Starting out a project with a .308 Winchester

[Wm Cook]

First off I have to offer that there are no right or wrong comments to any opinions given below. There are too many variables that can affect accuracy with any cast load. However being an inquisitive and I hope to be considered a logical person, I was looking for a center hold to start with.

Project is a 700 BDL VSS .308W with a new OEM barrel that will be used in competition @ 100/200 yards. The starting die will be the NOE 310-165-FN 30XCB. The powder and brass I'm starting with will be Lapua brass and Unique for a <1700fps load, 5744 for a >2000 fps load using Federal 210M primers. Magnum primers are on hand if the unique does not burn completely. The powder choices came from Mike Venturino. I've always had good luck with his recommendations. My sizing die options include .309, .310 and .311. And no I did not check the bore diameter or the leade. I'm assuming that modern rifles should be <+/-.0005 from .308. Please note the first three letters in assume. If an obvious solution does not pop up during load development I'll have to dig deeper like we all do to find a solution.

After the first half dozen groups I'll start moving the variables around. This questions is about what your first choice for sizing, powder and die would be before you loaded your truck to head to the range.

So what would be your:

• Starting sizing die
• Starting powders and expected velocity
• What currently available mold would you use.

Thanks, Bill.

And just as an add on, how many of you would want to shoot competition that are within driving distance of St Louis for a one day match. I'm trying to talk my club into setting up a cast bullet class for Bench Rest group shooting and for Hunter Class score competition.

Once again, for this current project my sole purpose is accuracy at 100 and 200 yards.

[Yodogsandman]

You'd do well to read all the threads you can find on the 30XCB's and the load developments already done. You'll gain a lot of knowledge from some of the masters here. Use the search function on the top, right hand side of the page.

[Larry Gibson]

For my CBA match load (accuracy at 100 and 200 yards being the selection criteria) in my .308W M70 match rifle using the NOE 30 XCB cast of #2 alloy, WQ'd and weight sorted I've tried numerous powders. I've settle on 23 gr RL7 with a Dacron filler in LC Match cases (additionally match prepped). Velocity runs 1980 fps. That may be a bit much for a 10" twist (the M70 has a 12" twist) so if yours is a 10" twist starting at 20 gr and working up to 23 gr is suggested. Have to say I've not tried Unique so can't comment on Mike V's suggestion.

Al Nelson cut my 4 cavity aluminum NOE 310-165-FN (30 XCB) mould for #2 alloy so the bullets drop at .3105......that is exactly what they drop at. I seat Hornady GCs separately using the GC seater on a Lyman 450 with .311 H&I die. Then I lube the 30 XCBs in that .311 H&I die with Lar's White label 2500+ lube. The LC match cases are fire formed and NS'd in a Redding Bushing die to just tightly slip over the mandrel of a Lyman .31 M-Die expander. The M-die expands the case mouth so the GC is hand started to it's depth. The 30 XCBs are seated so the bullet is just engrave on closing the bolt.

I'm getting 5 and 10 shot sub groups at 100 yards and moa groups at 200 yards. In the CBA matches I shoot in they are shot for score with the 10 ring being right at 3/4 moa........a tough target.

[sigep1764]

Uhh, Im in St Louis and am starting to gather the stuff for loading 270 Win in a Model 70. I'd be down to for the competition, if only to get better and learn. Ive never loaded or cast for a rifle before and will be learning myself. Ive never met another caster. Where you thinking for the comp?

[Wm Cook]

Sigep1765 give me a PM and we can share our misery, knowledge.

For most of the previous responses. I'm not interested in what shot well for them in their rifle, components, conditions etc. I was curious about the though process of where to start with a .308W project. You know the ritual; the first sizing die you used, your choice of powder, on or off the lands etc. As of today I can say that the first bullets dropped from the NOE 310-165-FN 30XCB looked great. After about 30 castings the bullets jumped out of the mold and the bullet measured about an average of .3105. So I'll be starting out with a .310 sizing die and dabble between Unique and 5744 looking at SD and first impressions of 3 shot groups at 10 meters.

Larry good write up on your load development. that's exactly what I was looking for. You went form .315 to .311. and what I learned was your use of Dacron. Once upon a time I used Dacron but strayed away from it by using magnum primers. I'm curious about your SD and ES on the loads with and without Dacron. Maybe you have some specifics on that? And RL 7 has come to the surface a few times and that will be my choice if 5744 fails to produce. Thanks for the help. Bill.

And another good lead was the one about the bullet touching the lands. I currently shoot BR with a 6PPC and we live on touching to +.015 into the lands. That I can count on. For cast I can't guarantee a starting point but touching the lands and then +/- .010 would be my first choices.

