Loading for a 300 RUM
 

I just finished barrel break in on my new Rem 700. So I have been reviewing some notes and trying to work up loads in the book sorta speak rather than test them. I have 4 different tips I will be trying. And I currently have 2 different powders. The bullets I was working with are 150 gr accubonds, 168 A-max, 178 A-max, 180 accubonds. The powder I have right now are Retumbo and Rx22. I would appreciate your thoughts on the givien criteria and also maybe what else I should try or do different. Please by all means share you pet loads too.

RE: Loading for a 300 RUM
 

I did a little reloading for the 300 RUM last fall - Retumbo worked pretty well with the 180 Swift Scirocco bullet, using a Federal 215 primer.

RE: Loading for a 300 RUM
 

Does anyone else notice a monsterous muzzleflash with 180gr bullets and retumbo in the 96gr area? I mean I was shooting one day and every came by to watch it.

RE: Loading for a 300 RUM
 

I was told when I started reloading this firebreather that 150 gr bullets were too light to be shot out of a 300 rum. I do not have any data to support this, nor can I remember the articles where I read it. But just thought I would share with you in case you have problems getting the 150's to shoot. 180's seem to be the lightest I've heard.

I shoot 180 Accubonds with 93 gr h-1000 seated to 3.59 Win Mag primers.

RE: Loading for a 300 RUM
 

Both 180gr and 165gr ballistic tips are very accurate in my rifles with r-25.

RE: Loading for a 300 RUM
 

I built a .30-378 Weatherby for a customer a few years back who had wonderful results with 150 grain bullets. I thought I would throw this out because this cartridge has even more case capacity than the .300 RUM. He used 150 OX bullets (Barnes X bullets coated with NP3) and a monstrous charge of Thunderbird - got groups in the 1/4" to 3/8" range at velocities that I am afraid to publish here for fear of being accused of fabricating facts. It did, however, have a 27" barrel and of course had a lot of muzzle blast. This gun has a trajectory almost off the charts - sight in 3" high at 100 yards and hold dead on out to 500 yards.

RE: Loading for a 300 RUM
 

Wow, I don't blame ya for not posting those numbers. 3" high at 100 and zero at 500 with a .52BC bullet and 150gr would have to be launched at 4400fps. And thats if you have 2" scope hieght.

RE: Loading for a 300 RUM
 

Very good . . . The actual velocity is 4080 - scope height is 2.1" - altitude is 8,000 - and the bullet is the Barnes XBT. Are you using Exbal? Should be about 3" low at 500 when zeroed 3" high at 100 . . .

RE: Loading for a 300 RUM
 

HOW LONG DOES THIS GUY HAVE TO WAIT BETWEEN SHOTS?!?!?!?!?

RE: Loading for a 300 RUM
 

The barrel is a 27" Hart #5 (1:12) - Cryo Frozen. It gets fairly hot after only three shots, but that doesn't seem to affect the accuracy. I know this sounds a little wacky - I didn't believe it either at first - had to shoot it over another chronograph to confirm. Apparently, the NP3 coating does some things with friction inside the barrel that regular moly can only dream of. I did read some stuff later about this coating that suggested that it will cut your barrel life by about 1/3 - which in the case of the .30-378, would make it about 500 rounds . . . .

RE: Loading for a 300 RUM
 

I was getting ready to ask about barrel life.......of course this gun doesnt sound like a "hey lets go to the range today and plink with it" type of gun. Shoot it in, load some bullets, and wait for hunting Season!!!! (Big game of course!!!!)

RE: Loading for a 300 RUM
 

About six months later, I began to think about my other .30 caliber rifles - .308 match gun and .300 Win Mag hunting rifle. Tried this bullet in both of them. In both instances, I was able to generally use 125 grain powder charges and get 125 grain velocities. Once I heard about the barrel life issue, immediately suspended testing these OX bullets.

The customer with the .30-378 wouldn't switch for all the tea in China. As you mentioned, he only shoots a few rounds each year - a couple to confirm zero (which does not seem to change) and a couple on game. He has taken three elk so far with the gun - two of them at around 300 yards and one at 600. The 600 yard shot was made by holding on the backline of the animal . . .

