Ogive question

[bigjoe8565]

I'm new to reloading and trying to determine the ogive for my rifle. I used the Hornady case length gage (formerly Stoney Point) and after many attempts it appears my ogive is somewhere between 2.1460 and 2.1470. My rifle is a Remington Varmit/Tactical in 308. I'm know there can be variation from rifle to rifle, but I'd like to know if my measurements seems too short.

Joe

 

[KeithR41]

Re: Ogive question

The ogive is on your bullet dude.

You want to know where your lands are.

41

 

[bigjoe8565]

Re: Ogive question

You're right, I am looking for the lands. The measurement I mentioned (ogive) is from the base of the case to the point I believe the bullet touches the lands. I'm trying to determine the proper seating depth for my rounds.

Joe

 

[Da-Law-Dawg]

Re: Ogive question

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: bigjoe8565</div><div class="ubbcode-body">You're right, I am looking for the lands. The measurement I mentioned (ogive) is from the base of the case to the point I believe the bullet touches the lands. I'm trying to determine the proper seating depth for my rounds.

Joe </div></div>

Joe,

That's the distance (measurement) from the case head (base) to the ogive (where the bullet actually kisses the lands) of that particular bullet you are using in your rifle.

The ogive varies from bullet to bullet, ie; a 168 SMK measured from the base to the ogive will vary from a 168 Amax measured the same as the bullet profiles at the ogive are different. That measurement needs to be taken more than once and averaged.

After you are satisfied with your measurement, work your seating depth accordingly.

PS- Dunno what bullet you are running, but that sounds fairly close. My Rock barreled FN is fairly close to what you're measurements come in at.

Hope that helps.

 

[Jig Stick]

Re: Ogive question

You need to make a dummy round to find the OAL for a bullet " jammed" to the lands. Take a piece of brass and very lightly use your press to seat a bullet shallow. No powder or primer either. Then place the dummy round in your chamber and close the bolt gently. Then gently extract the dummy round. Next use your bullet comparator to measure the dummy round from base to ogive. This will tell you exactly how long a bullet needs to be to be touching the lands. Now you can take this measurement and set your seating die to give you the OAL you figured out

 

[427Cobra]

Re: Ogive question

I suggest you load 175smk at 2.8 coal and shoot the shit out of it, the distance to the lands is probably 3.00 coal, which is way too long for mag length, stock Remmies are all that way, later as your reloading skills improve and your shooting have a Rock barrel installed with a custom chamber, then play around with exact jump.

 

[bigjoe8565]

Re: Ogive question

I'm loading 168 grain Hornady AMax.

Joe

 

[notquiteright]

Re: Ogive question

Then load them to 2.82" aol and shoot the shit out of them.

 

[BBeyer]

Re: Ogive question

big joe, ogive is the shape of the bullet, the higher the ogive number the pointier the bullet will be. What you are looking for is the O.A.L. to have the bullet touching the lands. Normally over the counter bullets do not give the ogive number, bullets made up by a custom bullet maker normally do. In 30 cal. I use either a seven or ten ogive bullet.

 

[Dilbert946]

Re: Ogive question

Joe,
i am new to this also, in fact this is my first post. i measure my bullet length to the ogive instead of to the bullet tip also because it seems more consistent for me. i had a good bit of difficulty using the hornady case length gage and finally gave up on it. my savage model 10 .308 measures 2.234 from base to the ogive of a sierra 168 matchking to touch the lans.

vinny

 

[bigjoe8565]

Re: Ogive question

I really had fits with the Hornady tool, so I'll be taking it back to Cabelas. I've figured out that my gun shoots very well with 43.5 grains of Varget , CCI BR2 primers and a 168 grain AMax. So now I'm going to experiment with the OAL to determine where the bullet hits my lands. I appreciate the feedback.

Joe

 

[Da-Law-Dawg]

Re: Ogive question

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: bigjoe8565</div><div class="ubbcode-body">I really had fits with the Hornady tool, so I'll be taking it back to Cabelas. I've figured out that my gun shoots very well with 43.5 grains of Varget , CCI BR2 primers and a 168 grain AMax. So now I'm going to experiment with the OAL to determine where the bullet hits my lands. I appreciate the feedback.

Joe </div></div>

Joe,

We've had tremendous luck running the 168 Amax at 44.0gr of Varget, Fed 210's seated at 2.800" OAL. It's one of those "go-to" loads for us and runs well in several different rifles.

FWIW, most of the time, the 168 Amax will prefer a bit of a jump compared to jamming them.

 

[bigjoe8565]

Re: Ogive question

Da-Law-Dawg:

I'll load a handful of your reciepe and give it a try.

Thanks for the information.

Joe

 

[Da-Law-Dawg]

Re: Ogive question

Glad to help, they are averaging right at 2650fps outta five different rifles +/- a few fps depending on the gun. We've seen 1/2 MOA or less in ANY rifle we've ran it thru.

Here's a good example.......

 

[CS95]

Re: Ogive question

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: bigjoe8565</div><div class="ubbcode-body">I'm new to reloading and trying to determine the ogive for my rifle. I used the Hornady case length gage (formerly Stoney Point) and after many attempts it appears my ogive is somewhere between 2.1460 and 2.1470. My rifle is a Remington Varmit/Tactical in 308. I'm know there can be variation from rifle to rifle, but I'd like to know if my measurements seems too short.

Joe </div></div>To answer your question here in your original post- Yes your measurements look correct. The .010" variation you are getting is from not putting the same amount of pressure on the push rod every time. You wont get it perfect ,but if you are careful you can get the pressure on the push fairly consistent. I generally can get it with in .003" over multiple measurements.

 

[M4-Pilot]

Re: Ogive question

Try using a wood dowel run down the barrel to push the bullet back and forth, in and out of the throat when using the Hornady or whoevers OAL guage. It gives you a better "feel" for where you start getting contact on the throat. A little extra pressure can cause 10 to 15 thousands of variance depending on how old the gun is or how the throat is cut. I find that I can get very consistent measurements on OAL doing it this way. On some older rifles the difference between an jumped bullet and a reasonably jammed bullet may be 20-30 thousandths bc of the throat and how its worn.