Range Report

Ian

Well-Known Member
#81
Along those same lines, when using hard cast bullets the difference between .010" off the throat and a jam fit can be an increase in over 10K psi. We're used to that not mattering with cast bullets, but when pushing things near the upper end just like with jacketed bullets it matters a lot.
 

waco

Well-Known Member
#82
The load I'm about to go test with RX15 is 40gr for a MV of 2430fps
It was almost too hard to close the bolt last time out. For these new loads I backed off the seating depth about .020"
 

fiver

Well-Known Member
#83
the Jam can affect pressure a lot.
one other thing I noticed is some powders act slower than others until they suddenly don't.
[AA's 2495 will track slower than AA's 4064 until you get to 168grs of bullet weight, then they suddenly flip and 2495 goes back to being 4895 [which it is in most other cases]
the nose jam can make that happen as can adding 10grs of bullet weight.

anyway the point of adjusting the jump to the lands is generally to kind of tune the sinewave to the bullets exit at the muzzle, most forget that it also tunes the powder burn some.
it and case shape can make a powder burn at least 1 step faster and possibly 2 if a hard jam is used in conjunction with a square case shape.
 

waco

Well-Known Member
#84
New range report for my Rem 700 .308 using the NOE 30 XCB bullet.
I had done a Satterle load test a couple weeks ago and decided that 40.0gr of RX15 would be a good place to start.
Today my brother and I went out to test some loads. I shot a 10 shot group at 100 yards after shooting 20 other loads. Same bullet and lube but using two different powders. Not sure how much changing powder affects groups?
Anyway. I let the barrel cool quite a bit before I started my 10 shot group. I shot these ten as fast as I could, single loading the rifle with as much accuracy as I could. Using a bipod up front and a sandbag at the rear. A cold bore flyer and a couple wild ones toward the end when the barrel was getting pretty hot. All in all I'm pretty happy with the results.
These were still pretty hard to chamber. Very much a crush fit.
Walt
9E96BA74-3ED6-4F5C-8449-CAADD451E5B8.jpeg 12F4D187-15F2-4711-B8A2-E1ED862FE9E7.jpeg 17162192-588C-4943-9560-DB30D5FF4313.jpeg 43A46A80-3F2F-4BB7-B6C6-42CC8B76E8DF.jpeg
 

Brad

Administrator
Staff member
#85
Nice work Waco. That looks like a load that deserves a little playing with. Maybe a different primer, seating depth, something.

RE15 is an awesome powder
 

waco

Well-Known Member
#86
Discount a cold bore shot and a couple hot flyers, That's a 7 shot group just over 1" at 100 @ 2490fps
I need to try my new batch of Starline brass. This was PPU.
I like the results so far.
 

fiver

Well-Known Member
#87
good thing you were using '2500 lube' cause if you'd been using 2450 lube you'd have been screwed.

heat can affect the groups of course, but a powder change can too.
the core is going through a state of change as you lay down the different powder residue.
I noticed it in my last tests with my lube that shoots dry.
it took 3-4 shots for the new load to settle down and then it shot well.
 

Brad

Administrator
Staff member
#88
good thing you were using '2500 lube' cause if you'd been using 2450 lube you'd have been screwed.
He might want to invest in some 2700+ just in case.

That is some fine shooting. I got good news today. Khornet I formed me he bought an XCB mould from NOE. A nice 5 cav too. After vacation is over I may be borrowing it.
 

Ian

Well-Known Member
#89
good thing you were using '2500 lube' cause if you'd been using 2450 lube you'd have been screwed.
:rofl:


I had exactly the same thing happen with my M1A earlier in the week, in my M1A, @ 2,363 average fps. The first shot I noted and marked, it always drops the first shot a tiny bit low with the suppressor due to the cold air inside, and I'm getting to the point where I ought to just aim 1/2 MOA high for it. the outliers were near the end, but not in sequence. I banged off this group in under two minutes, just taking long enough between shots to make sure the Magnetospeed recorded correctly. The barrel and suppressor were hotter than a two-dollar pistol afterwards and the chronograph mounting pad was starting to melt. If you discount the first shot and two flyers the core group is exactly an inch.

