My new 22BR!

[Simpsonrl]

[QUOTE="Evan, post: 37831159, member: 1276427"

I don't really track TIR or anything like that. I don't think it really matters since your bullet to bore alignment is determined by the relationship to the shoulder, not the body of the case. Nearest I get to being concerned with runout is when I seat the bullet: I lower the ram and turn the round ~180, and then run it up again. Takes a second and can theoretically straighten out a wobble if there was one. I didn't notice any improvements on target when I started doing this either, but kept doing it anyway because my seating depths were measurably more consistent - pretty much dead on instead of the occasional +/-0.001.[/QUOTE]


So I have been thinking about this and can’t quite wrap my mind around it. I take it that you believe that the bullet to bore alignment is obtained from the tight fit of the bullet to cylindrical throat (ie at the 0.224” dimension) as one point and the shoulder angle of the cartridge and chamber as the other point? And therefore slop between the body of the case and the chamber near the case head causes no concern?

Can you elaborate on the key points for bullet to bore alignment? Thanks

 

[Evan]

[QUOTE="Evan, post: 37831159, member: 1276427"

I don't really track TIR or anything like that. I don't think it really matters since your bullet to bore alignment is determined by the relationship to the shoulder, not the body of the case. Nearest I get to being concerned with runout is when I seat the bullet: I lower the ram and turn the round ~180, and then run it up again. Takes a second and can theoretically straighten out a wobble if there was one. I didn't notice any improvements on target when I started doing this either, but kept doing it anyway because my seating depths were measurably more consistent - pretty much dead on instead of the occasional +/-0.001.

So I have been thinking about this and can’t quite wrap my mind around it. I take it that you believe that the bullet to bore alignment is obtained from the tight fit of the bullet to cylindrical throat (ie at the 0.224” dimension) as one point and the shoulder angle of the cartridge and chamber as the other point? And therefore slop between the body of the case and the chamber near the case head causes no concern?

Can you elaborate on the key points for bullet to bore alignment? Thanks[/QUOTE]

The cone that forms the shoulder of the case is the alignment feature that centers the case in the chamber. The firing pin strikes the primer, pushes the shoulder into against the chamber, and whatever alignment is created there is what you've got. The body of the case has clearance in the chamber and the neck has clearance. I don't typically hard jam bullets, so the bullet cannot align the case by the lands.

I uploaded some pictures a while back describing this here: http://forum.accurateshooter.com/threads/concentricity-question-help.3980767/page-2#post-37513960

 

[Simpsonrl]

Thanks Evan!

 

[Evan]

I tried IMR-4064 and IMR-4895 today behind 80 ELD, 88 ELD, and the 95 SMK. I didn't have my magneto speed to get velocity, but 4064 and 4895 gave great accuracy (0.75" to 1.25" at 300 yards) and were shooting with the expected come-up at that distance for a speed in the ballpark of 2950fps with the 95 SMK. That also lines up with them crossing my ShotMarker at 2540fps or so. I wouldn't hesitate to recommend either powder! I need to get back out and run up a ladder on each combo with the magnetospeed so that I can update my charts.

 

[Superjet]

Hi Evan,

What is the bore dia on this 22BR barrel of yours?

Thanks

 

[Evan]

Hi Evan,

What is the bore dia on this 22BR barrel of yours?

Thanks

I don't know this for sure, but I believe it to be the "standard" 0.218 and not the looser 0.219 that has become more common to specify to help avoid blow-ups. It is a 5R 7twist from Bartlein.

 

[bozo699]

Hi Evan,
I remember talking to you last year about this I was going to build one and never did yet, actually I have one but wanted one for the heavy bullets so did you end up with 4350 or 4895 as your powder of choice?
Wayne

 

[Evan]

Hi Evan,
I remember talking to you last year about this I was going to build one and never did yet, actually I have one but wanted one for the heavy bullets so did you end up with 4350 or 4895 as your powder of choice?
Wayne

Hi Wayne,

My barrel doesn't like 4895. 4064 is ok. Varget/4320 and 4350 are very good.

I've been playing with it for a while, and while I think it's best rounds are behind it at ~1500 down the tube, it's still shooting ok. The bottom target is at 600 yards. Top is 330yards. It was much windier out on the grasslands at 330 yards, which I think is why the groups are so big:

The 2.7xx numbers are seating depths with my unzeroed comparators (I use dial calipers, not digital) and the load is somewhat anemic but keeps the bullets in one piece to the target. The sticker is a 1" dot. The barrel seems untune-able now and doesn't really respond to my efforts like it used to. I'm going to pull it once components become more available and I identify the next chambering I want to try.

