New long range rifle arrives

[Rapier]

The new long range gun just arrived. I bought this rig rather than build it because the price was right, the gun was built right and it is a pre 64 M-70 action.

It is one of four 240 Laser guns ever built. A pre 64 M-70 action with a SS Kreiger 28 inch barrel. It has a history of excellent groups and top notch velocity.

The 240 Laser is a creation of Engineer buddy John Bass, former VP of Hughes Aircraft Company and a world traveler who has shot in competition for years and understands what it takes to shoot well and to build what will shoot well. This particular rifle was John's personal rifle for many years.

The 240 Laser cartridge is a 280 Remington with the shoulder moved out .250 inches and the angle altered to 45 degrees. The case is necked down to 6mm. The idea was to push the heavy 6mm bullets to over 3,500 fps and retain sub .5 inch groups. The results far exceed the idea with a 105 VLD at 3,800 fps and groups of 1.6 inches at 500 yards.

Now I will get it set up for me. The attached picture is the loaded cartridge.
Best,
Ed

[Ridge Runner]

awesome, whats the roundcount on the tube?
RR

[Skinny Shooter]

Nice! :cool:

[Jack]

Wow, Nice rig!

[Rapier]

For most shooters a round count is a best guess situation, even with written records a field gun is still a best guess 90% of the time. In this case all I do know is the rifle still shot well when put up. The owner stopped shooting rockchucks and ground squirrels, many years ago and the rifle has set dormant since that time. The loaded rounds are loaded with H-870/AA-8700 which has not been "made" by Hogdon or AA since 2002. And the owner was not aware that H-870 was no longer made. Yeh, sometimes you must be a shade on the detective side. But with 50+ years in gun buying, it is not my first rodeo.;)

I have started my normal bore cleaning sequence on used guns. Tonight I will fill the bore with Shooters Choice (copper solvent version) and do a week's soak. Any copper will come out in gobs and we will be back to bare steel and as new a barrel surface as there is in this bore.

By the way, I sat down last night and determined the shoulder's base on the 280 was moved forward the length of the factory shoulder. The capacity of the case is 72 grains of water. The cartridge has 1 grain more capacity than the 240 Super Varminter listed in the Ackley Vol 1. So we shall see, as always, "the proof is in the pudding."
Best,
Ed

[Ridge Runner]

then basicly you have a twin to the 240 gibbs, my 6.5 gibbs has an H2o capacity of 72.3 gr. Do they reccomend sticking with ball powders to eliminate pressure spikes from bridging powder? also ball powder is kinder to the throats. good luck with it, give us a report when ya get it tuned in.
RR

[Rapier]

RR,
Yes and no. The 240 Gibbs is very similar but...... The Gibbs shoulder is a wee bit shorter, base to body juncture (2.145 VS 2.230) The soulder diameter is .455 compared to .458 and the shoulder is at 35 degrees rather than the 45 degrees of the laser. I do not have the capacity data but would guess given the differances, about 71-71.5 grains VS the 72 of the Laser. The load data with H-4350 and H-4831 is similar, but the data with H-870 is a good bit better in velocity.

As H-870 and AA-8700 (same surplus powder) are no longer available, I am looking at Retumbo to see if it might fill the void created by the withdrawal of the other two powders. I am also thinking of trying VN 560 as that is the powder I use in my 300 WSM. There are also some surplus 50 Cal powders to look at if I can not get where I want to go with the commercial stuff.

John did mention in 2008 that the Laser was very similar to the Gibbs.

Most loads with this style case, large capacity, long and skinny use the old standby extruded powders, 4350 and 4831. I guess I could try some of the equivelent WW ball powders, but, although I have several pounds, (gifts) in unopened cans, I have never put a grain into a case.

But, I am always willing to learn from experiance.
Best,
Ed

[Ridge Runner]

I shoot some of the mil-surp ball powders, WC-872, and WC 868 and a couple more you start with H-870 data. there is also US-869 from hodgdon which is very close to 868, but possibly too slow for the lazer.
just was curious if you or anyone else ever experienced powder bridging in the 06 based small diameter wildcats, heard it was why the 25 WSM was scrapped by the manufacturers, and I know of one 257 dia. wildcat, The 257 Allen Mag (sort of a 257/338 RUM Imp.) that is only feesable to shoot with ball powders due to pressure spikes from bridgeing.
RR

[Rapier]

RR,
I looked into an old can of AA-8700 that I had for several years, I believe it came from a guy that stopped reloading for a 300 Wetherby and a 6mm Rem, anywhoo It appears to be a ball powder, Hum, if that is the case, is the surplus WC-868 about the same as H-870? I have seen the refrence before to the load data being close enough to start at an 870 starting load and work up. Is the 868 also a ball powder?

I am not sure about bridging. But, I do note that 4831 to be as accurate as it is, will produce some 30-50 SD readings, even at best accuracy, in my 6.5x06 guns and that is with shall we say serious compression.
Best,
Ed

[Ridge Runner]

yes its a ball powder, as is H-870, AA8700, WC 872, , also WC-860, 860 also uses H-870 or AA-8700 data and its 9 bucks a pound can be found here www.gibrass.com
hope this helps
RR

[Rapier]

We are now ready for the first outing with the Laser. I let the bore soak for two weeks. No chunks came out, only black India ink looking stuff that indicated the copper was disolved.

I have bushhogged off a place about 100 yards long and the width of the power lines on the face of a hill, across a creek, on the farm. Shooting down the power lines from one hill to another, into the hill side, I now have a flat 200 yard range and the new 500 yard range within 300 yards of one and another. Just a short run with the clays cart.

The 240 Laser has 50 new rounds to fireform with false shoulders on the neck, with a crush fit. I have about 40 old rounds that I can also shoot.

My intent is to get the scope lined up while fireforming and then get into the accuracy loads later.

This is a picture of the 240 Laser with scope.
Best,
Ed

[Rapier]

Well, the first range report on the 240 Laser. I decided to shoot a few of the already fired cases by reloading them with IMR 4350 and sierra 100s then to fireform 50 new cases using 4350 and sierra 85s. So much for the plans of mice and men.

I found that the Sierra bullets do not like 1-8 twist barrels at 3,700 fps and tend to go "poof" about 0-60 feet out from the muzzle. Yep, I actually had a few readings on the crono of 30 fps or so, at 10 feet. So, I sent John an email and found out that the CRS had him by the throat and he forgot that the gun did not shoot Sierras without tearing the jackets off.... Oh, well.

After pulling bullets we now have everything loaded with Nosler BTs. I understand that Nosler claims you can not tear a jacket off their 6mm BTs. We shall see.

All was not a waste as I did get the starting data for my new article on the 357 Mag Rifle. So we had a bad start with the 240 and a very good day with the little Marlin.
Best,
Ed