RE: Loading for a 300 RUM
 

The problem with such a short barrel life is that by the time that you develop a load and shoot the gun at various ranges to verify it's trajectory and get used to it,you don't have much barrel life left to practise.I personally am not about to take a 500 yard shot at game with a gun that I haven't practised with a fair amount.

The thing that I find odd about the velocity claims is that the lazzeroni advertising for the warbird claims less velocity with the 130gr robar coated tsx and a 27" barrel than this 30-378 with the 150gr bullet.I am wondering just what pressure must be developed in this 30-378 to deliver such velocity.

RE: Loading for a 300 RUM
 

I agree completely. Otherwise, I would have built myself one of these already. This particular guy is a very skilled marksman and uses a Lazer rangefinder. After he had chrono'd his loads, I put the information into my Exbal program and printed him out a trajectory chart. He later confirmed the 500 yard drop figure at the range; and since, I understand, has just trusted the chart.

I really don't know about an exact pressure, other than there doesn't appear to be any overt signs and the primer pockets are still tight. The 180 grain bullets he tried intially could be stoked up to about 3450 - about normal for the caliber. And regular 150 grain bullets were getting warm at about 3750 - also about normal. It has to be this NP3 coating.

I have used this coating in the past to plate the internals of Colt 1911 match guns.
I could take a Series 70 Colt - tune the trigger to 3.5 lbs - remove the hammer, sear, and disconnector - send them off to Robar for NP3, and reassemble the gun later. The trigger pull would typically drop to about 2 lbs. And the stuff is hard enough to last for thousands of rounds. I guess that's the problem as well - its so hard and slippery that something else has to give - that being the steel of the barrel.

RE: Loading for a 300 RUM
 

Just because he needs a block and tackle to help lift the bolt handle after firing doesnt mean he has a "hot" load .......does it stubble???:D

RE: Loading for a 300 RUM
 

Lets not exagerate,a 4lb hammer is probably sufficient .As I previously stated,I am wondering why lazzeroni can't obtain the same velocity with the 130gr robar coated tsx that this guy claims with the 150gr bullet.Both case capacities are comparable and the barrel length is the same,the coating is the same, yet this gun supposedly drives a 20gr heavier bullet faster.

RE: Loading for a 300 RUM
 

Guys, I don't know but that has to be the flattest hunting bolt gun in the world. Seriously.

RE: Loading for a 300 RUM
 

I knew one guys who had the 30-378, said it was the loudest hardest kicking gun he ever owned.

Mossy, I have read the same things you have about going below 180... None the less I thought I would give is a shot. Loaded last night 150's with 92-94-96 grains of Rx22 seated to 3.601. I figured Retumbo might be to slow for this light of bullet. Plus I don't recall my Lyman book even putting Retumbo down for 150's.

Have any of you tried Retumbo? I see a lot of you use Rx25 or H-1000.

RE: Loading for a 300 RUM
 

I use retumbo on occassion. Seems to work nicely. But has the longest muzzleflash I have ever seen. I have a 190gr matchking load 96gr of retumbo, and it puts a flame 4ft out the barrel. Flash goes down some when you move up a few grains but accuracy went down. Others have observed this and Sierra techs thinks it the coating they use.

I have had one instance of good luck with Reloader 25. Seems to vary some from lot to lot however. It is the one powder you can probably get max velocity.

RE: Loading for a 300 RUM
 

please let me know how it turns out! I have a box of 150 Nosler B/T's that I might give a try......maybe:) I bet I could probably push those babies up around 3350-3400 man that would be a flat shooter, if they dont zing all over the place.

RE: Loading for a 300 RUM
 

You know I tried 150gr BT and IMR4350. Accuracy was good, but velocity was only like 3300-3350. I was a little disappointed on the velocity.

RE: Loading for a 300 RUM
 

Could you possibly use some H-4350 on 150 grains? I know you can't directly replace one for the other, but would there be a possible load there? I only ask because I had some left over from another cartidge I was test loading.

