Cast and the .308 Win

[RickinTN]

Something I recently discovered while playing with one of my 308'S. The new Starline small primer pocket "match" brass does not suffer form headspace shrinkage with lighter loads. I fired a single case several times with only the primer and the headspace didn't shrink at all. I bought 200 of the cases which should last quite a while with light cast loads.
Might want to give them a try.
Rick

[charlie b]

I've got plenty of old cases that I use for the plinkers. Once they get drilled out they seem to last forever.

Some folks have indicated that it is not necessary to drill the primer holes. I do it as a precaution.

[charlie b]

I've been experimenting with the Lee C309-180 for quite a while now. It has been a good experience for me but I wanted to try something else. After looking at some more cast bullet match results the Eagan bullet design seems very popular. So, I settled on the Accurate Molds 311-210E for my next series of development with this rifle.

http://www.accuratemolds.com/bullet_...=31-210E-D.png

I am still powder coating this one but have added nose sizing to fit the bore of my rifle. I cast, install gas check, size (to crimp the GC), powder coat, nose size and base size (NOE sizing setup). The bullets enter the rifling with a little bit of resistance and the drive bands engage the rifling as well at the OAL I am using. I still sort by weight after powder coating and sizing. These are 211-212gn.

I was hoping that this would be an accurate bullet and it seems to be. For a test case I loaded 26.0gn Varget and shot it along side my Lee 180gn loads. It gave a 1.5" group at 100yd. So, this week I loaded up a series from 26.0 to 27.6gn Varget in 0.2gn steps (5 rounds per group). I ended up with 2 groups of 4 rounds due to operator error The results speak for themselves. I am still not shooting my best after the quarantine, but, it is getting better. By the last group I watched two of the bullets go right where I had the cross hairs as the trigger broke.

There were a couple loads I did not shoot for group. Seems the lower vel loads just were not as accurate so I used them to experiment at different targets.



One thing to notice is that the series from 26.6gn to 27.4gn the bullets all landed near the aim point even though the avg velocities were different. I used the same scope settings for all of those loads. If I averaged all of the bullets of all those groups and overlayed them into one group it resulted in a 1.6" group with an average vel of 1811fps and an extreme spread of 97fps. That is with a change of 0.8gn of powder. I have been told that the ideal load comes when the change in velo and group size changes the least. I think I may have found that point my first time out. That would be nice, but, will verify it with my next series.

I also managed to find my first bullet after it was fired. This was fired into a dirt berm at 300yd. The first 4 or 5" of dirt was like soft sand. Then there was a hard layer where the bullet had stopped. Seems from the picture that the impact with the dirt made it tilt a little so it hit the hard stuff a bit sideways. You can see the powder coat stayed pretty much intact, even on the deformed portion of the bullet. You can also see where the lands took the PC off the gas check. The base of the bullet still looks pretty good too.



I am really happy to see these results at the velocities I wanted to be able to shoot. I might try some loads at a bit higher velo (closer to 2000fps) just to see if they still hold together. I am hopeful

Note that all of this is from someone who had never tried to load accurate cast bullets for a cartridge rifle before, just plinkers. After less than a year I am seeing results I had hoped for but did not expect without a lot more work.

[Martin Luber]

Are these high speed loads ( greater than 1600 fps) all gas checked?
Thanks

[charlie b]

Yes, all the loads I have put together were gas checked, even the plinker loads using the Lee mould.

I have found that if a bullet is designed for a gas check, most of the time it is more accurate with a gas check whether it needs one to prevent leading or not. That was true when I loaded .357 Mag bullets as well as the .30 Herrett.

[MT Chambers]

LBT spitzer(if you can get it to chamber), Saeco #315, Eagan MX2, MX3, MX4, right now I'm reacquainting my self with 311467(Loverin).

[charlie b]

There are lots of good 'shapes' to work with. The 165SIL and 311299 are great choices as well. I especially liked the 165SIL bullets I got from Montana Bullet Works. I did not get those moulds because I am powder coating. Those were both tights fits to my chamber and probably would not have worked with the extra size with the PC.

[richhodg66]

I have been playing with a Model 70 Heavy Varmint I bought to just bench shoot cast bullets with about a year ago. Hadn't gotten good results, but recently got fed up with the factory set trigger and replaced the trigger spring and adjust the over travel, now I can shoot it a lot better.

Most of my load development has been with the 311466 because it was Dad's favorite and I have a bunch he cast up. Today, I shot the best group so far with it using that bullet and 19 grains of 2400. I shoot ten shot groups at 100 yards and seven went into an inch with three flyers that made the group about two inches. I'm enjoying thie rifle and process. I think I am going to get some of that Starline brass that uses small primers and see if it makes a difference.

