I finally got to shoot my new 300 Ultra

[ss8541]

The weather here in Reno has been bad, so I have been dying to shoot my new rifle since I picked it up last week. I finally got out this morning and did some load development at 500. The wind really got the best of me though. My best 3-shot group was 2.2", with the 240 MK going 3004 (ave. vel. for group). I did have several, in fact nearly all, groups with 2 in 1" and another pushed a few inches to the side from the changing wind. The wind was a constantly changing 5-12mph. My largest group was 6.24", so I didn't have a real good average. I did get a feel for the gun though.
I specified a .338 kneck and a throat to allow me to run VLD's out a bit for max net case capacity. The problem is that I can only run the 240 MK at an COAL. of 3.69 with it's stubby nose, so it eats up a lot of case capacity. I think that even with my 29.5" barrel I will top out at 3050. I shot one load to check preasure at 3050 and didn't get any presure signs, but I had ejector marks at 3100. I found that H870 was the best so far. 101.2 grains gives me 3004 fps, with the bullet touching the lands. I have thought about backing it off to maybe .005-.008 out to see if this helps with the pressure problem. What do you guys think? I obviously need to work on a better accuracy load while I am at it , but at least I have the ball rolling. Another problem I ran into was using a 100 yard target in mirrage at that range. I think I will make up some 3" white squares with 2" black borders. The 100 yard targets just turned into a confusing blob through my Nightforce. Any helpfull input would be appreciated.
Thanks,
Vince

 

[Dave King]

Vince

Sounds like your having a good time! I wouldn't be too unhappy with a majority of my 500 yard groups at sub MOA on development.

What twist did you get in that barrel? You've probably posted it but I'm feeling a little lazy and don't want to re-read the previous posts.

Are you limited to the 3.69 OAL by the magazine or the throat? I assume by the throat as your reference to the 240's "stubby nose".

On the mirage at 100 yards, what power is your scope set on?

 

[ss8541]

Dave, I have a 1-10" twist barrel. I am limited to 3.69 by the throat. I was using a 100 yard target with a bunch of grid work and only a 1/2" center on it to shoot at 500 yards. It wasn't so much the Mirage as it was the target giving me trouble. I ended up using 22 power though. I shot 3, 100 yard groups with 210 bergers and H1000 today. It was way to windy to shoot any farther (very unstable wind speed), but I got an average of .334, and a small group of .21. I think this is going to be interesting out farther. I let one go right as a gust picked up about 5 or 6 miles per hour and that put that shot directly to the right of the group. I know better, but I did it anyways. That group was .412 with the lone flyer due to wind, the other 4 went into .181. My cold bore group measured .418. I really need to consintrate on the conditions more. Oh, these where 5-shot groups. Well, hopefully the weather will be nice and I can get some 500 yard testing in this weekend. One more thing has anyone tried VV 24N41 Powder with the heavy bullets yet?
Thanks,
Vince

 

[ss8541]

I finaly got down to 1.5" at 500 the other day. I only got two groups in before the wind got out of hand. The first was 1.5" the second was 1.63" for 3 shots. I was surprised to find out that I can only shoot the 210 berger 60 fps faster then the 240 sierra which I got up to 3140 fps with out to much case expansion. My best powder ended up being 50BMG by 100 fps, and velocity spreads in the single digits. I could get 4 more grains in under the bullet with a compressed load though. I have VV 24N41, and 20N29 on the way to try to improve on this. I would like to get 3200 fps from the 240 MK out of my 29.5" barrel. The soft brass is the problem though. My Average at 500 yards with two bullets and 7 different powders is .75 MOA. I think that this rig shows promise. I am out of bullets and waiting for VV powder though, I only had 35 of the 240 MK's to test so now I need to buy my own. I guess it is time to spend a week or two working up loads for the 6mm with VLD's. I am going to try to burn the nearly new barrel out of it by next hunting season for practice.
Has anyone tried the very slow VV powders yet? I really think that these may be just the thing.
Vince

 

[Darryl Cassel]

Vince

I have been watching your testing with interest.

