300 RUM load development questions

[Bart B]

The copper fouling seemed to get worse with the VLD's, and harder to clean. That doesn't make sense to me.
Are you saying above that copper will only build up just so much, and then it could be a good thing? If that's the case, and copper in my barrel may help, would I be better off focusing on carbon build up?

The jacket material across all bullet varies somewhat. Some will be harder to remove than others.

Note that with a squeaky clean barrel with no fouling of any kind inside, the first bullet fired lays down copper in the rough spots. As soon as it's past one, the fouling from powder and primer residue coat the copper. The next bullet pushes out some of that fouling, lays down a bit more copper mixed into the powder/primer fouling, then more powder/primer fouling coats that stuff.

It therefore is a compound issue. You cannot remove just one; both come out to varying degrees depending on the cleaning process used.

Best thing to do if one doesn't want to clean barrels too much is get one with less than 15 but more than 10 microinches of roughness on the lands and grooves. Perfectly smooth bores will wipe more copper off for some strange reason according to the top barrel makers. Such bores have produced sub MOA accuracy at the longer ranges for a couple hundred shots without any cleaning.

 

[MontanaRifleman]

It's interesting that you're getting a lot of fouling in your Hart. Most custom barrels don't foul all that much, or at least that's what I've read in these forums and elsewhere. All my current rifles are factory. I have 3 custom barrel projects currently in progress and they will get nitrided which should significantly reduce any fouling and hopefully much longer barrel life. You might want to do a break-in. Most fouling in customs is usually from the throat reamer.

Some barrels shoot well when fouled and some don't. As long as the rifle is shooting well, I don't mess with cleaning it. When accuracy starts to fade, then I clean.

I can't call myself an expert about many things, but one thing I might consider myself expert on is cleaning after having done a lot if it with numerous factory barrels.

The best products out there are Bore Tech and Wipeout. They are both equal to each other in copper removing ability and superior to all the other products including Sweets, Butches Bore Shine, KG-12, Montana Xtreme 50 BMG and others. I have compared them all against each other (except Sweets... Broz has compared Bore Tech against Sweets) and when all the rest stopped removing copper, Bore Tech removed more except against Wipeout.

When using Bore Tech, you need to use a nickel platted jag and nylon brush. It will immediately, upon contact, start to eat brass/bronze jags and brushes.

Here is a good thread on the subject.

http://www.longrangehunting.com/forums/f37/bore-solvent-70001/

 

[Tidesloe]

It's interesting that you're getting a lot of fouling in your Hart. Most custom barrels don't foul all that much, or at least that's what I've read in these forums and elsewhere. All my current rifles are factory. I have 3 custom barrel projects currently in progress and they will get nitrided which should significantly reduce any fouling and hopefully much longer barrel life. You might want to do a break-in. Most fouling in customs is usually from the throat reamer.

Some barrels shoot well when fouled and some don't. As long as the rifle is shooting well, I don't mess with cleaning it. When accuracy starts to fade, then I clean.

I can't call myself an expert about many things, but one thing I might consider myself expert on is cleaning after having done a lot if it with numerous factory barrels.

The best products out there are Bore Tech and Wipeout. They are both equal to each other in copper removing ability and superior to all the other products including Sweets, Butches Bore Shine, KG-12, Montana Xtreme 50 BMG and others. I have compared them all against each other (except Sweets... Broz has compared Bore Tech against Sweets) and when all the rest stopped removing copper, Bore Tech removed more except against Wipeout.

When using Bore Tech, you need to use a nickel platted jag and nylon brush. It will immediately, upon contact, start to eat brass/bronze jags and brushes.

Here is a good thread on the subject.

http://www.longrangehunting.com/forums/f37/bore-solvent-70001/

I agree, I expected less fouling with a Hart barrel, and easier to clean. That seemed to be true until I shot VLD's, and the fouling got worse, and more difficult to remove. Is this even possible?
I've been using Bore Tech Eliminator, and it gets it clean. I'm just still confused about the appearance of more fouling after shooting VLD's. Maybe, I'll not worry about that until accuracy is affected.

 

[Tidesloe]

Some top level competitors lap the necks out of standard full length sizing dies. They believe that such modified dies have necks better aligned with the die shoulder and body chamber. Bushings have a slight clearance tolerance but that doesn't seem to matter much. I lapped out my die necks decades ago long before bushing dies were even a dream in their designers head. I've got five .308 Win. RCBS full length dies all with different neck diameters for different case neck wall thicknesses.

Partial neck sizing ends up makeing cases bind up the bolt when they're chambered. I think the reason partial neck sizing's so popular is it typically make better ammo than when case shoulders are set back way too far; something that happens so often when sizing dies are against the shell holder when the case is all the way into the die.

