First OCW test, your thoughts. Update 2nd OCW

[gmelahn]

Okay this was my first time trying the OCW meathod for working up a load, I was wondering if I could get a little input on what I'm looking at and where to go from here. I was at an outdoor range, 100 yards, about 7 at night . I had to rush my last two strings of fire because I was running out of sunlight. Also I just got done remounting my scope and I had to re-zero and never really got it perfect; thats why the groups are high left so please take that into account. I started to notice slight pressure signs at 46grns which increased at 46.5. Also 46 grns only has 2 rounds long story. Please let me know if you need any more info.

<span style="text-decoration: underline">Components</span>
Rifle: Savage 10FLCP-k, 1-10vtwist, 24" barrel
Bullet: SMK 168
Powder: Varget
Case:Federal GMM(<span style="font-style: italic">don't get upset with me for using of federal cases</span>)
Primer CCI200
OAL(ogive) 2.211 .020 off the lands

<span style="text-decoration: underline">Weather</span>
Temp: 90F
Wind: SW7mph from 5 o'clock
Pressure: 29.8

Thanks,

G-

 

[Fuzzball]

Re: First OCW test, your thoughts....(pic heavy)

I'm not sure what you're asking of us.

Do you want us to tell you which group is smallest???

 

[Seawalker]

Re: First OCW test, your thoughts....(pic heavy)

It is unfortunate that you only got two rounds at 46 grs. which is usually an accuracy node for many rifles with the 168 SMK. Looks to me like you need to try 46 again, but not sure what pressure signs you were getting.

I would want to try groups at 45.6, 45.8, and 46. You could load your foulers to one of the best lower groups at maybe 45 to see if it shoots another good group while foulding and warming the barrel.

 

[gmelahn]

Re: First OCW test, your thoughts....(pic heavy)

Thanks for the post, as far as pressure signs the bolt was harder to open and the extractor pin left a small indentation starting with 45.5 and the went away by 46.5 also the case head increased by .001 starting at 45.5 on up.

It has also come to my attention that vertical dispersion is important to the OCW test.

Below is the vertical dispersion:

43.4......0.365”
43.8......0.642”
44.2......0.762”
44.6......0.786”
45.0......0.965”
45.5......1.232”
46.0......1.585”
46.5......1.900”

 

[Seawalker]

Re: First OCW test, your thoughts....(pic heavy)

I would expect the hotter loads to hit the target progressively higher. Depends on what you want to do with the load. If just target shooting for fun, then no reason not to develop a lower charge which will cost less to shoot and be easier on the barrel, but lots of rifles don't really come in until the charge gets on the upper end.

Were you seeing much carbon fouling on the outside of the casemouth at the lower loads. Sometimes the brass doesn't really seal good on the lower loads. Accuracy seems to improve to me when the carbon disappears as the loads increase, but if eveything looks good on the lower loads, you can probably develop the load somewhere in the middle of 44-45 gr. range.

Looks like you're doing good and shooting well.

 

[Unsichtbar]

Re: First OCW test, your thoughts....(pic heavy)

You need to not be looking at dispersion but for common POI point of impact. In this load range 44.6 to 45.6. Pick load in the middle. With those 3 load one round each at ( 300 yds ) or 2000 if that all you have. They should group with in 1 moa. then if that is the case middle load ajust seating depth to bring it in ( OBT optimum barrel time.

 

[gmelahn]

Re: First OCW test, your thoughts....(pic heavy)

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Seawalker</div><div class="ubbcode-body">I would expect the hotter loads to hit the target progressively higher. Depends on what you want to do with the load. If just target shooting for fun, then no reason not to develop a lower charge which will cost less to shoot and be easier on the barrel, but lots of rifles don't really come in until the charge gets on the upper end.

Were you seeing much carbon fouling on the outside of the casemouth at the lower loads. Sometimes the brass doesn't really seal good on the lower loads. Accuracy seems to improve to me when the carbon disappears as the loads increase, but if eveything looks good on the lower loads, you can probably develop the load somewhere in the middle of 44-45 gr. range.

