I'm kinda treadin in waters I've never been before. Right now I'm working up some accuracy loads for a tight neck, short throat .300 ultra using 180g Partition Golds (moly free). I learned quickly that with the short throat you have to back off loads by a few grains (toss out all the reloading manual data). I've gotten some baseline loads using RL22 to get a read on velocities. Now I want to try some different powders (7828, H-1000) What I did was go into Quickload, modify my case water capacity till a given powder weight matched the velocity I'm getting over the chronograph. With that parameter set, I've run simulations with the other two powders to see what charge weights and velocities were within the safe pressure range. Gives me an idea of where to start my loads at. Any thoughts on how to proceede?

Thanks, Al

[ 06-02-2003, 20:56: Message edited by: AJ300MAG ]

Carefully...

Curious on how short a throat you got? I know you got krieger to do some work for you in past. Did they cut the throat for ya. I got my gunsmith to cut my Krieger barrel and was disappointed. Has alot of freebore. So what do yo think the max COL you could have with the those noslers?

Hey bigcountry, This is a different rifle than the one I worked with last year. I did all the machining on this one myself. She wears a 27" Lilja barrel for something different. After talking with Dave Manson of Manson Reamers I shortened the throat by .050". He ground the reamer for me. With a OAL of 3.685 the Partition Golds will be kissing the lands. Rifle will put three 200g matchkings into 5/16" at 100 yards all day long. The partitions haven't done as well, I can't get groups to repeat what I've gotten with test loads.

I thought the Krieger cleaned up well, all through break-in and load testing I've yet to get any green out of this barrel while cleaning.

Thanks AJ. I was pretty disappointed when I got my 300RUM back and saw I had to set my COL to 3.825" to be able to touch the lands with a 180 Partition. I specifically told the gunsmith I wanted to be able to touch the rifling with a 180 Partition with my COL set to 3.66" COL. He didn't do as he planned and got a regular reamer from brownells with standard dimenions. But it does shoot great. Haven't got above an inch group with it yet at 100 yard. And got a few 3/10" groups at 200 yards with 180 partitions and 93gr H1000 and CCI250 primer.

Originally he said he could have special reamer with thoat section cut off. So he would ream the headspace first then another reamer to set the throat length to my specs. Its hard to get people to do what the customer specifies these days.

Congrads on the gun.

Bigcountry, Dave took an off the shelf reamer he had and re-ground it to the sizes he and I agreed to. Cost me $136.00 to have done, appears to be worth it. I've seen and have gotten the standard partitions to shoot well, prefer the "Golds" for elk hunting. I've had three shot groups under 3/4" with them, just can't seem to duplicate the load (mabey shooter error). My .338 ultra loves em, also worked up some loads for my 7MM Mag. I'm getting 1/2" groups without moving the BOSS from zero.

With that tight throat, you are in for a real treat. Believe it or not, theR22 and even H1000 are too fast for the 300 RUM...especially with the tight throat. AA8700 should be just perfect, and with the 27 inch bbl even better. You will burn it ALL. For 180 gr spitzers, start at 101 grs and look for 3000 fps. Work up to 113 grs, compressed, looking for 3300. With your barrel and throat, you may get there at 106 to 109 grs, which is good. Given your bbl length, you will likely be in the 59,000 to 62,000 psi range with a few grains if case capacity left over, but near the 100% load density. More velocity is there, if you need it, but I think you acccuracy and bbl life will benefit from a slightly reduced load doing 3300 to 3350 fps.

If you don't like Ball powders, R25 and Retumbo are more like the right burn rate. Remember, R22 is great in the 300 Win Mag, and THAT case holds 35 grains less powder with the same bore and the same bullets.

Good luck!!

Reloader 25 works the best in both of my 300ultras.Both will average 1/2" groups at 100 yards.Velocities with 180gr bullets are
rifle-1 96gr-3375fps
rifle-2 95gr-3395fps
primers are fed215 and overall length is 3.670 in both cases.

Thanks for the info Sabot & Stubblejumper. I've got the RL25 for my .338 ultra, I'll pick up some 8700 and give it a shot (may be like 12 shots). I did some rangework today with the H-1000 and the 7828, looks like part of the accuracy problem was a short between the earplugs. This rifle has a personality all of it's own. Lets you know real quick if your not consistent with your bench techniques.

You know what i have noticed. Was with 200gr and higher bullets, Re25, Retumbo, and 8700 is great, but don't do well at all 180gr and below. But for all around performance, I get better luck out of H1000. I got some Re25, and tried a few times, and it powder foules bad. I was talking to some people at Sierra, and they said the same thing. Anyone else see this?

I aven't seen a fouling problem with RL25, but the people shooting downwind of me question the "smokeless" aspic of the powder. 92g of H1000 gave me 3293FPS, 87g of IMR7828 gave me 3258FPS no pressure signs with either load. Both loads show promissing accuracy, SD is in single digits with both loads. I plan on picking up some 8700 this weekend, load up some more test loads with the other 3 powders I've shot so far, and let her run at 300 yards and see what groups come in like.

[ 06-05-2003, 01:06: Message edited by: AJ300MAG ]

109 gr of AA8700 and 180 Partition Golds (non-moly) gave me 3320 fps in my SAKO 75