the last 2)

results: no rounds extended more than 0.001 at any time, they all pretty much followed a pattern, 0 (original), +0.001, +0.0005:
1 -- 2.247, 2.248
2 -- 2.249, 2.250, 2.2505
3 -- 2.252, 2.253, 2.2535

All of them fed smoothly and also extracted smoothly via the charging handle, into my brass catcher.

here is a pic from today.


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#6
So will a reliable 1 moa be good enough to stop load development or will you keep on spending time money and barrel life in the search for "better"?
My money is on better but what is your goal that will let you say "done."?
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#7
For targets and general shooting, for a factory round, that’s decent. But for me the bullet I want to use is this 103eldx, esp as a hunting round. The quest therefore will continue. When their factory 103 comes out I want to see what it does, but something tells me I will want to roll my own. I am always happy when I can find both factory and hand loads shooting good groups... that’s a sign I’ve got a keeper barrel.
I figure I’ll find a node for the 103 around 2700-ish, which will be where I’ll be happy, 103-wise.
Part of my internal ballistics grand-theory is, a “faster” barrel is so because its internal friction is for some reason, lower... 5R, slicker insides, whatever. Generally then a given, expected powder load yields less than expected mv and pressure. But that’s the beauty, because you can tweak up the charge and the extra powder/pressure/energy sends the bullet scooting down the pipe faster.

A secondary goal today was to find if there is a barrel mfr (maybe just 1 barrel but a mfr more likely) that can handle 105s and etc at decent coals. So today also bolsters my feeling that some of the throats PP et al, got are too short n stubby, and the mfrs should fix ‘em. Just imo however.
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#8
Was on a live stream Lastnight and talked about the ARC, the concensious is the barrel life will be about what you'd get with a .223 Barrel and you get a full powder burn in a 18" barrel.

I know it's a different animal but one of the guys was getting 2900 fps with a 26" barrel I believe in a boltie. IMO Any platform you use with the ARC it's fair to say you could Be moa or or better. For me when I get my ARC built I'm hoping for 1/2 moa, but time will tell. Hope everyone is enjoying being the ground breakers to this awesome child of the Grendel!
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#9
Excellent range report Grayfox !

Thanks for doing the COAL test in the fashion that you did.

You may just have disproven my hunch that the bullets were setting forward under live fire....

My video obviously shows I can hand feed the 105s and can extract them with little effort - under bolt sent home feeding I have to use moderate force to extract them - under live fire I have to use heavy force to extract.

So using your data I guess it is possible that the Proof barrels may be on the small or short side ...... I may have to eat crow yet if Hornady is not at fault for these 105 issues .

Keep us posted on brass life - especially primer pockets - hopefully we can get 7-8 firings out of brass at full velocities .
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#10
No problem! Keep the crows piling up dead in the fields... this is all a new barrel so there's bound to be some ebb and flow to developing what's right. Even in the grendel archives there are mfrs who delivered shallow barrel chambers, yet professed everything was gtg -- think liberty/saturn...
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#11
Today, range trip, shoot some chrony data for the 103's using CFE and 2520.  Also I wanted to do a ladder for the Lever that I discovered in my stach... Smile
I'm still crunching numbers but it looks like my node is going to be somewhere around 2680.
I also graphed the powder response I got from these loads in this barrel, to the gas gun loads for the 100 Btsp. which since Hdy seems all over the map I picked that one as being "close" to the 103 Eldx.
Anyway, when I graph the book loads to what I get from the same range of powder, CFE for now, this barrel shoots 80-100 ft/s faster than the book data.  No signs of overpressure.
Note the data is for an 18" barrel and I have a 20", so that accounts for some of the delta, but I think I've still got 40-50 more than expected.
Which is good.  Now on to trying seating depth to tune the groups a bit.


