270 Ackley vs. 270 Sherman...?

[wilkup]

I'm trying to decide which of these two rounds to chamber my new "do-it-all" rifle in. I've got a #4 contour, 24'' barrel blank coming in. I'm be getting a Vias micro-brake installed on this barrel.
I'm trying to decide on a bullet to settle on and the jury's still out on whether I like the 140gr Cutting Edge Bullet or the 165gr Matrix VLD more as my perfect choice.
I plan to use this rifle to hunt all the big game I'd encounter/draw tags for in Washington state - cougar, bear, deer, elk, and possibly sheep or moose if I get lucky. Right now I can shoot out to 800yd with a slightly self-customized Savage chambered in 308 Winchester. I've run the ballistics and either of these bullets will hit that distance with enough energy at the elevation I hunt.
So, what are the advantages and disadvantages when considering each of these two rounds?
Here's my list so far:

Sherman/ Ackley
More powder/ Easy/ier? to fireform brass using 270 Win
Faster bullet/ Cheaper because of less powder needed

The Sherman sounds like it may be a bit tougher to get set up for reloading, but I may be completely wrong...
Hoping to be educated by some guys on here that have experience with both.
I'm not interested in getting talked out of either of these two rounds and have the barrel and action for this size cartridge already.

 

[FEENIX]

I have a .270 AI in Savage 110 LA with 30" Lilja 1:8, 3-gr #6 (.750") and am very pleased with it. Currently pushing the Matrix 175 VLD at 2993 FPS (accuracy load at this time) with 58 H4831SC, BR2, Win brass, .040" off the lands.

I've developed a pre-fireformed load of 2919 FPS (.010" off the lands) with the 175 to save time and barrel life. lightbulbgun)

You can always go from AI the Sherman later for an extra gain of ~100 FPS (IIRC) with the right load combination.

Good luck!

Ed

 

[wilkup]

Feenix, thanks for the info. I've read everything you've posted on your 270 Ackley build. Do you think it's realistic to expect ~3000fps from the 165gr with my barrel length?

 

[bigngreen]

Well IMO if your going to go through the extra effort of improving a chambering take it to it's best which I would say is to punch it with a Sherman reamer.

Your really not needing the extra umph for the 165 Matrix but the 140 CEB you'll want to run them as fast as possible, I've taken a lot of game with the 165 Matrix @ 3060 fps out in the 800 to 1000 yard range and last season I shot a bunch of animals with the 6.5 140 CEB @ 3180 fps with several being in the 800+ yard range. I like both bullets but at 800 yards your pushing the CEB so you really need to give it every advantage you can with velocity.

 

[wilkup]

Well IMO if your going to go through the extra effort of improving a chambering take it to it's best which I would say is to punch it with a Sherman reamer.

Your really not needing the extra umph for the 165 Matrix but the 140 CEB you'll want to run them as fast as possible, I've taken a lot of game with the 165 Matrix @ 3060 fps out in the 800 to 1000 yard range and last season I shot a bunch of animals with the 6.5 140 CEB @ 3180 fps with several being in the 800+ yard range. I like both bullets but at 800 yards your pushing the CEB so you really need to give it every advantage you can with velocity.

Could you provide details on which chambering and barrel length you're using to get these numbers with the 165gr Matrix?
If you are using the Sherman, bow difficult is it forming brass versus AI?

 

[bigngreen]

I shoot a 270 WSM with a 27 in barrel with the 165 Matrix, the 270 Sherman runs real close to the WSM from what CogburnR gets with his 270 Sherman.

The CEB 140 6.5 bullet I shoot from the 6.5 Sherman Short, the 270 cal 140 should run a touch faster but it will need it to with less BC.

We run a couple 6.5 Shermans as well and the 6.5 SS, if I did a 270 Sherman I'd just fire form with a bullet in a 270 Norma case jambed into the lands. You could size it up a cal then back down to 270 leaving a false shoulder and use the cream of wheat method.

The 270 case has so much neck that you can really get something out of it while still keeping a decent neck when improving it, the AI give you the shoulder but there is performance just waiting to be tapped!!!

 

[FEENIX]

Feenix, thanks for the info. I've read everything you've posted on your 270 Ackley build. Do you think it's realistic to expect ~3000fps from the 165gr with my barrel length?

I think it's possible ...

#12

09-16-2013, 09:28 PM
cowboyarcher

Silver Member
Join Date: Dec 2008
Location: Laramie, WY
Posts: 469


Re: 270 Win and 165/175 Matrix Range Report
3 shots over a loaner chrono tonight averaged 2840 FPS. That's the 175 over 58 gr H1000 in a 24" McGowen tube.
__________________

Good luck!

 

[wilkup]

Where would I get my hands on a Sherman reamer and what sort of cost should I expect to pay for this? The Ackley won't cost me anymore than a traditional chambering.
If I could do the Sherman for the same or close to the Ackley rechamber cost, I'd be all in =)

 

[bigngreen]

PM elkaholic, he's Rich Sherman and he can get you everything you need and talk it over with you and your smith. The good thing about the Sherman case design is you can comfortably run where the straight AI will need pushed so you do less fire forming new brass because of primer pockets loosening trying to make it happen. Rich has the dies figured out with Whidden so you get a great set of dies reasonably also.

 

[FEENIX]

Where would I get my hands on a Sherman reamer and what sort of cost should I expect to pay for this? The Ackley won't cost me anymore than a traditional chambering.
If I could do the Sherman for the same or close to the Ackley rechamber cost, I'd be all in =)

Forming is pretty much the same as an A.I. except that you leave a "false shoulder" on the neck by not sizing it clear back. You can use .280 or 280 A.I. brass and just size it back to 270 far enough to obtain stiff bolt closer or you can size 270 up to 280 and partial size it back. The other method is to simply load a moderate load and seat the bullet so it jams into the lands. This is important for proper head spacing. The cases come out looking just like an A.I. would but the body has less taper and the shoulder is moved forward.........Rich

Quote:

Originally Posted by FEENIX
I agree, those numbers are similar to that off my .270 AI! I've exceeded 3100 FPS with 175 Matrix but with too much pressure and accuracy started to open up; I've settled for 2993 FPS with 175 Matrix as my accuracy load at least for now.

This is some good info for you Trever. The Sherman should add 50' to an A.I. everything else equal. Bottom line, 3100' with a 165 might be a moderate load.......Rich

As previously noted, I have pre-fireformed brass accuracy load (the capability to use factory loaded ammo is an extra benefit) and fireformed brass accuracy loads to save time and barrel life.

If you need that extra few FPS with just a few more extra step and cost (???), the Sherman is the way to go. As BNG said, Rich will gladly help you if you go that route.

Not sure when I get to do a build but I really like his 6.5 Sherman ... of hell, all of his wildcats. lightbulbgun)

The bottom-line, you cannot go wrong with either one and I have not met anyone that were disappointed with their decisions.

Good luck!

 

[wilkup]

Decided against this caliber and today settled on the 6.5 Sherman. Started a build thread to keep people updated as things progress...

 

[FEENIX]

Decided against this caliber and today settled on the 6.5 Sherman. Started a build thread to keep people updated as things progress...

Good luck and enjoy it!

 

[wilkup]

Thanks. I'm really looking forward to the finished product next month!

 

[Big Jake Duke]

Good luck and enjoy it!

Feenix- I think that leaves you, me and budlight as the 270AI believers!

Pretty good company from where Im sitting!

Have you tried any of the Nosler LRAB in 150 yet?

With RL 19 I hit 3200 fps and great accuracy. Primer pocket life is a little short, but I didn't make this rifle to shoot at 308 velocities!