[Cosmic_Charlie]

My old model seven .308 is really doing well with cast. 10 gr. Unique or 16 2400 tumble lubed with 45/45/10 and a gas checked 160 gr. boolit and after 30 accurate rounds the bore remains pristine. I use Lee's mandrel neck sizer and an expander plug from NOE and no crimp. Titegroup also works well with even less powder. My alloy is 95/2.5/2.5. Mold is an Accurate 31-160G.

[charlie b]

I have been playing with a Model 70 Heavy Varmint I bought to just bench shoot cast bullets with about a year ago. Hadn't gotten good results, but recently got fed up with the factory set trigger and replaced the trigger spring and adjust the over travel, now I can shoot it a lot better.

Most of my load development has been with the 311466 because it was Dad's favorite and I have a bunch he cast up. Today, I shot the best group so far with it using that bullet and 19 grains of 2400. I shoot ten shot groups at 100 yards and seven went into an inch with three flyers that made the group about two inches. I'm enjoying thie rifle and process. I think I am going to get some of that Starline brass that uses small primers and see if it makes a difference.

Small primer brass might make a difference.

I'd weigh the bullets first. Sort them by weight and then shoot again. 2400 was the favorite for people like CE Harris.

I also found that your shooting position makes a lot of difference. At the slower velocities the bullet is in the barrel longer, so a good follow through is even more important to good cast groups. Many of my fliers are because of that. I get 'lazy' during a shot and it is usually the follow through that suffers.

FWIW, I have a batch of the 210E bullets I will load subsonic and see how they work. Should be interesting

[dverna]

Good thread...and I have three .308's. Tried cast in a .308 and no joy....but I know it is me.

Someday, when I need to find another project, I might try cast in one of them again. If I could get ten shots into 1 1/2" I would likely be very satisfied. You guys are well beyond my capabilities. I can only shoot tiny groups with jacketed bullets.

Again...nice work!!

[richhodg66]

Shot a few more group today with the 311466 in the Model 70. Until today, the 19 grains of 2400 was the best it had done, but had three of ten fliers. SHot a group today with 19 grains of 4759 and had one very slight flyer, the rest were on top of each other. The 4198 and 5744 didn't do as well.

Darn shame I can't get more 4759. I'm gonna keep working with the others, might find a sweet spot for one of them. I'm also about empty on the Lyman 450 and when that happens, I'm gonna try Carnuba red in place of the standard NRA formula stuff I normally use, not sure if it'll make any difference or not.

[charlie b]

Thanks Don. One reason I got a .308 instead of a smaller caliber was the idea I would try cast in it one day so I was happily surprised to see my groups approach the jacketed group size with this one. The difference is it is easier to get smaller groups with jacketed.

rd66, lube made a lot of difference for me. I tried a couple of commercial lubes and they did not do that well for me. I ended up with Ben's Red and would have tried the black version next (beeswax, moly grease, a little carnuba). I went to powder coat instead. The real test will be when I go to longer ranges. If the PC does as well as it is at shorter ranges I will stick with it.

If you want to try another powder, try 4895. It is another that seems to do really well with reduced loads.

[richhodg66]

IMR 4895 and 4227 are next to try.

[charlie b]

Next session with the A311-210E. I have to say that this bullet seems fairly easy to load for. Most loads go into less than 2" and many are less than 1.5". Also, there is very little change in elevation with these 0.2gn increases in powder charge. I suspect it is because it is a heavier bullet.

On this series I repeated a few of the better loads from previous sessions just to see if they were consistent. Also note several fliers from my bad trigger work. Yes, I have to get much better if I am to consistently keep below MOA.

Note that because of my mistake most of these bullets had the GC applied after powder coating. I have not yet found that applying the GC before or after is significant, but, I like applying them before as they seem to fit the heel of the bullet better that way. Once I settle on a load I will try a more extensive test both ways to see if one way is better than the other.

I will repeat the 26.6 and 28.4gn loads for next session and keep working up in velocity.



PS I also noticed a change in velocity for the repeated loads. This is also something I will track next time. Outside air temp for both sessions was 85 to 90F.

[charlie b]

After a couple other test series I have settled on a load of 28.2gn of Varget with the A31-210E bullet, powder coated and gas checked. Just this morning went out and shot a 10 round 1.85" group at 200yd followed by a 5 round 1.1" group also at 200yd. The average vel is 1830fps with an es of 54fps measured over a course of 30 rounds. Now to go to extended ranges with it. FYI, I have come to the conclusion that applying gas checks before powder coating results in fewer fliers and small groups. This is just for me and it not to be taken as gospel. Just that I will exclusively seat GC's before powder coating from now on.

