Long range load

[evol ways]

OK, fair enough.

Personally, what I meant though, was that if I was looking to achieve a certain velocity, while achieving the same ES/SD, I would be looking into trying different powders, projectiles, brass and maybe even different primers, etc.

Using the best load you achieve between 100-600 yards is great, unless you're looking to develop a 1k load.

btw Can't see your pictures.

OP

2.160" Base to ogive sounds short with a 175gr. SMK.

I'm loading to 2.231" and that puts my OAL at roughly 2.81". I say "roughly" because I find SMK to be all over the place from base to tip. I prefer and have been using the Nosler CC. Find their sizes to be much more consistent.

That was the average I was gettining when I used the hornady OGIVE Gauge multiple times. I was using a Sinclaire measuring insert in a hornaday digital caliper if it matters. Here's a pic of a measured case. Hard to see in pic but coming up 2.809"

Nice rifle… With that barrel length and powder you have some wiggle room with that MV..

I would make a top end ladder from the hottest safe load you have made so far to find your peak pressure area… maybe 1-2 cases per charge, in small increments. Fire them until you see the start of some pressure signs in your brass cases and back it off a little if you wish.

After you find your rifles max you can make another batch of ammo and do some accuracy testing, or another ladder within the top end of chat charge range to see what works best.

I would invest in a chrono, or make friends with someone that has one… more so to understand what the ES/SD of your ammo is than just knowing the velocity.

I want to say i only went up to 45gr of varget and saw now signs of pressure when I initially threw some loads together. I'm going to try a OCW test but run it through past 45g in .5 increments until I see signs of pressure. I'll most likely post the results up here for you to help me decipher what the holes are saying lol.

That sounds excessively slow. Are you using the correct BC in your calculator? I do not know Stelok, but if it only allows one value, a common error is for people to use 0.505 as a G1 for the 175 SMK. That's really more for 300 WM velocities and are not realistically attainable in the 308 Win. 0.485 is the more practical BC to use as it's the velocity more appropriate for a 308 to 1km. You may arrive at a higher MV.

There's really no correct MV to get you there, it's simply what works. I'd want 2,700, personally, with a 308. Your load data sounds good as you'd probably not want to go too much higher, but you should continue to increment your charges until your group spreads. With the long barrel life and cheap brass, there's no reason to hold back on 308, IMO.

I am using the G1 BC of .496 according to sierra and also the guys over in the hide.

So here's a pic of my target out to 1K. The reason I even bring this up other then being told the rounds are coming in slow was the head shot out to 1k. Adjusted scope to 11.1 mills and aimed dead center. But just a few weeks ago when I shot the 1k match I didn't see this kind of vertical. Hopefully the target shows something I don't see.

disclaimer... I am in no way shape, way or form good at the long range game. Lol I'm still learning as you can see some of my shots didn't even make onto the target lol.

[CK_32]

If your shooting a 700, your node pattern sounds similar to mine.

I loaded up to 47gr of Varget with no wear signs but stopped being I wouldn't shoot that much anyways. Kills the life of your brass.

But I saw my nose around 44.0 and another at 45.5. So you might want to look at loading up to the 46.0 range to get your MV if that's what you choose to run.

Should be about the 2650 to 2700 range. In a 22 - 20" barrel.

Also I always plug in G7. I remember a huge wright up most people classy and advertise 175's at G1, but technically they are more G7 than G1's. So rating them a G1 will just alter your calculations.

That's the lamens terms, I forgot who had a very, very in depth wright up as to why. I think it was sniper central or snipers hide. One of the 2 boards.

[bsumoba]

I would run a ladder test up and see what is your true max powder charge with the current OAL.

What kind of brass are you running also? If you are running LC brass, that typically has less case volume and you will need to watch for pressure signs earlier.

On another note, you do not have to be limited to your magazine length. Yes, I know you cannot mag feed, but maybe you do not necessarily need to for certain courses of fire. Remember, in the F-Class 3x1000 match, we all run singled feed actions and it takes the target puller 9-14 seconds (if they are decent) to get the target back up. In the prone position, I could probably run a single feed almost as fast as a mag fed rifle with the right setup.

