short range accuracy technique?

[kenndapp]

the purpose of this range trip will be to determine what ammo is the most accurate in my rifle as well as determine which ammo has the most effective range ( expansion/fragmentation threshold).

before i dive in to what i am trying to accomplish here let me give you all the specs.

- bcm 14.5" mid-length cl 1/7
- 2 moa aimpoint comp ml3
- shooting from bench using rail mounted bipod ( due to range rules this is not really optional.... i would go prone if i could)
- 50 yards and 100 yards
-5.56 ammo to be tested- ssa-70gr tsx, ssa-64g ppt, swa-70gr tsx, federal ab49 mk318 sost.

now here is my problem. i want to test the accuracy of my ammo and my weapon as well as crono data, NOT my ability (which is moderately experienced and more than sufficient). what can i do to put as little influence on the weapons system as possible? all i want to walk away from the range with is crono data and accuracy data which pretty much means i have to be consistently perfect. so of course i know, a consistent cheek weld, constant and proper trigger control...ext, ext. but what advise do you have for me that might not be so obvious?
also what i really need help with is:

- how long should i wait between shots (allow barrel to cool) for accurate crono data and constant bullet performance?

- is there a "proper amount of weight" to put on the bipod? should i just let the rifle rest on the bipod and keep my self entirely on the rear end of the rifle? i have heard the term "loading the bipod" what does that mean?

-you can see the experiment. i just want accurate data from my weapon alone, so i can select the ammunition best for my riffle. how do i do this with out ending up collecting data from my skill instead of my equipment?

-help me out here guys. thanks

 

[adam1122]

Re: short range accuracy technique?

Well, Im not real sure how hot your barrel will get with those loads - i suspect they will all be different. To be consistent I would wait about 45-60 seconds between shots if you are short on time or if you have alot of time and are only going to take a few shots with each ammo let it rest until you wrap your hand around the barrel all the way without pain. You can try (for giggles) if you want to see how much your accuracy degrades with a smoking hot barrel by doing 3-4 full mag dumps and then shooting a single round for pure accuracy vs. the slow barrel cooling method.

Next, loading the bipod...this just means that you are using proper techniques...pulling the rifle into your shoulder, firm grip but not death grip, put your non trigger hand far forward on the barrel...not up on the magazine well or holding onto the mag or magwell. By using a push/pull technique you will put some downward force on the bi-pod which will add stability and lessen barrel flip after the shot...which will give you faster follow up shots and overall better accuracy shooting from the pod.

Let us us know what ammo works best for you and post some pics if you can. Take your time and have fun with it...sounds like a good time at the range.

 

[kenndapp]

Re: short range accuracy technique?

i will. thank you for the response. i am going to run 20 rounds of each different type of ammo at both 50 and then 100 yards. if you cant tell i am little stressed out over the whole experiment. i am trying to take myself out of the equation entirely so can collect true data.

 

[ace996]

Re: short range accuracy technique?

If you're so inclined, I've seen some cheap benchrests at the local shops that would help eliminate/lessen your influence on your shots. I've never used one, so can't comment on their value, but it should help. About $50 bucks, IIRC, and one of them you use weights (barbell plates).

Be good,
TomK

 

[kenndapp]

Re: short range accuracy technique?

i own a cheap matrix rest.....i think the bipod will do me better. maybe im not doing it right but the rests never really felt right to me. is there any thing i should pay attention to that i forgot to mention or look at?

 

[mjh30]

Re: short range accuracy technique?

Kenndapp, the Aimpoint isn't going to cut it for accuracy testing at 100 yards, even if you dim the reticle.
I would use a scope of some higher magnification and a quality rest (the Matrix would be better than nothing).
I would shoot 3 groups of 5 from each box of ammo and please note your flyers.
I would boresnake the barrel between each test and shoot a couple of foulers of that brand of ammo before the next test.
I would shoot at a reasonable pace, approx 1 minute between shots.
I would chronograph not only the average mean speed, but also the es and sd of each brand of ammunition used.
I would record the outside conditions.

 

[kenndapp]

Re: short range accuracy technique?

thank you for that. an aimpoint is all i have to use at the current moment. i would not of thought to boresnake in between different brands of ammo. thank you.

 

[adam1122]

Re: short range accuracy technique?

Oh, watch the weather channel and record ALL of the weather conditions down to the barometric pressure then just use the JBM ballistics calculator to give you some good measurements. With a chrono and a benchrest (if you can afford a led sled get one). Then you will have some serious testing abilities.

 

[kenndapp]

Re: short range accuracy technique?

Okay. So maybe I have the wrong tools for the job. But I still want good results with this set up as this is the setup I intend to use for any serious use, like hunting, shtf, hd ext ext....... so it makes sense to test the ammo in the configuration that I will acctually use.

 

[mjh30]

Re: short range accuracy technique?

Even though this is your intended setup, it will not give the proper results when its comes to your actual ammunitons potential accuracy. Yes, you can check velocity es & sd, but when it comes to the rifles accuracy potential your results will be wanting. I run a NF 2.5-10x24 on my AR, but when it came to load developement, I switched the scope out to a 16x, my eyes aint that good anymore, so every little thing helped when it came to shoting groups at 200 yards, I also used a rest, to take any human error out of the question, but even with the rest I still had to account for the mistakes that I made, (one of the reasons I like to shoot 10 shot groups when testing). Once I found my load, its back to the NF and shes good to go, I am still using the same load, no need to change it even if I change the optics.

 

[KevinB-KAC]

Re: short range accuracy technique?

Front and Rear Rest and a good scope - otherwise your wasting efforts.

A bipod in the prone is okay, but tend to bounce on the bench, as you cannot dig it in like you would on the ground.

10rd groups, if you dont have ammo/time/patience to do a 10rds group then do 5 at the min.

I hate BoreSnakes - and for the amount of ammo your firing, I don't see the need to clean between strings, but if you do I would use a Tipton Carbon fiber rod, a brush with carbon cutter and dry patch clean.