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#12
Grayfox that is some great work and information. Thank you for cutting my work down on the load development for the 103 led-x. That is my next project.
Trashy
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#13
My next load is going to be the 100 gn BTSP on top of CFE and Lever, out of an 18"nd 20" barrels. Looking to achieve similar velocities as you did.
If you can not see the tyranny of having a gun ban enforced by men with guns... Then you fail to understand why the second amendment was written in the first place.
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#14
I have got to get me some 103 eld-x’s and get them measured in my chamber. If they will seat at 2.260 for me that cfe223 load of 29.5 grs at 2701 FPS that Grayfox put together should be just the ticket. I would work it up with LVR but there usually isn’t but just a couple tenths of grains difference between them all the way up the scale. Thanks again for taking the lead on the 103’s Grayfox.
Trashy
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#15
Definitely work up, my barrel seems to be on the fast side (which is good!) meaning lower pressures for book loads... also, while I like the CFE results, I am going to try the Lever b/c it's getting me up to 2700 or slightly above. The 29.5/2701 of CFE in the ladder (1 shot) seems to be more like 2685-2690 in the chrony data (sd-single digits). Which is still pretty good as far as I'm concerned... but getting to 2700 or a bit more, is worth the effort, especially since I have 2 lb of same lot# of the lever. My Lever ladder points to about 2715-2725 at about 29.5-ish grs. Still need to do some more shooting with it.

O yeah, when I get to the 90 TGK's I think I can get them up to ~2800, which is all I need out of them. Any SST loads ~2700+ will be gravy for me, I use them in my 243.

And the 87 vmax... can be my varmint load... yeah I know, the wish list keeps growing!!! Smile
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#16
Thanks for the update on the 103's, i look forward to seeing your range report on the 103 and LVR. The LVR sure shoots alot cleaner for me than cfe223 ever did.

I think you will do better than 2800 with the 90 gr TGK, i got 2682 fps with 8208 xbr under the 90 TGK and wasn't close to pushing it.

I don't know if LVR will be the 'right' powder but It wouldn't surprise me to see 3000 fps with the 90 and 87 grainers without problems, Hornady's data showed the 90's at 2750 fps. My barrel has been between 150 and 200 fps faster than Hornady's numbers (grain for grain).
Trashy
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#17
Range results on 103 Eldx and Lever powder. I think I'm settling in on 29.7 gr Lever and the 103. I loaded sets of 4 in 29.3, 29.5 and 29.7 grs of Lever at 2.253 OAL. I did one set of these in 1x brass and 1 set of them in new brass. Previously I thought I saw some delta in MV between the brasses, and today there was some but , well, not a lot. So in general I can dial in 29.7 grs at 2718-2720 ft/s. The two groups went 1.008" (2722, sd-9.5, Hd 1x brass), and 1.145" (2715, sd-9.5, Hd 0), at 100 yds, CtC. The 29.5's were also good at 2704/2705 with sd's of 6.8/10.1... not bad and with more shooting they would probably smooth out some more, but the groups were not as symmetrical, more spread out. I might be able to tweak them by adjusting OAL but for now I'll try the 29.7. Could always drop back to 29.5. Even though I'm not the PRS or polished shooter, I do believe I see better POI behavior for the 29.7's as opposed to 29.5. 2700 neighborhood puts me in good shape for a hunting load.

Footnote as per Trashy, the Lever does seem to be cleaner than CFE. So with a few more ft/s and a cleaner burn (CFE has never been known to be "clean"), Lever gets the nod.

I will now try to find a 2810-ish load for the 95 Sst's.
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#18
Were you seeing pressure signs at 29.7 or did it achieve velocity goal you were looking for with the 103’s? I am really interested to see your results with the SST’s for comparison to my work up with them. I got an average of 2793 FPS with 29.2 grs of LVR and 2828 FPS average at 29.5 grs LVR.

I know I am pretty pleased with LVR so far, hopefully I’ll have some results to share on the 103’s in a couple of weeks.
Trashy
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#19
No indications of pressure in the eldx loads.
I have some 95 sst's loaded, 29.6, 29.8, 30.0, 30.2, Lever, for magnetospeed testing.
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#20
Range test of 95 Sst loads today, using Lever, seated 2.185. 4 rounds each charge.
29.6, 2735 sd 1.7
29.8, 2767 sd 10.3
30.0, 2783 sd 17.2
30.2, 2813 sd 5.4

Groups, with the mgsp attached, the 30.0 was best but 30.2 was still pretty good, had some lateral spread I think was me, the vertical was under 1/2". No swipes that I could see.

So I'll do some groups without any chrony attached to see how they group, 30.0, 30.1, 30.2. I don't usually do it this way, preferring to do OAL delta's but I don't think there's a lot of room to vary this bullet in or out in this chamber. I think it will wind up in the 2.180-2.190 range for length, but in all a MV of 2780-2810 is the place I wanted to be.
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