Range Report

[fiver]

it never seems to hurt.
I have gone as high as .004 with some of the slower powders when I don't use a jam into the lands type of seat.
I'm just going to keep going around and around with all the powders I have and this batch of the lighter weight bullets.
I'm just throwing stuff down range to see what happens right now.
I REALLY need the trigger time anyway I missed a young rock chuck at 200 yds the other day.

 

[Will]

Shot the xcb’s loaded with Winchester 760 today and didn’t ever take pics of the targets. Best group I shot was probably 3”. Most were 6-7”.

Not sure why I had so much trouble with it unless it’s where I seated them out long to engrave when chambering. I may try them again with a little jump or try putting some 4350 behind them.

 

[fiver]

don't feel bad I found the compressive limit of the 4/6 alloy with H-414 today....51grs.
smokearama and a nice lead plating in my muzzle brake.
0-fer hits on the 100 yd target and ripped very unstable holes at 50 yds that barely stayed on a pie plate sized target.
the good thing was the muzzle brake kicked in and recoil went waay down.

maybe a bunch less would work.
I'm starting to really like about 45grs of CFE-223 in the 30" barreled 308 rifle.
I think I'm going to dip into the heavier weight bullets and do a 44.5 to 46.5gr ladder test.
I'm also going to revisit the 39-40 gr area with IMR-4064.
43grs of the accurate brand is too much also, it kept shooting well then blew up when the barrel warmed.
no pictures today the paper target I used was old and just kept tearing. making it look like I was shooting 3/4" groups.

 

[Will]

I had the same shiny crown on my barrel after shooting the 760 loads. The lead would just peel off at the end of the barrel but the actual bore is clean.
Here was my best XCB group

 

[fiver]

makes me believe the pressure rise is wrong for this bullet.
I went for the top end though just to see how far I could take things.
but it really sounds like the powder is a total mis-match.
back to the drawing board as they say LOL.
but the only way to know is to try, it's not like there is a manual to follow.

 

[Will]

I’m going to go 4350 next and thought about trying reloader 19 out.

Anyone tried varget? It’s whats I always end up using for jacketed loads in 308.

 

[Will]

Going to post my velocity info on the xcb using W760 for Waco or any others looking for a starting point. All of my data is from a 22” barrel using lake city brass 2.661” OAL 5 shot string
45gr. Av 2488 FPS
45.5gr. Av 2509 FPS
46.0gr. Av 2547 FPS
46.5gr. Av 2577 FPS
46.8gr. Av 2607 FPS
47.1gr. Av 2610 FPS
47.4gr. Av 2618 FPS
47.7gr. Av 2621 FPS

You can see there at the top I was getting all I was going to get out of the powder.

 

[fiver]

varget is close almost a duplicate in burn speed to 4064 39grs had a real nice node for me earlier.
that's why I tried jumping ahead with the slower AA version.
I'm pretty sure 43 is the wall, it really got sketchy when the barrel warmed up.

 

[Ian]

I was using much heavier bullets with H-414, which makes quite a difference. Also, I was using softer bullets by far, and softer bullets drag a lot harder at the pressure peak due to all the bumping-up, so that changes the pressure curve even more.

 

[Ian]

Time for a little update with the M1A.

Been working with the lee 312-155, three different alloys, two different powders, two different lubes, some water dropped and some air cooled. Too much to list. Short version is that nothing worked very well, the rifle just doesn't like thie bullet even though it fits pretty well. 2.5" groups at 75 yards an 5" at 100 was typical. Then, itried powder coating them, with gas checls and lube, because i was getting very irritated at the lead building up on my muzzle brake inside the suppressor. BINGO! Instant 1.5 moa, first try. Nice round groups with linear dispersion at 75 and 100, 2352 fps. I'll be loadig more of these!

 

[Brad]

PC and lube? Interesting. I know Dan at MountIn Molds was using both in some of his testing.
Any comments on what changed with the combination? Is the PC preventing a little gas cutting and the lube finishes the job?

 

[Ian]

Freakin' magic, I have no idea.

Here are your choices....

Fatter nose
Seated deeper
Coating helps bullet get engraved straight due to slickness and surface hardness
Coating holds rifling better
Coating prevents some other kind of damage from happening, that I've overlooked with thw uncoated ones.

All I know is that with little care and a terrible job cramming gas checks on coated shanks it nearly shoots as well as benchrest match prepped blank brass, carefully culled 30 sil bullets, and a highly-tuned, buffered load of h414.....and the ten rounds showed faint black soot instead of lead plating on my muzzle brake.

