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Discussion Starter · #1 · (Edited)
RE: 223 Rem 69 SMKs

I'm seeing some variation in the length of the bullets (69 SMK). This varies by as much as +/- 0.001. The bullet weights are consistaint though.

I would likely have to setup an optical comparitor to see where the difference is but without going through all that I tend to beleive the difference is in the way the point is drawn out (after the ogive).

I noticed this by seeing a difference in OAL and tracing it back to the bullets and it not being a process issue. Runout is not a problem as well as neck tension or its inconsistancy is also not an issue.

How is everyone else treating this?

I can fight my die and make them all the same OAL or I can set the die for the mean OAL and rely on the punch positioning the ogive in the same place on all the bullets which is what I want for accuracy as long as the seating depth is the same (I think).

I'm using a lyman pro ss seating die with the micrometer adjustment. I might check with lyman to see if they offer a punch optimised for the 69 SMK. The punch I have doesnt damage the bullet but it does leave a very light visible ring just ahead of where the bullet would meet the lands. I'm still confident that the difference is in the bullet length variation though. I could lap the punch I have to profile it but it would waste some of those gold priced bullets.

Any advise is welcomed.

Thanks, OS
 

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Discussion Starter · #3 · (Edited)
Try measuring the unloaded bullet lengths. That should tell you PDQ where your variation is coming from.
I have. Its +/- 1 mil and in just the nose of the bullet I think. Thats where the variation is coming from but it transfers over to the COAL also cause its measured off the bullet nose. I dont care if the point is a little longer or shorter - want it seated the same depth and consistaint in distance off the lands.

Is this a common issue with SMK bthp or all similar match bullets in general or did I maybe get a couple boxes of irregular bullets. The bullets look fine and are not beat up or anything - have to measure with a micrometer to find it. They weren't blems either.
 

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I went down to the bench and measured half a dozen 69 grain SMK's for you and am seeing the same thing. Just for grins I checked some .308/168 grain and .277/135 grain SMK's... Same thing, they all have that very slight variation in length.
If you're not getting runout and their accuracy is acceptable I don't think I'd worry about it.
 

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" I'm seeing some variation in the length of the bullets (69 SMK). This varies by as much as +/- 0.001. "
I wouldn't worry about it.
I used to use the cheap Sierra hollow point match bullets in my target rifles, which are far less consistent and still won trophies.
You are way over thinking this.
You have good bullets and hopefully good reloading practices. I think you should be looking else where in your chase for accuracy.
 

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Discussion Starter · #6 ·
I'm getting 1/2 min. Just looking to improve anywhere I can. Maybe get to 1/3 or 1/4. Eliminating one varible at a time will get me there.

I emailed Lyman and asked if they had a seating stem profiled for the SMK 69. If they don't I may lap and polish the one I have and get a spare oem one for back up.

I figured it was common to see in similar bullets the way they are drawn toward the HP nose.

Thanks for sharing info on yours.
 

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Discussion Starter · #8 · (Edited)
Ruger American Predator w/ a boyds bedded-in stock at the pillars and reciever only (nothing special). 22" 1 in 8 twist. It has a very good chamber in it for a production rifle though and the barrle doesnt seem to have any kinks in it.

Brass is only 2 mils from std CL after firing (at shoulder) and jam length with the 69 SMK is at 2.275. I found a sweet spot at 2.268 OAL (7 mils off the lands) and at 2750-2800 fps in this barrel. Should note I'm using a high end Wilson FLSD that is on the money and the Lyman Pro seating die - sure that makes a difference along with uniform necks and tension. LC 223 Brass once fired from same gun. 3031 and 2230 powder - I prefer single base in the winter and dont like burning up chambers for paper - would use my 22-250 or 25-06 if I wanted to do that.

I've purchased quite a few crappy firearms over the years but think I got a shooter this time.

Just call me lucky I guess.
 

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The first thing is that in mass production, nothing is going to be exactly the same. Next is that instead 9f worrying about length from case head to bullet tip, you should be measuring to the bullet ogive.
 

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1/2 MOA is impressive for a factory rifle.
All my rifles are full receiver bedded up to and including the first three inches of the barrel.
It is my opinion that you may very well have reached the maximum potential of your rifle. Anything from here on may be a guessing game as to what you can do to squeeze that tiny bit more accuracy without spending a lot of money.
 

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Discussion Starter · #11 · (Edited)
The first thing is that in mass production, nothing is going to be exactly the same. Next is that instead 9f worrying about length from case head to bullet tip, you should be measuring to the bullet ogive.
Thats right. 👍

That's why I want a seating stim that is profiled the same as the bullet ogive so I can put the ogive in the same place every time and not worry over the OAL variation that I'm seeing at the point of the bullet.
 

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1/2 MOA is awesome in the 223 Rem RAPR, Old School or Nothing. I have a good shooting 1st gen 223 RAPR as well, but the best I get in a fairly generous node is 0.7 MOA using 69 gr SMKs over Varget, so far. I don't measure concentricity nor do I chase the COAL, but I have been known to track the CBTO length to ensure consistency.
 

