Finding the right bullet

[tappedandtagged]

***See Post 18 for range testing of various factory loadings (with photos)***

I recently acquired a 14.5" SPR profile barrel from Ballistic Advantage and slapped her on my upper last weekend. The first few test rounds were a bit disappointing. For starters, my 55 grain Xtreme bullets FMJ hand loads were a 4" group at 100 yards. My 65 grain Sierra GK loads were about 2" at 100. Figuring these loads had been worked up for and optimized to my old barrel, I took the results with a grain of salt.

This past Monday I got to the range with a few factory Match loadings. The first I tried was Hornady Custom Match with their 75 grain BTHP. This resulted in a 3" group. I had another guy at the range try my rifle and he shot a 3-1/2" spread. He had been shooting sub 1/2 MOA with his 22-250 bolt gun before shooting mine, so I know it wasn't me. I tested this with my Specwar 556 on and off.

Right before I left, I shot 4 rounds of Federal GMM with the Sierra 69 grain MK. This shot right at 1.01" at 100 yards. I believe the 16 MPH gusts had a bit to do with this since the group was strung horizontally with only 1/4" vertical difference. Since I could only find one box of this ammo, I didn't reshoot without my suppressor. Also, I'm wanting to wait till the wind dies down.

Since those were the only 2 match offerings I could find locally, I went ahead and placed an online order with Midway. Next week I'll have the following to play with:

69 and 77 grain Federal Gold Medal Match (both Sierra bullets)
68 and 75 grain Hornady Custom Match
69 and 77 grain Nosler Match

Hopefully I'll be able to tell if my barrel likes the 68/69 grain pills or the 75/77 grain pills. Once I narrow that down, I'll probably buy a 100 round box of the bullet that seems the most consistently available and start load development.

Also, for those wanting specs on the rifle, they are as follows:
Windham Weaponry AR (the receiver and BCG anyway)
Vltor Emod stock
BCM Mod3 pistol grip
Geissele GS2 trigger
Geissele 13" MK 4 rail
SilencerCo Specwar 556
Burris 4-16X44 Signature Series scope
American Defense Recon-X mount
Samson Mfg BUIS
Ballistic Advantage 14.5" SPR barrel (from a contact overrun) with pinned ASR Trifecta mount
Edit to add per below question: 1/7 twist, 5.56 chamber, nitride finish

[Former11B]

What chamber and barrel twist rate? This makes a big difference on advice I can offer

What is your 55gr FMJ load, and same for the 65gr GKs?

[tappedandtagged]

The twist is 1:7, 5.56 chamber.

The 65 GK was 25.4 grains of H335 over a CCI 400 in a Remington case and shot just under 1 inch in my old 1:9 twist barrel. Velocity was 2675 in the old 16" barrel.

The 55 FMJ was 25 grains of H335 over a CCI 400 in mixed cases and shot around 2.5 MOA in my old barrel. I don't recall the velocity, but I believe it was in the high 2800's range, possibly low 2900's.

I know I'll be able to get the barrel to shoot (hopefully sub 1/2 MOA), but I am disappointed it didn't seem to like the 75 grain Hornady. As for the FMJ's, I actually only have a few hundred more of those, so I'll just shoot them through my work rifle and work up a new load with the new barrel later. The large groups with the 55 grainers really didn't bother me much at all.

Hopefully it'll like the 77 SMK or Nosler. I'm a fan of heavy for caliber bullets in general.

[alamo5000]

I have gone through the selection process a couple of times. My method was to basically try as many different types of ammo I could find. Mainly it was split up between grain weights. I found the best 55gr I could find, I found the best 62gr I could find, I found a box of 64gr, and 68gr, 69gr, and so on and so forth. I didn't need a lot of ammo. Just a box of 20 is fine.

