300 RUM load development questions

[MontanaRifleman]

I appreciate the advice Rifleman. Sounds all reasonable to me. It makes sense.
Would you care to share some creative ways to unstick a case?

First, even when using Imperial wax, your brass may still be a little stuborn, esecially the first few cases, If you feel any resistance in the sizing stroke, stop and back out and rub a little more wax on but dont use too much. That's just the way the RUM cases are. After you've done a few and the wall of the die gets lubed, it should go easier. You'll learn to feel how it's going and how much wax to use.

It's been a while, so I'll have to draw back on memory. You'll need a 5/16ths x about 1 1/2" lag screw and a washer wouldn't hurt and 1/2" wrench. A slightly smaller drill bit and hand drill. A crow bar and 2 chairs (one for each foot for good ballance ) Also some PB blaster which I didn't use.

OK, remove the spindle from the die. Spray the PB blaster into the top of the die and around the bottom of the die and stuck case. Let is soak, overnight would be best. After soaking, insert the die upside down into the press. I would hesitate doing this on a turret press. Screw the die up until the bottom of the die is just below the top of the press. Drill down into the primer pocket and make a hole slightly smaller than 5/16ths. Dont make the hole too big or too small, you may need to experiment. take the 5/16ths lag screw with washer and screw down into the hole in the base of the case. leave the washer and head of the lag about 1/2" above the case base. Get a rag and fold it a couple of times and lay it on the frame of the press where your crowbar will touch the press. You probably get the rest. It took a whole lot of effort on my part. Make sure your press is very secure. And if your married, you might want to wait until your wife is out shopping or something

 

[MontanaRifleman]

To remove your stuck case from a die, first slide the shell holder off its head then remove the die with the case in it. If there's no primer in it, then use a standard stuck case remover to get it out. If the primer's in it, then I'll need to know what cartridge case it is before giving more help.

If there is a primer in the pocket you can easily pop it out with a lyman flashole uniforming tool, or drill it out. If you do have a stuck case remover on the way, that's probably the best way to do it.

 

[MontanaRifleman]

As soon as I get my stuck case out of my bushing die. I'll experiment without and with expander. Checking concentricity. I think I believe you on the ex panders pulling necks off center.
Anyway thanks. I'll find what works best in the end. I'm getting some good suggestions here.

That's a very good idea. Nothing like seeing it yourself. It makes a bigger impression. FWIW, i just recently FL sized some fired 22-250 brass, fired 25-06 brass and some new 300 RUM brass. I took a handful of each and put them on my Sinclair gauge and the necks ran about 1 - 2 thou of runout. This was with standard New Dimension FL dies for the 22-250 and 25-06 and a standard Redding FL die for the RUM brass. These all size the neck about 5-6 thou smaller than the expander diameter. If you lube the inside of the neck and go slow, you can do a good job of keeping them straight. I didn't measure the runout of these cases prior to sizing, but usually they are just under 1 thou give or take.

One thing about using the expander with the bushing is you don't have to turn the necks. If you use a bushing only, it's best to turn the necks. If you're using a factory barrel, there is really no point in neck turning. Your neck space is already going to be generous and thinner necks will expand all the more.

Something else you might experiment on is sorting your loaded cartridges by run out and shooting them to see how much if any difference there is.

 

[Bart B]

One thing about using the expander with the bushing is you don't have to turn the necks. If you use a bushing only, it's best to turn the necks. If you're using a factory barrel, there is really no point in neck turning. Your neck space is already going to be generous and thinner necks will expand all the more.

I've had no problems full length sizing fired cases without any neck turning not using expander balls. In fact, I've not seen any significant difference between turned and unturned case necks using gelded dies (those without balls but with necks a bit smaller than a loaded round). Both shoot well under 1 MOA through 1000 yards. All with SAAMI spec chambers with lots of clearance around the loaded round's neck. How well a bottleneck case that headspaces on its shoulder centers in the chamber neck has nothing to do with their diameter differences anyway; a .243 Win. round centers perfectly in a .308 Win. chamber neck when fired.

