Hi Guys: Delville & Jim
Sorry to be so lax about getting back to you. Re: .2247L
Let me digress here for a moment. I have a .22 Dasher That like James Phillips, Guns of the week #30 ) will shoot 80 grain Hornady A-Max’s under 2†at 600 yards. It shoots better than any gun I’ve ever owned. I’m shooting them at 3330 fps. But I felt a need for speed and I would like to shoot the 90 grain Berger VLD’s. The Br. Case just did not have the capacity to drive a 90 grain bullet at the speeds that I wanted to work in.
I ordered a .22 x 47 Lapua reamer from Dave Kiff at Pacific Tool. I again wanted a no turn reamer and asked him to make it with a .253†neck
So I get another Wichita action and build a Identical mate to my .22 Dasher, only in .2247L. I have never used 90 grain .22 before. I observed a few posts that said if you wanted to use 90 grain vld’s you would need a 1 in 6.5 or a 1 in 7†twist to stabilize them. So I ordered a 30†Broughton 5C in .22 with a 1 in 7 twist.
WRONG !
I later learned that the posts regarding the fast twists were to be applied to the, 223/90 grain combo. In the .223 case, due to the slow speed of the bullet 2750 fps. A higher rpm is needed to stabilize the heavy bullet., 282,857 rpm’s )
It is amazing how good the 90 grain Burger VLD bullets shoot at 600 yards, that is if you can get them to 600 yards. My starting load was at 3400 fps., 349,000 rpm )
In a string of 10, I may have only blown one up. But the next string of 10 only 4 may have made it to 600 yards. I then slowed them down to 3300 fps,,339,428 rpm) still losing bullets. So down to 3250, nope, now to 3200. Things are looking up I’m only losing 1 of 10. Now down to 3150 Ah ‘, success. All bullets arrive at 600 yards.
But I’m now at 3150 fps,318,857 rpm ) still to many rpm’s to be reliable and I would like 3400 fps. The barrel now has about 300 rounds thru it. Remember it’s a 1 in 7â€.
Order new 31†barrel with a 1 in 8 twist.
New ball game. 80 grain Hornady A-Max’s happy at 3600 in the cool of the morning. I shoot in So. Ca. at approx. sea level, Maybe 500 ft’ elevation. Two weeks ago I tried this load in a Varmint silhouette match. I started at crows @ 300 yards 9:30 a.m. 68˚ got all 10. Next were squirrels at 400 yards approx. 10:15 a.m. 76˚ got all 10. Now to rabbits at 500 yards. Approx.11:00 a.m. 82˚ missed one, me-hua ) also blew-up one bullet. At Prairie dogs at 600 yards I missed two, wind ) and blew-up three more bullets. On to field mice at 200 yards. It’s about noon and 86˚ I again missed one and blew-up one bullet..
But in the 80 degree range only 3550 or they will come apart. Note: the 80 grain Hornadys I have were from a prototype run, The current production 80 grain Hornady A-Max’s Are of a newer design. They tell me that they are good for well over 3600; I will try some as soon as I shoot this 8000 up.
, I tried 3 at 3700 fps. In the early A.M. at 100 they cloverleafed, I think the group was about .230†).
I’m now shooting 90 grain Berger VLD’s. The velocity is about 3370 fps,That’s at 303,300 rpm range ) But I’m still in the testing in the heat. The Bergers will come apart at 3425/3450., That’s 310,000 rpm ) As I shoot at sea level I do not know how altitude is going to affect them.
Somebody told me that the 90 Sierra’s had a thicker jacket and would take noticeably more velocity. Well I ordered 500 and they will shoot about 25 to 40 fps faster than the Bergers before they blowup. I called the Sierra folks and was told that they were designed for the .223/90 combo at approx 2800 fps. The same as the Bergers and that the jacket was the same thickness as the Bergers, just a little different in design.
All three of the above mentioned bullets will shoot at .500†or less at 100 yards. I’ve had 2’s, 3’s and 4’s with all of them.
My powder of chose for the .2247L is Re-22. I have found that the 47L case is not finicky; I have had some success with H-4350, N160, Re-19 also N204.
, Try to keep your loads in the 270,000 rpm range and you will not blow-up bullets ) As an example the 6mm 105/107 VLD’s seem to shoot best at 2950 to3050 fps. That would be from 265,000 to 274,000 rpm in a 1 in 8 twist barrel. Every bullet weight has it’s own optimal rpm, the lighter the bullet the faster you can spin it.
I also would like to mention that I use moly on every bullet I shoot. I love the stuff!
Until next time, John
