oal worry's..

Hi all.. Just got meself a 12 F/TR in .223 and will be reloading .. But came across something the other day that troubles me?.. Using the Hornady oal gauge and bullet comparator kit and measuring from the ogive, I measured the oal to lands using a 77 smk.. The measurement I got was 1.835”.. So I loaded to 1.823” which is .012” off the lands as a starting point for testing. This gave me an oal to the tip of 2.259.
Then.. just to be on the safe side, and for warranty reasons, I bought some Federal Gold Medal factory match ammo. with the same 77smk bullet, to shoot first before trying my handloads. These have an oal to tip of between 2.246 and 2.251 (they vary a bit!) but using the same method with the comparator kit the measurement on these gives an oal to ogive of around 1.864” to 1.867” (again they vary a bit).
So here be the predicament - As my oal at ogive was 1.835” that tells me that the federal ammo will be seating .030” into the lands??. That does not seem right and worry’s me.. Am I wrong in my calc’s somewhere? Can anyone advise on this.. Thanks..

1st I would recheck your initial measurement of your barrel's ogive. Sometimes a bullet will stop in the modified case neck before touching the lands.

I don't have any 77gr SMKs to compare but I usually run 1.9xx" to 2.005" to lands with an assortment of bullets in a hog hunter and weather warrior.

The distance is, whatever the distance is, regardless of gun or cartridge.
Im sure the various tools for measuring work just fine. But here you are
questioning the tools. So why not try the old method still used by many
hand loaders without the tool. Take a sized case without a primer and powder.
A case with a neck split is easier but not necessary. Partially seat the bullet in the case.
Then insert it into the gun and force the bolt closed which will finish seating the bullet.
Extract the cartridge and turn your die adjustment to match the seating depth. Turn the die
another full turn in and reseat the bullet deeper. Then using a match to smoke the bullet or
a sharpie marker, blacken the bullet. Reinsert in the chamber, and carefully extract, then examine for rifleing marks.
Repeat the process with adittional die seating depth untill all rifleing marks are gone. Them move back out about .005
on the aol and you will be right at the rifleing. Thats the exact depth for that bullet in that gun. If the ammo you bought
is longer you can seat it deeper.

What yobuck said.

Quote:

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Originally Posted by yobuck

The distance is, whatever the distance is, regardless of gun or cartridge.
Im sure the various tools for measuring work just fine. But here you are
questioning the tools. So why not try the old method still used by many
hand loaders without the tool. Take a sized case without a primer and powder.
A case with a neck split is easier but not necessary. Partially seat the bullet in the case.
Then insert it into the gun and force the bolt closed which will finish seating the bullet.
Extract the cartridge and turn your die adjustment to match the seating depth. Turn the die
another full turn in and reseat the bullet deeper. Then using a match to smoke the bullet or
a sharpie marker, blacken the bullet. Reinsert in the chamber, and carefully extract, then examine for rifleing marks.
Repeat the process with adittional die seating depth untill all rifleing marks are gone. Them move back out about .005
on the aol and you will be right at the rifleing. Thats the exact depth for that bullet in that gun. If the ammo you bought
is longer you can seat it deeper.

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thanks.. good advice.. but I'm not questioning the tools.. I've measured 4 or 5 times and used half a doz. random bullets from the box... and the result is always within .002 or .003, So I'm happy with the rifles ogive to lands with this bullet.. Just can't figure why the factory ammo's measurement with the same tools is so different?.

Agreed with yobuck. I use once fired brass from my rifle's chamber to use as a modified case on the OAL gauge. I use 3 different brands of brass for my 308 so I've made 3 different modified cases, one for each brand... That's just me and my OCD

I believe you have done your measuring correctly. So the answer is, your chamber is not throated for 77grn SMK's loaded to SAMMI specks. To me, your barrel is "short throated", a condition not uncommon to Savage factory barrels lately. Seems there have been many reports of this with 308Win's.

Edit: please remember, if you seat those bullets in your factory loads deeper in the case, you will be reducing case volume, and increasing pressure. Might not be enough to cause a problem but it needs to be considered.

Quote:

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Originally Posted by FW Conch

I believe you have done your measuring correctly. So the answer is, your chamber is not throated for 77grn SMK's loaded to SAMMI specks. To me, your barrel is "short throated", a condition not uncommon to Savage factory barrels lately. Seems there have been many reports of this with 308Win's.

Edit: please remember, if you seat those bullets in your factory loads deeper in the case, you will be reducing case volume, and increasing pressure. Might not be enough to cause a problem but it needs to be considered.

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thanks.. makes sense.. is that, or could that, be a problem or affect accuracy etc.?