There is one advantage of turning case necks. If their wall thickness is 2 thousandths or more, then turn them so at least half the neck cleans up. Zero tolerance isn't needed for best accuracy but a lot of folks think it is.

 

[MontanaRifleman]

I've had no problems full length sizing fired cases without any neck turning not using expander balls. In fact, I've not seen any significant difference between turned and unturned case necks using gelded dies (those without balls but with necks a bit smaller than a loaded round). Both shoot well under 1 MOA through 1000 yards. All with SAAMI spec chambers with lots of clearance around the loaded round's neck. How well a bottleneck case that headspaces on its shoulder centers in the chamber neck has nothing to do with their diameter differences anyway; a .243 Win. round centers perfectly in a .308 Win. chamber neck when fired.

There is one advantage of turning case necks. If their wall thickness is 2 thousandths or more, then turn them so at least half the neck cleans up. Zero tolerance isn't needed for best accuracy but a lot of folks think it is.

Never heard the "Gelding" descript before. I'll have to remember it. This is interesting since I was just visiting my smith about a week and half ago to determine the reamer specs for my New 300 RUM (currently shooting a factory Sendero) We are goibng with the PTG 300 RUM Match which has a little tighter neck. We also discussed neck sizing vs FL, neck turning, etc. Going into this project a while back, I was going to turn the necks but after talking with him and others, I decided not to. He is an avid shooter and long ranger as well. He is a FL sizer and is happy and successful with it. He also said, that when a round is chambered, it will sag under it's own weight and not not be perfectly centered. If it does, I suppose it might throw the neck off center a little when the round is discharged? I don't know. My necks seem to come out of the chamber fairly concentric.

Anyway, I would say that if there is a lot of variation in neck wall thickness, it would probably be a good idea to turn them, but I haven't seen a lot of variation. I also like the idea of bringing the expander back up through it to get any variations pushed to the outside. I don't think that would throw the necks off much, if at all, if your only pushing it out 1-2 thou and the inside of the neck is lubed. That could be easily measured and i will be doing just that when this project is complete.

 

[Bart B]

Going into this project a while back, I was going to turn the necks but after talking with him and others, I decided not to. He is an avid shooter and long ranger as well. He is a FL sizer and is happy and successful with it. He also said, that when a round is chambered, it will sag under it's own weight and not not be perfectly centered. If it does, I suppose it might throw the neck off center a little when the round is discharged? I don't know. My necks seem to come out of the chamber fairly concentric.

Your avid shooter doesn't understand how a rimless bottleneck case fits the chamber when it's in there with the bolt closed and especially when its fired. But then, neither to most other shooters understand this.

When chambered, if the bolt's got an in line ejector, that pushes the round full forward into the chamber where its shoulder centers in the chamber shoulder. Its back end gets pushed where the extractor presses it against the chamber wall, usually. When the firing pin smacks the primer, that further drives the case shoulder hard into and well centered in the chamber shoulder before the firing pin dents the primer enough to crush the pellet against the anvil and finally fires the round. And there's typically a bit of clearance all around the case before and when fired except at its back end that's pressed against the chamber wall. Rounds do not lay in the bottom of the chamber except when they're in it and the bolt's open and not touching the case head whatsoever.

Ask your avid shooter where the shoulder of a NO GO headspace gauge goes when the bolt tries to close on it in a GO headspaced chamber, but it won't. Then ask him what's the difference betwen this and what happens to a live round in that same chamber when it's smacked hard by the firing pin. You can probably figure this out all by yourself.

 

[MontanaRifleman]

Well he is a very experienced shooter and very experienced and talented smith. A number of LRH members I know are very happy with his work. Whether his theory about sagging cartridges is accurate, I don't know and don't really care. What I do care about is results. Predictable, repeatable and reliable results.

To me as a long range shooter, I would like to see these results in Sub MOA shooting to 1K and maybe farther.