Looks like you're doing good and shooting well.</div></div>

Thanks for the reply,

I did notice and carbon build up around the case mouth with the lower weights and it started to disappear at about 44.6 the general consensus has been between 44-45 with the upper end being closest to the OCW.


<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Unsichtbar</div><div class="ubbcode-body">You need to not be looking at dispersion but for common POI point of impact. In this load range 44.6 to 45.6. Pick load in the middle. With those 3 load one round each at ( 300 yds ) or 2000 if that all you have. They should group with in 1 moa. then if that is the case middle load ajust seating depth to bring it in ( OBT optimum barrel time. </div></div>

Thanks for the reply,

I just got done loading groups of three with .2 grain increments from 44.2 to 45.4, I think I may pull the 44.2 and start at 44.4 and add a group of 45.6 to the other end.

I am also going to try and and push the target as far back as I can just to see how which load performs the best. Then on to bullet depth.

I really appreciate the replies, they help me out a lot as I'm just learning to reload and don't really have any mentors.

Thanks,

G-

 

[mdmp5]

Re: First OCW test, your thoughts....(pic heavy)

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Fuzzball</div><div class="ubbcode-body">I'm not sure what you're asking of us.

Do you want us to tell you which group is smallest???</div></div>

small groups don't mean anything in ocw testing. you are looking for consistency between charges

 

[Unsichtbar]

Re: First OCW test, your thoughts....(pic heavy)

All you need to do at pushed back distance first is to shoot supected OCW bracket loads, one round each to check comon POI. Select middle load run seating depth ajustment to bring it in ( ajust both forward and back, closer to the land does not assure accuracy).

There is no need at this point in to backing off and shooting loads for preformance. All your looking for is a spread of loads say a .8 gr range that shoot to the sam POI with in a minute of angle. The rest will come together in fewer rounds and less effort if you do not divert from the process.

PS 168 smk were made to shoot 300 yd comp. ( boat tail is at a different angle)past 700 they start to preform less well and at a 1000 yd experienced long range shooter will tell you they are a poor choice, unless shot a elevated altitude and special conditions.

 

[gmelahn]

Re: First OCW test, your thoughts....(pic heavy)

I have heard less than favorable things about the 168 for long range, I'm wondering if I should switch it and try another bullet? I have 168 Hornady's as well. I may try 155 or 175s, what do you recommend for 300-1000 bullet?

I understand the procedure behind the OCW method and even Dan Newberry commented that pushing the 45 grain weight is where he thinks is the best.

Thanks

G-

 

[Unsichtbar]

Re: First OCW test, your thoughts....(pic heavy)

Yes use something if else besides a 168 smk if you are looking past 700 yds. There have been endless dicussions 175 smk vs 155L ( heavy vs light), there are advantages to both, depends how you shoot, best to do a search.Even better load up both and see what works best for you.

 

[gmelahn]

Re: First OCW test, your thoughts....(pic heavy)

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Unsichtbar</div><div class="ubbcode-body">Yes use something if else besides a 168 smk if you are looking past 700 yds. There have been endless dicussions 175 smk vs 155L ( heavy vs light), there are advantages to both, depends how you shoot, best to do a search.Even better load up both and see what works best for you. </div></div>

Yeah thanks,

If there is one thing I have learned on this site, it's that the search feature is my friend. I bet the 175 will work better as I have a 1-10 barrel.

 

[okiefired]

Re: First OCW test, your thoughts....(pic heavy)

You're getting pretty good advice here on the testing and sounds like you're doing well. If you dont have too much invested in the 168's already, with that 10 twist barrel I'd definately be runnin the 175's.

okie

 

[Unsichtbar]

Re: First OCW test, your thoughts....(pic heavy)

Maybe, maybe not theres a bit more to the twist thing than the bullet weights x so I need x twist. Bearing surface just to mention one, a Lapua 155 is about as long as a 185 Lapua and flys fine out of several barrel twist.

