I really like 8208. I have had really outstanding results in my Bartlien Barrelled Tikka with it. Cleans up nicely too.
I have shot both Varget and RL15 through a different barrel but I've only shot RL15 in this gun once at a 600y any/any match, noticed with the increase in temp throughout the morning my shots climbed in elevation. Not a huge deal to compensate for if aware. I think its a good idea to try both of those again, I have both. Also want to try Tac, which shot worse that the groups I posted. When I tried it that was with Hornady 75gr bthps. I have Fed GMM AR primers, CCI 41s, 200s and some Rem 7 1/2. Only used the 41s so far.
No ball powder will rival the performance of a quality stick powder for heavy bullets in terms of accuracy and SD numbers. You can get some juiced velocity though.
I am pretty experienced shooting over a bipod, I am leaning more towards the rear bag being an issue. I was using a basic bag under the A2 stock. I have purchased a nice leather protektor rear bag that will hold the gun in a much more consistent manner. Some of my groups looking like they are split in two separate groups feels like a position shift to me.
Is your receiver face lapped/trued? Is your barrel bedded tight in the receiver? How much can the back your bolt carrier move in the upper when in battery? Any slop between upper and lower?
Does it split consistently? First few go in one area and the next set goes in the other? If that's the case its more likely bolt carrier tilt while in battery. An enhanced buffer tube with contact points forward into the upper and a couple of raised points on the end of the carrier can eliminate/limit tilt in battery without significant impact on reliability like a fatter carrier would. If its random in its split you may have some space in your barrel bedding or extension contact on the receiver face or gap in your upper/lower fit. Or its how you handle it. search for
Joe Carlos ar15 accurizing for some ideas.
You may just want to see if it shoots better with a different carrier/bolt combo if you have more than one.
Pretty firm grip on the gun, bipod loaded consistently, pulled in to the shoulder more than I do with the bolt gun. I did notice an improvement handling the gun in a more firm manner.
This can be rifle dependent. I would caution against trusting that unless you have a lot of data on both conditions. The more contact and force you put into a rifle the more you move it usually. More in more out. I would argue That minimal contact (only enough force through the bipod that the rifle doesn't jump off target when fired is better than significantly more than this level of force through the rifle. Rifle length gas is better than mid if thats what you have.
Bipod loading puts torque through the upper receiver which can change your poi based on the amount.
If you are concerned if you are the factor throw it in a lead sled and see if it acts differently.
Brass prep is nothing fancy, LC brass matching head stamp, FL sized in a Hornady custom die, shoulder bumped .003-.004",trimmed to 1.750". I have only recently started to anneal. champfer/deburr on RCBS case prep station. Bullets seated with Hornady custom die with micrometer insert.
Some things that can help here is to get a custom honed fl die to give you useful neck tension without expanders. I like .003 for auto loaders. That way you can get a good neck tension without without oversizing down then having the expander reset to a useful neck tension which can change the shoulder measurements or neck alignment. This will produce the most dimensionally consistent brass and concentric brass (externally).
I would suggest if you are loading for a single rifle and not sharing ammo between a few to keep a master piece of brass to match resized dimensions to so you are reproducing the same dimensions instead of bumping back from that particular firing's dimensions.
Get a chamber style seater that aligns on the now very concentric body not just loosely on the neck.
Individually seat every round to the same B2O length. Your B2O measurement is going to be more accurate than your seater due to seaters being usually higher up on the ogive.
Neck trimming is the next level which can help since you wont be into the lands and will therefore be resting on the neck in the chamber. But thats a good amount more work.
I am aiming to keep things simple and really am not a huge competitor. I have shot the local 600y any/any matches but that's it so far. I am liking the bolt gun for that. I am finding the Service Rifle world very intriguing lately. Most of my shooting is stationary from a bipod so the heavier 20" barrel makes more sense to me, don't mind the slight velocity bump and I think it looks better than the 18". For now I will keep working with the 18".
I just haven't had the time to really do the testing I want and side lined the gasser to focus on the bolt gun load developement. Hopefully in the next few months I find a go to load or two for the AR. I am really just a hobbyist that likes to tinker more than a serious competitor.
If it functions reliably an 18" rifle length of the same muzzle diameter or larger will likely outshoot a 20" from the same manufacturer.