 

[Bart B]

Well he is a very experienced shooter and very experienced and talented smith. A number of LRH members I know are very happy with his work. Whether his theory about sagging cartridges is accurate, I don't know and don't really care. What I do care about is results. Predictable, repeatable and reliable results.

99+% of all 'smiths building excellent rifles think loaded rimless bottleneck rounds rest in the bottom of the chamber when loaded and fired. Only 2 out of many dozens I've dealt with understand that. And far less shooters do.

If you understand that too, it'll help you know what's important in producing good ammo.

 

[Tidesloe]

To remove your stuck case from a die, first slide the shell holder off its head then remove the die with the case in it. If there's no primer in it, then use a standard stuck case remover to get it out. If the primer's in it, then I'll need to know what cartridge case it is before giving more help.

Theres no primer in the pocket. My stuck case remover will be here today. My chamber is not factory. I dont the details of the reamer used, but I can find out.
If using a bushing die will I need to neck size down more than once? I guess maybe my chamber dimensions will determine that. I did talk to Redding about bushing dies, and they said that you cant bush down more than. .005 without having concentricity problems. If more sizing than that is needed bushing down more than once may be required.
I'm on a new Hart barrel, and like I said I dont know the details of the chamber. So far it appears to be fairly tight. I'll measure some neck diameters after firing and see exactly how much sizing is needed. That I have not done yet.
When I stuck the case I was experimenting more anything, and was just bushing down a fired case with a concentric nech to. .336 and then check to see if that gave me any concentricity problems.
Anyway, it sounds like experimenting will be further needed before I just start throwing ammo together. My first rounds were easy as the Nosler brass was already sized and concentric. Now I'll see what sizing operations are going to give me the best results.

 

[Tidesloe]

That's a very good idea. Nothing like seeing it yourself. It makes a bigger impression. FWIW, i just recently FL sized some fired 22-250 brass, fired 25-06 brass and some new 300 RUM brass. I took a handful of each and put them on my Sinclair gauge and the necks ran about 1 - 2 thou of runout. This was with standard New Dimension FL dies for the 22-250 and 25-06 and a standard Redding FL die for the RUM brass. These all size the neck about 5-6 thou smaller than the expander diameter. If you lube the inside of the neck and go slow, you can do a good job of keeping them straight. I didn't measure the runout of these cases prior to sizing, but usually they are just under 1 thou give or take.

One thing about using the expander with the bushing is you don't have to turn the necks. If you use a bushing only, it's best to turn the necks. If you're using a factory barrel, there is really no point in neck turning. Your neck space is already going to be generous and thinner necks will expand all the more.

Something else you might experiment on is sorting your loaded cartridges by run out and shooting them to see how much if any difference there is.

Sounds like, I'll just have to experiment with various things. Thats great I enjoy it, and it helps educate me. You guy's are giving excellent direction, and I appreciate all the input. In the end, it sounds like experimentation is still what I need to do.
I'm not very experienced at the long range game, but am very fascinated with it and wamt to learn. I think I have the tools, and now learning how to use the tools to give me the best possible results is where I'm at now.
I actually have another LR custom being built as we speak in 7 STW. Maybe I have more money than sense lol, yea right. This hobby is keeping me tapped out. I need to find somebody in my area thats into this stuff.
Thanks for the input

 

[Tidesloe]

First things first! Your runout issue, is probably q result of your resizing process, and it is hard at times to correct it. Typically what happens is when you resize, and when you pull the expander ball back through the case, it sometimes " pulls " the neck a little out of square, or centerline, with the body of the brass. So, then when you seat the bullet, it is then exaggerated. You need to ensure that your expander ball is dead center of your die. Also , lubricate the INSIDE of the neck before the resize stage, that way, the expander will not bind, and that's usually what starts the distortion.
As to the jump, when I used to load VLD's in my RUM, I loaded to box length, then manipulated the load in small increments to find the "sweet" spot. The RUM is free bored by design, and unless you are single feeding, you can not touch or come close to the throat, and still fit into the box.
Read your instructions that came with your dies to ensure you are centered correctly with the expander, and that will help out a lot. Good luck, and enjoy the ride.