I would do this if you want to get more speed and are okay with single feeding:

* Measure your freebore using a hornady OAL gauge of some sort. Do this multiple times to get a good idea of your average as it is actually a little tricky to measure your freebore with the barrel on the action (I typically measure my freebore with the barrel out of the action). Use a comparator to measure the rounds base-to-ogive, not OAL. You want to see how long you can load a round in the chamber such that it just touches the lands. This will tell you about the max length you can run. For the SMKs, they typically like to be jumped, so I would start around 20-40K off the lands. Once you determined this, then do load development with this new OAL. I am certain you will see that you can get more velocity out of the gun because you can pack more powder in without increasing pressure all that much. You might even see some increase in accuracy

[evol ways]

I would run a ladder test up and see what is your true max powder charge with the current OAL.

What kind of brass are you running also? If you are running LC brass, that typically has less case volume and you will need to watch for pressure signs earlier.

On another note, you do not have to be limited to your magazine length. Yes, I know you cannot mag feed, but maybe you do not necessarily need to for certain courses of fire. Remember, in the F-Class 3x1000 match, we all run singled feed actions and it takes the target puller 9-14 seconds (if they are decent) to get the target back up. In the prone position, I could probably run a single feed almost as fast as a mag fed rifle with the right setup.

I would do this if you want to get more speed and are okay with single feeding:

* Measure your freebore using a hornady OAL gauge of some sort. Do this multiple times to get a good idea of your average as it is actually a little tricky to measure your freebore with the barrel on the action (I typically measure my freebore with the barrel out of the action). Use a comparator to measure the rounds base-to-ogive, not OAL. You want to see how long you can load a round in the chamber such that it just touches the lands. This will tell you about the max length you can run. For the SMKs, they typically like to be jumped, so I would start around 20-40K off the lands. Once you determined this, then do load development with this new OAL. I am certain you will see that you can get more velocity out of the gun because you can pack more powder in without increasing pressure all that much. You might even see some increase in accuracy

For ladder tests, isn't it recommend 200yard minimum and better at 300? My local range is limited to 100. I think concord had a members only 200 yard range. Not sure of this since I'm not a member.

Brass is Hornanday match.

I did use the Horndaday OAL gauge to measure to the lands. That measurement was 2.160 base to OGIVE. I was using the Sinclair comperator inserts to measure. Right now they are just loaded to touch the lands. I read over on the hide to start loading with the bullet touching the lands and once charge weight was narrowed down adjust the seating.

[J-cat]

You can't develop LR loads at 100 yards without a chrono. Get a chrono. Magnetospeed makes a cheap basic unit. Get one.

[bsumoba]

For ladder tests, yes you want to do at the farthest range possible, 300-500 yards.

Once you find a range of charge weights (usually 0.3-0.7 gr range) that yields similar vertical, then you can work around that charge weight in 0.2-0.3 gr increments at 100 yards. Once you get a load that yields similar POI and group sizes over say a 0.4-0.5 gr, bracket that node and choose the middle charge weight, then work the seating depth to tighten the groups.

So, if your ladder test says 45.0-45.6 gr is giving you similar vertical at 300+ yards, then run a sort of OCW test at 44.8, 45.0, 45.2, 45.4, 45.6, and 45.8 grains @ 100 yards. If you get similar POI groups at 45.2-45.6, then I would use 45.4 gr and use seating depth tests to tighten the groups up. I would also run this load for velocities over 5-10 shots to see if the ES/SD is acceptable.

[CK_32]

Results do sometimes show at the 200 yard range for ladder.


But sometimes they don't. It's a crap shoot. Luckily my last node was able to be seen at 200 yards. I'm also limited to about 200 yards unless I want to drive a good distance.

I've done others where there was almost 0 noticable vertical spread. I usually take measurements with a micromiter and plot those on a graph. Because looking at numbers confuse and overwhelm me.

Here is my last one for my 700 with 175 load.



As you can see with a graph it's much more apparent. Note this whole chatrt is a matter of a 2" spread @ 200 yards.