Anyone have a .277 bullet comparator AND the new 150 ablr?

[kraky]

I've got a number of comparators but not .277.

I was wondering how much rifling bearing area the new ablr has. Just trying to get a finger on how "sticky" this bullet might be.

Using some hillbilly measurements using two calipers I'm coming up with the actual caliber width of the shank being surprisingly short compared to how long the bullet is.
In other words subtracting the length of the boattail and the length of ogive to tip I'm actually coming up with the ablr being less shank than a 140 AccuBond.....and being real close to a conventional cup and core.

Can someone check this out via a. 277 comparator?

 

[rick smith]

Have the compar. but not the bullet. All compar. will have a small difference in diameter so the numbers generated might not match yours. I was wondering of what value the generated number would be.Rick.

 

[kraky]

Well, ever since the old days of the long regular Barnes x bullets I've been a little Leary of how a long shank going down a barrel increases pressure. Some will say comparing a mono to cup and core is not apples to apples....or that the pressure comes from the longer bullet eating up case/chamber space.
I've come to believe that how much shank is riding the barrel is a significant factor. If the shank of the AccuBond is reasonably short I don't think its gonna create much more pressure than other 150 bullets.
Ramshot just came out with a new on line manual that sort of proves my thinking. (At least to me).
Looking at hunter powder data it took 1.3 grains more powder for the super long ttsx 150 grainer to get Max pressure over the plain Jane hornady 150 spire point. All those grooves reduce the friction of what would be a very long shank of the Barnes bullet.

 

[Teknys]

I'm with you Kraky on this one. All other things being equal - longer shank = more friction. The bore surface quality i.e. tooling or fouling...etc would all come into play but if all is equal then I would agree longer shank more friction.

As far as pressure - there is a lot to consider.
Case fill%
Neck Tension
Distance to lands - running start?
shape of ogive - engaging lands
depth of grooves - again engagement
Shank length
dirty bore?
chamber dimension - waste energy expanding case in a large chamber compared to a tight chamber - bass type ... etc.
Primer choice...

That's what make reloading so challenging / fun. Infinite possibilities with in reason!

I have recently shot my 270WSM with 150gn BT and PT - same powder charge. I just loaded the ABLR and I will check next week end the Vel and accuracy.

 

[Silentstalker]

Please share your results! I am awaiting my own box of AccuBond LR. Cant wait to see everyone testing them!

 

[kraky]

Got some test rounds loaded. Because of magazine length can't get close to rifling in my marlin xl7.
But found I can hang em out to 3.400 oal and use the gun as a 2 shooter. One can go in the pipe and the 2nd case sits on top of the magazine w/the tip started up the ramp...seems to function fine this way