300 RUM load development questions

[MontanaRifleman]

Your right Rifleman, shell holder. We're not done here yet if you guy's are gonna get me up to speed. Bart seems to have a wealth of knowledge, and so do you. I read on here justifiable, reasonable defenses for one end of the spectrum to the other in nearly every aspect of the loading process. I at times become more confused after being on this site. More questions than answers, but thats a good thing. Questions lead to more questions, which in turn lead to more answers. In the end the answers I have to find for myself, but couldn't find any of them without all input, and knowledge from all you guy's. I think any dumb question is the one that isnt asked, and I'm full of dumb questions lol!!!

More to come fer sher!

I have a little knowledge and experience, but Bart and others have a lot more than I.

Bottom line is there are a lot of ways to skin the reloading cat and many of them work very well. There are highly experienced handloaders with different philosophies and methods that all get good results.

I think the main thing is to develop a good process that works for you and be as consistent as possible. You'll probably fine tune it over the years or maybe make major changes in your process.

I have made several major changes along the way and learned a lot in the process and I am still learning and refining my process. It's never ending.

This site has a wealth of experience and knowledge and I have benefited greatly from it.

 

[Tidesloe]

I have a little knowledge and experience, but Bart and others have a lot more than I.

Bottom line is there are a lot of ways to skin the reloading cat and many of them work very well. There are highly experienced handloaders with different philosophies and methods that all get good results.

I think the main thing is to develop a good process that works for you and be as consistent as possible. You'll probably fine tune it over the years or maybe make major changes in your process.

I have made several major changes along the way and learned a lot in the process and I am still learning and refining my process. It's never ending.

This site has a wealth of experience and knowledge and I have benefited greatly from it.

I agree completely Rifleman. It's gonna be a life long learning adapting experience. If it weren't for this site, I'd still be looking at equipment and wondering "what does this do"? I know a few guy's who reload, but they are mostly handgunners, and when it comes to rifle loading they think they have a winner with 1 1/2" 100 yd groups, so I ended up here, and this site is awesome!
I do believe that I'm on a good track so far with A process that appears to be working. Most certainly not the best, or most efficient, but something to build on, and adapt to my needs. I've got lots of experience yet to be had. I sure do thank you for the input and direction. It really helps.

STAY TUNED!

 

[MontanaRifleman]

Cerwin,

Per request, here's my current handloadiing process. Some of this is actually new for me.

Starting with new brass,

Lube w/ Imperial Sizing Wax including inside of neck and FL size with bushing and expander. I will use a bushing that will shrink neck to about 2 thou smaller than expander ball.

Measure all case lengths and pick a length to trim to.

Chamfer outside and inside necks with VLD tool

Debur flash holes

Square and uniform primer pockets

Weigh brass and cull anything excessively out of acceptable weight range.

Weigh bullets and cull the heaviest and lightest out for load development, fowlers, etc. This is not necessary for CE or GS bullets.

Prime pockets with RCBS hand priming tool. I like to feel the primers being seated. It gives a good idea as to the condition of the brass.

Measure powder with RCBS Chargemaster, Spot check charges with RCBS 10-10 scale occasionally

Seat bullets. I use Reading micrometer and Horandy New Dimension. I will be putting VLD plugs in them and upgrading the Hornady's with micrometer tops.

Fired brass. Run through the tumbler with crushed walnut shells. Am considering getting a Lyman ultrasonic cleaner.

Then repeat process.

FL size just enough so brass fits snugly but easily into chamber. I will probably adjust the neck bushing to leave about a .020 fired donut around the base of the neck.

Remeasure fired and sized brass again and trim if necessary.

Clean primer pockets.

Seat primers.

Charge cases and seat bullets.

I may add a step to the new brass prep the ream inside of necks to remove irregularities in thickness.

I will play with using and not using an expander ball, check the runout and see of there is a shot group difference. If not, i will remove the expander ball and use a neck bushing to size for about 2 thou neck tension.

And that's where I am in handloading process.

I load for 22-250, 25-06, 7 RM, 300 WSM and 300 RUM. 6.5 WSM and 6-284 on the way.

I use standard non-bushing FL dies for the22-250, 25-06 and 7. That may will probably change.

 

[Tidesloe]

Cerwin,


Square and uniform primer pockets

This I have not messed with. I've been a little hesitant to mess with primer pockets. Any tips on that?


Measure powder with RCBS Chargemaster, Spot check charges with RCBS 10-10 scale occasionally

I considered buying a Chargemaster, but am still using an RCBS balance beam, not the 10-10, but I think a 505, its the entry lavel scale.


Fired brass. Run through the tumbler with crushed walnut shells. Am considering getting a Lyman ultrasonic cleaner.

I've got a Hornady ultasonic cleaner, and a tumbler. I love that ultrasonic cleaner. I'm still using both from time to time, but may stick with the ultrasonic. It sure as heck cleans both inside and out.


I may add a step to the new brass prep the ream inside of necks to remove irregularities in thickness.

Would this be an alternative to neck turning?