 

[okiefired]

Re: First OCW test, your thoughts....(pic heavy)

I didn't say it had anything to do with bullet weight. The 175 SMK's have a longer bearing surface than the 168's and just about always do very well in a 10 twist especially when you're talking 500+. Hell, they do much better in my 12 twist LTR than the 168's do. In my rifles, I've never found a situation where the 168's outperformed the 175's. Just my experience.

okie

 

[Unsichtbar]

Re: First OCW test, your thoughts....(pic heavy)

okie my responce was directed to G coment "I bet the 175 will work better as I have a 1-10 barrel".
He appeares to be less experienced than yourself, there is this a buy in among some new to this that in you have to have x twist or a bullet will not preform, in .308 I have not seen that much of a sensitivity to twist rate, my 1/12, 11.25 and 1/10 shoot with excelent results 155-185 range of wieghts. I am not a big fan of 155 smk or (168 smk past its intended range applications and there are better bullets for that also IMO).

For other cals. twist rate can be more critical, but then the real proof is to go shoot the darn things and see how they preform. Besides position and wind call usually trumps minor twist rate effects in the normal range of .308 bullets.

 

[okiefired]

Re: First OCW test, your thoughts....(pic heavy)

Hey Unsichbar, wasn't meaning to slam you in any way. After rereading my post, it did sound a little harsh and sure wasn' meant to be that way. I've never been a 168 fan in the .308's and I just never saw an advantage of the 155's over the 178 Amax's I use, especially in the 500 to 1K range. If the OP is planning on staying <500 than I dont think it would be too critical as long as his barrel performed well with the bullet weight he chooses but if he plans on going on down range then I would definately advise the 175's (178's

). But....everyone knows what opinions are like

. Shoot well.

okie

 

[gmelahn]

Re: First OCW test, your thoughts....(pic heavy)

Thanks for the help guys, nothing like a little back and forth banter to teach the new guy some new stuff.

I did however know that there is a lot more than just the twist rate that affects the bullet.

I do however appreciate it the knowledge shared. I'm off to the range today to do my second OCW with this bullet and loads ranging from 44.4 to 45.6 in .2 grain increments.

I am however going to Sportsman's to buy some new bullets, any suggestions?

 

[gmelahn]

Re: First OCW test, your thoughts....(pic heavy)

Here is the latest, today was windier full value left to right at about 7 MPH. Just like people have said, 45 looks the best. I think I'm going to load 44.8 or 44.7 and start playing with the seating depth. Unless that is someone has any other suggestions.....

 

[Seawalker]

Re: First OCW test, your thoughts....(pic heavy)

POI is pretty close from 44.4 to 45.2. Agree,looks like 44.8 is about the middle of that range and should give a wide OCW for you. I would load 3 rds. at 44.6, 44.8, and 45 and shoot at 200 or 300 to see if they group close at distance. Looks like they will, and in fact it looks like 5 rds. from 44.4 to 45.2 will group under MOA for you. If 44.8 works like it appears it will then you can probably get the MOA even tighter with seating depth.

 

[gmelahn]

Re: First OCW test, your thoughts....(pic heavy)

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Seawalker</div><div class="ubbcode-body">POI is pretty close from 44.4 to 45.2. Agree,looks like 44.8 is about the middle of that range and should give a wide OCW for you. I would load 3 rds. at 44.6, 44.8, and 45 and shoot at 200 or 300 to see if they group close at distance. Looks like they will, and in fact it looks like 5 rds. from 44.4 to 45.2 will group under MOA for you. If 44.8 works like it appears it will then you can probably get the MOA even tighter with seating depth.</div></div>

Thank you Sir,

I'm glad I can get the help from everyone here on the Hide, seems like there is a little more participation among members.

 

[kyreloader]

Re: First OCW test, your thoughts....(pic heavy)

I would rock on at 44.7g and work on OAL. I think you found your load.