300 RUM load development questions

[Tidesloe]

First off, do what the others are saying and dry lube your necks with graphite or brush a bit of case lube through the necks and toss 'em it the tumbler for an hour. Then uniform your length at .010' under or so. If you can't square up your bullets the load won't be as good. That said I don't even have a concentricity guage; I get 1/2 moa in a good rifle without one with my rock-chucker.

I've been able to get **** near any pill I've put through my rem 300 rum to 1/2 moa quickly(usually 9 shots). I really like the 180 hornady with rl25 in rem brass lit by a 215. For long range I'm working with the 190 hornady and 225 hornady. All are capable of 1/2 to 2/3 moa consistantly in an un-braked 9# rifle.

Lefty I sure would like to hear how you get loads to 1/2 in 9 rounds. Are you loading for single shot or mag length.

What I did with the 180 Accubonds, I just started at. .020 off lands started at bottom of data in Nosler manual and went up to max in 1 gr increments. Thats 5 loads of 3 rnds each. Did a round robin test at 100. The top 3 looked promising, so I loaded 3 round each from 79 to 82 gr in 1/2 gr increments. Thats 5 more loads of 3 rnds. 81- 82 all looked good with the max of 82 gr IMR 4350. Printing identically both times at just under 1/2". Exact same POI. 1 week between tests, but similar conditions
'M up to 30 rnds before I've even started testing seating depth. I've thinking I'm gonna go through that many rounds getting my seating depth right.
If I'm getting the Accubonds seated without runout, should I just start at mag length, and start over at 79 to 82 gr in 1/2 gr increments?

 

[Tidesloe]

First off, do what the others are saying and dry lube your necks with graphite or brush a bit of case lube through the necks and toss 'em it the tumbler for an hour. Then uniform your length at .010' under or so. If you can't square up your bullets the load won't be as good. That said I don't even have a concentricity guage; I get 1/2 moa in a good rifle without one with my rock-chucker.

I've been able to get **** near any pill I've put through my rem 300 rum to 1/2 moa quickly(usually 9 shots). I really like the 180 hornady with rl25 in rem brass lit by a 215. For long range I'm working with the 190 hornady and 225 hornady. All are capable of 1/2 to 2/3 moa consistantly in an un-braked 9# rifle.

Lefty I sure would like to hear how you get loads to 1/2 in 9 rounds. Are you loading for single shot or mag length.

What I did with the 180 Accubonds, I just started at. .020 off lands started at bottom of data in Nosler manual and went up to max in 1 gr increments. Thats 5 loads of 3 rnds each. Did a round robin test at 100. The top 3 looked promising, so I loaded 3 round each from 79 to 82 gr in 1/2 gr increments. Thats 5 more loads of 3 rnds. 81- 82 all looked good with the max of 82 gr IMR 4350. Printing identically both times at just under 1/2". Exact same POI. 1 week between tests, but similar conditions
'M up to 30 rnds before I've even started testing seating depth. I've thinking I'm gonna go through that many rounds getting my seating depth right.
If I'm getting the Accubonds seated without runout, should I just start at mag length, and start over at 79 to 82 gr in 1/2 gr increments?
I am separating brass by weight, and making sure they are all squared to same length

 

[MontanaRifleman]

A lot of good suggestions and I'll ad some input. I have had good luck with Retumbo. It's an ideal powder for the 300 RUM, especially with heavier bullets... slow burning and very stable and produces good velocity. I haven't tried the 215 hybrids yet but from what I've read I will be.

I also started out with the Redding bushing neck, body die and comp seater. I have since gone with the FL sizer and it works fine. If you neck size only until you need to bump back, every time you shoot you will have different brass. I FL size the new brass and after each firing and that way i have consistent brass. When you go to body or FL size, you might find cases wanting to get stuck. I was using One Shot spray lube which worked well on other cases, but not my 300 RUM. I went to imperial sizing wax and it works great. I also stick the necks about half way into the wax and that helps greatly with a smooth pull out of the expander. You might want to put just a little on the expander before you start. if your concerned about lube in the neck, then run them in the tumbler for a few minutes or swab them out with a q-tip. It hasn't been an issue with me.