I load for 22-250, 25-06, 7 RM, 300 WSM and 300 RUM. 6.5 WSM and 6-284 on the way.

Sounds like you've got your hands full with all that going on. I cant seem to find enough time to work with the 2 I've got now, and I'll be adding another next month. It keeps me busy, and out of trouble lol.
Like you say, theres different ways of skinning that cat. My process is not much different. I have for this RUM about every type of die there is, and tried them all. Once I figured out my runout issues, all the die types have done good. I did end up eliminating the expander ball though, and am working with Redding bushing dies now.

What are you loading your RUM for? Hunting? I'm curious as to exactly what components are you using, and what your getting out of it as far as velocity, and consistency. Are you chronoing?

 

[Tidesloe]

Hey, I see I just got bumped up to Bronze member. I got a raise! hahahaha

 

[MontanaRifleman]

Sounds like you've got your hands full with all that going on. I cant seem to find enough time to work with the 2 I've got now, and I'll be adding another next month. It keeps me busy, and out of trouble lol.
Like you say, theres different ways of skinning that cat. My process is not much different. I have for this RUM about every type of die there is, and tried them all. Once I figured out my runout issues, all the die types have done good. I did end up eliminating the expander ball though, and am working with Redding bushing dies now.

What are you loading your RUM for? Hunting? I'm curious as to exactly what components are you using, and what your getting out of it as far as velocity, and consistency. Are you chronoing?

I haven't loaded for several of these for while. As soon as it warms up a little and I get some powder and bullets in I'll be getting busy.

For the 300 RUM, I am using Rem brass. Not the greatest, it lasts about 4-6 firings with max loads. I have a Sendero 300 RUM and another being built. In the Sendero I worked loads for

180 E-Tips, 98 gr Retumbo 3400 fps
200 AB's, 93 Retumbo, 3200 fps
210 Bergers, 92 gr Retumbo, 3130 fps

Accuracy was about .5 MOA for all loads. The E-Tips were most accurate out of my rifle.

Bullets were seated to about .020 off the lands and too long for the mag box, My new build will have a longer mag box.

I will develop loads in the RUM for 200 CE bullets and 230 Hybrids. I will try Retumbo and RL33.

Yes, I chrony. I will be order an acoustic chrono this spring. And yes, The 300 Rum will be used for hunting.

 

[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.

Hey stw,
I got the runout issues corrected, and things are looking good with VLD's. My initial seating depth test with a moderate chg 88 gr Retumbo shot sub 1/2 MOA at 200 yds. at .010 off lands.
I only have access to a 200 yd range short of traveling, or packing a couple miles back in to the forest to shoot. Do you have any recommendations on how to proceed with fine tuning a load? I dont really want to burn my barrel out searching for a load, but I'd love to burn it out LR shooting with a good tuned load.
At 88 gr. its shooting good, but I think theres got to be something on the upper end that will shoot as well.

 

[Tidesloe]

I haven't loaded for several of these for while. As soon as it warms up a little and I get some powder and bullets in I'll be getting busy.

For the 300 RUM, I am using Rem brass. Not the greatest, it lasts about 4-6 firings with max loads. I have a Sendero 300 RUM and another being built. In the Sendero I worked loads for

180 E-Tips, 98 gr Retumbo 3400 fps
200 AB's, 93 Retumbo, 3200 fps
210 Bergers, 92 gr Retumbo, 3130 fps

Accuracy was about .5 MOA for all loads. The E-Tips were most accurate out of my rifle.

Bullets were seated to about .020 off the lands and too long for the mag box, My new build will have a longer mag box.

I will develop loads in the RUM for 200 CE bullets and 230 Hybrids. I will try Retumbo and RL33.

Yes, I chrony. I will be order an acoustic chrono this spring. And yes, The 300 Rum will be used for hunting.

Thanks,
What would you recommend to me as far as further load testing. How do you find your loads? I'd like to get a load nailed down at the upper end in the least amount of rounds possible.
When my RUM was in all factory condition, I burned the barrel out looking for something it would shoot consistently well. Never did find that with all factory ammo, and rifle.
The only thing left of that original rifle is the completely blueprinted action. It would appear that I'm on to something good, but I dont want to stop where I started. There should be something at the upper end that will shoot as well.
I see your at book max with 210 VLD's. Should I bump back from that a couple grains and work up to that max, seeing what it does?

I'm using Nosler brass, 215 primers. We'll see how much life I get out of the brass. That stuff is hard to come by these days.

I got a 7 STW coming next month, and I've been trying to get brass for it for 6 months now.

 

[Tidesloe]

I have a few hundred rounds through my 30 rum now and it is very predictable. I'll usually shoot a low, mid, and top charge at 3.650" (just inside of max. mag length) and at least one of the groups will fall inside of 2/3 moa. I use only hornady bullets in this rifle as it seems to favor them. I'm using rem brass(necked up) left-over from my retired 7rum and 215 primers. I've been burning rl series powders with rl25, rl33, and rl50 all used. The only times I've gone over 12 rounds is when there was no data at all to start with, ie. when I was working with mil. surp. powder or rl50. Those took 18-21 rounds to get to pressure and find accuracy.
Playing with seating depth and using very small charge variations can at times be beneficial but is often used as a band-aid for the barrel not really liking the bullet.

