Matching factory loads point of impact.

[Shadow9mm]

So im looking at switching bullets for my 223 defense rifle. I am wanting to have some factory ammo for the gun and hand loads to practice with. Was looking at imi razorcore 77g, which use the 77g smk. If i buy smk and load to a similar velocity and tune the loads, what are my odds of being able to get them to shoot the same poi? For reference i am running a 16in barrel with a 1-6 power optic shooting out to 500yds.

Is this worth trying to chase down or is it a total gamble trying to match poi?

 

[sako2]

If you get the velocities the same it should happen.

 

[Metal god]

If you get the velocities the same it should happen.

I don't believe that is true . Powders come in very different burn rates . This means you can get the same velocities with quite a bit different barrel times resulting in POI shifts . Its the very reason two different factory loads can have the same velocities with different POI .

As to the OP , what do you mean by defensive loads . Yes I understand the general point but specifics can help narrow down the answer . Meaning just about all defensive incidents happen well inside 200yds and likely inside 100yds so the question I have is . How big is your POI shift you are trying to reduce for lets say inside of 100yds ? Although I have had some big POI shifts from load to load . Those often are because the bullets are very different . When using the same bullets my POI shifts at 100yds tend to be at most 1" with the same premium bullets . That's plenty close enough in a real world someone shooting at me need to return fire as fast and accurately as I can situation . At the range shooting steel at 100yds , my sub moa loads just don't ever seem to shoot sub moa with rapid fire off hand , I'm lucky if I get 6moa

So what I would do is try to find the same bullet and powder the manufacture uses . Then do a load work up that has the closest POI . I'd say if you can find anything that both shoot inside the same 2" circle at 100yds regardless of where inside that circle , you are GTG in a real world situation .

 

[Unclenick]

You want velocity and barrel time to be the same. In general, the slower the powder, the longer the barrel time to get to a particular velocity, so you could shoot the IMI rounds to measure velocity and then work up loads with several powders with different burn rate positions on the charts to achieve that same velocity. If you are lucky, maybe they all will be close to the same POI, given that your 16" barrel is less prone to flexing than a longer one is.

 

[Shadow9mm]

I don't believe that is true . Powders come in very different burn rates . This means you can get the same velocities with quite a bit different barrel times resulting in POI shifts . Its the very reason two different factory loads can have the same velocities with different POI .

As to the OP , what do you mean by defensive loads . Yes I understand the general point but specifics can help narrow down the answer . Meaning just about all defensive incidents happen well inside 200yds and likely inside 100yds so the question I have is . How big is your POI shift you are trying to reduce for lets say inside of 100yds ? Although I have had some big POI shifts from load to load . Those often are because the bullets are very different . When using the same bullets my POI shifts at 100yds tend to be at most 1" with the same premium bullets . That's plenty close enough in a real world someone shooting at me need to return fire as fast and accurately as I can situation . At the range shooting steel at 100yds , my sub moa loads just don't ever seem to shoot sub moa with rapid fire off hand , I'm lucky if I get 6moa

So what I would do is try to find the same bullet and powder the manufacture uses . Then do a load work up that has the closest POI . I'd say if you can find anything that both shoot inside the same 2" circle at 100yds regardless of where inside that circle , you are GTG in a real world situation .

To clarify, id like to be capable out to 500yds. I understand this is well beyond what is typical, but i want to be capable as far as i can shoot. Seeing as the longest range i have access to for practice is 500yds thats my limit.

For purposes of effectiveness, say the goal is to hit a paper plate, say 10-12in or so in diameter. with both factory and hand loads at any distance out to 500yds

Ill have to do some digging into the powder used, bullet is the 77g smk so thats easy at least.

 

[44 AMP]

For purposes of effectiveness, say the goal is to hit a paper plate, say 10-12in or so in diameter. with both factory and hand loads at any distance out to 500yds

As a technical exercise, fine. 500yds is way past my personal ethical distance for shooting game animals, but not rodents. I cannot think of any situation outside of military combat where shooting people at that distance would be found justified self defense.

As a first step to getting your handloads to match the POI of your chosen factory loads, you have to shoot both at the same distances, and see just what kind of difference in POI you get.

Obviously, matching the factory bullet and velocity as much as possible will be the start point. After that, you need to see real world results from your gun, and with you shooting it.