As far as seating depth goes, you might have to choose between accuracy and the mag box. I ended up seating to just off the lans maybe .010 - .020. Although I could load all the way down into the box, I could still put one down with nose just above the box and have a second shot if needed. That's life with the RUM depending on throat design. You can get a Wyatts extended box to help a little.

Hope that helps,

Mark

 

[Lefty7mmstw]

Lefty I sure would like to hear how you get loads to 1/2 in 9 rounds. Are you loading for single shot or mag length.

What I did with the 180 Accubonds, I just started at. .020 off lands started at bottom of data in Nosler manual and went up to max in 1 gr increments. Thats 5 loads of 3 rnds each. Did a round robin test at 100. The top 3 looked promising, so I loaded 3 round each from 79 to 82 gr in 1/2 gr increments. Thats 5 more loads of 3 rnds. 81- 82 all looked good with the max of 82 gr IMR 4350. Printing identically both times at just under 1/2". Exact same POI. 1 week between tests, but similar conditions
'M up to 30 rnds before I've even started testing seating depth. I've thinking I'm gonna go through that many rounds getting my seating depth right.
If I'm getting the Accubonds seated without runout, should I just start at mag length, and start over at 79 to 82 gr in 1/2 gr increments?
I am separating brass by weight, and making sure they are all squared to same length

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.

 

[Tidesloe]

Lefty I sure would like to hear how you get loads to 1/2 in 9 rounds. Are you loading for single shot or mag length.

What I did with the 180 Accubonds, I just started at. .020 off lands started at bottom of data in Nosler manual and went up to max in 1 gr increments. Thats 5 loads of 3 rnds each. Did a round robin test at 100. The top 3 looked promising, so I loaded 3 round each from 79 to 82 gr in 1/2 gr increments. Thats 5 more loads of 3 rnds. 81- 82 all looked good with the max of 82 gr IMR 4350. Printing identically both times at just under 1/2". Exact same POI. 1 week between tests, but similar conditions
'M up to 30 rnds before I've even started testing seating depth. I've thinking I'm gonna go through that many rounds getting my seating depth right.
If I'm getting the Accubonds seated without runout, should I just start at mag length, and start over at 79 to 82 gr in 1/2 gr increments?

This is some good stuff. I'm getting some good input. I have a FL bushing die that I used last night with one shot case lube and sure enough, I stuck a case in it. It just so happens that I have a stuck case remover on its way. Should be here this week. I also have Imperial sizing wax, and I will be using that from here on out.
I still wonder if I should even be using these bushing dies if I'm not turning necks.
I'm learning things the hard way, but you guy's are a great help.
When I get the system down I'll probably have a pile of dies that I wont use anymore.
I do have an RBS standard FL die. Maybe in the end I go back to a standard die set. I dont know
Anyway thanks for all the input

 

[Forrest Ebert]

Ok, I don't understand these 9#-10# 300 RUM's but anyway I have a load of 95.0 grains of Retumbo, Bob Cauterucio 211 grain bullet CCI Mag. primer ,Rem. brass COL 3.667 measured velocity of 3150 fps out of a factory 26" tube and shoots all day long in the .2-.5" and this with a rig that weigh's 7.75 fully loaded. I did try the 215 Hybrids and they worked almost as good as the 211's good luck as once you find the sweet spot they are very accurate and a joy to shoot! I almost forgot and this is unbraked as well.

gun)

 

[R.Morehouse]

Looking forward to trying the 215's as well. But for now I am shooting the 208 A-Max at 3050 with 92g Retumbo in the 2's. With the 208's being 1/2 the price of the 215's it may be a little while. There is a place out here that armores up the Hummers for the military, I was able to secure a window cut-out piece of steel they use. Put it out at 100yds Sat. and put a perfect 30cal hole in it with the A-Max........Not sure quite what to think about that...But I did find it interesting. Also hit it with some 223 green tip and a 222 cooking along at 3400+ that bairly left a scratch. gun)

