SA20 Accuracy

We shall see!

I am in my shop right now reloading the brass I fired today. Another 25rds at 24gr this time.

I like to have sighters/foulers/practice rounds as well as the test loads. The 23gr did Ok today. Seeing as that is minimum, and there were no signs of pressure I went to 24gr. If the 23.5 and 24gr test loads don't develop pressure signs during testing I have a few more to play around with.

Alec
 
I got 1.5 moa out of it magpodded at 100m with hornady 75 grain bthp 556. Factory ammo with a zeiss conquest. Can it do better? Probably.
 
Consider a very accurate scale... with the smaller case volume, charge weight adjustments as little as 0.1gr will have an affect on target. Work up in smaller increments.

BR shooters usually charge by volume. That will not work in the 223 and a semi especially if using an extruded powder.

Consider testing various primers especially in cooler weather.

If possible, adjust the cyclic force so that the BCG moves just enough to ensure 100% cycling but doesn't toss cases into the next time zone.

Good luck,

Jerry
 
Should I try the entire range in smaller increments? My plan was to find a charge or two that it showed preference toward. Say for example that 24gr and 25.5 showed promise. I would then load and test some at 23.8, 24.0, 24.2, 25.3, 25.5, and 25.7. Or should I start at 23gr and go to 27gr (or wherever my max may be) in 0.2gr increments?

I don have a click type powder measure; I charge by weight all the time. I trickle my charges on a balance beam scale for the test loads.

How do I adjust the cyclic rate of my SA20? It doesn't have an adjustable gas block. Should I try a heavier buffer?

My CQB loads were minimal charges of 4198 or 8208. With the slower burning BL-C(2) I noticed the significant increase in gas port pressure right away; even with the minimum charge.

I use TulAmmo Small rifle primers. The only reason I chose them was the 5000 I purchased for $130. Would you suggest I try a Magnum primer, or just another brand. For Large Rifle and Large pistol I use CCI.

Thanks,
Alec
 
Longshot338 said:
Should I try the entire range in smaller increments? My plan was to find a charge or two that it showed preference toward. Say for example that 24gr and 25.5 showed promise. I would then load and test some at 23.8, 24.0, 24.2, 25.3, 25.5, and 25.7. Or should I start at 23gr and go to 27gr (or wherever my max may be) in 0.2gr increments?

I don have a click type powder measure; I charge by weight all the time. I trickle my charges on a balance beam scale for the test loads. point 1

How do I adjust the cyclic rate of my SA20? It doesn't have an adjustable gas block. Should I try a heavier buffer? point 2

My CQB loads were minimal charges of 4198 or 8208. With the slower burning BL-C(2) I noticed the significant increase in gas port pressure right away; even with the minimum charge. point 3

I use TulAmmo Small rifle primers. The only reason I chose them was the 5000 I purchased for $130. Would you suggest I try a Magnum primer, or just another brand. For Large Rifle and Large pistol I use CCI.

Thanks,
Alec
Click to expand...

point 1, add 4 kernels of 8208 to the scale... does it register that amount (that is pretty much 0.1gr)... add 4 more and see if the change is consistent and linear. Most beam scales aren't that sensitive so the reading may not represent what is actually in the pan. +/- 0.2gr is pretty typical and that will pull you in and out of the desired node and drive you bonkers cause you will get "flyers".... which they aren't.

With a properly set up and accurate 223, I can see 0.1gr of powder weight change on target.

Point 2 - get an adjustable gas block and a heavier buffer and spring. Ideally, the BCG will not hit the back of the buffer tube before moving forward... yep, a bunch of swapping parts and testing but it is possible to get this way down vs factory which in many set ups is horrid.

Point 3 - get ready to test powders for the bullet weight you want to use. Again, it is balancing chamber pressure, port pressure, gas volume, accuracy, velocity and BCG cycling. Why so many just don't get it right or give up trying.... change A to get B but that affects C so you need to tweak D and hope that doesn't mess it all up again.

I first started by controlling the BCG to get it functioning reliably around the max pressures I wanted... then started tweaking the loads. Semis are the biggest PITA to tune.

As a final step when you have all the above sorted out, do test other primers. Maybe your rifle is sensitive to care... maybe it will not. Some SR primers aren't hot enough to ensure complete and consistent ignition with lower charges especially in the cold. The hottest ones will change your load weights enough you shouldn't just randomly swap in primers... always work up with change of ANY component.

To keep from going bonkers, I set up my barrel for a specific bullet weight range (Service rifle - so anything 70gr and heavier and still fit in the mag). That narrowed down the components that would work.

finally, you need to match the bullet to your chamber throat... that can be fun but again, with so many variations on the AR set up, you need to measure and know what you are up against. maybe this is the first place to start. Also, alot of AR barrels are made to pretty generous specs. Many just don't shoot.

Sounds impossible but it isn't... For me, I just speced what I wanted in a match barrel. Worked on the moving bits and then focused on load tuning.

But the results are certainly worth it...