 

[Metal god]

Thanks , I kinda thought you might be talking longer ranges then what might be typical . I wont get into the why's if's ands or buts . Me ..... I'd just hand load something that does what I want and use that . Ok one "why" would be manufactures change things all the time . Like Fed GMM no longer uses IMR 4064 and have went to AR-comp I believe . I have confirmed the powder is different in so much as the sticks are much shorter in length now . I had stocked up on Fed GMM and pulled some bullets from old and new batches . There was a couple year period I could not figure out why my rifle/s all of a sudden couldn't shoot Fed GMM worth a darn anymore . Now I know why , its not the same and not only did my POI shift my groups almost tripled in size .

Interesting thought now that I think about it is ... I do have a duplicate-ish GMM load that shoots really well . I don't remember if I shot it through a chronograph but it shoots almost as good as the old GMM , sub MOA "all day" The interesting part is I never actually shot my load and GMM side by side to check POI differences , I should do that haha .

FWIW the load is
308 Win
168gr smk
43gr IMR-4064
Fed GMM primers
LC-10 brass

 

[gwpercle]

You will not know what powder the manufacturer uses to load factory ammo ...
they don't use the cannister powders we reload with ... So , you might need to try a few different powders ... but your idea is doable .
Chrono the factory ammo out of your rifle ... Now match the velocity .
Similar profile bullet at same velocity and the burning rate of the powder will have to be tried/ tested ... no way to know ...find a powder with similar burn rate and Viola' (Wah-Lah) now you got the load by the tail on a down-hill drag . Your "practice" load may not be Exact POA-POI but a few adjustments will get you "Close Enough" practice load .
Find a similar bullet of matching weight & profile and match the velocity of the factory load . Note plated bullets are not as accurate as jacketed so do not expect best performance / accuracy with plated ... they are Cheaper !
Test them at range and see what shakes out . A slower or faster cannister powder may be required ...but noting that a little testing will not reveal on targets .

 

[44 AMP]

Another way to do it, is simply not try to get an exact POI match with the factory stuff. If your "practice" ammo is consistent, always off an inch or three in the same direction, simply adjust your sights to be "on" with the practice ammo, keeping track of how many clicks in what direction is needed to do that. Write it down. THEN memorize it.

Then shoot (trust, but verify) changing the sight setting back and forth to be right on with each different load.

set for the factory stuff, click, click, click you set for your practice stuff, and when done, click back to the right setting for the factory stuff you're going to use for defense. You might go so far as to make witness marks on your sights so you can see at a glance which setting you are on.

Good sights are essentially infinitely repeatable, unless you break them. Cheap stuff, on the other hand, is a dice roll.

 

[Metal god]

Yep 44 has it , and I know the OP knows what it means to DOPE your load . I have several loads I need to adjust my clicks for . The only thing I’d do differently then 44 is have the sights zeroed to the factory load and adjust to all others. That way when it matters you just go back to zero/zero and you’re gtg .

 

[sako2]

Metalgod op said he wants to use the 77gn smg in factory ammo and reloads. I said if he got the velocities the same he should be good. You said it's not true. Then you say when you use the same bullet your poi is usually less than a inch. Which is it.

 

[Metal god]

Correct , when using premium bullets my poi shifts are not that big at 100yds and was my point . When shooting sub moa which I’m guessing the op is talking about based on many other posts over the years by the OP . A 1” poi shift would be huge .

As to what you said as being wrong , not true or inaccurate. I believe I got that right as it pertains to only using velocity. Your first post was one sentence and I read it as a blanket statement. Maybe since the OP already said he was using the same bullet you felt it was not needed to be included in your first post ? Fair enough sorry for the confusion.

MG

 

[Mike / Tx]

Going on my own experience with doing what your looking into, you can get real close but probably not exact.

That said choose your powder wisely and go with one that is very temp stable. That will be your biggest nemesis. Have a real close load at 65° that sprawls at 85°does ya no good.

I used H4895 to make up some loads for both my little Ruger Compact in .308 as well as 30-06. Both rivaled the factory Remington 150 and 165gr ammo. The best part is I actually got a smidge better groups, probably from adjusting the seating depth more than anything. That said, I used Remington CL'S in both weights, and worked up to the factory velocities. The loads run within about an inch overall of the factory loads out to 300yds. All will group right together however which was what I wanted. Just something that I could switch to in a pinch. At the time we were doing pig patrol on a friend's property and having the option of running to the closet wallyworld for extra ammo was nice.

For 5.56 there are a ton of powders that work well and some that are excellent. The latter however may or may not be equivalent across a broad range of temps. This is where the Extreme type powders shine. Even if they are off by 20-40fps they will still be better than popping primers with a rise in temps. I personally went with the Shooters World Precision Rifle to do my bulk loads and the RMR bullets. So far the 69gr have done absolutely great. I haven't moved to the 75gr yet but plan to soon.