May I offer some light reading? http://www.6mmbr.com/223Rem.html

The gun would be the best to answer the accuracy question. I personaly cant see the rational for shooting heavy bullets in a 223.
If i wanted to shoot those bullets id be using a bigger case like a 22/250. But not everybody would agree on that.
Id think you might need an 8 twist barrel to make those things shoot well anyway. Keep an open mind on what weight bullets you prefer
till you try the lighter ones also.

Quote:

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Originally Posted by yobuck

The gun would be the best to answer the accuracy question. I personaly cant see the rational for shooting heavy bullets in a 223.
If i wanted to shoot those bullets id be using a bigger case like a 22/250. But not everybody would agree on that.
Id think you might need an 8 twist barrel to make those things shoot well anyway. Keep an open mind on what weight bullets you prefer
till you try the lighter ones also.

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I've got a 1-7" twist so a 77 is about 'middle of the road'.. can't shoot 22/250 in F/TR

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Originally Posted by Jaysee

I've got a 1-7" twist so a 77 is about 'middle of the road'.. can't shoot 22/250 in F/TR

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THIS. Plus light bullets don't carry well to 600 plus yards.

Jaysee just work up your load and forget about factory loads. If your barrel is short throated reloads are the way to go.

Jaysee, I agree with yobuck, 77SMK's in a 223 is sort of a special case. Requires tight twist and a chamber throated to handle that pill without taking up too much case volume. Doesn't make sense to use a heavy bullet that requires the muzzle velocity to be reduced because it requires reducing the load because of reducing the case volume. I have a 223 that will absolutely not group anything heavier than a 55grn pill because of the slow twist. This is not uncommon with standard factory barrels.

If you try to use those 77grn SMK's in your chamber as described, they may not jamb all the way in the chamber, rather they may push back into the case, and it may not happen evenly every time. This will affect accuracy and could increase pressure. Since you reload I feel you should load to the chamber you have with a bullet it will reasonably accept. If I remember correctly, some members have been successful at getting Savage to adjust their throat?

Edit: I was typing @ the same time as everyone else. 1 in 7 is fast enough for the 77's, and if so, why the short throat??

I have some "stock" Savages that I accept as they are. The rest have been reduced to the bare action and built back up in the configuration that I want. Just bought a barrel in 308Win throated for 190grn pills.

It bothers me that Savage it putting out chambers/ throats that will not properly chamber Factory Ammo that is to SAMMI specks. Someone please enlighten me! :-)

Quote:

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Originally Posted by earl39

THIS. Plus light bullets don't carry well to 600 plus yards.

Jaysee just work up your load and forget about factory loads. If your barrel is short throated reloads are the way to go.

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thanks Earl.. seems that's the way to go.. not sure I want to shoot them Federal's now.. Also got me thinkin' about how the throat will cope with longer pills such as 75 or 80 A-Max or VLD's? that I was hoping to load for long range F/TR..

Jaysee,

I seems to me that you're trying to compare apples and oranges with your OAL measurements. I would not assume that the advertised bullet in the FGGM is exactly identical to what you have purchased to load. It could be a second, or an over run, or similar bullet run on a different production line that does not have exactly the same profile. If in doubt about the FGGM ammo, and can't wait until at the range, simply remove the bolt from the action, drop the round into the chamber and press firmly on it with your finger. Tilt the barrel up and if the load does not simply fall out, run your cleaning rod down the barrel and give it a tap.
Look at the bullet carefully and see if it's actually making contact with the lands.

The problem I have with the Hornaday OAL gauge is that the bullet may stick in the throat, and not hit the lands, so measurements will be inconsistent. So I do like Yobuck suggests; make a dummy round and chamber it to see if it engraves the lands. Then keep it as a standard, with paperwork to document your efforts.

If hand loading and wanting to confirm lands measurement, one method I'd read about and now use is to start with a few neck sized cartridge brass previously fired from the subject gun. Seat the desired bullet long into the otherwise empty (dummy) brass and chamber it. The bullet will probably be driven back into the brass by this action and stick in the lands. Tap the dummy out with a cleaning rod and place it in your press with a seating die. Adjust the die to drive the bullet back just a few thousandths. Then using a new similar brass, install a new bullet slightly deeper and chamber it. Remove as before and inspect. Adjust your seating die again and keep doing this until you get no engraving on the bullet. Some use the same bullet over and over and clean/paint the bullet each time. I like to see/measure the progression so i use several.

Quote:

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Originally Posted by earl39

THIS. Plus light bullets don't carry well to 600 plus yards.

Jaysee just work up your load and forget about factory loads. If your barrel is short throated reloads are the way to go.

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+1................

There is also the chance the bullet is showing a false throat. As in a burr it is catching on and you end up with a longer throat measurement after 30 or 40 rounds has removed the burr.