Need help with new 300 ultra mag
 

I just bought a 300 ultra mag and I reload my own ammo. I would like some advice for some proven loads to start with. I am going to be shooting 180's out of it, only I don't know what bullets I am going use. I have shot seirra all my life in my other rifle's, but would like to try something differant with this new gun. I will be hunting black bear in Pa. and elk out west. I would be greatful for opinions on bullets and loads. Thanks, Tim

RE: Need help with new 300 ultra mag
 

I would try reloader 25 powder and bullets such as the accubond,partition or tsx if they shoot well in your rifle.

RE: Need help with new 300 ultra mag
 

I shoot 180 gr Nosler Accubonds with 93 gr of H1000, seat bullet to just clear your magazine, should be in the 3.59-3.61 range. I got most of my info from Bigcountry or Stubblejumper, they are the guys on here to listen to. If I can be any help pm me Id be glad to help you out. One note, higher velocities in these guns (3500-3600) have been known to reduce barrel/throat life, I try to keep mine in the 3200-3400 range.

RE: Need help with new 300 ultra mag
 

Try the 180 gr. Swift Scirocco - great all around load at about 3300 fps.

RE: Need help with new 300 ultra mag
 

Hey RR thanks for the info, but could you tell me how many grains of that powder. I can't find that info. Thanks Tim

RE: Need help with new 300 ultra mag
 

Try www.accuratepowder.com.

RE: Need help with new 300 ultra mag
 

My Uncle is currently using 180gr Hornady Interbonds with his Ultra Mag.
Although (I think) all he has done is punched holes in paper so far,
he is very impressed with the overall accuracy from 100yrds outword towards 500yrds.He also says there is 100 bullets/box and the the price of them is lower compared to similar makes in different brands.

RE: Need help with new 300 ultra mag
 

I am curious as to your reasoning for this statement.Have you actually tested identical, barrels cut with identical reamers shooting the same bullets at the same velocities with several powders until the accuracy began to deteriorate,in order to determine if the powder used makes a significant difference?

RE: Need help with new 300 ultra mag
 

I think this is one thing alot of people dont realize....reamers do wear out, slowly, so a barrel made #1 will be slightly different than barrel #47 and then they may change reamers at barrel #75 and then #76 will be cut from a new one. Good point stubble

RE: Need help with new 300 ultra mag
 

Actually my point was that different reamers are made with different throat lengths which can have a great effect on throat erosion and therefore accurate barrel life.

RE: Need help with new 300 ultra mag
 

I think what is being inferred here is the general tendency for ball powders to not wear the throat of a rifle out as quickly as extruded powders - all other factors being equal. This phenomenon has been documented by a number of reliable sources, including the American Rifleman staffers.

RE: Need help with new 300 ultra mag
 

To start with throats do not wear out as in wear caused by friction.Rather they burn out due to a combination of pressure and temperature.As to the rate of the throat burning out just what documented tests can you show us for the 300ultramag or any cases of similar bore and case capacity?Just what type of differences are you claiming?Is it 1%,2%,5%?

RE: Need help with new 300 ultra mag
 

The process I believe is referred to as "particle erosion", and is most pronounced in the area of the bore immediately ahead of the throat due to higher heat and pressure as the bullet starts to move down the bore. Ball powders generally develop pressure at a lower flame temperature than extruded powders, hence less throat erosion. In the test done a number of years ago by the American Rifleman, the increase in useful barrel life was something like 15 - 20% more in the .308 Winchester if I recall correctly. May not be as much in the .300 Ultra Mag class of cartridge.

Another similar phenomenon is the shorter barrel life one experiences with heavier bullets. I have two .243 Winchesters - both with Krieger barrels - and cut with the same reamer. One has a 12" twist and is used for varmint hunting with mostly 70 grain Nosler Ballistic Tips. The other has an 8" twist and is used exclusively for long range target shooting with various VLD bullets in the 105 to 107 grain range. The 12" twist gun has about 3,000 rounds through it - and shows less throat erosion (through the Hawkeye bore scope) than the 8" twist gun that has less than 2,000 rounds. Reason??

Even though the heavier bullets use less powder to reach full throttle velocities, and the full throttle velocities are lower; the heavier bullet takes longer to get moving down the barrel; exposing the area just ahead of the throat to the forces of particle erosion for a longer period of time.

