140's in short throat 260

[TDH]

I am having a M2008 action built into a 260. I am mag feeding from an AICS mag and was worried about having to try to jump the 140 VLD's so I decided to go with a .060 free bore reamer. This will obviously seat the bullet deeper in the case. This will obviously increase pressure so most of the load data posted for 260 doesn't help.

What would be a good starting point with H4350 for this rifle? Is anybody running a similar setup and if so what powder are you using with the 140 Amax and 140 VLD's.

 

[4Rail_Gunner]

Re: 140's in short throat 260

I'm not an expert on this, but can't you run a different mag on The Badger Action? Like the AW Mag?
I think this gives you more room in the mag.
Maybe someone can chime in that knows more.

I Shot 140 VLDS at 42.7gr H4350 loaded to mag length in my AICS Mag.

Another idea is to pop that front plate out of the AICS Mag and weld up the spot weld holes.
Will give you extra room and i dont think you will have to clearance the reciever feed ramp.

 

[427Cobra]

Re: 140's in short throat 260

My Smith asked me what bullets I planned on shooting, I told him 139 Scenars, he wrote 2.760 on the work order, he said I would have plenty of room to grow, 41 of H4350 lit by CCI primers should be a safe place to start IMHO.

 

[TDH]

Re: 140's in short throat 260

I'm going to play with the Berger 140 VLD's and Rob01 was kind enough to give me some 130 and 140 Amax. I have an inkling I will probably stick with the 140 VLD but if the Amax shoot as well as I think they will my pocket will probably choose them.

 

[ChadTRG42]

Re: 140's in short throat 260

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 427Cobra</div><div class="ubbcode-body">My Smith asked me what bullets I planned on shooting, I told him 139 Scenars, he wrote 2.760 on the work order, he said I would have plenty of room to grow, 41 of H4350 lit by CCI primers should be a safe place to start IMHO. </div></div>
Big +1. Your seating depth is fine for the chamber specified. You have good room to grow with the throat.

 

[4Rail_Gunner]

Re: 140's in short throat 260

Are you Running a AICS Stock or Badger Bottom Metal?

 

[TDH]

Re: 140's in short throat 260

I'm running an AICS system. I learned today that I could run the AW mags with the M2008 action. After that I might consider using a different reamer. I hadn't decided yet. My choices are a .060 or .100 reamer. I was worried about having to jump the bullets using an AICS mag and decided to go with short throat. The barrel hasn't been cut yet though.

 

[wnroscoe]

Re: 140's in short throat 260

With the .100" FB Reamer and 130 Bergers in the lands my COAL is 2.930"ish depending on the bullet tip length.

The loaded rounds I have now range from 2.928" to 2.935" This is due to the bullet nose lengths being slightly different from bullet to bullet.

I've never had much success jumping Secant (VLD) Ogive bullets. When trying to decide on a throat length bullet selection always dictates the choice, hence the dilemma. Tangent Ogive bullets will always tolerate a little jump and most shoot best between .005" and .020" from the lands.

I spoke with Terry Cross some time back about his .260 Reamer. With his touch point length I called and ordered my Reamers from PTG. Terry's FB worked out to .090" and most smiths were having their 260's ground at .100" FB.

After I built my 260 it wouldn’t shoot the 130's jumping so I modified an AI Magazine to support the longer COAL by removing the front plate and cutting a small .125" radius notch in the center of my feed rail. The 130's bug holed after that. For the 123/139/142 grain Tangent Ogive bullets a FB of .100" would work great with a non-modified magazine. For mag feeding VLD's from an AI magazine and not modifying said magazine, .060" FB would be a better choice.

I've built several .260's and all have been tack drivers. With the .100" FB Reamer and VLD bullets, you'll have to modify an AI magazine to reach the lands and mag feed. If you don’t want to modify an AI mag either run the AW mags or opt for the .060" FB Reamer.

If I had used the .060" FB Reamer for my rifle the 130 Berger COAL would be approx 2.870" with the base of the bearing surface approx .060" deeper in the case body. The 140's would be slightly deeper in the case. I'll continue to run the 130 VLD's in my 260's because they work great but, if I were to ever change, I'd run the 139 Scenars.


I'm the smith TDH has been referring to.