I believe that the best neck tension is what's the least that will keep bullets in place during normal handling and loading. If case necks' elasticity changes, use a different bushing diameter. A few folks buy two sets then lap one set out half a thoiusandth so they'll have more exact control over neck tension. But I think one thousandth steps is good enough.

I also believe than bullet runout under 1% of bullet diameter is good enough. Having shot enough 1/2 to 5/8 MOA test groups at long range with 30 caliber bullets having up to .003" runout, why beat your brains out trying to get it smaller? Seat the bullet to engage the rifling when chambered and it'll center well in the rifling then shoot the darned thing out the barrel; it'll fly just right.

Bart, I've been looking on here for info on lapping out necks, haven't found much other than that people are doing it.
Would that be something that the die manufacturer should do, or should any machinist be able to do it, and maintain straight concentric necks?
I do have access to a machine shop.

 

[Bart B]

Lappin' out a full length sizing die's neck. . .101

I've lapped out a dozen or more full length dies with a simple tool. If you've access to and know how to use a lathe, it's easier that writing a bad check.

For my 30 caliber dies, I took a 1/4th wood dowel, used a fine cut thin saw to put a slot in one end about 1 inch long.

Took a 2" or so long 1" wide strip of 400 grit crocus cloth and slipped on end into the slot, then wrapped the rest around it so it would be a tight fit in the die's neck. A dab of super glue on the flap stuck it in place.

Chuck the die bottom out in the lathe headstock with jaws on the threads, then put a dial indicator on it's inside edge at the bottom slowly turning the headstock to ensure the die's centered. A couple of times I had to put a few thousandths shim stock under one or two headstock jaws. This ensures the die turns on center and doesn't egg-shape the neck nor get if off centered at its new diameter.

Turn the die about 200 - 300 rpm, put a dab of oil on the crocus cloth then run it in and out of the die's neck a few times. You may have to remove some crocus cloth or add some depending on how tight it fits. This is the testy part of the task, but easy to do if you know what happens when you change the amount of crocus cloth on the dowel.

Take your expensive "lapping tool" out, clean out the die and clean the lap, then use a hole micrometer to measure the neck diameter.

Repeat the above until the die's neck diameter is what you want.

The details are how thick the crocus cloth is, what its grit count is, how tight it is in the die's neck and how fast you want to remove metal from the die's neck. If you know about basic machine shop stuff, this is the easy part.

 

[Tidesloe]

Re: Lappin' out a full length sizing die's neck. . .101

I've lapped out a dozen or more full length dies with a simple tool. If you've access to and know how to use a lathe, it's easier that writing a bad check.

For my 30 caliber dies, I took a 1/4th wood dowel, used a fine cut thin saw to put a slot in one end about 1 inch long.

Took a 2" or so long 1" wide strip of 400 grit crocus cloth and slipped on end into the slot, then wrapped the rest around it so it would be a tight fit in the die's neck. A dab of super glue on the flap stuck it in place.

Chuck the die bottom out in the lathe headstock with jaws on the threads, then put a dial indicator on it's inside edge at the bottom slowly turning the headstock to ensure the die's centered. A couple of times I had to put a few thousandths shim stock under one or two headstock jaws. This ensures the die turns on center and doesn't egg-shape the neck nor get if off centered at its new diameter.

Turn the die about 200 - 300 rpm, put a dab of oil on the crocus cloth then run it in and out of the die's neck a few times. You may have to remove some crocus cloth or add some depending on how tight it fits. This is the testy part of the task, but easy to do if you know what happens when you change the amount of crocus cloth on the dowel.

Take your expensive "lapping tool" out, clean out the die and clean the lap, then use a hole micrometer to measure the neck diameter.

Repeat the above until the die's neck diameter is what you want.

The details are how thick the crocus cloth is, what its grit count is, how tight it is in the die's neck and how fast you want to remove metal from the die's neck. If you know about basic machine shop stuff, this is the easy part.

Sounds easy enough, but I bet I could make a mess out of it. I have a good friend who owns a machine shop. I may try it. I have a standard RCBS FL die. Thats not what I've been using, but without expander ball it gives more concentric necks than my Redding FL bushing die.

 

[Bart B]

Re: Lappin' out a full length sizing die's neck. . .101

I have a good friend who owns a machine shop. I may try it. I have a standard RCBS FL die. Thats not what I've been using, but without expander ball it gives more concentric necks than my Redding FL bushing die.

Too bad it makes the case necks too small for bullets, but with the neck lapped out a few thousandths (1 or 2 less than a loaded round's neck diameter) the same thing will happen.

