14 months in the making...300 RUM

[WSMDRT]

Ok here it is newest member of the family....other family members to be posted soon. I will invite insight into holes in my collection...I hope I'm close to finished.

More family...6.5x284

Built by:
John Myer
Custom Gunsmithing
Boyce, Va

Action - Left Hand Remington 700, action faced, bolt face trued, lugs lapped. Bolt handle added. Jeweling removed from bolt. Timney SS trigger set to 1.5lbs.

Barrel - 32" Brux custom contour straight for 5" straight taper to .9 @ 32", fluted, 1:10", 5 port muscle brake.

Stock - Greyboe Ridgeback, bedded recoil lug. Bead blasted mlok panels.

Entire barrreled action bead blasted.

Empty weight(no bipod) 13lb 3.4oz

Scope will be Sightron SIII 6-24x50 MOA-2 with Sightron rev count turrets.

....230gr hope to be around 2950-3000fps. That 230 A-Tip is right at the lands at 3.92 COAL. Must remove bolt to expel loaded round.

More pics to come. And with some load data. Will link in this post if I post loads in reloading section.

 

[Len729]

Wow … Nice looking gun

 

[Mike D Texas]

I think you are underestimating your velocity with 230s unless you are downloading it.

26" 300 Norma Improved rifles are kissing 3100.

 

[WSMDRT]

I hope I am....

 

[Lefty7mmstw]

yup, he's not asking for a lot in the velocity realm. I'm getting 3K fps with 95 rl 33 or 102 rl50 and 225 hdy hpbt in a pair of 26" 300 rum rifles in rem brass with 215's lighting the fire. He should be able to get 3100-3200 fps with the extra bbl. length.

 

[WSMDRT]

Testing starting loads are 85gr-90gr of retumbo...i been comparing data from lots of places. Am i way off?

 

[Mike D Texas]

According to Quickload 85 grains is way low assuming you are going to seat at 3.92". I keep forgetting how much longer the RUM case is than the Norma case. Usable powder capacity is virtually the same as the 300 NMI I'm going to build but my COAL will be 3.700 and a I have a calculated usable case capacity of 100 grains. Your setup has the same 100 grains of usable case capacity but your overall capacity is almost 5 grains more. So you are eating up powder space with the long RUM case and having to seat the bullet deeper.

Anyway QL calculates max load of 93.7 grains of Retumbo before you hit pressure for a calculated velocity of 3097fps. 101.3% case fill, 100% burn inside the barrel.

RL33 calculates 99.5 grains max load at 3170fps. 99.6% case fill, 100% burn inside the barrel.

RL50 calculates max load at 103.4 grains at 3172fps. 103.8% case fill, 100% burn inside the barrel.

N570 calculates max load at 95.0 grains at 3184fps. 97.8% case fill, 100% burn inside the barrel.

 

[WSMDRT]

So max should be closer to 93gr at 3.92" or was that for 3.7"? Thanks for the info. Retumbo and H1000 is what i have to use. Blessed to have those at least. Thanks for any data to help saving supplies.

 

[Mark37082]

Nice rifle! I hope you have an ample supply of powder and a gun porter to carry it. I pity the steel you will be shooting.

 

[lancetkenyon]

You should exceed the 3k mark, closer to 3150-3200fps with a 32". I am at 3113fps pushing a 230 Hyb with a 28" Rock Creek and Retumbo.

 

[Wedgy]

Very nice !
I have run several 26" barrels just under 3,000 fps at mag length ~2.7" SAAMI chamber with the Berger 230 OTM with ~89.9 grains of Retumbo so you should get an extra 100 fps with your long barrel. I think starting at 85 is good, you can go up a grain at a time as it is a small percentage 1.2% of the load until you hit pressure. Shoot a ladder at no less than 600 yards, these big bullets need range to show a node. What type of hunting/shooting are you doing, doesn't seem to be a pack gun or you are young and strong.
The only thing I may advise is to go with a 9 twist barrel next time, bullets are only getting bigger and need more twist.

 

[WSMDRT]

In have a handful of 245gr EOL bergers see if all that powder and barrel can spin em'. We'll see. I rechecked my data you guys were right. I'm running starting loads with Retumbo and 230s 87-91gr and 245s 83-87gr. I will be posting results.

I like to think myself young and strong but this more of a drop me off here and pick me up with the truck at dark rig...

 

[Mike D Texas]

So max should be closer to 93gr at 3.92" or was that for 3.7"? Thanks for the info. Retumbo and H1000 is what i have to use. Blessed to have those at least. Thanks for any data to help saving supplies.

Those are at 3.92".

 

[WSMDRT]

Feel better testing up to 91gr first trip out rather than 89gr.