9x45 AR

[HMC710]

By Popular Demand...… drum roll..... The 9x45 AR

Since we have been doing the 357/358 ARMax, half of our inquires are about a "full length" maximum AR for deer hunting.

My answer is always the same....

#1. Find out if your state has a maximum case length. Some are 1.6"
#2. Find out if your state requires a real case headstamp. (that means no wildcats)


Can it be done? Sure




My first super heavy was a 9x23 loaded with 300gr hard cast subs. Wow, nice sledge hammer.

Running Quick Design on the 357 Maximum and stretching to 45mm allows a 2.25" OAL with a 225gr hard cast seated in the crimp groove. I suggest 9mm to put some body taper in the case. We are already blowing out the base of the .223 with the 357 ARMax's.

Quick Load says we can hit 2100 fps with a 180 gr Hornady SSP at 50,000 psi chamber pressure. Others on the web say the 357 Remington Maximum can outperform a 35 Remington, but I do not agree. Especially when you run our 35ARem! But, stretching out to 45mm.... Boy Howdy! as they say. Yes, you can truly have 35 Remington performance in the AR.

So the question are: (and this is where allyall need to jump in)

1. What caliber? 35 (358) with a solid supply of bullets, 357 just because, 9mm to gain some body taper to autoload the AR, or... something less than the .356?

2. We need a name: 9x45 was what I called the first one because I used 9mm dies to size my virgin Maximum brass as the 357 dies over did it.

3. Bullet weight? Light ripper or heavy hammer?

4. Barrel twist? 357's usually are 1:20 (see Mike Bellum's page on this data); 35 cal are 1:14; 9mm are 1:10. Stabilizing the bullet takes RPM. Slow & Fast, or Fast & Slow..... 450 Bushmaster is a prime example of Fast & Slow: Fast bullet, sloooow twist.... 1:20 or 1:24 I think. Pushing a 180 - 200 gr bullet at 2000 fps, makes it interesting.

5. Reamer design: Of course, based on the results of the above.

[paulsblackrifles]

Great!
I like a light weight bullet running fast. Not sure it is the best but it seems lighter recoil.
One thing bad about a fast light weight bullet is will a bullet hold together in a hunting situation?

Paul

[HMC710]

Different strokes as they say. The 450 Bushmaster is a prime (and probably only) example of a (relatively) light bullet and high velocity with a slow twist. They are popular here in MI, and I got one for my Dad. I would guess a 45acp bullet wouldn't be the best choice for a 2000 fps rifle on medium game.

[HMC710]

Cut a 9 x 45 barrel this weekend. Actually, not a 45 mm (1.77") but cut to Maximum chamber 1.600" which would equal 40.6mm, but that's a crappy name. We'll see how the 9mm Maximum will do first, then take a look at bumping it up.

[HMC710]

Loaded up some 300 gr cast boolits for the 9ARMax.



On the far right are two of the 300 gr Hunters Supply .359" hardcast 300 gr boolits. I loaded them up to a predicted 1100 fps and will try them in the 358 ARMax with 1:14 and the 9ARMax with 1:10 twist. I'll push them through my sizer if the 9mm doesn't like the dia.

I also loaded up some 9mm FMJ rounds to see how the 9AR feeds and functions compared to the 357 and 358s