Then I got out my led sled and chrono... I would do 3 round groups carefully picking my aim point. I actually used 1/2" neon stickers stuck on a foam insulation board as my target. Each group I would 'map'... which one was first, which one was second, third and so forth. By 10 shots you have a good idea. 10 is plenty. It's important to map em because it can indicate what is going on. If you see how the spread is and what pattern it creates you can see a lot. I can share more on this later, but suffice it to say that these 'shot maps' will help a lot. It doesn't have to be perfect. Just something scribbled on a note pad works with some basic measurements thrown in there. Shot 1 1/2" left... shot 2 1" high, etc etc.

Rinse and repeat for each grain weight. It takes a little while, but it should be meticulous but it's an investment in time that will ultimately pay off. Just be a bit scientific about it. If you have a chronograph it helps a lot. Just log it with each shot what the velocities are.

After you go through all those (use a fresh target for each type of ammo) you will see a lot of good information.

Don't worry about a specific zero, just use a specific aiming point and concern yourself with the impact points. In fact don't rezero or even concern yourself with that. Just aim for your 1/2" sticker and map your groups and their actual impact points. Think of one of Molon's posts when it comes to 'mapping'.

After you get the maps of your shots out you can see based on the patterns what is going on, but a lot of the variation in velocity round to round will be the culprit. This is where a chronograph helps weed out no deals. If you find out of your 10 shots 3 with similar velocities scattered all over the place then that is a bad sign. However if you find 4 shots with similar velocities and good impact points that's a clue to run with it.

Throughout this whole process take your time and you will find something interesting and make discoveries. It's not the most velocity you are after... it's the right velocity you are after. It does take some trial and error but for me I can do my approach and maybe test 3 or maybe more types of ammo like this in an hour. It's not like it's going to be a month of sundays. In 2 hours you can have in narrowed down quite a bit.

[alamo5000]

As far as load development goes once you find the grain weight that seems better than others then you can do development. The key is to have consistent velocity. Your brass will matter the most in this. After that you can work up with it. On one load I started with Varget and would just be careful and bump the charge .1gr on each ten rounds. Then I would re-test using the above mentioned set up. It works quite well since I can shoot in the back yard.

[tappedandtagged]

0.1 grains is a pretty small increment. I usually test with a larger increment looking for POI and velocity consistency between increments as well as group size. Once I identify my "windows" I retest with smaller increments within the window that gave me acceptable accuracy and velocity.

I'll start prepping/sorting brass tomorrow. I'll likely use Remington since that's who my PD is currently using for our .223 ammo (55 UMC ball for training, 62 grain Premier Match for duty).

If I don't get satisfactory results from my load development, I'll start over using different brass. I'm hesitant to even use Remington as I've always had worse results with Rem brass than Federal or Lake a City (love LC, just haven't been seeing any on the range).

I'm certain when it's all said and done, I'll be well under 1 MOA with the match bullets and under 2 MOA with the 55 grain plinkers. I've done it plenty of times before, even taking a $300 bolt .243 from a 2.5" rifle (with premium factory ammo) to consistent 0.8"-1" with my handloads.

[tappedandtagged]

On a side note, has anyone tried the Swift 75 grain bonded Sirocco 2's? Those look like they'd be a great pill for wild pigs, if I can find them in stock. Since they don't seem to be consistently in stock, I'll probably end up using the Barnes 62 grain TSX or TTSX.

[mustangfreek]

Maybe I missed it but what kind of round you looking to develop ,just a overall good shooting load or some heavy grain match type shooting Ammo ?. I'd start with the 55's, get a good/decent load worked up,I load extreme and Hornady 55's and with polished mil spec triggers any of my rifles will usually shoot 1-1.5 Moa if I do my part at a 100 yards. Also how does factory 55gr stuff shoot in it?

MY 55 gr plinking load for h335 is 24.9 grains at 2.20 , CCI 450, lc case
I get damn near same results with Hornady usually a hair better, but these are just my blister loads, same everything but with AA2230 gets me better results, but last 8lber just ran out and have not seen any for a long time

I also experimented with crimping and a light to medium crimp is where I settled as for accuracy and piece of mind, no crimps didn't shoot any better.