[Wm Cook]

Larry one last question. What's your plus and minus on bullet weight for CBA competition. I just finished a 22 K Hornet project which kept the +/- at .000. So before I start to load for the .308 it would be a great help if I hand a realistic +/- that's acceptable. From the first batch of bullets I've case so far it looks like I'm about 50% at 160.3 to 160.5. That being with a four bullet NOE mould using #2 Alloy. Thanks, Bill.

[Larry Gibson]

My bad Bill......My #2 alloyed 30 XCBs drop at .3105 not .315. So when I lube them in the .311 H&I die there is no sizing.

Here is how I have learned to weight sort for maximum accuracy. This is from another thread;

Weight Sort 30 XCB Cast Bullets


"For your theory, that lighter bullets in a batch are less accurate than the heavier ones we must assume: 1. that light bullets are caused by voids, 2. that those voids are not too near the longitudinal axis and, 3. that they are large enough to be significant."

Ergo is the problem in this discussion. I do not subscribe to any of those 3 assumptions. In fact if you re-read my post with the graph I explain what I've found to be the real problem and it is not the suspected or assumed "voids" in the bullets. Yes, that's what we've all been told for probably a hundred years and it is what we've based our testing on.

Ten years ago I thought I was casting pretty good bullets, excellent in fact. However. the more I got into shooting cast bullets at HV I found while I was casting good, excellent bullets I too hit the accuracy wall that joeb is alluding to. I also found that when those cast bullets were pushed to really HV (2500 - 3000+ fps) they did not do as well as expected. Back then I was weight sorting as we've all been told to. If you line them out by weight you get the so called "bell curve". In proving insanity I, like you and everyone else, then did the same testing of each .1 gr testing over and over again expecting different results.....we all got the same results; accuracy was not really improved via that method no matter how many times we ran the test. You are asking me now to run the same test and think I will come up with different results? It wouldn't happen.

Let's assume we have a mould that will cast perfectly even bullets in all dimensions. Not an assumption but fact is that mould has a finite capacity for any alloy. Thus if we cast with a good alloy giving the best fillout then only those that weigh the heaviest will have filled the mould out completely. Any bullets with less weight are then not dimensionally the same. We may not be able to measure other than weighing that difference but the difference is there in lighter weight bullets none the less. Now that difference in weight (mass) is there but it is not predictable.....we don't know where in or on the bullet that difference in weight is missing from. The missing weight is what creates the imbalance. I suspect voids in the alloy are not the problem but rather other aspects are which I have previously discussed.
I recently cast 542 NOE 30 XCB bullets of #2 alloy. I have just completed weight sorting them. In the next post I will show the graphed results of the weight sort which should aptly demonstrate what I'm saying. Have to copy, download, etc. so it will be an hour or so.

Here is the results of the weight sort. 542 bullets were cast of Lyman #2 alloy and WQ'd. They were then aged about 12 days before I got around to weight sorting. Here is my set up for weight sorting. I visually inspect each bullet for any defect. If any is found that bullet is rejected to be melted and recast at a later casting session. Those that pass my anal visual inspection then have any remnant of the sprue cut off. That is done on the lead block with a sharp blade on the pocket knife. The bullet is then weighed on the Redding balance beam scale. While waiting for the beam to settle I then visually examine and sprue cut another bullet. With the magnifier in front of the scale I can readily and accurately see what the weighed bullets exact weight is. The bullet is then placed in a bin for that weight.

Of the 542 bullets weighed 22 were rejected for a visual defect or because they weighed less than 186.9 gr which means the weighed ones had passed the visual inspection but still weighed way lite. The remaining 520 XCBs were weight sorted into separate bins of .1 gr increment from 186.9 gr to 188.0 gr......a 1.1 gr spread.

Attachment 218299

Here is the rough graph of the weight sort. As you can see there is no "bell curve". The curve rises from 156.9 gr slowly to 157.5 gr and then rises sharply. The "curve" then plateaus out at 157.7, 157.8 and 157.9 gr with 113, 124 and 110 bullets for each weight. The "curve" then falls sharply to just 9 bullets at 158.0 gr. Of those 9 bullets only 2 actually weighed 158.0 gr. The remaining 7 bullets weighed between 157.9 and 188.0 gr. There were no bullets heavier than 158.0 gr.

Attachment 218300

The weight sorting is showing us the 113 bullets of 157.7 gr, the 124 bullets of 157.8 gr and the 119 bullets (I'll put the 158.0 gr bullets in with those) of 159.9 gr weight has the highest weight/mass of alloy in them. Since the curve dropped off suddenly we see those weight bullets are the most consistent and the best the mould will produce with that alloy. Those 356 weight selected bullets will be used for best accuracy.

The 157.6 gr bullets will be used as fouler/sighters as I expect they will give very good accuracy also given only a .2 gr +/- difference in weight.