XCB in M1A 2.jpg
 

Will

Well-Known Member
#90
Looks like everyone is getting good results. I really think we are getting closer to piecing the HV puzzle together. Really enjoy seeing everyone post their results.
I really think fivers alloy may have a lot to do with it. Notice that no one is shooting horrible groups.

Hopefully next week I’ll be able to chime in with some xcb results. I have them loaded up with W760 from about 90% load density to I can’t hardly get the bullet seated.
 

Ian

Well-Known Member
#91
I'm very interested in your results with the W760. That has always been one of my favorite powders, starting back with the Swedish Mausers. It's also how I got the 50/50 alloy and self-aligning bullets to get to 2400/1 MOA in my bolt-action .308. It really came together right as the powder was settled in at the body/shoulder junction and granulated buffer was sifted in for about 3/32" compression when seating the bullet. The alloy just didn't want any more powder than that.

This XCB bullet with the harder alloy is definitely working for all of us, my only issue is with the flyers we keep getting, which actually may be a problem with the alloy itself breaking down in a hot barrel. I was having to size the bullets down just under .310" to chamber in my M1A, and seating them to lightly crimp in the top lube groove gave me a few thousandths jump to the freebore as is required for the function of the rifle.
 

fiver

Well-Known Member
#92
good choice, I was eyeballing H-414 loads today for the 308.
I did put together 2 more loads for the XCB rifle today, and have an idea I want to work on for the 308 cases.
it and CFE-223 look like real good choices, that new Alliant MR-2,000 [it's a ball powder] also looks like it might have some possibility's too.
 

USSR

Active Member
#93
waco,

You might to change your 10 shot test criteria from shooting as fast as you accurately can, to spacing out the time interval between shots. When I was involved in 1,000 yard F Class Competition, we would fire about 25 - 30 shots in 30 minutes. And even with the bull barrels we all used, those barrels would get quite warm. If you have a slender profile factory barrel that was not rifled using the cut rifling method, there is a good chance of your getting a wandering POI as the barrel heats up. Just MHO.

Don
 

Will

Well-Known Member
#94
Waco that’s an excellent 10 shot group. I get wild flyers after 6-7 shots in my heavier barreled rifles with jacketed bullets.
I figured the RL15 would be a little bit fast burning for this application, but I really think the alloy and bullet design is allowing us to get by with powder choices that wouldn’t work with 50/50 heat treated alloy.
 

fiver

Well-Known Member
#95
15 is close to 4064.
4064 is showing a ton of promise in the 308 in this application.
I'm liking the 4064-4350 powder speeds with this alloy and case size.
a case all but full of powder and a slowish pressure rise with good expansion ratios seems to be working well.
I think the shape here isn't providing a big pressure spike and the slickness of the alloy is also contributing to the initial engraving spike staying low.
if you don't have a big spike or hard resistance at the start you don't need to use a real slow powder and make it burn faster.
I have been thinking of trying a faster powder like 3031 or aa-2230 just to see if I can back off the oal a bunch and still run the speeds up.
 

waco

Well-Known Member
#97
waco,

You might to change your 10 shot test criteria from shooting as fast as you accurately can, to spacing out the time interval between shots. When I was involved in 1,000 yard F Class Competition, we would fire about 25 - 30 shots in 30 minutes. And even with the bull barrels we all used, those barrels would get quite warm. If you have a slender profile factory barrel that was not rifled using the cut rifling method, there is a good chance of your getting a wandering POI as the barrel heats up. Just MHO.

Don
USSR. I would usually take my time shooting groups. We were pressed by weather and other factors so I was forced yesterday to hurry.
I agree that slowing down might well be beneficial.
Walter
 

waco

Well-Known Member
#98
If you have a slender profile factory barrel that was not rifled using the cut rifling method, there is a good chance of your getting a wandering POI as the barrel heats up. Just MHO.
It is a fairly heavy factory Remington barrel.
 

Ian

Well-Known Member
Slowing down does help. I was short for time too, and had a semi-auto, and it was feeling really good in the bags and on my shoulder, so I didn't want to break form. Sometimes it's good to push things so you know where the failure points are.