RE: Need help with new 300 ultra mag
 

To add a few more variables to the equation.First have you any way to measure the pressures developed in each barrel being that pressure is a very important factor in throat erosion? Are both bullets the same distance from the lands in the two rifles?I ask this because the closer the bullet is seated to the lands,the more force necessary to engrave the bullet into the rifling which could cause an additional pressure spike at that point and result in more throat erosion.Are both bullets of the same relative hardness for the same reason?Is the longer bearing surface of the heavier bullet(rather than the extra weight) resulting in the resistance to acceleration that is causing the extra throat erosion?Lastly from my experiences,barrels with a quicker rate of twist generally produce less velocity with the same bullet weight than barrels with a slower rate of twist possibly due to the extra work required to rotate the bullet at a faster rate in the quicker twist barrel.Is the faster rate of twist a contributing factor in this case?Since there are so many differences in this case(unknown pressure developed in each barrel,rate of twist,bearing area of bullet,bullet hardness,bullet to lands distance)i would not be so sure that the difference in throat erosion can be attributed to the heavier bullets used in one barrel.

RE: Need help with new 300 ultra mag
 

Since the powders used in the 308win offer a very different burning rate than those used in the 300ultramag and the case capacities are very different(roughly twice as large in the ultramag case) how do you know that the example you offer would be at all applicable concerning the 300ultramag?

RE: Need help with new 300 ultra mag
 

I appreciate the debate, but no one has really given me any suggestions as to what loads I might try ( bullets, powder, how many grains you are shooting in your loads). I would still like that info . Thanks, Tim

RE: Need help with new 300 ultra mag
 

No one????? I thought this posts pretty much summed up what i was shooting.......was there something I missed??? Except maybe that I use Win Mag primers?????

RE: Need help with new 300 ultra mag
 

180gr bullets-92gr to 95gr of reloader 25.

RE: Need help with new 300 ultra mag
 

Ok, taw, try that load from Mossy. I gave it to him and it shoots great in my two 300RUM's and Mossys. Seems to be a very dynamic load.

I also have wonderful luck with 89-91gr of Re25 and 180 Barnes TSX.

Lastly for a long distance target load, I shoot 96gr of Retumbo and 190gr Sierra Matchking.

All of these with 215M primer. Remember COL can make a big difference with Barnes bullets. My COL runs anywhere from 3.59" - 3.635". My target load has a COL of 3.68".

RE: Need help with new 300 ultra mag
 

I am very sorry mossy33oak you were very helpful and thanks to everyone else who has helped out with some info. Tim

RE: Need help with new 300 ultra mag
 

no problem man, I was just bustin your chops a little .......you know like hazing on a football team for the new guys!!:D

RE: Need help with new 300 ultra mag
 

Taw. I'm reloading 95 grains of H1000 with the 180 grain Nosler Partition. I worked up from 91 or 92 grains to include 96 grains (max load). I got a bit tighter group with the 95 grain load. I'm shooting minute of angle at 100 yards with a 700 BDL. Have also gotten about the same with IMR 7828, but I don't have that load data handy at themoment.

RE: Need help with new 300 ultra mag
 

Guys, I have seen it many times. This is a very dynamic load in many guns. Anywhere betweent 93.5-95 has worked in probably 5 guns I have seen. Mossy substituted partitions for the accubonds but same result. It won't hit 3300fps but will definately work.

RE: Need help with new 300 ultra mag
 

I don't shoot 5 shot groups with my ultramags or my 7mmstw's.I also don't normally shoot h-1000 although I have tested it in my guns.I keep my barrels from heating up by limiting my groups to 3 shots and I do not normally shoot in hot weather.My barrels are also of heavier than normal contours and are fluted.

RE: Need help with new 300 ultra mag
 

How about providing us with some test data gathered with two equal barrels and cartridges that demonstrate just how much the use of this powder will increase barrel life.I accept actual data much more readily than theories.Then again you are assuming that all guns will provide optimum accuracy with this one powder which is certainly not likely to happen.

RE: Need help with new 300 ultra mag
 

Stubblejumper - this stuff that Ridge Runner is posting is considered common knowledge among ballistics engineers. I know its good to ask questions and request quantifiable proof; but he really isn't out on any sort of limb here.