Can Someone Confirm or Correct My Reloading Process?

[ESBVader]

I am reloading .308 and getting some pretty wide ranging results in accuracy. My SD is around 5 across several strings so I think I have that dialed in possibly, however, I will get .3 inch groups and then with the same load, get a 2 1/2 inch group... I have a fully customized (by LRI) Remington 700 in an AICS AX chassis with a Minox ZP5 in a Spuhr mount. Shooting suppressed with a SilencerCo Omega. It's a Remage setup using a 26" Criterion barrel (Varmint Profile) with around 500 rounds through it. I've verified the torque several times on the action screws (53 in/lbs.) per AICS spec. Also verifed that the Sphur mount is tight and not loose on the rail.

It's making no sense so I thought I was ask here.

I am using Lapua Brass, Berger 175 OTM's, 4064 Powder and FGGM (210M) primers.

Process below:
1) De-prime brass with RCBS decapping die (not sizing) in a Dillon 650. (Do I need to use an Expander Mandrel or just stick with what I am doing in step 4? It didn't make sense to expand the neck just to size it in step 4 with a bushing)
2) Clean brass in Frankford Arsenal with Stainless Steel media using dish soap, hot water, and a tablesppon of Lemi-Fresh
3) Anneal Brass with an Annealeez setup
4) Spray the brass with Dillon case lube and Full length resize brass with a RCBS competition bushing die in a Dillon 650. I use a carbide .336 bushing. The shoulder is taken to a few thousandths below the headspace in the rifle (measured with a gauge and calipers). I also seat the primers in this step as well while they are in the 650. (Should I be cleaning the lube off the brass at any point? Does it make any difference in the load quality?)
5) Trim brass to 2.005" and use a little hand held RCBS deburr tool to chamfer the inside and outside of the brass mouth.
6) Hand dispense 42.8 grains of powder that is checked in a RCBS 10/10 beam scale.
7) Seat the bullet, using a Forster Co-Ax press and a Forster Co-Ax Competition Micrometer die to approximately 5 thousandths off the lands. I use a comparator with a pair of Mitutoyo calipers to verify length to OGive.

Just trying to eliminate the human error from the equation. Thanks in advance for any help or advice!

 

[BLDTYLRY]

You might want to have another shooter try shooting your rifle/load.

 

[ESBVader]

LoL, that might do it! However, I can keep .5 moa fairly easily on my Surgeon as well add my Vudoo at 100. Not saying it isn't me, but it doesn't feel as likely as load or gun related.

 

[Bradu]

Grab a box of fgmm and see what it does with factory ammo, that will let you know if it's the rifle or an issue with your reloads.

 

[remaction]

How did you proof the load? It almost sounds like you went for a small SD and expected it to shoot well because of the SD. From a good solid bench, has the load proven itself to be accurate?

 

[Sniper266]

.3 too 2.5 is a massive jump in group size. My best guess would be that you should invest in a digital scale to weigh your charges. I persally never liked beam scales.

Whats the range temperature variation from the .3 group to the 2.5?

Ive also learned the hardway that low SDs do not mean good groups.

 

[eklarsen]

Okay, yes you should remove the lube... I typically size then tumble, then prime before adding powder.
I don't see anything wrong with your process but have you verified your barrel is not touching on firing the round? It sounds like the barrel could be making contact or you are not in a good accuracy node, if you buy into that, which I certainly do.

Look up OBT "Optimal Barrel timing" and OCW "Optimal charge weight", it is slow and painful work but very worth it in the end.

P.S. You don't need to use the expander mandrel unless your case mouth is messed up, if you do you will just be working the brass more then needed. size it using your bushing so it gives you a couple thou of neck tension and call it good.

 

[ESBVader]

Thanks for all the replies!

@Bradu That's something I considered as well. Going to try and find some local tomorrow. Thanks!

@remaction Correct, I went for small SD first. I was going to tweak accuracy with seating depth. However, I really don't have a lot of room to play with that before I start to compress the load... Maybe .040? so I am kind of stuck with tweaking that aspect very much.

@eklarsen I am going to look at switching up the order of my operation so that I can get rid of the lube. What you suggested actually makes sense.

 

[remaction]

ESBVader: I believe that barrel has a 12 twist. What does Berger recommend for a twist rate on those 175's?
Working up a load, I look for group first, then SD. Some powders give me low SD's but don't group as well as those with larger SD's.
Some charges will group in relatively the same place across several tenths of charge difference. Google "OCW load development".
If your equipment and shooting form is good, then it sounds like you have a 2.5" load and will sometimes get .3" as those few shots find a similar place in what would be a larger group if you plunked some more shots into it.

 

[Precision Underground]

How many shots are in the groups?

 

[ESBVader]

@remaction It's a 1 in 10 twist match stainless barrel.

I've looked at OCW and Barrel Time development. I used this method: 6.5 Guys Load Development albeit with several more strings than they ran.

 

[ESBVader]

So I went and purchased 40 rounds of Federal 175 FGGM to test. I re torqued all the screws (Scope, base, action, etc.) Heck, I even switched scopes thinking there might be an issue with the Minox. The group sizes were the same (1-2") initially but started to shrink after 25 rounds. By time I got to the last 5 rounds my group size was just over .5" with the previous being about the same size. Consider me baffled.

I just got it back from LRI so I am wondering if there was a burr or something in the barrel or some other part that is slowly working itself out?

 

[eklarsen]

@remaction It's a 1 in 10 twist match stainless barrel.

I've looked at OCW and Barrel Time development. I used this method: 6.5 Guys Load Development albeit with several more strings than they ran.

Did you get flyers when doing the OCW and BT time tests?

 

[ESBVader]

Did you get flyers when doing the OCW and BT time tests?

Just to clarify, when I said I looked at them, I meant I just read over the process. I didn't try them.

 

[ESBVader]

Shot 6 groups today. The first was 1.5" or better. The second was about the same. The third was 1.106", the fourth was .685", the fifth was .572 and the last was .285...

I did lightly clean the barrel the other day with Hoppes 9. Just a nylon brush through it and then patches till it was clean. Could this be related to copper fouling? Seems excessive for something like that, but I am struggling to find an explanation.