Hard Cast Bullets in 30-06 -- Trouble getting a decent group!

[Jim_K]

All,

I've just decided to join this forum after over a year of using it for information. Many thanks for all the good useable advice I've received to this point.

I am working up a 30-06 hard cast load for an M1917 Eddystone. It is standard configuration, 26" barrel, 5 grooves. Seems to shoot 150 & 180 grain jacketed bullets okay. But...

I'm nearly unable to group 5 shots of 165 gr RNFP (no gas checks... yet). These are hard cast from SlashK, they purport that these bullets are 15 on the SAECO hardness scale (~35 BHN). They're .308" and 0.93 inches long.

I'll explain what I've done so far and hopefully someone can point me in the right direction.

I've loaded these buggers with 18 gr Alliant 2400 to 3.050" COL. I put a heavy crimp on these rounds and they shot terribly. Something like 18" 5 shot group at 35 yards. No key-holes but these things are high, low, port and starboard from where I'm asking them to go.

Finally, I changed two things at once (very scientific, I know!). 16 gr Alliant 2400 and zero crimp. This yielded a better group, maybe 5 inches. Still a long way to go.

Any advice or hints would be much appreciated.
Thank you, Jim K.

[s mac]

What size is your bore? You boolits need to be .01. .02 larger than your bore. .308 is most likely too small.

[petroid]

I would start at about 13 grains of 2400 and work up to 16. And only use a light crimp. 2400 is a pistol powder. It doesn't need a heavy crimp to build pressure like slow rifle powders do. The crimp is really only to prevent bullet setback from recoil which should be minimal. Also you didn't say what your bore slugged at and how the bullets were sized. An undersized boolit will not be accurate. If the above doesn't help, try some gas checks. If its a gc boolit it may not be supported well without the check.

[HARRYMPOPE]

My Eddystone and Winchesters(5grv and 4grv barrels) like .311 bullets and do well with from 16-22g of 2400.I doubt the hardness has as much do do with it as bullet size as mentioned above also.Unless you have the apparatus measuring a 5 groove barrel will be tough from a slug.You dont need to slug the bore just seat as big of bullet that will chamber and shoot it.Even after you know the dimensions that's all you will do anyway.My buddy used .315 dia with a 303 nose in the P-17.

If using no GC 10-12 g is a proper load.

[RPRNY]

.308 and über hard cast is not a recipe for success. I bet your Eddystone has a generous throat. You need to check and clean the barrel for leading; I'm betting you have at least some smear on the groove edges. Slug your bore and throat. Try to fill the throat or at least go @ .003" over bore diameter and at under 2000 fps, I would use a softer alloy, like 18 -21 BHN so as to get some obturation.

[Blammer]

I'd start with a .310 dia projectile and no crimp and see how it does.

oh yea, are these GC bullets and you're not using the GC? or are they plain based?

[Jim_K]

Thanks everyone, I'll try out some larger diameter bullets. Being that there are 5 grooves, I have not tried slugging the barrel.

If I seat these bullets really low, about 3.050" COL and cycle them through the rifle unfired, I get 5 very light witness marks on them from the rifling.

If I seat them very high ~ 3.210" COL and cycle them through, I get 5 heavy witness marks, basically flattened out segments on the bullets. I think they're fitting in the bore but they may be too small to snug up really well so I'll try out some larger .309s or .310s as well.
I'll also try going down to 13 gr of 2400 and working up toward 16. Gas checks have been ordered and will be installed as soon as possible thereafter to see what if anything they can do for me.

Any other thoughts please let me know, I'm just starting out with hard cast in rifles, so I've got a lot to learn.

[Jim_K]

Blammer,

These particular bullets are bevel based,

[nicholst55]

Once you lower your powder charge and install some gas checks, try some slightly softer bullets. The term "hard cast" was coined by commercial bullet casters as a sales ploy. They cast their bullets harder than woodpecker lips so they won't be distorted during shipping. That is the only reason they're so hard.

[jbltwin1]

I suppose you actually WEIGHED the bullets to verify that they are close to the same WEIGHT? Mike.

[MT Gianni]

Even being that hard they are far less than the hardness of an aluminum can homemade check. You cannot put a regularly designed check on a bullet without a check shank so that is out. They may do OK @ speeds under 1600 FPS but even at that point they are too hard for that speed.

[waksupi]

Gas check first. Second, I am betting you need a larger diameter.

[Jim_K]

I suppose you actually WEIGHED the bullets to verify that they are close to the same WEIGHT? Mike.

Mike,

I weighed a small handful and they are between 164.2 gr and 164.5 gr.

Thanks,
Jim K

[45-70 Chevroner]

No GC chank no GC. You can't put GC's on a bevel base. HARRYMPOPE has the right answer. 10 to 12 grs. of 2400 and you will probably see a lot better results. You could even try Unique at the same grains.

[MtGun44]

First: Why do you call it a "hard cast load"? This immediately makes me wonder if you are
off track to start with, imagining that "hard" is a major factor in this, and of primary
importance to success. It is not.

You need to FIT the boolit to the gun - at least to the groove diameter plus a couple thousands,
and in rifles, it helps a lot to fit to the throat to align the boolit properly at launch. .308 is
almost guaranteed to be TOO SMALL - add in TOO HARD (35 BHN!!) and you will not
likely succeed. For a .308 groove diameter, you will want .309 at least, and many find
.310 to .311 works best.

Hard may be OK, harmful, or helpful - but is NOT a primary consideration and you are
using the term "hard cast" like the nutball commercial casters do, and they know next to
nothing about making boolits. A softer boolit with a GC AND fit properly is much more likely
to succeed in a rifle.

Fit, design, lube are all critical to success, "hard" may be necessary as you push the rifle
faster and faster. Ordinary air cooled wheel weights works fine for moderate loads in the
1700 fps or so range.

Bill

[Blammer]

are you waiting on GC's from me?

[Jim_K]

Bill,

I'm aware of the commercialization of the term "hard" cast. I assure you I'm not a nutball, although I'm not sure I'll be convincing anyone of that. Part of why I'm using that term is because I'd get the same reaction in the opposite direction if I simply said "lead bullets" So I'm not sure how I can win this one with you.

All,

A partial update: Tested 12.5 gr 2400 and had even better success than 16 gr and far more results than the 18 gr.

I do have IMR 4227 laying around as well, and 4198 (which I use in .223 rem) if that gives anyone additional thoughts. After that is just my jacketed load powders (IMR 4895 and 4350) All of this was done with neck sized brass bell'd to avoid shaving the alloy while seating it.

Thanks,
Jim K

[HARRYMPOPE]

Same charges of 4227 for plainbase 10-12g shoot well in the 30-06.Bullet weight from 150 to 200g.

[Adk Mike]

I've shot thousands of cast thru my 1917. 314299 @.311 or 311644 @.311.13 grains of Unique. I try other loads every month but that Unique load works good.

[runfiverun]

if this is the magma bevel based 165 rnfp that just about every commercial caster sells, you actually can put a gas check on it.
I have the mold and I have put some on and tried it.
it don't shoot much better with it, but it does take and keep one and you can push the boolit a bit faster.
anyway these boolits were designed to be used in 30-30's at sedate velocity's for cowboy action shooting out to 50-100 yds.