Load development? 300rum, 230gr, RL33

[dodgefreak8]

Going to start load development for my 300rum and I am not real sure where I should start powder charges at. I have read a few threads here and charges seem to range from 95gr-103+ depending on the rifle. I plan on doing a ladder test (my first ever) to get it narrowed down but with components so scare I really don't want to throw more led than I have to down range. So I would like to know where I should start? Also if I am understanding this correctly I load one round each in 1/2gr increments and look for the sweet spot correct? I am looking for around 3100+ fps if attainable in my rifle. The rifle is a custom build with a 30" Bartlein barrel throated for maximum mag length in my Seekins DBM (3.900") COAL is about 3.850"

So for the ladder test what should be my starting point and ending point on charge weight?

 

[Catfur]

Trying RL33 in my 300 RUM with a 200gr Accubond was a no go.

I can't fit more than 96 gr or so in the case, because at mag length so much bullet is shoved into the case, and velocity was around 2900 something. IMR 7828 drilled it though. I can't imagine you fitting over 100gr in the case with a 230gr long nose bullet shoved back into the case for mag length.

 

[Wachsmann]

The rifle is a custom build with a 30" Bartlein barrel throated for maximum mag length in my Seekins DBM (3.900") COAL is about 3.850"

Catfur....Not to be rude but his mag and cartridge length is no where near sammi specs or anything close to a regular ultra mag length. I have one and I'm single feeding it. My 230 berger load want fit in the mag. I'm at or I think I'm somewhere around 3.79 for my COAL. With that long bullet it almost usless to try and fit in the mag. I wished Remington would of made the mag a lot longer.

But on another note I'm really interested in what the R33 brings to the table. I like the retumbo only because my load seems to be spot on. Well at 200yards so far. I have not streched it legs out. But it shot about a .3 inch group at 200. I was able to crono 2 loads and was getting 2960 and 2970 on the 2. I have read some post where the R33 was giving some good results up in the 3100ish fps also. Probablly the same ones you read. I been thinking that with a 28 inch barrel I may be able to get to 3050 with the same load. 89.4 grns of retumbo and yes brass, bullets, and powder is like tring to find gold well expecially the powder. I have not been able to score any retumbo in 8 to 10 months. I bought 4 boxes of reduced recoil loads just for the brass. I have had a hard time paying for the high priced stuff that is supposed to be ready to load. its like getting the taste slapped out of you mouth when you see the price on that stuff.

So was the 30 inch barrel just a thought are is there some good research behind the length, with maximum powder burn and optimum velocity? Reason I ask it seems like the RUM with that large powder charge could really benefit from a longer barrel. I've read a lot of post on custom RUM's and it seem a lot usually have 28inch barrels. My gun is a stock Rem Sendero 26 inch barrel with a side ported brake. Trigger been tuned and it's been bedded.

One more quick note about the ladder test. Instead of powder I worked on seating depth first and then the powder. It brought my load development in a lot quicker. I was using increments of 15 thousands in between loads. I found a sweet spot with about 18 rounds. Next time I went out I set up for .005 on either side of the sweet spot to see if I could obtain a tighter group. This was 9 more rounds. I also had loaded almost all the charges at 1 grain off max book charge. The next time out was to increase powder in 1 or .5 grain increments. So now I am at 89.4 grains of retumbo which is 1 grain over the berger manual. I think the 89.4 is 100% of load density for the 230 berger. There is another shooter on here that made an almost to goog to be true group at 1000yrds. It is so freaking unreal but that gun and the shooter can shoot. Well anyway enough bla bla bla...Hope the R33 works out well.

 

[AZShooter]

I was lucky that everything fell together so well with my 300 RUM. It is a post 64 model 70 with a Wyatt's mag box. The first 300 RUM barrel was a Lilja without enough twist to shoot the 230s. I just had to try them so I ordered a reamer from PT&G and rechambered and fitted a 24" 300 win mag Rem takeoff to see what it would do.

Around the same time I got my hands on some of the first RL-33 sold. There was no load data available. Did some comparisons of available load data and concluded RL-33 is slower than Retumbo. I discovered with several over bore cartridges that mid to uppper range load of Retumbo is a good starting point.

Here are the specs for my rifle: 3.775" OAL
100 gr of RL-33 most accurate at 2975 fps (loaded to 102 grs with no signs of excessive pressure)

The bullet doesn't engage the rifling but to be honest I only seated to fit and feed the mag box don't even know the jump. I thought I might have to tweak the seating depth later but it ended up being very accurate so I never bothered. Seems to be a trend with those hybrids.