Heavy loads I have not played as much with have some 77's but yet to do anything, have a good 69gr smk load that shoots under a Moa when I last ran any, that was with varget though, tried some h335 but not as good 1.5-2 Moa

Also what powders do you have available to play with?

[Former11B]

Mustang brings up a good point, one I was going to touch on. For accuracy loads, you might consider another powder. Varget and Reloder 15 are pretty hard to beat; I currently shoot RE15 with 69s, 75s, and 77gr bullets. My 16" and 18" barrels require slightly different charges to maximize precision, so you just have to work towards them.

For 55gr FMJs, I use 27.0gr of CFE223 or 22.5gr of Reloder10x.

[tappedandtagged]

The only suitable powders I have on hand at the moment are H335 and W748.

As for what I'm trying to accomplish, not really sure. I'd like a really nice accurate load that I may or may not start playing with at longer ranges (350 yards is the longest I can shoot without cutting trees down or building a tower.

Once I figure out which factory load my AR favors, I'll try to duplicate the loading. Not really sure why I want to do this, I just have the itch to piddle and have some fun.

I'll pick up a few pounds of R15 next time I see some available. Anyone try BLC-2? It seems to be a popular choice for heavier bullets.

[Army203]

RAM-TAC is a good powder that I use for my 69 & 77gr SMK stuff.

[mustangfreek]

RAM-TAC is a good powder that I use for my 69 & 77gr SMK stuff.

Yep heard only good, and it favors the heavies from what I hear, have a few pounds to try out.

Tapped , you should be able to get some decent results from the h335, just not match quality Imo ,post up what you find out, also double check all the scope mount screws and what not. Also not needed but chrono info is always nice

[alamo5000]

Anyone try BLC-2? It seems to be a popular choice for heavier bullets.

I have an 8 pound jug of it. It works ok. I haven't tried to do a full on accuracy load with it but it seems alright.

0.1 grains is a pretty small increment. I usually test with a larger increment looking for POI and velocity consistency between increments as well as group size. Once I identify my "windows" I retest with smaller increments within the window that gave me acceptable accuracy and velocity.

Whatever increments you use is fine. Make a system that works for you... but using a sled and writing down the results during testing to me at least makes my test shots count and gives me valuable information with as little variance as possible. I try to remove as much of the 'me' screw up variables as possible.

[tappedandtagged]

Whatever increments you use is fine. Make a system that works for you... but using a sled and writing down the results during testing to me at least makes my test shots count and gives me valuable information with as little variance as possible. I try to remove as much of the 'me' screw up variables as possible.

Agreed on documentation and using a solid rest/sled. I have a binder of ammunition tests including weather, velocity for each charge weight, group size etc. also in the binder are the actual targets themselves with the same data written on them (although I only write the average velocity on the targets).

The binder is getting quite thick as I even keep results from guns I don't own anymore.

[alamo5000]

Agreed on documentation and using a solid rest/sled. I have a binder of ammunition tests including weather, velocity for each charge weight, group size etc. also in the binder are the actual targets themselves with the same data written on them (although I only write the average velocity on the targets).

The binder is getting quite thick as I even keep results from guns I don't own anymore.

You are in my opinion being very smart about it. I don't keep my data but I probably should. I keep it until I find what works and then go on about my business.

Weather though is a very good thing to note. Especially for people up north. Down here it matters but not as much mainly because it's 75 degrees in January sometimes. But if you shoot especially at long distances 80 degrees and 50 degrees can mean the difference between a hit and a miss.

For my AR an 80 degree dope with all the other stuff being exactly the same at an 800 yard target is 37.4 MOA based around an 800 yard target. A 50 degree dope changing nothing else is 39.8 MOA. Difference of 2.5 MOA hold over based solely around a 30 degree temperature variation. That is easily the difference between a hit and miss. Just the temp difference alone would put me 20+ inches off target at that range.

Load development at different temperatures though... I haven't really gotten into that so much. I am sure it can make a big difference.