Knowledgable folks have been doing that since the 1960's. It's amazing how well case necks end up being concentric when the case body's held aligned with the neck when its sized back down from its fired position. This is what benchresters finally learned only a few years ago.

 

[Tidesloe]

Re: Lappin' out a full length sizing die's neck. . .101

Too bad it makes the case necks too small for bullets, but with the neck lapped out a few thousandths (1 or 2 less than a loaded round's neck diameter) the same thing will happen.

Knowledgable folks have been doing that since the 1960's. It's amazing how well case necks end up being concentric when the case body's held aligned with the neck when its sized back down from its fired position. This is what benchresters finally learned only a few years ago.

Yep, I think your right. Of 3 different dies. One standard, and 2 bushing, the standard die gives pretty consistently concentric necks. The bushing dies give good results sometimes, but are inconsistent. I guess moving parts inside bushing housing leaves the potential for error.
I'm coming to the conclusion that the standard FL die works consistently. So now, just to get the neck lapped out.
So do the die threads with ring locked down actually bring the die off center? It would make sense to me. I hear various theories, but to me with the upward pressure into the die the same thing would occur. With die floating,. or with a rubber o ring between die ring and press body, the upward pressure would seat the die into the threads taking pressure off the o ring? Or does it actually dampen that effect?

 

[Bart B]

Re: Lappin' out a full length sizing die's neck. . .101

So do the die threads with ring locked down actually bring the die off center? It would make sense to me. I hear various theories, but to me with the upward pressure into the die the same thing would occur. With die floating,. or with a rubber o ring between die ring and press body, the upward pressure would seat the die into the threads taking pressure off the o ring? Or does it actually dampen that effect?

Most well built presses have the pilot hole for the die threads and ram bored and reamed at the same time. After the threads are put in the die hole, I doubt there's more than a couple thousandths error in the alignment of their axes. Would not matter if there was as much as a .005" misalignment.

As shell holders have a few thousandths tolerances in their sized relative to SAAMI spec'd case rims, there's plenty of room for the case head to slip and slide around as the fired case goes up into the die. Whatever misalignment there is between die axis and shell holder axis is insignificant as the case head moves sideways in the shell holder. If it was, then there wouild be all sorts of stuff in every media on earth about it. I"ve never seen anyone's dimentional complaint about such trivia. How many "out of round" measurements have you seen on case heads? How many folks have complained about that uneven pressure ring caused by uneven brass thickness making the case head a couple thousandths off center of the case?

Therefore, I'm convinced that any concern about this is a waste of time.

You're one of the few I know of who has figured out that an O ring under a die is a waste of time. The die's threads center them in the press's threads; a tiny bit by the O ring but a lot and finally by the force of the die being pushed up by the case friction on it. I call O rings so used a placebo for ingnorant reloaders; it makes them feel good about a problem that does not exist.

 

[Tidesloe]

Re: Lappin' out a full length sizing die's neck. . .101

Most well built presses have the pilot hole for the die threads and ram bored and reamed at the same time. After the threads are put in the die hole, I doubt there's more than a couple thousandths error in the alignment of their axes. Would not matter if there was as much as a .005" misalignment.

As shell holders have a few thousandths tolerances in their sized relative to SAAMI spec'd case rims, there's plenty of room for the case head to slip and slide around as the fired case goes up into the die. Whatever misalignment there is between die axis and shell holder axis is insignificant as the case head moves sideways in the shell holder. If it was, then there wouild be all sorts of stuff in every media on earth about it. I"ve never seen anyone's dimentional complaint about such trivia. How many "out of round" measurements have you seen on case heads? How many folks have complained about that uneven pressure ring caused by uneven brass thickness making the case head a couple thousandths off center of the case?

Therefore, I'm convinced that any concern about this is a waste of time.

You're one of the few I know of who has figured out that an O ring under a die is a waste of time. The die's threads center them in the press's threads; a tiny bit by the O ring but a lot and finally by the force of the die being pushed up by the case friction on it. I call O rings so used a placebo for ingnorant reloaders; it makes them feel good about a problem that does not exist.

Yep, I agree

 

[Tidesloe]

I did some more load testing today. Temp in low 30's. Windy, but not much cross wind component. Wind was at my back and gusty. The testing didn't go quite as good as I had hoped, but not bad. I'm looking for advice. If I need to post pics, I can try to figure that out.