I must have missed this response Lefty, I'll try picking charges like your saying. To this point I know that 210 VLD's are shooting sub 1/2MOA at 200 with 88 gr Retumbo. Thats the only charge weight I've fired so far. Looked for seating depth with that charge and it shot all seating depths good, but .010 off lands was the best.
I'd like to find something at the upper end that shoots as well

 

[bigbuck]

Thanks,
What would you recommend to me as far as further load testing. How do you find your loads? I'd like to get a load nailed down at the upper end in the least amount of rounds possible.
When my RUM was in all factory condition, I burned the barrel out looking for something it would shoot consistently well. Never did find that with all factory ammo, and rifle.
The only thing left of that original rifle is the completely blueprinted action. It would appear that I'm on to something good, but I dont want to stop where I started. There should be something at the upper end that will shoot as well.
I see your at book max with 210 VLD's. Should I bump back from that a couple grains and work up to that max, seeing what it does?

I'm using Nosler brass, 215 primers. We'll see how much life I get out of the brass. That stuff is hard to come by these days.

I got a 7 STW coming next month, and I've been trying to get brass for it for 6 months now.

I couldnt reach the max load in my .300 RUM while using Noslaer Custom Brass . I had stickey bolt lift way befor I got to the high side. Just thought I would mention my experience. Good luck with your shooting.....

 

[Tidesloe]

I couldnt reach the max load in my .300 RUM while using Noslaer Custom Brass . I had stickey bolt lift way befor I got to the high side. Just thought I would mention my experience. Good luck with your shooting.....

Did you switch to different brass?:

 

[RTK]

To this point I know that 210 VLD's are shooting sub 1/2MOA at 200 with 88 gr Retumbo. Thats the only charge weight I've fired so far. Looked for seating depth with that charge and it shot all seating depths good, but .010 off lands was the best.
I'd like to find something at the upper end that shoots as well

If you are shooting sub 1/2 MOA at 200 yards be happy. Don't shoot out another barrel chasing the ultimate, I've been down that road before......

 

[MontanaRifleman]

Thanks,
What would you recommend to me as far as further load testing. How do you find your loads? I'd like to get a load nailed down at the upper end in the least amount of rounds possible.
When my RUM was in all factory condition, I burned the barrel out looking for something it would shoot consistently well. Never did find that with all factory ammo, and rifle.
The only thing left of that original rifle is the completely blueprinted action. It would appear that I'm on to something good, but I dont want to stop where I started. There should be something at the upper end that will shoot as well.
I see your at book max with 210 VLD's. Should I bump back from that a couple grains and work up to that max, seeing what it does?

I'm using Nosler brass, 215 primers. We'll see how much life I get out of the brass. That stuff is hard to come by these days.

I got a 7 STW coming next month, and I've been trying to get brass for it for 6 months now.

My Sendero shot everything well and I believe that has a lot to do with Sendro contour heavy barrel. Your #4 may be a little more finicky.

That said, you're off to a good start. If you want to minimize development, pick one bullet and one powder. IMO Retumbo is the #1 powder for the 300 RUM. RL 33 may change that and others may disagree. But if you do search on 300 RUM loads, you'll probably see Retumbo more often than any others and with good velocities and accuracy. After reading Broz's threads, I would recommend considering the 215 Hybrids. He got better accuracy and velocity than the 210's and they have a better BC.

The way I would approach it is to work up a grain at a time from where you are now until you reach max. Then shoot for groups at max. The local gun range here only goes to 427 yds and that's where I made decisions on which loads to go with.

If you're happy with the performance at max stay there. If not, you might try some different seating depths as per Berger instructions. If nothing works there then work down in .5 gr increments until you are happy.

I'm a high velocity kinda guy and that is why I have a 300 RUM and other overbores. So if I'm mot getting good groups at or near max it's time to try another bullet and/or powder or try . I would stay with Retumbo.

If you want to shoot a very accurate bullet that's easy to load for, get some CEB's. They are spendy, but you will probably spend less time, bullets, powder and barrel life load developing them. I did put some through my Sendero a couple of years ago and they were extremely accurate. However, if you load the 200 gr C22's you will not get them in your mag box. What i did with long bullets that didn't fit the box was to just put one down in the top of the box and the nose tip would rest just above the rim of the box. That way I still had a quick second shot if I needed it.

I also use the 215 primers and I have also heard the Nosler brass to be on the soft side.

 

[Tidesloe]

If you are shooting sub 1/2 MOA at 200 yards be happy. Don't shoot out another barrel chasing the ultimate, I've been down that road before......

Yea, thanks for that. I don't want to do make the same mistake again. I'm new to hand loading, and the first load out of the gate is shooting that good. Maybe not the velocity I'd like, but is every last drop for all its worth necessary for LR? Probably not. Still have not been back to see how consistent this load will be. I actually am happy, I know I've got a good load ( I think ) if I don't find something at the upper end soon.