Second thing is I finally broke down and bought a new mold. The NOE 310-165-FN-H3, otherwise known as the 30XCB. These are the GC version which I also powder coat after seating the GC's. I cast up a sample batch this weekend and loaded up a small bunch to test today. Due to the short throat on my Savage, and powdercoating, the bullets have to be seated deep. OAL is 2.54" with the bullet jammed lightly into the throat. Due to deep seating of the bullet I started conservatively with 26.0gn of Varget. After using several rounds to get zeroed I proceeded to shoot a 1.1" 5 shot group at 200yd. The velocity was only 1755fps with an es of 63fps over 15 rounds. I will be increasing the velocity to see how things go. Hopefully I can get a bit over 2000fps before groups open up (1-10 twist barrel).

This was a great day for me, seeing how my chosen load worked with the heavy bullet and seeing excellent results from the 30xcb first time out.

[charlie b]

Just wanted to follow up with some recent shooting sessions.

Accurate 31-210E bullet has proven to be fairly accurate and works well up to about 2100fps. After that groups open up a little. It is a solid 1.5MOA performer across several powders and loads. The key for me was 1) nose sizing after powder coating and 2) weight sorting to smaller groups of weights, ie, 0.3gn batches. The nose sizing was such that chambering the round was an interference fit in the bore. I found it slightly more accurate in the 1800fps range, but, 2000-2100fps was needed if shooting to 600yd to keep the bullet supersonic. I found that it loses accuracy when in transonic region. I have had decent luck with Varget, IMR3031 and IMR4198. The 3031 seems to do the best when shooting in the 2000fps range. 4198 does better at the 1800fps range. Just today fired 35rounds, average of 1826fps, extreme spread of 33fps and an sd of 8.2fps. The brass I use is Hornady with the flash hole drilled with a #35 drill. No filler. The loads are just over 50% density. I 'wiggle' the rifle just a bit to make sure the powder is laying evenly in the case. It does make a difference. A filler could probably be used, I just don't want to mess with it.

NOE 310-165 XCB. As noted above this one is also accurate, even with me needing to seat it fairly deep due to the short throat in my rifle (and powder coating). Also good for 1.5MOA or less. I have not tried it at longer ranges and it is also limited to the 2100fps range due to my 1-10 twist barrel. I have had some outstanding groups with this one, 10 rounds into less than 1" at 100yd. 'Normal' is less than 1.5MOA out to 300yd.

The bonus is this one is also good with reduced charges of Blue Dot at around 1000-1100fps. So if I want a fun plinker this is the one I use.

Note that I have not used 2400. Once I can find some I will try it with both bullets.

Bottom line is that just about every bullet I have tried with the .308 has worked well, as long as it is sized to fit the bore/throat. Best performance is with the bullets touching or slightly jammed into the throat and/or closely fitted to the bore.

Velocities over 2100fps have reduced the accuracy. Sometimes by a lot, sometimes a little. If you only need 2 or 3MOA you might try yours faster and see how it does.

I am still trying to get consistent groups under 1". Yes, I think I am chasing my tail, but, I am still trying. The fliers are the frustrating part. 4 shots into 1/2" and the other 1" out. At this point I think it is simply the variation in the cast bullets, but, I don't have a way to verify that.

[oldblinddog]

Use RL22 with that 30XCB. About 42.0 grs and work up. I get 1” groups at 100 yds in my 12” twist .308 using 44.5 grs. Velocity is ~2350 fps. Accurate 4350 will give you higher velocity but maybe less accuracy. You will have to try it and see. Start at the same 42.0 grs.

[Cosmic_Charlie]

I enjoy shooting cast out of my .308 offhand at 50 yards at a 6" gong. Great way to stay sharp with your bolt gun.

[charlie b]

Use RL22 with that 30XCB. About 42.0 grs and work up. I get 1” groups at 100 yds in my 12” twist .308 using 44.5 grs. Velocity is ~2350 fps. Accurate 4350 will give you higher velocity but maybe less accuracy. You will have to try it and see. Start at the same 42.0 grs.

With the 1/10 twist that would not work for me. Too high velocity. I assume RL22 is just as sensitive to temps as RL15? If so it is a no-go for me. Temps during a shooting session out here can swing over 30deg. Have you tried a CBA bench competition? Frequently a 1" group will win a match.

CC, I agree. Every now and then I do off hand shooting at the steel ram the range has set up at 300yd. Don't hit it a lot but I am getting better