NOE/RCBS 311-180-fp

[Junior1942]

Another great mold, Al!! I cast my first batch with this mold yesterday. Alloy was reclaimed shot. AV weight = 199.6; AV diameter = .3115". AV Ready To Load weight = 203.56 grs. That's with Hornady GCs and 2 coats of LLA. Let's call it 204 grs.

When it stops raining these will be tested through my YUGO SKS along with bullets from the Fat 311041 @ ~181 grs Ready To Load.

[Junior1942]

204 gr NOE RCBS 311-180-FP @ 204 grs RTL;
reclaimed shot alloy; rejected, wrinkled bullets;
2 coats of LLA & Hornady GCs;
1.78cc/23.3 grs S4895; (Note change from 1. 8cc to 1.78 cc! Powder weight is correct @ 23.3 grs.)
new WW cases.
3 shots = 1710, 1710, 1718. AV = 1714fps; SD = ~4; ES = 8. Round primers.

1.7cc gave 1652 fps, one shot. The bolt locked back as it did with the 1.8cc loads.

[NYBushBro]

Junior:

What was your OAL?
Was the powder compressed, or was there room for any more?

I just did the math on that velocity (1712) out of a 1 : 9.45" barrel twist (standard SKS twist), and the RPM is running ~130.6K - right around midway between Larry Gibson's 120-140K 'threshold' window.

(NOTE: Larry's MAX 140K rpm in this twist calculates out to be at 1837 fps; I wonder whether this is do-able with H-4895? This would make a GREAT deer round - 200 gr @ 1800 fps... in a 10 round semi-auto!

Looking forward to some pics of your loaded rounds... as well as targets.

SKS prices will probably spike (even more) after you post a write-up of this in your SKS HOG RIFLE saga.

[NYBushBro]

How many grains of your S-4895 fit into a 1.9cc measure... and would it actually FIT in the case? I'm curious.

[Junior1942]

The COAL = 2.164". 1.9cc of my s4895 = ~ 25 grs. A FL-Resized case will hold 1.9cc with an original RCBS 30-180-FP, but it is heavily compressed. Even with a heavy crimp, I would be afraid the compression + recoil would un-seat a bullet in the magazine. One Chrony shot with the original RCBS round, @ 197 grs, over 1.9cc s4895 gave V= 1848 fps and gave a normal primer but violent bolt action, NOISE, and hard recoil. The round was too hot!

1.8cc s4895 with the fat 311041 @ 181 grs gave ~1700 fps, but did not lock the bolt back with every shot. The case ejected 95% of the time, but the bolt locked back maybe 33 1/3 % of the time.

1.9cc s4895 with the fat 311041 @ 181 grs gave AV = 1785 fps and 100 % bolt lock back.

There is not much difference in downrange--75 yd, 100 yd max--ballistics between the 181 gr fat 311041 and the 204 gr NOE RCBS copy. AV = 1785 fps fat 311041 @ 181 grs and AV = 1713 fps NOE copy @ 204 grs.

However, the longer 204 gr bullet has more TKO and a higher SD. I think I will decide which bullet to use for hunting based on how well they shoot. But I do like the idea of hog hunting with my SKS loaded with 10, 204 gr bullets There's a thing called "cool factor" which is in the eye of the beholder.

Yes, the 204 gr bullet extends into the case about .150" below the neck. I don't think it makes a dang bit of difference. The groups will tell.

NOTE: MY S4895 IS NOT THE SAME AS H4895 AND IMR4895!

[Junior1942]

I had h e double l getting the 5D sight on my SKS adjusted after moving the sight as mentioned in article #3. But it's zeroed and the 204 gr NOE + 1.8cc s4895 just shot a 3-shot, 50 yard group of 2 1/8". That's really good considering (a) I used reject, heavily wrinkled bullets; and (b) I waited too late and the target was in the shade; and (3) my 71-year-old eyes aren't peep-friendly. I ought to put a scope on the rifle, but I'm not. I can see the front red fiber optic plenty good enough for deer/hogs to 75 yards. "Good enough" means minute of paper plate. For the zero shots and the group shots I used a small-diameter aperture.

One good observation: I shot maybe two dozen rounds yesterday and today, and every hole in the targets was perfectly round. That means no yaw. And that means the length & weight of the 204 gr NOE bullet matches my SKS twist.

PS: That 204 gr NOE bullet @ 1713 fps through a circa 7 1/4 lb rifle kicks!

[Junior1942]

Conclusions:

(1) My SKS's 1 - 9.5 twist doesn't like MY ALLOY cast bullets @ over 1700 fps. Velocity must give circa 120,000 rpms or less. My alloys are wheelweights and reclaimed shot. Straight each, not mixed.

(2) I don't have a rifle powder capable of giving the f311041 enough pressure to reliably operate the action and also give circa 1700 fps. My suitable rifle powders are s4895, Varget and H4198. H4198 gives ~1600 fps with high pressure. S4895 and Varget are close to being right. But close to right isn't right.

(3) The NOE 204 gr at ~1650 to 1700 fps works fine with s4895 and probably also with Varget. "Works fine" means decent accuracy and 100% reliable bolt lock back.

Note: just because a bullet/powder combination ejects cases from an SKS doesn't mean it will have enough pressure to reliably lock back the bolt. Only one jam in 100 shots doesn't sound like much. But one jam in a dangerous game rifle could be a ticket to the morgue. So run many single-loaded rounds through your rifle and see if the bolt locks back every shot. At a V = ~1650 - 1700 fps, my YUGO SKS locks back every shot with the NOE 204 gr, but not with the 181 gr f311041.