I will be very interested in your final results with a 30" barrel. IMO I don't think you need to vary your powder charge weights by 1/2 grain during workup. Maybe later for final tweaking if you find it necessary.

 

[Lefty7mmstw]

AZ is right on the load work up... I hop a couple of grains a step on my 300 rum. I'm shooting 95 grains rl33 with the 225 hornady in my 300rum with a col. of 3.650". I'm at 3000 fps with a 26" factory bbl. It seems the bergers are taking a couple of grains more powder to get to the same pressure from what is said here on the forum.

As to the comment that you can't fit more that 96 grains of rl33 in the case.... I'm running 102 grains rl50 (a bit lower loading density than rl33) with the 220 nosler 220 hpbt on test run ups and she's still got shake left in the case at 3.650" oal. I've also got a bit of shake with my 225 hdy/rl33 load; I just don't feel like pushing the rifle as the load works well now and is already 100 fps over what most powders will do in the rum with a 220.

 

[dodgefreak8]

With the 30" barrel I'm just hoping to squeeze out a little more velocity. I had planned on rl33/230 berger from the start and with that large amount of a slower burning powder I figured more tube was better. The rifle will weigh 17lbs so a couple more inches wasn't a big deal. I really want to start my load development with my powder since I want to do the ladder test. I'm thinking this is a faster scenario based on my 7mm stw development. With that i did seating depth first but when i started increasing powder I found that my accuracy increases with the bullet closer to the lands. Might have been a fluke though. So where is a good starting powder charge for the ladder test? 95gr? Then increase a grain at a time instead of half a grain? Then look for the accuracy node, hope it's close to my velocity goal and start tweeking from there? Thanks for all the suggestions!

 

[4xforfun]

I'll let you Rum owners hash out the load data, but , for the best, most readable results in ladder testing, do your test at the longest range possable. It will be much easier to read the results of a 600 yard target over, say a 200 or 300 yard target.


Just my .02
Tod

 

[AZShooter]

Yes start at 95 grs of RL-33. Increase one grain at a time.

I have had good results with hybrids in various calibers/chamberings seated from .010" to over .200" from lands.

 

[barnesuser28]

Doublezranch is running 101.3 of RL 33 at 50 thou off in his 300 rum with either a 26" or 27" tube. I believe he is over 3100 fps and got up to 3230 at 102.7. Max Load though!

 

[dodgefreak8]

Sounds like I shouldn't have any issues obtaining 3100fps+! I'll keep everyone update on my progress. Rifle should be here in a couple weeks!

 

[Wachsmann]

I agree with 4xforfun on the longest range possible. It was very difficult to tell anything even at 300 yards. I tried this with the 210 bergers and got somewhat bummed out; actually the 210 VLD were giving me a fit. But 600yrds proved out which powder charge was working the best on the 210. It seems like it was night and day moving out to 600yrds doing the ladder test. Even this being said the 210's still was very finicky which I gave up on and read some of these post on the 230's and said why the hell not. I'll try them. I been please every since.

There I one question that I have to anyone that uses them is how do they work on game like at 1000yrds? The bullets I loaded are the 230 hybrid OTM's. For the most part this a 30 cal 230 grain bullet so it like a sledge hammer. But do they expand like a VLD or hold together? I have a cow tag here in Utah and hope to god I can get one this year.

 

[dodgefreak8]

Great advise! I'll do my ladder test at 500yrds. I'm loading the OTM as well. Couldn't get my hands on anything else at the time.

 

[dodgefreak8]

Did some load testing looking for pressure today. Started at 96gr and loaded 2 rounds each up to 102gr. I'm not real sure what to think. My accuracy was great with all loads under 1/2" at 100 yrds. I showed faint ejector marks on one of the 99gr rounds, one of the 100gr rounds and then I blew a primer out on one of the 101gr. There was never a hard bolt lift and the ejector mark even on the blown primer is still very faint.... Bad case maybe?? All these were loaded 10thou off the lands. Velocity really didn't increase until I got the the 99gr load. It shot average of 3075fps. I shot over my chronograph at about 15' away but it's not looking like I'm gonna reach 3150fps. I'm fine with that but the blown primer has me a little lost since there were no real pressure signs before it happened. Even on the other 101gr round...

 

[dodgefreak8]

Thought you guys might wanna check out the rifle.

Defiance Deviant action
Bartlein 30" 5R barrel spiral fluted by Karl Kampfeld
Manners T2A stock
Seekins Lapua DBM
JE Customs Assassin brake
Timney 510U trigger
Burris 5-25X50 XTR II Scope
American Custom Rifles M10 Rings
Phoenix Custom Rifles put her together. 1.5 months after I sent the parts and it was DONE.