Had we lumped all the visually selected bullets into one group 70% would have been with the excellent bullets, another 15% would have been with the fouler/sighter bullets and the remaining 15% would have been with bullets having a weight/mass difference of 1.1 gr. Now, had I done that I probably would have got nice 1 1/2 moa groups with 7 +/- shots going into moa or less and 2 -3 +/- shots going out of the group in the 1 1/2 moa +/-. How many of you shoot groups like that with bullets only visually sorted?
It is with such weight sorted selected bullets (the 157.7 to 157.9 gr bullets) that I am able to hold moa accuracy to 300 yards and beyond with a 2900+ fps velocity.

That is how I weight sort and why it makes a difference. Here is an 11 shot group I shot at 600 yards with my HV 30x60 XCB rifle. It is a 5.9" group or sub moa at 600 yards.

Attachment 218301

[Wm Cook]

This was the first casting out of this mold and after recycling the first 20 drops out of the four cavity mold I cast about 200 or so. I'm in the middle of weighing/sorting them this week.

Another quick question. How do you manage consistent bullets with a multiple cavity molds? With other molds I've found that each cavity has their own sine wave. On the .22 Hornet project I just finished I had a crossover of heavy from one cavity and the lighter ones from another. Weighed as a group they looked, weighed the same but they were different. I found this out by separating each cavity bullet into two separate grouping and weighed/sorted each one individually. There were clearly a crossover where the light ones from one cavity crossed over with the heavy one from the other. I pulled these out and marked them as crossovers to be used as fouler's. That doesn't mean that a four cavity mold isn't manageable but before I put them all into one pile, weighted, sorted and shot them I would think we need to have confidence in consistency. Shooting the groups you did at 600 yards requires a lot of attention to detail.

Originally my target was 100/200 yard hunter class competition and I was looking for .75MOA at 100 yards. The platform has a couple one in 10 Krieger's, Schmidt & Bender, trued, bedded Remington action using a Jewell trigger. Its purpose is life is to serve as a competition switch barrel rifle that can go from the stock .223 Remington barrel to .223AI, .308 tight neck HV, tight neck .308 Remington Varmint weight barrel and back to the stock .308 barrel.

As is, the rig should be able to shoot short range Hunter class, tactical, 600 yard F class TR.

Since accuracy is this rifle's only purpose I'm leaning heavily toward setting the four cavity mold aside and getting a two cavity NOE 30 XCB mold. Dropping the two bullets out of that into two separate piles and sorting to see what the bell curve is on each. Only then could I make the decision as to whether I would shoot either bullet from each cavity in the same group. I would have started with the two cavity mold but they were out of stock.

Larry thanks for sharing so much. I'm head over heels in short range Bench Rest with my PPC's but I have more fun planning and preparing for shooting tight groups with cast bullets. Cast bullets accuracy has a lot more variables and it's more satisfying. I would trade a .099 group with a 6PPC for a five shot .750" cast group any day.

[Larry Gibson]

Bill

How do you manage consistent bullets with a multiple cavity molds?

The NOE 30 XCB mould I use and the Lyman 311466 mould I use are both 4 cavity. I find no difference in bullet quality between the aluminum and iron blocks. I did find the NOE blocks with 5 cavities did not cast bullets as consistently as the Lyman 4 cavity mould. So when Al Nelson ask me how I wanted my NOE mould I told him to make it a four cavity, not five and to cut it for Lyman #2 alloy not COWWs. AI also asked for the bullets to drop between .3105 and .311. That is what Al did and it is a wonderful mould. I have found no weight variation between cavities.

When casting I use the following technique; with the Lyman Mag20 I use 2 thermometers in the alloy; one measures the alloy temp in the bottom half and the other measures the alloy temp in the top half. I maintain a temp of 715 +/- 10 degrees when casting. I adjust the spout flow rate to keep it consistent regardless of the alloy amount in the pot. I only use the one NOE mould at one time. I maintain a consistent cast tempo w/o getting the mould too hot or letting it get too cold.

Using that technique with the Lyman 4 cavity mould I also find no variation between the cavities. I also have 3 other NOE moulds and several Lyman 2 cavity moulds that give consistent weight between the cavities. The alloy also plays a very important part. An alloy the gives a lot of shrinkage in the mould when hardening will not give as consistent weights, especially between cavities. Also an alloy that does not have a balance of Sb to Sn will give more shrinkage. If the antimony is not mixed with the tin forming the sub metal SbSn to stay in solution in the lead then the antimony will harden first creating light weight pockets. Those cause imbalances and the antimony shrinks more.

Shooting the groups you did at 600 yards requires a lot of attention to detail.

Yes it does. The devil is in the details for sure. Getting the best accuracy at regular cast bullet velocities and high velocities in particular require paying very close attention to those details.