178 Amax and BTHP over 2000mr?? Won't shoot

[Dshooter]

Went out today to do more load development for this Krieger barreled .308. I was testing 2000mr with 185 jugs, 178 Amax, and 178 bthp. I found a halfway load for the 185 between 47.6-47.9. That was seating them .060 off. The Amaxes I had .020 off lands and with several different charge weights, I had single digit SD over 5 rounds...I'll be damned if they would group though. Same issue with the 178 bthp. Now the good group from the 185s had an SD of 13 and another group was 17. If neck tension was off, wouldn't the SD be higher on the 178? Not sure what's giving here. Only difference amongst all of these....the 185s brass was only neck sized and didn't even bump shoulders, both 178s I tested were in FL sized brass and had .0015 more neck tension. Any thoughts? All brass was winchester once fired in this gun. Barrel is 26 in with 12tw. Excellent velocity out of everything fired. All 2690 or better. Most all loads were 2710-2780

 

[jcampbellsmith]

I've no idea. Can I suggest you test one thing at a time? Your post describes you testing different bullets, powders and brass.

Regards

JCS

 

[XTR]

Went out today to do more load development for this Krieger barreled .308. I was testing 2000mr with 185 jugs, 178 Amax, and 178 bthp. I found a halfway load for the 185 between 47.6-47.9. That was seating them .060 off. The Amaxes I had .020 off lands and with several different charge weights, I had single digit SD over 5 rounds...I'll be damned if they would group though. Same issue with the 178 bthp. Now the good group from the 185s had an SD of 13 and another group was 17. If neck tension was off, wouldn't the SD be higher on the 178? Not sure what's giving here. Only difference amongst all of these....the 185s brass was only neck sized and didn't even bump shoulders, both 178s I tested were in FL sized brass and had .0015 more neck tension. Any thoughts? All brass was winchester once fired in this gun. Barrel is 26 in with 12tw. Excellent velocity out of everything fired. All 2690 or better. Most all loads were 2710-2780

One thing I can confirm, that node you found for the 185 has been identified by more than one person. You probably need to play with seating depth on the 185s. MV seems to be in the right place.

 

[TonyR]

You might try jamming the Jugs 0.010-0.015 inches. Not the conventional wisdom, but that's where I shoot them. There is a node just over 2600 fps with a 26 inch 1:12 twist barrel on my gun.

 

[Dshooter]

@j...I am only testing one powder with three different bullets. I am in advanced stage of testing with the 185s, that is the reasone for a different brass prep and seating depths. As far as the 178s I am in initial testing with those, only changing powder charges. I keep record of all so that is how I can perform different testing on a single trip to the range. Thanks for all the input so far and keep it coming. I am mainly playing with seating depths on the 185s. They are shooting great. My main concern is these darn 178 Amaxes....I figured they would shoot great. I don't want to change seating depth yet until I have found a charge weight. I just picked a depth off of majority of what all you guys are saying works best, somewhere close to lands(.020 or so). My fault for not clarifying better. The 178s are in FL sized brass, again starting from scratch on these, but neck tension is about a thou and a half more than what the 185 brass is running due to neck sizing only on 185. Yes my dies are a touch different. Neck sizer is stock and I polished the rod on my FL die...

 

[rminut]

I could not deduce what load you used with the Amax's but your load of 47.5gr for the 185 is what I used with 178 Amax's in a TRG22 and it shot very, very well. About 2700 fps over the chrony. If you're shooting much more than that behind the Amax you are probably pushing it too hard. Berger's seem to do fine pushed hard, not so much with Amax's. The seating depth didn't really change anything either, .020 off or mag length.
I suggest just finding a mild load and go learn it's wind characteristics instead of testing every little combo with an additional 75fps, it won't matter on the target enough to justify all the trial and error.

 

[Dshooter]

Rminut....I will slow them down some more then. I tried from 47.0 to 48.1 & I got nothing that worked out, when I say nothing I mean over 1 moa. I test at 200yds and everything 178 was a 2in group or worse. 47.6 gave me avg of 2749, maybe should drop into the 46 gr range. I would love to test wind characteristics but if the gun is having trouble with shooting a certain bullet, it's pointless to go further. I mainly test to find a load that works, then I play with wind and range. I'll load them slower and try that. Kind of my assumption; being pushed to hard. Just wondering if .004 neck tension would cause problems too? Had great SD numbers though??? Hhmmm

 

[rminut]

47-47.5 has worked for a lot of people but every rifle is definitely different. I used some in a AR service rifle and using regular dies I am sure the neck tension was .004 or more and it shot just fine. my guess is as long as the tension is consistent and you are not stripping copper from the jacket that higher neck tensions won't cause problems to a point. A good chamfer is needed with higher neck tension.