300 RUM, 240 SMK, US869 Initial Results

[Jon A]

I think I'm going to like this powder. /ubbthreads/images/graemlins/wink.gif Unfortunately the range was fairly crowded today and I didn't feel like messing with the chronograph so I didn't get any velocities, sorry. But I felt like shooting the ones I loaded up to check for pressure signs anyway. Here were the results:

Load developement? What's that? 5 different powder charges in new crappy Rem brass, bullets just seated to fit the mag (3.6"), one shot with a clean bore.... I think this combo might have some potential. /ubbthreads/images/graemlins/laugh.gif

I also fired 101 and 102 grains, but since I had already put 5 into that hole (and it was so pretty) I shot the last two at a different target. They would have opened the group little, if any. No pressure signs at all, even at 102 grains. I really expected to hit one before then or I would have loaded a 103. I have to be getting close...time to bust out the chronograph.

 

[Jon A]

A few additional notes:

As some may be wondering, even stuffing the long bullet so far into the case, the 102 grain load was not compressed at all. This stuff is dense. Pretty full though, it would only shake a little. That's with new cases that have a slightly smaller capacity than fireformed ones will.

Also, I think 102 grains is definately getting there. Kirby did such a good job on this chamber, this thing chambers and extracts fired cases effortlessly while my old chamber/barrel had no prayer of doing that even with very mild loads. Anyway, while extraction was effortless when I fired the shot, the 102 grain case is the only fired case from yesterday (even including a 97 grains of Retumbo behind the 200 AccuBond) that shows even a hint of resistance to extraction when I chamber it now. Nothing scientific or obvious as a bright, shiny ejector mark like I was expecting, but I think it gives some indication that 102 is starting to get up there pressure-wise.

I think I'll load up some at 100 grains, check velocity, consistency and 300 yd accuracy as the next step.

Please approach these loads with caution (notice I started at 95 grains) as this 3-groove Lilja seems pretty slick so others may top out sooner.

 

[jwp475]

Congradulations,Jon A, nice shooting and a nice rifle indeed

 

[Eaglet]

Jon A,
Awesome shooting Jon A, I'm glad you're sorry because it's frustrating to some us not being able to know what velocities you're getting. I've been waiting for something like this with US869. /ubbthreads/images/graemlins/smirk.gif /ubbthreads/images/graemlins/confused.gif How can you do this? .... OK!, OK! We forgive you because you're sorry... /ubbthreads/images/graemlins/smile.gif I'll be waiting for the report when that chronograph comes out!!! /ubbthreads/images/graemlins/smile.gif

 

[royinidaho]

That's pretty sweet!!!

Where'd your targets go. I like the looks of that one, without that puny group /ubbthreads/images/graemlins/grin.gif /ubbthreads/images/graemlins/grin.gif I use others of your targets but really like the looks of that one.

 

[Fiftydriver]

Jon A,

Nice shooting, I think she will work out pretty well for you!!! Let us know on the velocity results!!! Then stretch er out and lets see what those 240s will do at long range, I think its a shooter from the looks of it!!!

Kirby Allen(50)

 

[Jon A]

Thanks guys. I think I'm going to be very happy with this rifle.

Eaglet, I know, it's killing me too. I'll do my best to get some numbers within a week. But as it was, I barely got off my last shot about 2 minutes before the range closed...I have never spent so much time cleaning a barrel in all my life! My arm is actually sore from scrubbing the bore so many times...**** these break-in proceedures anyway! /ubbthreads/images/graemlins/wink.gif

Roy, thanks for reminding me I haven't updated my target page in years. I've been planning to, just haven't gotten around to it. In the meantime I could send you some files if you'd like.

Yeah, there's no doubt she's a shooter Kirby. 300 yd groups soon and more out to 1000 & 1100 yd within a couple months if I get the new gong built. My current one only goes to 800 and I think that's going to get boring with this rifle.

 

[Fiftydriver]

Jon A,

I think your right, 800 yards will not be a problem with you and your rifle.

Keep us posted,

Kirby Allen (50)

 

[bailey1474]

That is very similar to the results I got w/the 240 and Retumbo. 13 different charges went into about .8" @ 100 yds!!!!

Anxious to see what velocities you are getting.

 

[jwp475]

Bill, What velocities did you get?? Barrel lenght?

 

[Jon A]

Yeah, I certainly can't complain about Retumbo's accuracy with this bullet. But after being used to H870 the velocity was just depressing, lagging behind by a good 100 fps. I was getting 2850 with the 26" factory barrel. At 26.7" I'd expect this one to top out at around 2875 or so with Retumbo at the same sensible max pressure.

So that shouldn't be tough to beat. That's all I was really hoping for with US869—a powder that will keep the accuracy, be somewhat temp stable and beat that velocity (especially with an eye on even heavier bullets in the future). Basically a replacement for H870 with the added bonus of being temp stable (claimed, at least). H50BMG would beat it by 50 fps but accuracy was lousy.

I'd say US869 has already passed the accuracy test for me, and velocity-wise Retumbo sets the bar pretty low—it's just too fast to be optimum with bullets this heavy. If my educated guestimates are correct, it should beat it by a significant amount.

 

[bailey1474]

The bbl is 30" 4 groove Lilja. I ran it up to about 2950 fps but I saw huge node where my velocity only jumped 40 fps over a range of 83-87 gr. So I went w/85 gr and the rifle shot under .25 MOA.

I have no complaints other than this bullet does absolutly terrible in my rifle once it enters the transonic phase. It does good to keep them on a basketball court!!

 

[Varmint Hunter]

Bill,

At what distance does the 240 SMK enter the trans phase?

I was always under the impression that the heavier bullets with the higher BC's would outperform the lighter/faster bullets over the long haul. Would a lighter and faster SMK eliminate this problem?

I've avoided the 240's because if my rifle kicks be any harder its likely to break my neck! /ubbthreads/images/graemlins/grin.gif

Just curious.

 

[bailey1474]

Somewhere between 1500 yds and 1600 yds. Looking @ exbals #s it should not be going into the transonic phase yet but, it would go from kicking dirt on pds to hitting in a 10' circle around them!! Might also be that I'm shooting them out of 10" twist. Don't know why, I just know that is what it does.