My next project hunting gun is going to be based on the 300 Ultra mag Improved with at least a 34" to 40" barrel and use nothing but 240 Gr Sierra MKs.
I know it won't be capable of what my 338/416 does with the 300 gr bullet but, I want to show some of my doubting LR buddies that the 240 gr 30 Cal will out perform the 250 gr 338 bullet from their 338/378 long barreled guns, at 1000 plus yards.

I always liked the 240 in my 30/378 Weatherby and could do the testing using this gun. I want to add insult to injury here and show that it can be done with a standard magnum action instead of the high cost customs. I do have big custom actions on my 30/378 and the 338/416IMP.

The problem you may encounter ( I found this out years ago) is that some of the slow VV powders you mentioned may not burn complete in the 29 1/2" barrel. This is another reason we like the longer barrels (at least 36") to allow the burn rate enough time and then we can use those powders effectivly.

I think that if you are getting 3140 with a 29 1/2 " barrel without much pressure signs, that could make for great longrange potential.

I ran, on my ballistics program, the 240 (30 Cal) against the 338 250 gr and even gave the 338 a 100 FPS head start and at far less then 1000 yards the 240 outperformed it all the way around. I started the 338/378 250 gr bullet with a BC of .587 out at 3350 (my buddies are getting that velocity with LONG barrels) and the 30/378 (Mine) with the 240 gr (BC of .711 as Oehler stated) bullets out at 3250 and the 240 had more retained velocity and energy starting at 400 yards and continuing on out to 2000 yards and beyond.
Even at 3150 the 240 will catch the 250 gr 338 and out perform it ballisticaly.

Keep us posted and I will do the same on my project. I will be using an Improved version of the 300 Ultra and hope that Federal and Norma will supply us with brass soon for the 300 Ultra. The Remington brass has been the down fall of the case and the MAIN reason I have not been too interested in it up to this point.

How much BMG are you stuffing in the Standard Ultra case?

Later and good shooting.
Darryl Cassel

[ 12-10-2001: Message edited by: Darryl Cassel ]

 

[ss8541]

I am stuffing 100 grains of 50BMG in with the 240 and 102 with the 210 berger. This load is a very light compressed charge. I believe this is why I am getting very low velocity spreads. Ramshot also has a new very slow powder coming out ,called Grizz, just for this purpose. I have 2 pounds on the way. It helps to have good bussiness contacts. In the 300 Ultra with a 26" barrel and a 200 grain bullet they are getting 3100 fps with only 53,000 psi. I belive it will be very good for the big 240 MK. The tech guy I talked to seems to think I might pass 3200 with my barrel length. I will keep you posted.
Vince

 

[steve smith]

ss8541 I wish I had your contacts, but since I don't can you fill me in on the new Western powder, Grizz. How slow is it? What's the cost per pound? I trust it's a ball powder like all the rest of Ramshots line. The reason I ask is I just recieved my rifle (30" barreled 270-300RUM) and looking to have back up powders incase WC872 and AA8700 don't work out.

[ 12-12-2001: Message edited by: txhunter ]

 

[ss8541]

Txhunter, Grizz is going to be between h870 and H50BMG in burning rate but have a curved pressure curve like big boy. It is too slow for the 200 grain bullet in the 300 Ultra. They got 3100 fps from a 200 grain bullet with only 53,000 psi though. I think it may be perfect for the 240 MK. One of there tech guys is getting 3500 + with a 180 barns from a 26" barrel 30-378 with no pressure signs what so ever. It will cost about the same as Magnum powder costs. It should be good stuff. Will be out this spring. I am a full time student and I work at a gun shop 4 days a week. It pays for toys and gets me good contacts. I had to promise not to give any to a customer, and say nice things about their magnum powder to get a couple of pounds early.
Vince