Stag 10 accuracy issues and thanks for the add to the forum

[Michael Smith]

Anyone else have accuracy issues with the Stag 10 including ejector swipes. Have loaded several different combos in 6.5 Creedmoor for it. Known accurate loads in my Compass that group well under 1 MOA haven't worked. Rifle has been sent back to Stag but still won't come around. I have the rifle now (it is my son's). I have loaded 143 ELDX,123ElDM,130 Gamechanger all around 2-3 MOA. I have loaded now Horn. 140 BTHP with 4350,CCIBR2 with Starline brass I will try out Monday..

Any input welcome

 

[cohunt]

accuracy issues and ejector swipes-- sounds like its over gassed and need a good adjustable gas block--almost every "factory built" AR is going to have a slightly over sized gas port so that ALL factory ammo will operate the system "reliably". An adjustable gas block can be used to tune the timing, and reduce the gas volume to the BCG--I have multiple gas block settings based on what bullet weight, powder, velocity, suppressed or un-suppressed so that it operates with the proper pressures and extraction.

a band-aid fix can be to use a heavier buffer, but then it may not cycle correctly with some low powered loads

you'll never be able to get the same speeds from your AR as a bolt gun as the AR vents some gas and pressure off while cycling --may times "known" bolt gun loads don't work well in AR semi auto rifles, gotta try to build a load just for that rifle

I don't have a 6.5cm AR, but my 308 always shows best accuracy with varget powder with every bullet I have tried-- its a good burn rate for an AR also

here is the one I recommend: https://slrrifleworks.com/index.php?route=product/product&path=104&product_id=124

also, AR's take a different style of shooting to shoot them accurately, though your rifle does appear to be pretty heavy so that shot help

if you are reloading, make sure you have enough neck tension, the recoil and feed ramp can drive bullets into the case causing inconsistencies with handloads

where are you empty brass casings ejecting to? straight out to the right, back behind you, or in front of you?

 

[Michael Smith]

Cohunt
He sent it back to Stag and they put and AGB on it. I will look for the indicators you mentioned. Haven't tried Varget I have loaded RL16 and RL17 also neither made a difference. I will check the neck tension the earlier loads were with Hornady dies. I have since gotten a Forster sizing die and Forster Micrometer seater die. I have a mandrel die I run the creedmoor brass through for the bolt guns. Gives a neck tension of .002. That may not be enough the Forster sizing die runs about .004 neck tension. I have two ar15 platform rifles and there is a learning curve to shoot accurately with them. I will check the ejection pattern but as far as the ejector swipes I was thinking more of a chamber/headspace issue. I will have some data Monday after I run these loads through it. Thanks for your input.

 

[cohunt]

have you tuned the GB for the loads you are shooting?
what are the loads you are shooting?
how long are you loading them?
have you checked the JTL measurements for the bullets you are loading?
If you are concerned with headspace you can buy or rent a no-go and field gauge or take it to a local smith to have it checked
what weight buffer? what buffer spring? according to their web site gas length is rifle length, right?
have you tried building a load from the ground up? or have you just used loads that worked in your compass?

just trying to get more info to see if I can help

 

[Michael Smith]

The loads I sent to him were all ladder tests in .3 gr. increments up to book max 5 rounds each at each increment. I have the rifle here now. I am going to test depth to lands with the bullets I have on hand. Problem is with the Magpul mags depth adjustment is very limited max appears to be 2.836 we will play with that a bit. Depending on what happens Monday I will probably rent those gauges. None of the LGS's around here have them.

 

[cohunt]

Get asc mags, they allow loading longer.

Have to checked the barrel for copper fouling?

 

[Michael Smith]

Get asc mags, they allow loading longer.

Have to checked the barrel for copper fouling?

Very interesting observation yesterday on depth to the lands. Hornady ELDx 143gr 2.901, Hornady 140 HTHP Match 2.829 this could get interesting.

 

[Michael Smith]

Got some work to do sorry about the messy target. Got some very slight ejector swipes on the upper end. I am going to back off another .010 and reduce the charge with another ladder. Mainly a just get to know each other session.
Stag10 22" barrel
Larue MBT trigger
H4350
Starline brass
CCI BR2
Oal 2.807

 

[Kansaswoodguy]

Pick up a lee crimp die and give it a try mine just seems to prefer a crimp don't know why don't care just works for my 6.5 AR

 

[Michael Smith]

Pick up a lee crimp die and give it a try mine just seems to prefer a crimp don't know why don't care just works for my 6.5 AR

I have heard that before, the only cartridge I have ever crimped is .30-30 I will order one.

 

[cohunt]

did you tune the gas block to your loads yet?--are you under gassed, "sweet spot" or over gassed--it is hard to tun a gas block while you are doing load work up so I usually use factory ammo to do the initial gas block tune, then go for a powder ladder test-- once I find an accuracy node, then I re-tune the gas block to that load and then do a seating depth adjustment if needed

here is how to tun a gas block if you are unfamiliar:

 

[Michael Smith]

Gas block was tuned by Stag they installed and tuned it.

 

[cohunt]

you have to tune an adjustable gas block for your load-- thats why they are adjustable, so they ca be adjusted-- its not just set it and forget it--you can do it that way, but most of the time it could be over gassed which hurts accuracy

problem with being over gassed: the bCG will start moving while the bullet is still in the barrel, when the bolt moves, the case starts to turn/spin and extract from the chamber before the bullet has left the barrel-- this causes 2 issues, 1st is the movement of the heavy BCG can cause the gun or shooter to move, 2nd is you will never have low sd or es as the brass breaks the chamber seal and gas pressure will vent off and cause inconsistencies in velocity.

cartridges like the 223 or 300bo can get away with using 1 gas block setting as the recoil is low and so is the powder charge-- but in a 308 sized case like the 6.5cm, you can have anywhere from 1 to 4 clicks different on your gas block settings between my different supersonic loads, not even getting into subsonic loads.

check your ejection patter with each "ladder test" to see if you are correctly gassed :

 

[Michael Smith]

Thanks for the info I will check that I used that chart on a Grendel build to get it right thanks again for the heads up. I was unaware of that issue.