I have my runout issue corrected, and got a VLD seater plug. I' m now getting a TIR of no more than .002 usually less, around. .001.
I did a seating depth test based on Berger manual at a starting charge of 88 gr Retumbo. Surprisingly all of the Berger recommended seating depths shot well at 200 yds, best of those was. 010 off.
Last week I went to the range with 5 rnds of the starting 88 gr, .010 off lands to center on target at 200 for a ladder test. The first 2 shots got me on center. The next 3 rounds came in at just over 3/4" at 200. I had no idea that right off the bat for starters I'd get this kind of accuracy out of it.
I had planned on starting at 88 gr, and working up in increments to max, and see what happens. It seems to want to shoot the 210's well.
What would you guy's suggest I do from here?

 

[Tidesloe]

Never heard the "Gelding" descript before. I'll have to remember it. This is interesting since I was just visiting my smith about a week and half ago to determine the reamer specs for my New 300 RUM (currently shooting a factory Sendero) We are goibng with the PTG 300 RUM Match which has a little tighter neck. We also discussed neck sizing vs FL, neck turning, etc. Going into this project a while back, I was going to turn the necks but after talking with him and others, I decided not to. He is an avid shooter and long ranger as well. He is a FL sizer and is happy and successful with it. He also said, that when a round is chambered, it will sag under it's own weight and not not be perfectly centered. If it does, I suppose it might throw the neck off center a little when the round is discharged? I don't know. My necks seem to come out of the chamber fairly concentric.

Anyway, I would say that if there is a lot of variation in neck wall thickness, it would probably be a good idea to turn them, but I haven't seen a lot of variation. I also like the idea of bringing the expander back up through it to get any variations pushed to the outside. I don't think that would throw the necks off much, if at all, if your only pushing it out 1-2 thou and the inside of the neck is lubed. That could be easily measured and i will be doing just that when this project is complete.

Hey Montana and Bart, I got rid of the expander ball, and have tried a couple different methods. My runout problem is solved. Firct off, I replaced my case holder, then sized without expander ball, then Sinclair expander die for consistent neck tension. This leaves me with little to no runout. Almost forgot, I got a VLD seater plug. I think that was the biggest part of my problem. Also getting no runout issues with a Redding bushing die. Thats what I'm using.
I've done a little testing with 210 VLD, and surprisingly for starters at 88 gr Retumbo to get centered on target for further testing, I shot just over 3/4"group at 200 yds. This was with virgin Nosler brass.
I have some further test loads ready to go. I'm loading at. .010 off lands. It seems to like the 210 VLD's. I'd like you guy's opinion as to where to go from here.

 

[Bart B]

I'd suggest using a slightly faster powder than Retumbo. In similar size cases used in competition, IMR4350 or others at that speed (VV550 or Re-17, too) typically produce much better accuracy. But the compromise is bullets leaving 50 to 100 fps slower. So one has to choose between more accuracy or more power on target at long range. Rarely does one get both.

 

[RUMBALL]

Hi guys
Im sorry for jumping in on this thread but im having some issues with my loads for my rum I use redding s type match dies which has the neck bushing die,I have been using it without the expander ball and going down in stages to my desired neck tension.
As the rifle is factory sendero bedded,1.4lb trigger muzzle brake I dont think its the cause of the inconsistant accuracy so im assuming my reload practice.
From what I have read here so far I would be better off with a full length bushing die and use the expander ball .
Im using nosler brass truing necks before loading virgin brass get good results at the range then after fire formed clean brass neck size.
Commence tweeking data from new brass session sort out load now after cleaning this brass and neck sizing and reloading next time out the load is not as tight.
All cleaning practices in place and no long shot strings have checked scope rings and checked acti8n screws set them at 45in lbs.
So I guess what im asking are my thoughts on fl sizing the way to go before i go buy 4 fl bushing dies as I have 4 sets of these dies.
Cheers
Rumball.