Heres what I did, and where I'm at.
Nosler cases - 3rd firing, FL bushing sized, bumped .002
215 primers
Retumbo
210 gr. VLD's, seated .010 off lands
200 yd target

1st group of 3, 88 gr.
Shot 1 - 3015 fps
Shot 2 - 0?
Shot 3 - 3044 fps / ES 29 fps
#1, first shot of day, 2 3/8" left, shots 2&3, .414" 1 probably a flyer. Toal group 2.79"

2nd group, 88.5 gr.
#1 - 3037
#2 - 3044
#3 - 3016 / ES 21 fps
Group size 1.349"

3rd group, 89 gr.
#1 - 3058
#2 - 3044
#3 - 3072 / ES 28
group size 1.175"

4th group, 89.5 gr.
#1 - 3065
#2 - 3072
#3 - 3079 / ES 14
group size 1.445"

5th group, 90 gr.
#1 - 3108
#2 - 3086
#3 - 3093 / ES 22
group size 1.941"

Group 1, shot #1, I'm calling a flyer - 1st shot of day. Kick that shot out, and its the best group. The best groups had the highest spread in velocity. Group 4, best ES, and not all bad at 1.445". Under 3/4 MOA.

After 3 firings on brass, cases will not fit back in Redding comp shell holder. Goes in RCBS shellholder just fine. Is this case head swelling? I'm assuming primer pockets may now be too loose. Are these cases done? I have more, but not much, I'll be out soon. Why would the best groups have highest ES? I'm confused. Should I go with that low ES, and work on seating depth? Should I go on up to max loads?

What to do from here?

 

[bigbuck]

Hi, Cerwin.
I shoot a 210 Berger in my rifle at the starting load for Berger data.

85 Grains of retumbo.
federal 215 Match primer.
Remington Brass.
seated .022 thous. off the lands.

I have had this load shoot a 3 shot group at 200 yards that you can almost cover up with a dime.
333 Yard group was a perfect triangular pattern that could be covered with a quarter.
752 yards 2 1/2 inch 3 shot group.

Try this if no one has mentioned it your velocity spreads seem like they vary a little too much with what retumbo powder can do .
The high side of the loading chart doesnt work if your accuracy doesnt meet your requirments and or standards.

After you work your brass and install a new primer take and get you some "Graphit" from redding , take your newly primed brass case and sink the case mouth into some graphit material give it a complete spin rais it up and tapp the hull on the container of graphite charge with powder and seat bullet . This should allow consistent bullet release and help your groups. Note once you tighten up your groups this will help that itty bitty extra.

You may have already known this........ Carlock told me about it.

 

[Tidesloe]

Hi, Cerwin.
I shoot a 210 Berger in my rifle at the starting load for Berger data.

85 Grains of retumbo.
federal 215 Match primer.
Remington Brass.
seated .022 thous. off the lands.

I have had this load shoot a 3 shot group at 200 yards that you can almost cover up with a dime.
333 Yard group was a perfect triangular pattern that could be covered with a quarter.
752 yards 2 1/2 inch 3 shot group.

Try this if no one has mentioned it your velocity spreads seem like they vary a little too much with what retumbo powder can do .
The high side of the loading chart doesnt work if your accuracy doesnt meet your requirments and or standards.

After you work your brass and install a new primer take and get you some "Graphit" from redding , take your newly primed brass case and sink the case mouth into some graphit material give it a complete spin rais it up and tapp the hull on the container of graphite charge with powder and seat bullet . This should allow consistent bullet release and help your groups. Note once you tighten up your groups this will help that itty bitty extra.

You may have already known this........ Carlock told me about it.

Did not know that. I learn something new ever day. The spreads did seem too much to me.
What would you consider acceptable?
I'd give up velocity for accuracy any day. What is your velocity at min load? That is a direction I would possibly go. I think I will try lighter loads, and see what it does. That start charge of 88 gr, I've had come in right at 3/4" twice, until I shot it today. I think the first shot was a flyer, and 2&3 was at. .414", but spread was bad.
You may be on to something going lower. I'll give that graphit a try.

 

[MontanaRifleman]

I personally would not settle on a load of less than 90 gr because that would leave you with less than 90% capacity.

Graphite may help a very small amount but you may not even see the difference. Your ES's aren't too bad and I do not put much stock in chrono reading as they are imperfect instruments. Even an Oehler can have a few FPS eror. They can give you a general idea of what's going on but I would never pick or discard a load because of what a chrony showed. I go strictly by groups and by looking at your group results there's not much to go on IMO. They are all basically in the same range.


Bergers are known to be sensitive to seating depth. I would recommend varying seating depth. Seating closer to the lands will push pressure up slightly. You might try .005 off the lands and work up until you reach max. Generally tighter is better than looser. If that doesn't work, you can work down seating the bullets farther into the case. E-Tips usually shot .1 - .15 better in my Sendero than the 210 Bergers, but I never messed with seating depth.