300 rum load development

[DoubleGobble00]

3.887 OAL (0.010 off lands)
No lands marks on Bullet

Case Length
Brass trimmed to 2.833 (trim to shortest case)
2.85 Saami Max
2.882 Measured Actual Max

 

[tbrice23]

This is the only Rum I own so the brass does stay with the rifle. The bolt is tight but not too tight. I think my head space is too tight.

I was hoping to stay with 230 to maximize long range potential. The only other bullet I'd like to shoot is the 245 when available.

I hope to make this a 1000 yard gun, use my 300 win mag for closer, then 308 for under 400.

Another reason for my suggestion to FL size the fired brass is to make sure your dies aren't going to bottom out before they are sized enough to fit your chamber. If you dies won't size enough you'll always have headspace issues with the brass.

 

[DoubleGobble00]

Lol, that would have been useful info earlier.
I'd still try to FL size the brass.

I learned reloading by Wilson hand dies. I was hoping to try them for a while and see how many firings I got before FL sizing. Also, don't currently have FL dies or press but can get one.

I set headspace real tight to avoid over working brass. That could be my problem. I thought it would minimize brass growth

 

[tbrice23]

At your current pressure you'll lose your primer pockets WAY before you get case head separation.

 

[DoubleGobble00]

Overall, I assume I should be able to get 3100 out of this 29" barrel with the 230s. If I can't get that, I'm not sure why I'm shooting a Rum when my 300 WM can get 3000 or more with 215s.

I need to check head space and try another powder. Otherwise I can try the 215s and see what velocity I get up to...

 

[jwing]

You can get there with vit n 570 or very close.

 

[DoubleGobble00]

You can get there with vit n 570 or very close.

Only problem is the N570 is a ghost...

 

[combatcurt]

I shot my first rounds of hand loads this weekend for my 300 Rum. I loaded the following:

Nosler brass (first 5 new brass, others 1x fired)

215 M primers
Imr 8133 (88.5 to 91 grains)
Berger 230
Neck size only

The 89.5 and 91 loads had primer cratering bad. All shots had ejector marks and slight crater. I'm thinking my headspace is too tight that could cause this? My brass is pretty tight when chambering. All my factory ammo shows ejector marks also. I was hoping to get more velocity since I have 29" barrel.

On separate note, which do you think I should start next steps of load development? Also, if I full length size could I get more velocity and lower pressure?

Thanks,

DoubleG

Just my .02$-
87 to 88 looks promising. My bet is your brass took quite a beating on the higher end. It may be worth it to anneal the whole lot before resizing. They will at least be consistent, and at the very worst, bring back some life to those higher charged ones. As far as having zero valuable data, I'm gonna say horse ****. There is more than someone apparently thinks. Although IMR claims this powder to be temperature insensitive, it will only be to a certain extent and the closer those velocities within a given range of charge weight, as well as point of impact, could very well indicate a very stable load throughout the seasons.

Another thought, and if only for science sake, I measure the web diameter of the brass after I reasize and also after I shoot it. I don't do this after load development because honestly, If I blow a few primers after I have a good working load, I chalk it up to being a RUM case (bit of laziness and lack of dedication ) and try not to kill any of the few brain cells I have remaining. This being said, the average of measurements taken throughout this, can sometimes squash any doubt about the lack of excessive pressure.

I have a 300 RUM and I full length size every single time. In my opinion, (Uh-oh, I hear the sound of urologist rulers coming out...) neck sizing has no advantage over full length sizing for hunting cartridges. I have built, shot and reloaded (with great success) many different cartridges that visit the upper extremities of brass comfort on a regular basis. Remember folks, before you feel the need for hemorrhoid doughnuts, this is from my experience. Reloading is almost as satisfying to me as cake is to Rosie O'Donnell.

As for your factory ammo leaving ejector marks, my experience has found thatt factory ammo left serious extractor marks on my wallet.

In all seriousness, take my words with a grain of salt- be kind to each other and keep the love for this amazing science alive!

 

[whirlwindjml]

neck sizing has no advantage over full length sizing for hunting cartridges. I have built, shot and reloaded (with great success) many different cartridges that visit the upper extremities of brass comfort on a regular basis.

I had troubles with a neck sizing magnums as well. One pressure spike on one particular round swollen to max and suddenly its not cycling. On hunting rigs I need them to function as much as be accurate so I treat them like I'm loading for semi auto. The bolt face and the shoulder square it (cartridge) up to the bore and I personaly Havnt ever been able to find accuracy suffers from full length size So I don't do it. Especially on the magnums.

 

[theosmithjr]

Honestly, I was just using the target to glean some data while looking for max load. I think there is some good info in the velocity and maybe some of the vertical data on target. Further would have been better but I'm limited at my place. This was all I could get.

Why even try to GO FURTHER? It's a waste of time until your shooting 1 hole, or at least a Clover leaf at 100, or 225 as you stated. Your just BURNING POWDER! YOU ARE however Breaking in the barrel. Later today I'll dig out my .300 RUM data and help you out.
Theosmithjr

 

[FURMAN]

Why even try to GO FURTHER? It's a waste of time until your shooting 1 hole, or at least a Clover leaf at 100, or 225 as you stated. Your just BURNING POWDER! YOU ARE however Breaking in the barrel. Later today I'll dig out my .300 RUM data and help you out.
Theosmithjr

This is the exact reason this forum is falling apart. You obviously have no clue. That is fine up until you start giving others advice. This is a long range hunting forum. I can only assume the intent is to shoot long range. In a perfect world you develop the load at max distance you intend to shoot. There are methods that will yield good results at 100 yards but they are not optimal. I can show you several loads developed at 100 yards that will not shoot long range. 1000 yard bench rest guys who are winning are not developing loads at 100 yards. The notion of not starting load development until a barrel or brass is broken in is absolutely wasting components and barrel life. If/when a barrel speeds up after you have a load developed you simply reduce powder charge to get back to the same velocity. The same with brass.

 

[lancetkenyon]

This is the exact reason this forum is falling apart. You obviously have no clue. That is fine up until you start giving others advice. This is a long range hunting forum. I can only assume the intent is to shoot long range. In a perfect world you develop the load at max distance you intend to shoot. There are methods that will yield good results at 100 yards but they are not optimal. I can show you several loads developed at 100 yards that will not shoot long range. 1000 yard bench rest guys who are winning are not developing loads at 100 yards. The notion of not starting load development until a barrel or brass is broken in is absolutely wasting components and barrel life. If/when a barrel speeds up after you have a load developed you simply reduce powder charge to get back to the same velocity. The same with brass.

 

[FURMAN]

LOL! How to you get that gif to display?

 

[combatcurt]

Why even try to GO FURTHER? It's a waste of time until your shooting 1 hole, or at least a Clover leaf at 100, or 225 as you stated. Your just BURNING POWDER! YOU ARE however Breaking in the barrel. Later today I'll dig out my .300 RUM data and help you out.
Theosmithjr

Waste of time? You are on a reloading forum telling someone to quit as soon as they get started with load development. I'll try not to speak for all of us here, but most of us get a LOT of satisfaction tuning our rifles/loads.

On a brighter note, I would love to see your data for the 300 RUM. Mine is all sloppy, hand written in a small notebook and quite frankly, an embarrassing mess that I wouldn't dare to subject the most patient translators to. Thankfully, I invented the language that it is scribbled in- I'll call the language "going at it like killing snakes"