I really have no basis for factory loads since I have only one box of Winchester 64gr that I purchased just to pop a pig with. More so to simply sight the rifle in with since the pigs we HAVE gotten were with 64gr Sierra TGK's. I load to just under mag length and they shoot great. The following are from 100 and 200yds. The first is actually the 200 and the second the 100, they uploaded backwards.

 

[ocharry]

what 44 AMP said is exactly what i did with my 223....i have 4 loads(different bullets for different things) worked up that shoot really well...they are in the same weight class...so i picked one(64gr sierra game changer) as the base line and made that load 0-el and 0-wind....funny that there wasnt a lot of difference...a couple the shift was maybe 2 clicks L or R and no elevation change or maybe a click or two up or down and no windage change

then i put each load on a target and shot a group from 0-0......brought each group to center and recorded the shift...so..on a tape sticker i wrote it down and it went on the ammo box lid... inside

i did the same thing for my Grendel...i have 3 different bullets and loads worked up for it that it really likes.....i will use the 105 sierra blitzking for the base...0-0 and make NOTED changes for the other two(120gr sierra pro hunter and 129gr hornady interlock) and put them in the ammo box with the loads....havent got that far yet as i just finished with the 129 hornady interlock load last week and deer season is fast approaching and i still have to go trick or treating with the boys...lol

but that worked really well for me...open the box make the change....go shoot...and back to 0-0 for the base line...i did verify the changes a couple times....just to be sure...so far works every time

my .02...YMMV

ocharry

 

[MarkCO]

To clarify, id like to be capable out to 500yds. I understand this is well beyond what is typical, but i want to be capable as far as i can shoot. Seeing as the longest range i have access to for practice is 500yds thats my limit.

For purposes of effectiveness, say the goal is to hit a paper plate, say 10-12in or so in diameter. with both factory and hand loads at any distance out to 500yds

Ill have to do some digging into the powder used, bullet is the 77g smk so thats easy at least.

I shoot primarily 69TMKs. Coyotes, Team Matches, 3Gun, out to about 900 yards. I got a few boxes of Nosler 69grain OTM, and they were hitting about 2 inches lower at 600 yards than my load. The Hornady TAP 77s hit about 6 inches low at 100. I just went through all my loads on my app (Shooter) and the Elevation at 600 yards goes from 4.1 to 5.2 mils. That includes 50 to 77 grain in mid-level .223 to just below the top of the 5.56 loads. That, at 600 yards is a difference of about 20 inches. Match the velocity and you will be within an inch at 600 yards.

FWIW, if anyone is interested, I shot my 69TMKs with a slightly slower MV to match the MV of the 77MKs and the 69TMKs did, in fact retain more velocity at 583 yards than the 77MKs. I was hitting the truing bar (3" tall) with the 77s, dialed for that distance and the 69s were hitting just above the truing bar.

 

[Shadow9mm]

Got notifications selected on several sights for the 69g tmk on several sites, no luck yet. Only thing im finding readily available is the 77g smk. Plus they are easy to find in loaded ammo.

Will be buying some imi 77g razorcore, and some 77g smk next payday to get this ball rolling.

 

[FrankenMauser]

I don't see the big worry about barrel time.
In my experience, matching velocity is generally better than standard dispersion - and I mean that in the sense of "random" group size.

If they're close in velocity, they'll be close in POI, with some vertical separation.

Obviously, some barrels could be problematic. But you'll know that very quickly, if it happens.

 

[Unclenick]

Usually, barrel time comes in if the load seems in any way "tuned" to your gun. It is not particularly unusual to match several powders to a given velocity but have one that shoots tighter groups than the others because of this. It's one reason some manuals have "best accuracy" loads listed among their others. Barrel time difference seems to be responsible for most of that, though ignition speed and consistency, and loading density can affect it, too. In any case, if you don't see that happening with your gun, then no worries; you now have a wide range of powder choices.

 

[MarkCO]

I don't see the big worry about barrel time.
In my experience, matching velocity is generally better than standard dispersion - and I mean that in the sense of "random" group size.

If they're close in velocity, they'll be close in POI, with some vertical separation.

Generally concur.

I am less and less inclined to believe much of the "voodoo" that folks followed in almost cult like lockstep in the 1900s. I have found that if a load shoots well in one rifle, it will in the other...if the chambers are really close. But I do believe that nodes are a thing, and if matched properly, again, much of the "voodoo" can be ignored because you have a wider window in which minor inconsistencies become irrelevant.

 

[jetinteriorguy]

Given all the little details involved in making my own loads shoot consistently I’d think the difficulty in duplicating a factory round not knowing all of these little details would be quite tricky. Good luck, you’ve taken on quite a challenge.