28" Bartlein 7.5 HV 0.218 22BR

[padom]

Decided to take my most recent 22BR Bartlein out today. I did extensive testing with my Mullerworks 1-7 22BR that PVA chambered with their reamer which I believe is 0.104FB reamer... I had my own 22BR reamer made with 0.130fb a while back and got a Bartlein 1-7.5 HV blank that I had PVA chamber with my reamer last year. I never did load development on the new barrel.. Just loaded up known good loads from my MW 1-7 barrel and shot maybe 100rd through it. It was a tack driver with those loads.

I decided to do a mini OCW today with my favorite bullet, 90smk with IMR 4166. This powder performed great in my first barrel and I have a few 8lb jugs of it so why not.

POI was so consistent across all but the very last charge... Low node right at 28.7-29.0gr with stupid low ES/SD and excellent accuracy. Also a high node around 29.9 - 30.2gr, also with amazing accuracy and stupid low ES/SD. I didn't experience any heavy bolt lift or pressure signs until that very last charge of 30.5gr and it was a hot humid day out... Started to just get a little heavy bolt lift.

High node is too fast for my needs even though the group is in the 0.1's and SD 2.. Ill shoot the low node around 3000 with same SD 2 for barrel life. Will load up a seating depth test with 28.7gr and see if I can shrink that group any more...

Just going from 7 to 7.5 twist in 22BR has really made everything stupid consistent with the heavies. The 7 twist really hammered the 80smk and 80 VLD but I would get unexplained fliers, inconsistent accuracy. That all went away and shoots like any BR with 7.5 twist...

https://imgur.com/LuOyQrM

https://imgur.com/Q4oD1i2

 

[padom]

Went back to the shop and loaded up a seating depth test with the 28.7gr charge. We have a pretty nasty storm forecasted here in a few hours, possible tornado, hail and guaranteed high winds/heavy rain. Wind was starting to pick up from this morning's OCW test. Was gusting between 10-13 mph but it obviously didnt matter with these results!

Farthest I tested from the lands shot the tightest group at 0.112". But, every single seating depth shot in the 0.3's or better so this load is pretty darn solid if you ask me. I didn't chrono each seating depth test separately, but I did run the Labradar for all of the tests combined and it still shot 2980 SD 7. The rounds closer to the lands were registering roughly 10-12fps faster than the farther from the lands.

I don't chase velocity. Never have. Accuracy over velocity all day. My 220TB 90smk load I shot for years was 2983 SD 7 with 28.6gr Varget, so this is pretty dead on what I've always shot these 90smk's at.

Time to load up 100rd and get some groups tested from 300-700yd next.

https://imgur.com/MNGuMe4

 

[urbanrifleman]

Went back to the shop and loaded up a seating depth test with the 28.7gr charge. We have a pretty nasty storm forecasted here in a few hours, possible tornado, hail and guaranteed high winds/heavy rain. Wind was starting to pick up from this morning's OCW test. Was gusting between 10-13 mph but it obviously didnt matter with these results!

Farthest I tested from the lands shot the tightest group at 0.112". But, every single seating depth shot in the 0.3's or better so this load is pretty darn solid if you ask me. I didn't chrono each seating depth test separately, but I did run the Labradar for all of the tests combined and it still shot 2980 SD 7. The rounds closer to the lands were registering roughly 10-12fps faster than the farther from the lands.

I don't chase velocity. Never have. Accuracy over velocity all day. My 220TB 90smk load I shot for years was 2983 SD 7 with 28.6gr Varget, so this is pretty dead on what I've always shot these 90smk's at.

Time to load up 100rd and get some groups tested from 300-700yd next.

https://imgur.com/MNGuMe4

So, more jump was better then?

 

[padom]

So, more jump was better then?

Yep, went back out and did a seating test and about 0.02 shot the tightest.

 

[urbanrifleman]

Yep, went back out and did a seating test and about 0.02 shot the tightest.

I would have figured that the Sierra would probably be best at .015 to 0.020.

I need to test those next.

The 90 Sierra matchking with its incredibly high ballistic coefficient even higher than the ELDM 88, would be a great answer for a shorter free bore. And that one place sells them in bulk really cheap. I can't remember the name.

 

[padom]

I would have figured that the Sierra would probably be best at .015 to 0.020.

I need to test those next.

The 90 Sierra matchking with its incredibly high ballistic coefficient even higher than the ELDM 88, would be a great answer for a shorter free bore. And that one place sells them in bulk really cheap. I can't remember the name.

RMR Bullets is probably what you are referring too...


In all my previous barrels the 90smk shot best at 0.01 off.


90smk / 220TB

https://imgur.com/d7BVRr1

https://imgur.com/CPstTvv

https://imgur.com/TcU9zU3