 

[fiver]

I think the lube does something else besides act as a better seal and a lube,
it also helps keep the drive bands from trying to shove forward.

I did a little testing with the Barnes bullets years back when they first put those grooves on them and lubing them helped cut the fouling and they shot a bit better.
I didn't want to dump a bunch of money into the project, I just wanted to see, but there was enough of a difference that I would work my loads that way again.

 

[Ian]

I really don't have a clue anymore. It wasn't the alloy, or the alloy temper, the propellant, or the lube. I fit the bullets the same smidgen off the ball seat coated as uncoated, there was about a .020" difference in depth but the nose parked in the throat the same way. Bands sized the same. Same load of 3031. It wasn't the velocity difference of the PC that mattered, I had already shot the uncoated ones with a load that happened to be almost exactly the same speed and got bad horizontal stringing. At 75 yards one shoots a group it takes two hands to cover and the other one shoots a ragged hole. I didn't even shoot the equivalent uncoated one at 100 because my berm isn't big enough, but the coated one drilled a nice 1.4" group with the first two touching, and at the same basic POI on the target, just about 1/4" more right and 1/2" lower due to the distance, so no stupid looping going on.

 

[fiver]

yeah it seems the more we learn the more there is to know.
you know I like to say 'sometimes I'm amazed we even hit paper' and then we do with stuff that shouldn't work, and don't with stuff that should.

if you notice I described many of the groups as the speeds went up and kept the 2 rifles separate.
there was several instances where the 10 twist 308 outshot the XCB system and done so at a higher velocity.
I have learned to say stuff like will, should, can't, and always with a lot of thought behind those words.
because too many times they ain't, didn't, did, and wouldn't even though they did, didn't and would for me.

 

[Ian]

Remember my thread "It shouldn't work, but it does"? 300 BLK AR-15 and Savage .308 loaded every way momma, greenhill, and lyman said not to, shoots ragged holes. You never know until you try. [Shrug]

 

[Ian]

Interesting discovery: those pc bullets that shot so well were 50/50 coww/soft lo-tin scrap, water dropped, then coated, baked, and aged a couple of years. Green pc which means 340f. Checked the hardness of several tonight and got bhn of 10.4. Ql says load peak pressure is 31kpsi.

So I took some more raw castings from the wd batch, checked, sized, cleaned, coated, baked for 22 minutes at 340f, air cooled.....and guess what? Knocked the 18 bhn right out of them! Back to 8.0
That's not supposed to happen, but it did. That also explains why the ones I coated years ago were 10.4, that's the normal aged, ac hardness for the alloy and these I did tonight will end up there too in a few weeks.

I'm scratching my head that 10.4 bhn bullets shot so well with little or no gas cutting from a 22" barrel at 2350fps....and survived being fed from the magazine of an M1A no less. Really scratching.

While I was at it, I checked and coated some .22s to see if i can't improve how my Mossberg mvp does with hv cast.

 

[fiver]

I wish we could do a definite BHN on cooked powder coat. [just the coating]
we know it's slick, but what else does it do?
it definitely isn't adding any lateral or structural support, all the testing I have done and seen says it just mashes along with the lead.
maybe it's just allowing the bullet to get to the barrel with less damage.
well?,,, I say 'just' like that's nuthin and we know better.

 

[Brad]

I do wonder if it is all about getting from the case to the bore with less damage. Might reduce damage in the throat?
It certainly doesn't perform like a jacket.

 

[fiver]

I definitely think it makes it easier to get there.

I have been looking at a few other lube additions, one of them is/was nano diamonds, and it put me on to another substance I don't remember the name of now. [peterite sumthin like that]
anyway they all basically do about the same thing.
they work their way into the metal surfaces and increase the surface area for the oil to flow over.
this increases the shear levels on the oil because of the way it ends up flowing, so the additions need to be burnished into the metal to become effective, and the oil needs to be changed because it is worked to death in the process.

eventually you see some benefit to using the metallic/hardened carbon addition, but in the mean time your spending double for oil.
I think right now we are spending double for the oil and don't know what the benefits are going to be, how to get them, or what part to focus on.

unfortunately it's going to take a whole other generation of bullet casters to find that out,
too many of us are too heavily invested in getting the old way working to change focus.
it sucks because I think with the proper application method and careful measuring of the core there is a definite advantage and jacketed type loads could be achievable with accuracy on par with a copper wrapper.