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View Full Version : At what point do you dimple your mould?



3584ELK
12-22-2005, 12:04 AM
....The reason I ask is that I have two 30-06 rifles, and strangely the M1 Garand outshoots the Remington 760 thus far. So, how big a role does bullet orientation play? I have set the OAL to match the Remington, and slugged the bore, which came out at .309", this shoved me to using unsized bullets at .312" diameter. Still I have crap for group size. I am using the Lyman Cast Bullet Handbook for loading reference.

BTW- the Remington has turned in .680" 3 shot groups at 100 yds before with jacketed bullets. Oh, and I am shooting water quenched WW at about 13 BHN cast in a Lee 160 gr. FPGC.

Any ideas?

Bullshop
12-22-2005, 12:28 AM
I dont think orientation is going to make a whit of difference in rifles of that type. If your thinking thats the problem with grouping I would re think if I were you. You say your quenching WW and getting BN#13, but 13 is pretty standerd for straight WW AC.
You may have started with a powder/charge/primer thats just not right for your gun. Dont limit yourself to powders listed by Lyman for cast boolits. Many times you will find good grouping from powders listed for the same weight jacketed bullet.
I was shooting today with a rebarreled Rem 700 short in 6x45. Using the RCBS 100gn in straight WW quenched at BN#20. A load that has worked so well in a 222 rem with 60gn boolit is 19gn H-4895 (not listed for cast) with CCI-SRM.
I thought it should work for the 6/45 too.
At about 2300fps it kept most shots inside an inch. I thought to try a standard SR primer so went to the very mild Rem #6 1/2. With this I was hard pressed to keep them inside 4" and a few were wider than that.
Point is because a certain powder or load didnt work so well dont mean the gun wont.
BIC/BS

44man
12-22-2005, 06:25 PM
Bullshop is right. Also I don't think your bore is that large. Every Rem I ever measured was closer to .308. You should try sizing to different diameters and testing each instead of shooting such large boolits. That Rem will shoot, give it a chance.

slughammer
12-22-2005, 07:08 PM
Any ideas?

The groove is .309, what is the bore? That is a bore rider design. Try sticking one into the muzzle end and see how it fits.

I'd also recommend a throat slug. I did one on my 7600. The change is pretty abrupt going from chamber neck to the throat. IIRC the throat on mine came in about .310. At .312, the boolit could be getting deformed when you chamber it.

I'd look at those 2 things first. Last winter I did quite well in the postal match with a Lee 150 and 16GR of 2400. It dropped with a .301 nose and I sized to .309.

3584ELK
12-22-2005, 10:45 PM
Thanks guys-

I do have faith in that Remington, it shoots condoms better than some bolt rifles!

I will check the throat and muzzle for fit with that bullet, as well as tinkering with the load.

As for the WW hardness- I am using an LBT cheapie, and so every measurement is relative to whatever it was calibrated against. I cast hot (950°) and drop the bullets into a bowl of water from about 10". I sometimes shoot them within a week, sometimes not within 6 months. What kind of time is needed before age hardening takes any effect?

Bullshop
12-22-2005, 11:54 PM
3584elk
I cast some two days ago in straight WWQ tested right at 20 on an LBT tester yesterday. Shot them today at 2300 to 2400 fps with some sub MOA groups. I can test a couple sluggs, mark them and send them to you to calibrate your tester if you want.
BIC/BS

Char-Gar
12-23-2005, 12:40 AM
.312 is probably too large for the throat of a commercial rifle. I would bet you are scraping lead of the bullet body as it passes through the throat. You can get by with .312 is most military rifles, but .310 would be better for your use.

Of course measuring the throat and sizing your bullets for an exact fit is the best route, but baring that .310 will probably get you some decent groups.

I have one 1954 vintage Model 70 in 30-06 that will accept bullet no larger than .309.

StarMetal
12-23-2005, 12:44 AM
I have a rather new CZ 550 in 30-06. It has a fat groove, almost .309. It shoots jacketed subpertly. It shoots cast even better. Mainly the 311284 and the 314299. It loves the 314299's sized at .313. The rounds have no problem chambering.