Jerry
 
redryder said:
Please describe this "well looked after" Colt thing. What does it consist of??
Click to expand...
Most Colt rifles shooting IVI belong to the Queen. Those rifles tend to be cleaned to "military" standards, which means scrapers, stripped bluing and steel rods down the barrel. End result is a 2-3 MOA rifle. If you look after your stuff, protect the crown and de-copper your barrel from time to time you're golden with a Colt. Colt makes great stuff.

Anyone winning competitions with a C7 isn't using a rifle that's been randomly pulled off the rack.
 
cancer said:
Most Colt rifles shooting IVI belong to the Queen. Those rifles tend to be cleaned to "military" standards, which means scrapers, stripped bluing and steel rods down the barrel. End result is a 2-3 MOA rifle. If you look after your stuff, protect the crown and de-copper your barrel from time to time you're golden with a Colt. Colt makes great stuff.

Anyone winning competitions with a C7 isn't using a rifle that's been randomly pulled off the rack.
Click to expand...

Thanks for this cancer. What else are the winners doing to these rifles to enhance them? And finally what is a shooter in "Relish" as Bolivar puts it?
 
I believe what Bolivar is trying to say here is that if a CF member with issued equipment and a less than ideal optic can win most of the time, then chasing accuracy isn't as beneficial as working on you shooting skills.
 
Bolivar said:
Longshot - all the advice above is great.

Every ORA SR match for the last two years was one by a shooter in Relish, with a C7, Elcan and IVI.
Click to expand...

Gear will never trump SKILL ... and I bet those that are on the podium usually show up on the podium on a regular basis cause they are GOOD at the tasks presented in their competition.

But give them more accurate rig and see if their scores go up even more. Or maybe in SR, the scoring rings are big enough that improving mechanical accuracy has little bearing on the final result?

That would be an interesting test wouldn't it???

Jerry
 
Mystic Precision said:
point 1, add 4 kernels of 8208 to the scale... does it register that amount (that is pretty much 0.1gr)... add 4 more and see if the change is consistent and linear. Most beam scales aren't that sensitive so the reading may not represent what is actually in the pan. +/- 0.2gr is pretty typical and that will pull you in and out of the desired node and drive you bonkers cause you will get "flyers".... which they aren't.

With a properly set up and accurate 223, I can see 0.1gr of powder weight change on target.

Point 2 - get an adjustable gas block and a heavier buffer and spring. Ideally, the BCG will not hit the back of the buffer tube before moving forward... yep, a bunch of swapping parts and testing but it is possible to get this way down vs factory which in many set ups is horrid.

Point 3 - get ready to test powders for the bullet weight you want to use. Again, it is balancing chamber pressure, port pressure, gas volume, accuracy, velocity and BCG cycling. Why so many just don't get it right or give up trying.... change A to get B but that affects C so you need to tweak D and hope that doesn't mess it all up again.

I first started by controlling the BCG to get it functioning reliably around the max pressures I wanted... then started tweaking the loads. Semis are the biggest PITA to tune.

As a final step when you have all the above sorted out, do test other primers. Maybe your rifle is sensitive to care... maybe it will not. Some SR primers aren't hot enough to ensure complete and consistent ignition with lower charges especially in the cold. The hottest ones will change your load weights enough you shouldn't just randomly swap in primers... always work up with change of ANY component.

To keep from going bonkers, I set up my barrel for a specific bullet weight range (Service rifle - so anything 70gr and heavier and still fit in the mag). That narrowed down the components that would work.

finally, you need to match the bullet to your chamber throat... that can be fun but again, with so many variations on the AR set up, you need to measure and know what you are up against. maybe this is the first place to start. Also, alot of AR barrels are made to pretty generous specs. Many just don't shoot.

Sounds impossible but it isn't... For me, I just speced what I wanted in a match barrel. Worked on the moving bits and then focused on load tuning.

But the results are certainly worth it...

Jerry
Click to expand...

Jerry; I am interested in discussing this further. I will send you an email or PM later on.

Alec
 
I recommend a couple of things:

1) loading with a ball powder in an AR: you really need to run those loads over a chrony. The AR will not always give you 'signs of pressure' before it starts spitin' primers - which at that point you are well over pressure...

2) there is a whole bunch more, but I recommend you purchase, read, and then re-read a copy of "The Competitive AR15, the mouse that roared" by Glen Zediker.

The book contains a lot of information from various highly knowledgable sources, including the USAMU on everything for this rifle. It is susinct and easy to read. A fair bit of it is geared to the US high power shooter, but most of it is general info. It goes over the 'to dos', the 'nice to haves', and the myths as well.
 
Longshot338 said:
I believe what Bolivar is trying to say here is that if a CF member with issued equipment and a less than ideal optic can win most of the time, then chasing accuracy isn't as beneficial as working on you shooting skills.
Click to expand...

Yup, exactly. No reason to not chase accuracy in your ammo/rifle/optic...but don't sacrifice practice of shooting skills. Most of us don't have unlimited time and money to spend so you have to focus on what is going to get the most bang for your buck. Different shooters at different skill levels can get different returns on time invested at the reloading/testing/bench rest vs cardio, positional shooting, mental management.

Of course, once a person as a good load developed, they can stop chasing that particular aspect. Skill maintenance/development tends to be a continual thing. My advice is to not sacrifice the later for the former.
 
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