I like the 22BR a lot and have a new 7.7 twist Krieger all ready to thread onto my Borden BRL when the 6.5x47 barrel on it is done.

 

[dskogman]

I chambered one up for my PRS gun and love it. Shoots as well as a 6BR with less recoil. I shot it one relay at a 300yd F-Class match and it shot a 200-14x with 25¢ 88gn ELDMs. With a little tuning and better bullets it would be really tough.

 

[SBS]

Don't keep us in suspense -- What powder, primer and brass?

 

[dskogman]

Don't keep us in suspense -- What powder, primer and brass?

30gn of Varget in Lapua cases with Cci 450’s. 7 tw Bart.

 

[SBS]

30gn of Varget in Lapua cases with Cci 450’s. 7 tw Bart.

Thanks, looks like a great load.

 

[moorepower]

Is a 1-8 too slow to stabilize?

 

[Evan]

Is a 1-8 too slow to stabilize?

Not sure. An 8 twist might stabilize 90s where I live and shoot at 5000+ ft of elevation, but all the twist calculators suggested it was on the edge. I have some 95 SMK reserved to try in the new 7.7twist to see if it's stable. I'll report back when I get that barrel threaded on and try it.

 

[moorepower]

Not sure. An 8 twist might stabilize 90s where I live and shoot at 5000+ ft of elevation, but all the twist calculators suggested it was on the edge. I have some 95 SMK reserved to try in the new 7.7twist to see if it's stable. I'll report back when I get that barrel threaded on and try it.

Thanks! I was interested if it might help the 88's from blowing up. I think that they would pop Pdogs.

 

[Evan]

I haven't updated this in a while, but I recently got some new, pointed 90gn SMK and went out with some initial loads with IMR-4320 to check it out at 600 yards. You'll also see my 6.5x47 on these targets too which are noted with larger 37.8-38gn loads. For reference the small groups seen in these pictures measure around 1.75". Really not too bad! I didn't find my node with the small ladder that I loaded. This was the node for the 88ELD and the 90 VLD, but the 90 SMK seems to have different needs.

 

[Ramblerman]

I haven't updated this in a while, but I recently got some new, pointed 90gn SMK and went out with some initial loads with IMR-4320 to check it out at 600 yards. You'll also see my 6.5x47 on these targets too which are noted with larger 37.8-38gn loads. For reference the small groups seen in these pictures measure around 1.75". Really not too bad! I didn't find my node with the small ladder that I loaded. This was the node for the 88ELD and the 90 VLD, but the 90 SMK seems to have different needs.
View attachment 1344348
View attachment 1344349

Wow, looking good buddy! I need to set aside some time to get some load development done on mine...I'm just having too much fun elsewhere, apparently. Hahaha

 

[Evan]

New weekend and another play with the new bullets. Weather was pleasant at 70 degrees and sunny, but th wind was tricky. Light wind around 4mph peak, but it was gusting on and off and moving from 6 o'clock to 3 quickly.

I think 28.3 to 28.5 is a node, but it's a little inconclusive. Regardless, the 2.855 seating depth (un-zeroed dial calipers) seems to be a pretty good spot. Shot well last weekend and this weekend with another 1.75 inch group (purple).

 

[jlorenzo]

Do you run into a lot of people up there? I haven't been to Pawnee in a while, I avoid Bakers Draw (or any public range for the most part). I like to go shoot on weekdays so its not a huge deal. Just curious as I haven't been up that way in awhile.
Very cool rifle and great posts. Keep it up.

 

[Evan]

Do you run into a lot of people up there? I haven't been to Pawnee in a while, I avoid Bakers Draw (or any public range for the most part). I like to go shoot on weekdays so its not a huge deal. Just curious as I haven't been up that way in awhile.
Very cool rifle and great posts. Keep it up.

Weekends, starting at about 9am you start to see more and more people. Weekdays, in the morning, you'll have it pretty much to yourself. I drive pretty far in, but the place I go to is known as a good long range spot, so on the weekends I have to be up the earliest to beat the other guys to my favorite spot. Helps that the wind is usually the best right at sunrise too!