Joe

sundog
12-23-2005, 10:17 AM
Indexing a boolit isn't going to help much unless its properly fitted and being pushed by the right pressure curve for the combination of variables invovled. My feeling is that fit and concentricity must be acheived to fulfill accuracy. That said, I have several moulds that are indexed, and I have on ocassion shot carefully prepared and indexed ammo, but not in a bench gun, where its full potential can be realized. Did it help? Yea, sorta, but what a PIA.

Here's what works for me. For best accuracy, visually cull, then run the boolits across a scale. I use an electronic as I'll do several hundred at a time. Cull the light weights and segregate the other into - you pick the spread - maybe one percent boolit weight. Even if a boolit weighs right, if it doesn't look right, cull it. Now, if these boolits don't FIT, well find a boolit that will. Lots of trial and error.

One other thing. Felix can weigh in on this. Continual use of the same indexed ammo has the potential of eroding a throat. Think about. Boolit leaves the case exactly the same every time, so flame escapes the same every time. I'm not a BR guy, but the explanation makes sense to me. sundog

e15cap
12-23-2005, 10:18 AM
Don't mutilate that mold with any marks, just look at the base and you will see all the marks you need to orientate your bullet. Regards Roger

sundog
12-23-2005, 10:31 AM
Well, there's more than one school of thought on indexing a mould. Marks on the bottom of a boolit are no longer visible after checking or loading. I've recovered ALOT of my own indexed boolits, and the index is NOT visible. The mark is so small it does not interfere if it is properly placed. In fact smoe of the marks are barely visible. Of course, if you don't want to index your mould, that's okay, too.

I'll go back to my previous comment. In most rifles, fit and concentricity and an appropriate pressure curve need to be acheived if accuracy is to be obtained. Some rifles are easier than others. sundog

MT Gianni
12-23-2005, 11:52 AM
I indexed a 429215 so i could tell it from the other lyman nosed heavier bullets [429421 & 429244] if some were left in a speed loader for to long to be sure what they were. Gianni.

felix
12-23-2005, 12:16 PM
Yep, don't index loaded rounds in a chamber that is known to be round. The barrel will be ruined in no time, and will require the same indexing scheme from then on to shoot. Just don't do it, unless the chamber is already in bad shape and you are just trying to stall for time in changing out the barrel anyway. ... felix

Maven
12-23-2005, 02:22 PM
All, Instead of indexing, wouldn't it make more sense to segregate bullets by cavity if using a multi-cavity mold and then weigh them? I know it's a PITA, but it may also be the better way. What do you think?

3584ELK
12-23-2005, 02:24 PM
Maven,

Not to change the subject, but are you in a Narrow Gauge locomotive in your signature pic?

sundog
12-23-2005, 04:05 PM
Maven, exactly what I am getting ready to do for my latest batch of 30-180-SP. They're already weighed in two batches +-.5 -- lightweights culled for bbl warmers. As I check and lube them they will be boxed separately by cavity (index) and then shot as a single cavity boolit. I'm not really expecting anything very much different than what I have been getting though by weighing and not cavity segregating, but who knows?. After all, they're not being shot in a custom bench gun. Now, this sort of anal persnicky attention to detail might start making a big difference in something like cavity segregated .22 boolits weighed to +-.1, ya thank?

StarMetal
12-23-2005, 04:22 PM
I have indexed 45acp bullets in my tuned 1911 magazines and it made a difference on the target. Never indexed for rifles.

Joe

Maven
12-23-2005, 04:33 PM
Maven,

Not to change the subject, but are you in a Narrow Gauge locomotive in your signature pic?

3584ELK,

That's a standard gauge Alco (Montreal Loco Works under license from Alco) S-4 built in 1956. It has a 6 cyl. turbocharged diesel engine rated @ 1,000hp turning a generator that supplies electricity to [4] traction motors mounted on each axle. The loco is decorated in an early D & H paint scheme and is owned by the Cooperstown & Charlotte Valley RR in upstate NY. If you google Leatherstocking Railway Historical Society you'll see several pix of it (#3051) and its twin, #3052.