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Thats right. 👍

That's why I want a seating stim that is profiled the same as the bullet ogive so I can put the ogive in the same place every time and not worry over the OAL variation that I'm seeing at the point of the bullet.
I would contact Lyman, maybe they would machine a searing stem to fit that specific bullet. I know several other manufacturers will. You just have to send them a few sample bullets. I have a couple of Lee rifle dies that I have bored out the center of the stem so that the bullet tip makes no contact.
 

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Discussion Starter · #14 ·
I would contact Lyman, maybe they would machine a searing stem to fit that specific bullet. I know several other manufacturers will. You just have to send them a few sample bullets. I have a couple of Lee rifle dies that I have bored out the center of the stem so that the bullet tip makes no contact.
I sent them an email but hadn't heard back.

I went ahead and lapped and polished the stem in it to mate with the SMKs profile. I'm no longer getting the sharp edge light ring marking the bullet so think it is seating okay and pressing the bullet in from a little closer to the ogive.

My runout and conc. was exceptable but not having that sharp edge may let the bullets self align a little better.

A trip to the range should tell if its an improvement or not.
 

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Discussion Starter · #15 · (Edited)
A few photos:

Home on the 200 Yrd Range (another 200 behind but need to add to backstop for that). The yellow box center frame is the target - little right of the way the rifle is pointed.
Sky Plant Natural environment Natural landscape Tree


Layout (Got to get the ms some new material - Urban camo I guess). Micky probably doesn't know he is a gun supporter :ROFLMAO:.
Plant Tree People in nature Outdoor furniture Grass


Some test Loads
Wood Textile Orange Handwriting Paint


Also use 2230 but 23 grns of it is about the same as 22 of 3031 w/ 69s. Both keep the heat in the barrel up to about 2-3" from the end which I find usually works well for accuracy. Have a small box of 77 SMK on the way to test in this rig. I'll switch over to the 2230 for the little extra umph for those and maintain the 2775 FPS which should be close. I'll drag the crono out and check SDs for those. I usually do crono testing out behind my reloading shack where I have a 25 & 50 Yrd pistol test range set up.

The penciled in groups are from an earlier trip on a different day. The 1-2 is 60 grn VMAX - for some reason they print this way at 200 yrds. Tried another test load with it with a 4 shot group and it was the same pattern with the same 2 hits at the top left and another touching hole at the bottom right (more powder for those maybe or maybe flat bottom bullets not seating as uniform)? The other 3 shot groups were SMKs at 200 - The wind was averaging about 8mph that day to the right which is easily seen. The elevation was scope adjustment - I don't change scope settings or zoom while testing loads.
 

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I load for consistent CBTO lengths. I don't care about OAL because I know the bullets are not all identical. But my jump is consistent. I use a Forster micro seating die.

More to your point, I gave up on Sierra bullets.
Maybe 5 of 100 will be the same in length or weight. I went to Berger bullets and never looked back.
 

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Discussion Starter · #17 ·
I load for consistent CBTO lengths. I don't care about OAL because I know the bullets are not all identical. But my jump is consistent. I use a Forster micro seating die.

More to your point, I gave up on Sierra bullets.
Maybe 5 of 100 will be the same in length or weight. I went to Berger bullets and never looked back.
The 69s are doing okay. Since I lapped the seating stem its placing all at the same CBTO. Loaded 20 that where all the same length bullet and all came out the same OAL which means the die is working fine. If the tip is in/out a little it shouldn't make that much difference. I'll try some of the 77 smks to see if they do better/worse but if they work that will help me down range some when I move back to 300/400/500 yrds. The rifle uses ar mags so I'm limited on OAL unless I cut the ends out and the way this rifles bolt and mag mate loading single is a bear. Might try some bergers eventually. For what the rifle is it is doing well beyond expectations. I'm starting to see operator error come into play now - Im just not as consistant as back in the day.
 

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Discussion Starter · #20 ·
Update:

77SMKs are shooting about the same if not a little better than the 69SMKs - about 1/2 min at 200 Yrds in the 1:8 twist barrel.

After a little charge adjustment, the A2230 is working as good with a little more FPS than the IMR3031.

77SMK loads are running around 2750 with good SDs in the 22" barrel (this would be maybe 2800 in a 24" and maybe 2850 in a 26" +/-). The 69s seem to like 2700 FPS better. Both like about 7mils from the lands - 77s at 2.281 OAL & 69s at 2.268 in this barrel. Both of those lengths run okay in the AR Stoner metal type 5/10 rnd mags. The 77s will not but the 69s do okay in the plastic P-Mag 10 rnd Mags. The P-Mag could be modified with a round file in the tracks of the bullet points but I think using the metal mags for the 77s only should help me keep up with what's in which mags better at the range.
 
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