RE: Loading for a 300 RUM
 

hey hillbilly.....whats wrong with 3350 fps??? especially if you can get sub moa??? Id love to have my rum shooting that speed!!

RE: Loading for a 300 RUM
 

3350fps with 180gr bullets is quite fast with a 300ultramag.3350fps with 150gr bullets is quite slow for a 300ultramag.

RE: Loading for a 300 RUM
 

Seriously If I could get 3350fps with 150's and still maintain sub moa I would switch right now!! I just dont think it could happen. It seems like every powder I use to achieve great groups, kills me on velocity! Im not argueing with you stubble, Im just explaining MY situation.

RE: Loading for a 300 RUM
 

It sounds like either you just haven't hit the right load combination or there is a problem with your rifle.

RE: Loading for a 300 RUM
 

Nothin to wrong with it I suppose. I don't mind being on the low side velocity. I do remember getting a cluster of groups that were one hole then a flyer 1.5" away. Happened a few times. i got to look at my target again. I only gave it one shot.

RE: Loading for a 300 RUM
 

Stubble should we be getting 3500+ with a 150 grain pill? Do you have any suggestions on getting the 150's to shoot? Which powder?

RE: Loading for a 300 RUM
 

I don't suggest IMR4350 to get 3500. At least it didn't work for me. I bet RL22 might be the ticket.

RE: Loading for a 300 RUM
 

I have only tries 165gr and 180gr bullets and r-25,h-1000 and imr7828 all provided good results with r-25 being the best in my rifles.In my opinion either imr4350 or h4350 would be too fast for such a large case.

RE: Loading for a 300 RUM
 

stubble, do you plan on trying the 200 grain accubonds? I am working with it now, I just haven't had the time to go shooting yet. Well thats not totaly true, I have spent some time shooting my new bow. Thats the problem of loving both rifles and bows, I don't have the money and time for both but I try my best.:D

RE: Loading for a 300 RUM
 

I know Bigcountry uses 200 gr accubonds but I cant remember what powder he uses

RE: Loading for a 300 RUM
 

I have no plans to use any bullet heavier than 180gr in .308" as they just aren't required for any north american game.However,I do plan on trying the barnes tsx's very soon.

RE: Loading for a 300 RUM
 

That is kind of what I thought. I saw one person on reloadersnest.com using Rx19, and I kind of thought that might have been fast. Alliant's website recommends Rx22. I will see how it goes.

RE: Loading for a 300 RUM
 

Think I use 90gr-91 of H1000

RE: Loading for a 300 RUM
 

BC, I had been told H-1000 is a temp. sensative powder. Is there any truth to that?

RE: Loading for a 300 RUM
 

All powders are temp sensitive. H1000 is part of Hodgdon's extreme line which says its much less temp sensitive than others. I do know that Alliants is very temp sensitive. I built this wonderful load for my 300Rum and RL25 when was 10 degrees. When I shot it in 80 degree day, it locked the brass up in my chamber.

RE: Loading for a 300 RUM
 

That is why I do all of my final load testing at 60F to 70F.I lose a little velocity at colder temperatures,but the loads are safe in all hunting conditions.

RE: Loading for a 300 RUM
 

Elkhntr. The Nosler reloading manual, 5th Edition starts with the 125 grain wt. bullet for the .300 RUM.
For the 165/168 grain bullets six powders are listed, IMR4350, H4831, IMR7828, AA3100, RL22 and H1000

For RL22 MAX load is 90 grains @ 3368 fps. Most accurate RL22 load was 88 grains @ 3312 fps. Also listed was 86 grains @ 3249 fps.

For H1000 MAX load is 98 grains @ 3335 fps. Most accurate load was 96 grains @ 3270 fps. Also listed was 94 grains @ 3198 fps

RE: Loading for a 300 RUM
 

For loading the stw's,ultramags and wby mags,the nosler manuals are poor choices as their loads are extremely mild compared to most other sources.In most cases their velocities are below those produced by factory loads.