180 grain - DeepCurls and the .300 RUM

[TBASTIAN]

After last weekend's bear hunt, I realized the need for a tougher bullet in the .300 RUM. I've been playing around with some loads for some time now, but haven't found anything other than the 180 grain Sierra BTSP that would shoot under MOA.

This week I received an order of 180 grain Speer DeepCurls...the price just couldn't be beat! Headed out into the hills to try two different loads yesterday. My wife and kids were with me so I wasn't able to spend the amount of time cooling the barrel between shots and groups. The first three shot group shot right about 1.75", the second load (using the same combination that works with the Sierra - 96.0 grains of H-1000) shot the following group. The first two bullets touched, and were dead center, the third was a flyer, and opened the group to 1.67"...I'm hoping that the hot barrel was the reason for the flyer.

Will be loading up another 6 shells of this configuration to confirm the load later this week, when I have the time to truly focus and let the barrel cool between shots. Here's hoping for a great load.

 

[JD338]

I have found that the RUM's groups will open up quickly (3rd shot) if you don't let them cool off a bit.
If you are looking for an accurate robust bullet, try the 180 gr PT. It will hold together at 300 RUM velocities, even up close.

JD338

 

[TBASTIAN]

Agreed. I had hoped to have used the 180 PT as my go-to bullet for this rifle. Here are the results from my load development with it thus far. I now need to try the 96.0 grain load of H-1000 with the PT as well.

I really like the DeepCurl's design, with no exposed lead tip. The PT and GameKing seem to get pretty deformed in the magazine.

180 Grain Nosler Partition B.C. .410 S.D. .248

Loads Tested:
IMR 4350 - 80.0 Grains (Nosler)* 1.34"
H-1000 - 94.0 Grains (Nosler) 1.89"
H-1000 - 93.3 Grains (Hornady) 2.36"
RL 25 - 92.5 Grains 1.85"
RL 25 - 94.8 Grains (Sierra) 3.24"
RETUMBO - 97.0 Grains (Nosler) 1.64"
RETUMBO - 99.5 Grains (Hornady) 1.03" & 2.93"
RETUMBO - 100 Grains 1.55"

 

[JD338]

Nosler also makes a 180 gr PT with a protected point, no exposed lead tip. It was actually designed for the 300 Win Mag.

JD338

 

[TBASTIAN]

Not looking too shabby.

 

[SJB358]

Those Speers are probably pretty good bullets. I have had great luck with them in different calibers. Shoot some into some water jugs and post some pictures. They do look like a great bullet. Scotty

 

[DrMike]

Those bullets are almost lost in that massive cartridge! I really appreciate the pictures, however. All that I have read of the DeepCurl point to another good bullet. I wonder how your rifle would digest the 180 grain PT, however, or even the 200 grain AB?

 

[TBASTIAN]

Tried the 200 grain Accubonds with RL 25 and Retumbo to no avail...only tried 4 loads before resorting back to the 180's. I have one of the new Redfield's atop this .300 and its Accurange reticle is set for the 180's...Tried the 200 grainers due to all the great comments about them on this board, and really hoped that they'd worked.

Tried the following loads:
Retumbo 95.0 Grains (Forum)
RL 25 92.0 Grains
RL 25 91.5 Grains (Nosler)
and RL 25 91.3 Grains (Sierra)

All shot between 1.5" to 2.75".

 

[Mountain Goat]

I'm wondering if you're trying to force feed your RUM heavy bullets when it really wants something lighter. The 168 E-Tip would make a great long flyer out of the RUM, if it shoots well of course.

I forced 100gr bullets down a .243 for many range sessions and was ready to sell the darn thing untill I dropped to a 90 grain bullet. I couldn't believe it was the same rifle shooting those groups.

I'm not saying that you don't know your rifle well, but sometimes we need to separate our wants from the rifle's needs.

I bet if you shot that group with a cool barrel, I wouldn't have made this post.

 

[OU812]

When I was loading for a freinds 300 rum here is what I found to be accurate with Nosler bullets. Both loads shot .50 or slightly less at 100 yards.

180np, seated at 3.660 (just fits in the mag box) fed 215, retumbo 95 grains.
200 AccuBond seated same as above, fed 215, RL-25 91 grains.

 

[tpbscha]

I've also been looking at the Deep Curls for my 300 Win Mag. May have to give them a try. When I do load development, I always wait 2-3 minutes between shots to cool the barrel. Then I may wait 5-10 minutes between strings. Load testing is about consistency and that includes barrel temp as well as environmental conditions.

 

[1Shot]

Man you have gotten those bullet seated deep. You have the bullet seated to the o-give. There could be some of your accuracy problems. They must be jumping a mile before they hit the lands.
I would make up a split neck case and with a bullet finger inserted slightly in the case place it in the chamber and close the bolt. Remove it carefully and measure the OAL to see where the lands are. I would then start seating the bullets 10 thousands deeper, (10 thousands off the lands) and then do a ladder test on the powder to find my most accurate load. I would then do a ladder test seating series of my best powder charge by seating 20, 30 and 40 thousands off the lands to see what happens. For hunting loads I will never again seat a bullet closer than 10 thousands to the lands. I have stuck a bullet in the bore seating to the lands and ruined a day of hunting once. Just my 2 cents worth.

 

[Guest]

I agree those appear to be really seated deep. My 180 AB load in my 300 Ultra is 20 thousands off the lands. I'm shooting 95.0 of Retumbo, 215 primers with the 180 AB. I would encourage you to re-visit the Nosler loads you posted and adjust your seating depth. I may have missed all the dialog here but what gun are you shooting? Did you check to be sure the barrel is not binding on the stock? Is your barrel truly clean, free from copper build up? All these contribute to lousy accuracy issues. Are your stock screws torqued tight, the scope mounts and rings too?

The barrels on most 300 Ultra mags heat quickly given the powder charges used. You must allow cooling time between shots, if not the barrel could walk opening your groupings no matter the bullet used. I'm an advocate of where it prints on a first shot from a cold barrel for hunting with this caliber.

Do You have a heavy trigger? Some rifles have those for liability/ safety reasons.
Somethings to think about, but you may have the bases covered too.

Good shooting,
Don

 

[Alaska]

What is length of the 180gr Deep Curls?

 

[TBASTIAN]

Alaska the length of the DeepCurls is: 1.21" OAL

Load development was about 1.6" with the additional loads I tested this week...ended up loading 5 new loads this evening and pushed the OAL out to 3.65"...we'll see how that changes things.

 

[SJB358]

Good luck. Looking forward to seeing how they do. Scotty

 

[JD338]

TBASTIAN

I load my RUM tojust shy of the max magazine length. There is a lot of free bore in the Remington so I have never tried to get close to the lands, just feed through the magazine. Accuracy has been excellent.

As mentioned by Scotty, shoot a couple bullets into some water jugs and post your results.

JD338

 

[TBASTIAN]

Thanks, JD. Took your advice and loaded them to 3.650". Longer than the Nosler manual suggests, but still clears the magazine with a bit to spare. Appreciate all the help!