Sweet pics ss7mm!!!
Well, the dynamic duo is finished, Got out this morning before the major heat and tested Lerch's 270 AM. Performed very well.
His rifle uses the Super Varmint model by Choate which I feel may be a bit easier to use on the bags but the Super Sniper BJ used also proved to work well also. Both will work well off a bipod as well.
You can see the special custom contour used in this barrel. THis contour was designed for use in my Extreme Sporter V-Block rifles to offer the stability of a full blown V-Block barrel bedded rifle but in a sporter weight barrel. In this system it would be fitted to a 7" V-Block in the forend of an appropriate sporter stock and the receiver would be totally floated.
With this rifle which is conventionally bedded, the reason for using this contour was because there was a barrel order mishap and this barrel blank was offered to be used for Lerches rifle. All the important partied involved know who offered the barrel and lerch and myself are extremely thankful for this fine example of the quality this guy is. No names need to be mentioned, he knows who he is and we greatly appreciate his gesture.
This contour design was also designed for use on conventionally bedded rifles to serve one purpose, to counter the extreme barrel strain that is produced when you drive a heavy, long baring surface bullet to very high speeds. In a traditional barrel you will get a "wringing" effect in the barrel as it is torques severely by the bullet resisting the initial rotational forces of the rifling.
These stresses are mainly generated in the first several inches of barrel. Once the bullet has accelerated and is rotating down the barrel this wringing stabilizes out.
For this reason it was my opinion that the first 6" of barrel are the most critical to have alot of barrel mass in to control these unique stresses.
Basically this contour offers the stiffness of a full 1.255" diameter straight cylinder barrel but with dramatically less barrel weight stressing a conventionally bedded receiver.
This is the first of its kind I have tested but so far it looks to be performing very well. Again, this contour is now offered by Lilja.
I woke up this morning to some strong winds and quite warm temps. By the time I got to my 100 yard range it was about 83 degrees with a 15 mph crosswind. Still I was not concerned with this wind testing the 270 AM at 100 yards. Wild is not a consideration at this range in any wind really.
I used formed cased from BJs rifle and loaded them up with 104.0 gr of WC872 which produced 3377 fps in BJs rifle at around 70 degrees in temp.
I got set up after bore siting the rifle and fired the first shot. Shot number 2 landed roughly 1/2" above the first shot from the oily barrel and the third shot landed within .3" of the second shot.
I let the barrel cool and fired three more for record and was happy to see a sub 1/2" group form. Having not performed any barrel break in I decided that was plenty of accuracy to prove the rifle is a 1/2" or under rifle easily.
I went up and pulled the target and found the last group measured .454" ctc with the first two shots breaking the 1/4" barrier from a freshly machined barrel, I was satisfied.
The average velocity in this load at around 85 degrees was 3402 fps compared to 3377 fps for BJS rifle in 70 degree temps so I suspect they will be nearly identical in same shooting conditions with this level load.
All in all, the new Lilja proved to be very impressive in performance.
My 500 yard shooting position is currently under about 5" of water from irrigating so that was out. Still, I know Lerch will have no problem holding sub 2" groups at 500 yards after the barrel break in process is complete.
Rifles should ship tomorrow down to OK. Then we should see what these rifles will really do!!