OAL and Ogive Questions

[D.A.T]

I have been reloading for less then 2 years so I am still in that long learning curve.

I recently got a hornady LNL OAL gauge and Ogive gauge to attach to calipers.

I checked the freebore in my sisters thompson encore .308 and it was long as hell. a 168 would barley seat in kissing the lands.

I then moved on to my savage 10fp with hs stock.

On my gauge a 2.80 oal is 3.230 ogive in my gauge. this was checking some previously reloaded ammo of mine. 168 gr smk in lapua brass.

I then used the gauge to check the free bore. OAL was about 2.82 to lands and ogive was 3.250.

So far i understand, my rifle has a very short freebore.

next i used a 168 gr a-max bullet. I measured oal on my calipers at 2.80 and then put the same in my ogive which turned out to be 3.224. (kinda short i think)

I then used the lnl gauge and the oal to kissing the lands was 2.792 and ogive for that measurement was 3.211.

I thought I did somthing crazy wrong since this would put oal under the standard 2.80

I would like some insight on why a-max would be under the 2.80 oal kissing the lands.

 

[918v]

Re: OAL and Ogive Questions

Because it has a secant ogjive and more bullet shank sticking out past the case mouth than a comparable SMK or Nosler. More shank out the mouth, the sooner the bullet hits the rifling.

 

[D.A.T]

Re: OAL and Ogive Questions

can you point me to some reloading data for a-max bullets, am intersted in both the 168 and 178 gr bullets.

 

[42769vette]

Re: OAL and Ogive Questions

im not suprised with your tc results. i had a 243 prohunter and with a berger vdl my oal would have had to been 3.02 to touch the lands. i know the vdl has alot of o give but that would make a long 243 with any bullet

 

[Tcanupp]

Re: OAL and Ogive Questions

The way I was taught is your ogive measurement should be less than your oal measurement. I think you need to zero your caliper on the ogive guage. For example my 175 smk 308 load has an ogive of 2.210 and an oal of about 2.80.

 

[coues7]

Re: OAL and Ogive Questions

I'm with Tim586 on this one.

 

[Fuzzball]

Re: OAL and Ogive Questions

"I would like some insight on why a-max would be under the 2.80 oal kissing the lands."

First, it's clear that neither the bullet maker nor the rifle maker checked your loading manual so they didn't "do it right."

Thus, use your OAL tools to do it right. That's what they are made for, not so you can duplicate something in a book.

 

[sobrbiker883]

Re: OAL and Ogive Questions

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Tim586</div><div class="ubbcode-body">The way I was taught is your ogive measurement should be less than your oal measurement. I think you need to zero your caliper on the ogive guage. For example my 175 smk 308 load has an ogive of 2.210 and an oal of about 2.80. </div></div>

Ogive length is always shorter than OAL. But, many folks give the ogive length including whatever comparator they use.


The OP is trying to translate OAL from OAL vs ogive (plus comparator) length from SMK's to Amax's using the same relation of OAL to ogive that he got with the SMK's-ain't gonna happen, as the ogive on the Amax's is further back (hence what the OP is reading as "shorter OAL").


Just take the comparator off and measure the OAL of the Amax's once you've found the lands. <span style="text-decoration: line-through"> Good luck fitting that in a 700's magazine, it is definately longer than 2.835" with a factory throat.</span> Forgot the Savage part. When I had a 10FP I ran 168 Amax's at 2.845" OAL and they were +/- .010" off the lands and fit in the Savage magazine fine.

 

[918v]

Re: OAL and Ogive Questions

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: D.A.T.</div><div class="ubbcode-body">can you point me to some reloading data for a-max bullets, am intersted in both the 168 and 178 gr bullets.</div></div>

It depends on your brass. The data is different for new vs fired vs different brands with different capacities.

 

[D.A.T]

Re: OAL and Ogive Questions

your kind of grumpy... with no help.

 

[918v]

Re: OAL and Ogive Questions

your kind of juvenile... throw out a bunch of vague bits of info expecting a dissertation.

 

[gnfiter3]

Re: OAL and Ogive Questions

Show what a science this whole thing can be. All that info, and when all is said and done, for a gas gun, it needs to fit the mag.

 

[Mag 300]

Re: OAL and Ogive Questions

Sobrbiker has this corrct my measurements are with the comparitor and are longer than the oal measurement. the best thing to do is beleive the comparitor its telling you where to plave the buller in relationship to the lands of the barrel.

and it is true for a semi auto like am M1A they have to fit the magazine and this blows the hell oout of the .010 off tha lands theory

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: sobrbiker883</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Tim586</div><div class="ubbcode-body">The way I was taught is your ogive measurement should be less than your oal measurement. I think you need to zero your caliper on the ogive guage. For example my 175 smk 308 load has an ogive of 2.210 and an oal of about 2.80. </div></div>

Ogive length is always shorter than OAL. But, many folks give the ogive length including whatever comparator they use.


The OP is trying to translate OAL from OAL vs ogive (plus comparator) length from SMK's to Amax's using the same relation of OAL to ogive that he got with the SMK's-ain't gonna happen, as the ogive on the Amax's is further back (hence what the OP is reading as "shorter OAL").


Just take the comparator off and measure the OAL of the Amax's once you've found the lands. <span style="text-decoration: line-through"> Good luck fitting that in a 700's magazine, it is definately longer than 2.835" with a factory throat.</span> Forgot the Savage part. When I had a 10FP I ran 168 Amax's at 2.845" OAL and they were +/- .010" off the lands and fit in the Savage magazine fine. </div></div>

 

[jr81452]

Re: OAL and Ogive Questions

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Bill Stoffels</div><div class="ubbcode-body">Sobrbiker has this corrct my measurements are with the comparitor and are longer than the oal measurement. the best thing to do is beleive the comparitor its telling you where to plave the buller in relationship to the lands of the barrel.

and it is true for a semi auto like am M1A they have to fit the magazine and this blows the hell oout of the .010 off tha lands theory</div></div>

that's why they make custom barrels with short throats bill

 

[Mag 300]

Re: OAL and Ogive Questions

Agreed
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: jr81452</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Bill Stoffels</div><div class="ubbcode-body">Sobrbiker has this corrct my measurements are with the comparitor and are longer than the oal measurement. the best thing to do is beleive the comparitor its telling you where to plave the buller in relationship to the lands of the barrel.

and it is true for a semi auto like am M1A they have to fit the magazine and this blows the hell oout of the .010 off tha lands theory</div></div>

that's why they make custom barrels with short throats bill

</div></div>