charlie brown

bigcountry-

I think that could have to do with several factors. One that I feel is probably most prevalent is the fact that the Barnes is and all-copper bullet, producing higher pressures with less powder than the Partition with its lead core bullet, thus attaining a max load with less powder. Could also be the barrel that they tested in, does it say exactly, could it be a standard test barrel, or an actual firearm? Just some things to consider.

bigcountry

Charlie, thats what I am trying to tell you. Max load for the Barnes 140gr is like 4gr over max load for a Nosler 140gr. It typically is always the other way around. Your right about the barrels used. But historically, it has been said with the STW, factory loads are underloaded and not near the 65KPSI. There has to be a reason for it.

driftrider

I wonder if it's not just because of liability, but also because the ammo makers don't want to really stoke the 7mm STW to its max potential because they don't want it to drastically outperform cartridges like the 7mm Rem Mag or their namesake cartridges. I can especially see this as a factor as to why Remington would underload the STW, considering that the margin between a full power STW and their 7mm RUM isn't that big, but by loading it down a bit, Remington can make the Ultra Mag look more "ultra" than it really is. Remington wants the Ultra Mag to sell, and to do that they need to show that there is a clear benefit to burning a lot more powder in the way of a notable velocity advantage over its nearest competitor cartridge.

I think there is a good chance that the underloading may be more for marketing reasons than practical reasons.

Mike

bigcountry

Maybe, who know. But the STW was underloaded I think long before 7RUM came out on the scene.

stubblejumper

Remington also underloaded it's 300wby factory loads.

charlie brown

Bigcountry- I must have misread your original post regarding that 4 grains. It looked to me like you were saying Barnes was at, say 75g, and Nosler was at say, 79 grains, which would make sense, I guess it is the other way around, even though I looked at it like 5 times before posting[8D]

Elkhntr04

Stubblejumper,

I was discussing some of the things you were talking about with my gunsmith, but regarding the 300 Ultra. I had read some posts from a few months back about some guys critising the 300 ultra and talking about how inaccurate they were. Some of the guys were blaming the round. After discussing this with my gunsmith, he was saying people are to quick to blame a round. That in his opinion it comes down to the rifle. I think why you were seeing good results on multiple loads was that you had a custom rifle. Not doubting your ability to handload good, but if your gunsmith who blueprinted the action and rebarreled the gun for you was any good then you should have no problem shooting any quality bullet with 1/2" accuracy.

bigcountry

I have a 300RUM, and have had a few. And I like them. They are finicky. They will have large velocity spreads upwards of 50-70fps. This is pretty well understandable with a overbore cartridge like the 300RUM that uses upwards of 101grs of powder. Also, there is some freebore in the chambers. It helps get to those velocity numbers safely.

Inheritly accurate calibers generally don't have these attibutes. So if its too hard for your gunsmith to understand, you need to find a new gunsmith. I like the RUM's but also understand how it can be inaccurate. I have a few loads that are .5MOA. But it takes twice the amount of work for me to hone in those numbers. than it would a WSM or 308win.

Elkhntr04

So you think it has nothing to do with the machining of the gun that cause the inaccuracy? Or could you explain why you think they are inaccruate?

Elkhntr04

I do agree that is is much easier to get the smaller case capacity rounds to shoot .5MOA or less pretty easy.