Load developing my Accuracy International

[jphillips63]

Today I began working up some loads trying to duplicate the FGMM ammo this rifle likes so well. I shot all groups at 100 yards and off the bipod. I'm a benchrest shooter so getting use to using a bipod is a bit tricky on holding and keeping it from bouncing. Anyhow the loads and groups posted are from virgin lapua brass and using the sierra 175 MK



This next group and my final group of the morning is six shots I pulled my fifth shot to the left so I loaded up another rnd to verify it and put that sixth shot in the main group. Either way this rifle is a solid sub 1/2" shooter and I will now go back and fine tune my load for the fired brass.



Comments and input welcomed.

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[173rdABN]

What is your COAL? And OAL?

[jphillips63]

What is your COAL? And OAL?

I will check and report back, I know they are magazine length is about all I remember I set my sweater die to seat them same OAL as FGMM ammo, as I'm trying best to duplicate the load and accuracy since my rifle stacks them into one hole.

[LawEnforcementSalesTN]

Yessir!

 

My Covert loves the FGMMs as well - suppressed and non.  What's your powder and charge on these?.. sure be nice to duplicate the factory rounds and save a few pennies... getting pretty expensive to feed this thing and I just picked up 338 this week.... don't even want to start thinking about that one ;o)

 

I've been trying to develop a nice sub sonic recipe for my AI.  Had started with the 180 RNs but I think I'm going to step up to the 208 AMAX... heard they do well in the coverts.

 

Thanks for sharing.

[173rdABN]

Hey mike, I was about to ask that as well. Had to zoom in on the pictures to notice the info is there. He's using 4064 at 41.2-42.4 grains.

4064 is amazing powder. And that's why the mk316 mod 0 rounds went back to it. I've been working up a load in my MATEN with the exact same bullets and powder as well. But I'm limited to PMag length at 2.805 for reliable feeding. If I could seat further out than that I feel I'd be able to get better groups.

So far your groups look amazing for the first batch of test rounds.

If my mp5 ever sells I'll be joining you gentlemen in the AI club.

[LawEnforcementSalesTN]

Ha didn't see the forest for the trees :o) duh!

Thanks Kris. Picked up a sweet DTA last week. 338/308 deployment kit. USO scope. It's nice. Still liking the AI though. Got a Eberlestock GS2 and she folds up so nicely in the back of it. Even without the scabbard deployed.

Let me know when you guys are shooting again and I'll fill the truck up and come on down.

[jphillips63]

Yessir!
 
My Covert loves the FGMMs as well - suppressed and non.  What's your powder and charge on these?.. sure be nice to duplicate the factory rounds and save a few pennies... getting pretty expensive to feed this thing and I just picked up 338 this week.... don't even want to start thinking about that one ;o)
 
I've been trying to develop a nice sub sonic recipe for my AI.  Had started with the 180 RNs but I think I'm going to step up to the 208 AMAX... heard they do well in the coverts.
 
Thanks for sharing.

If you want to duplicate the FGMM ammo you will need to use 41.7 grns of IMR 4064 in the Federal cases and fed 210m primers and the Sierra 175 grn MK bullets. Seating OAL should also be same and same neck tension. I'm unsure how one would know how much tension they have but you'll need a good bushing neck die and various bushings to get there. The load given is exactly what Federal does use.

[jphillips63]

Got back out today testing fire formed cases and working with different neck bushings.
Below is a series using 3 different neck bushings with same charge of powder. The .334 bushing will be my choice the .333 showed too much horizontal stringing and there's no way to eliminate this and it really shows further out. The .334 has a nice triangular group and this is what you look for.
Below is the neck bushing tests today.



Here's my next group its five shots using the .334 bushing and 42.3 grns of IMR 4064 F210m primers and lapua case with the sierra 175 MK



I will do a bit more fine tuning with seating depth of the bullet now and I should be done with this rifle.
Thanks for viewing.

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