300 ultra sendero

[RUMBALL]

Hi guys new to this site and a great site it is im just venturing into long range hunting and Im just starting to do some handloads for the rum.
I was hoping some fine chap out there using the 208 amax could give me a oal or base to orgive measurement to compare what I have measured in my rifle.
Has remington reduced the freebore in later model senderos than those from the past.
My measurements are 2.945 from base to orgive
OAL 3.670.
The rifle is all standard sendero any load data to refer to would be nice I have AR2225/RETUMBO and AR2217/H1000
NOSLER BRASS AND FED GOLD 215 MAG PRIMERS.
Have loaded 89gr to 93gr of 2225 to try out with first so I will see how that goes.
Rifle has been bedded ,rifle basix trigger and aps muzzle brake scope is nxs nightforce as are rings and base more mods later after stock barrel is toasted.
Cheers.
RUMBALL. [THOSE MEASUREMENTS ARE ON THE LANDS]

 

[Long Time Long Ranger]

Load the 208 Amax touching the lands with 91 grains Retumbo and you will do just fine. I have done very well with that load in several rifles. Some rifles will carry up to 93 grains Retumbo but all will do 91 that I have tried. The 208 Amax likes to touch the lands for best results so get that measurement and load it there. Then work powders and charges with fed 215 match primers and you will be on your way. Depending on the rifle Retumbo will get you 3150-3225 fps safely at max with that bullet. It is an extremely accurate bullet that carries a bc right at .65 in all the testing I have done with it. It is an excellent choice.

 

[RUMBALL]

Cheers LTLR,
Thank you for the info I have been reading alot of your posts over the last few months plenty of good advice in them.
I will be using my 5r milspec 308 for the learning process as to not burning the rum barrel out to fast and have 168 and 178 amaxes for that rifle and theres plenty of loading data on this sight to use as reference.
So thanks again for your reply LTLR.
Cheers,
RUMBALL

 

[badandy970]

I have been having great luck with my 300 RUM her are the two Loads i have and they are great.

210 Berger VLD hunting
92.5gr Retumbo
CCI large rifle mag primers
remingtong brass 3.600 Coal

168 Hornady AMAX
100gr Retumbo
CCI large rifle mag primers
remingtong brass 3.600 Coal

 

[RUMBALL]

Thanks for the info badandy.
As I stated in my first post about my sendero may have a short throat as all data that I have read I can not seat my projectiles at many oals listed I cant even seat at listed depths in the hornady manual at 3.600.
The 178 amax is on the lands at 3.565
The 168amx is on the landa at 3.530
Still waiting on 210 bergers so cant measure them yet to compare to other data.
So If you know or know anybody that can tell me their length to lands measurements with these projectiles oh and the 208amax is 3.670 on the lands,in a standard sendero 300rum barrel so I can find out how short the throat is to others.
I will give those loads you listed a whirl soon just started with the 208amax so would like to get that sorted first.
Cheers.
Rumball

 

[BlackKnight755]

I dont know how many rounds you have down the RUM barrel but you could have the throat extended so that you could seat your bullets farther out. This is an easy task with the proper tool. The gunsmith doesnt have to dis-assemble the rifle, just slide the bolt out and put the tool in the chamber and with a few turns of he tool the throat is extended to the length you want it.

 

[Spuds]

210 Berger VLD's with my Sendero have a COL of 3.790" at the lands, +/- a couple of thousandths. The measurement was taken using a Stoneypoint OAL gauge with their standard modified case.

 

[RUMBALL]

Cheers for the info I should have bergers next week this will give me some idea,my concerns were that having less freebore would I be better off using AR2217/H1000 guess just load up with both AR2217 and AR2225 and put them over the crony and see how they go.
My gunsmith said just go shoot it there will be enough performance for what I need and that accuracy will be better not having such a big jump and barrel life would be enhanced if treated properly and that I would be chasing the lands soon enough once there has been a few rounds through it.
It seems to me that the short throat is hindering the rifles performance but Im only new to this type of cartridge so maybe I should just go and enjoy it and stop reading into things that I dont know much about.
Cheers guys.
Rumball.