 

[Lefty7mmstw]

Ok, I don't understand these 9#-10# 300 RUM's but anyway I have a load of 95.0 grains of Retumbo, Bob Cauterucio 211 grain bullet CCI Mag. primer ,Rem. brass COL 3.667 measured velocity of 3150 fps out of a factory 26" tube and shoots all day long in the .2-.5" and this with a rig that weigh's 7.75 fully loaded. I did try the 215 Hybrids and they worked almost as good as the 211's good luck as once you find the sweet spot they are very accurate and a joy to shoot! I almost forgot and this is unbraked as well.

gun)

Ditto for my 30 rum. I've got a 6-18x nikon on top and she weighs in just under 9# with no brake. The rifle just shoots.

 

[MontanaRifleman]

This is some good stuff. I'm getting some good input. I have a FL bushing die that I used last night with one shot case lube and sure enough, I stuck a case in it. It just so happens that I have a stuck case remover on its way. Should be here this week. I also have Imperial sizing wax, and I will be using that from here on out.
I still wonder if I should even be using these bushing dies if I'm not turning necks.
I'm learning things the hard way, but you guy's are a great help.
When I get the system down I'll probably have a pile of dies that I wont use anymore.
I do have an RBS standard FL die. Maybe in the end I go back to a standard die set. I dont know
Anyway thanks for all the input

Actually, a FL bushing die with an expander is probably a good way to go. That way you can use a bushing to minimize the working of the brass by not taking the neck down as far as a standard FL die. I am planning to do that with some of my other cartridges. I used to turn necks but didn't find any noticeable difference n accuracy with unturned necks, especially if you're not using a customized chamber/neck reamer. Just stick with your Redding FL bushing reamer and maybe get the next smaller bushing and put and expander on the spindle.

Also, there are some "creative" ways to get you case unstuck. I had to do it 3 times. I was a little slow in learning! lol

 

[Tidesloe]

The replies I've gotten here are very imformative and helpful. Thats why I'm here. I have much to learn. I think what I have will work for me, but my techniques need mucj improvement. I hope to be testing these techniques out this weekend.
I'll try at mag length and see if anything looks promising. If not maybe I'll consixer a Wyatt box. I'll make a seater plug change, and go with the FL sizing.
I've got a box of 210's and thought I should try them. Would still like to fimd some hybrids.
Sounds like I keep hearing Retumbo repeated over and over. I have some and will try it.
Thanks guy's, I'll let you know if I hit what I'm looking for.

 

[Bart B]

For what it's worth full length sizing dies that don't use expander balls (bushing type) end up with the sized case neck best centered on the case shoulder. This is why so many benchresters have given up on neck sizing and now use full length bushing dies. Any time an expander ball's used it tends to bend case necks a bit off center, especially when the die sizes the case neck down too far and the expander ball has to be pulled up hard to get it out of the case.

 

[Tidesloe]

Actually, a FL bushing die with an expander is probably a good way to go. That way you can use a bushing to minimize the working of the brass by not taking the neck down as far as a standard FL die. I am planning to do that with some of my other cartridges. I used to turn necks but didn't find any noticeable difference n accuracy with unturned necks, especially if you're not using a customized chamber/neck reamer. Just stick with your Redding FL bushing reamer and maybe get the next smaller bushing and put and expander on the spindle.

Also, there are some "creative" ways to get you case unstuck. I had to do it 3 times. I was a little slow in learning! lol

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?

 

[Tidesloe]

For what it's worth full length sizing dies that don't use expander balls (bushing type) end up with the sized case neck best centered on the case shoulder. This is why so many benchresters have given up on neck sizing and now use full length bushing dies. Any time an expander ball's used it tends to bend case necks a bit off center, especially when the die sizes the case neck down too far and the expander ball has to be pulled up hard to get it out of the case.

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 expanders pulling necks off center.
Anyway thanks. I'll find what works best in the end. I'm getting some good suggestions here.

 

[Bart B]

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.