I worked for them for three years as an engineer from 6/02 to 8/05, but will work at Steamtown in Scranton next summer if I pass my NORAC rules test.

Paul

3584ELK
12-23-2005, 04:45 PM
Maven,

That's a pretty cool hobby that I am interested in. I live in Narrow Gauge territory and used to live real close to Chama, NM. http://www.traincams.net/ and www.ghostdepot.com

Good stuff!

trk
12-23-2005, 06:21 PM
I would get smaller groups by indexing the high spot (loaded round) in the same position in the magazine (M14) 7.62 Nato. But that was with the loaded round. It works, but the amount that you would make adjustment for by indexing just the bullet would be much less than that. It sounds like a different issue. Indexing the bullet is a fine-tuning technique once the groups are small, get them smaller.

If you measure the runout of the bullet in a loaded round, you will find that commercial ammo is crap. Even casually loaded hand loads are much better. But you need to prove that for yourself. I used .002 runout for the longest distances and worse ones for closer and for plinking. Some commercial will run .012 to .015 on the average.

3584ELK
01-02-2006, 12:40 PM
You guys were right, the unsized bullets wouldn't even chamber in the Remington 760. I slugged the bore again and came up with a bore of .3005" and groove diameter at .3085". SInce my sizing die is .309, I guess load development is the path the follow...thanks for everyone's help!

Idaho Sharpshooter
01-15-2006, 02:23 AM
welllllllllllllllll,
I index mark my moulds for BPCRS, index the boolit in and out of the luber/sizer, index it to the filed notch in each case (at the spot the tubing mike sez is thinnest) and index that round at noon in the chamber. It works, I won't change; as "Old Frankly" used to say.
JMHO

Rich

NVcurmudgeon
01-15-2006, 02:59 AM
I have marked a Lyman two-cavity mould for my best CB shooter. By segregating and orienting boolits I have managed to reduce five-shot group size at 100 yd. about 0.200". I doubt that it would be worth the trouble to do that for any other rifle that I have, nor for any purpose other than competition.

9.3X62AL
01-15-2006, 10:52 AM
NV C--

So, yer sayin' that indexing the #313249's for my Walther PP x 32 ACP is a waste of time, then? THERE's some days and hours out of my life that I'll never get back.

JBMauser
01-15-2006, 11:41 AM
Lots of good info given. I just wanted to make an observation from your original post. I would not compare any load for a garand to a bolt gun. Each should be built up totally from the ground up. OAL, charge, sizing .. the works. The garand load must be worked up with full re-sized brass, the bolt gun I would neck size. Even the bullet hardness could be different. In the Garand you must be concerned with lead shaving and inevatable lead build up in the gas system. In the bolt gun you can run a softer bullet and less pressure as you have no mechanical system to power. Also the harmonics of any two barrels in the same gun will be different let alone a gas gun and a bolt action. use the info given to work up you bolt gun from scratch. Remember that in loading for the Garand the finished bullet must feed like M2 ball because if the bullet offers resistance in the chamber you can get a discharge without the bolt in full battery and that is not a good thing. You have a lot more lattitude with your bolt gun with OAL and bullets touching the lands etc. You can compare groups but feed them diffent fodder. JB

NVcurmudgeon
01-15-2006, 11:51 AM
Deputy Al, yes, not only is indexing boolits for pocket flyswatters a waste of time, but even in my full military size 1895 Nagant revolver, I could find no improvement in accuracy when weight separating castings. Very strange considering that the Nagant has visible sights and a mere 10 lb. (single action) trigger yank.

C1PNR
01-16-2006, 11:42 PM
NV C--

So, yer sayin' that indexing the #313249's for my Walther PP x 32 ACP is a waste of time, then? THERE's some days and hours out of my life that I'll never get back.
[smilie=p: [smilie=l: :bigsmyl2: :shock: