Cannelure above mouth of case

[zeenon 0]

Figure I ask the NJ experts here, internet seems to think this is standard and ok:

 

I just bought some 150 gr bulk .308 hornady bullets to try out for plinking, instead of the MK 168gr I normally use. I made only 5 rds but the cannelure is above the mouth of the case. Are they ok to use?

 

I'm going off the Sierra (5th Ed.)

 

41 to 42gr of RE-15 (.3gr increments)

COAL 2.775"

TTL 2.005"

(Note: Hornady has a COAL of 2.780 for FMJ-BT)

 

Shooting from a Savage 10FP bolt action.

 

 

 

Z

[tony357 386]

yah, man dont look right.. ill check my book and see what it say,s for that bullet if it is listed..

 

150 gr showing 2.735 oal. I am thinking that bullet would be better in 30/06 case..

[Old School 611]

The cannelure is there for a place to put a crimp. A crimp on a cannelure is used to prvent bullet set back under recoil. But not all bullets have cannelures as you know. So... as long as your bullets are not setting back and you load to the same OAL all the time you will be OK.

 

The reason you must be consistant is the air space above the powder will change your pressures. So what I am saying is if you shoot the bullets loaded

to this depth and you decide to seat the bullets deeper in the future you'll have to start developing your load all over again. Additionally if you ever decide to crimp you have to develope your load over again as well because the additional resistance of the bullet being forced from the neck of the case.

 

I hope this all makes sense. Since it seems these are plinking rounds and you are shooting them in a bolt action there are only two considerations regarding OAL. #1 that your bullet is not too close to the rifling in the throat of the chamber(because the bullet needs a little freebore to drop chamber pressure). and #2 that loaded cartridge feeds from your magazine if you decide to use it.

 

Have fun and be safe.

 

Frank

[Old School 611]

yah, man dont look right.. ill check my book and see what it say,s for that bullet if it is listed..

 

150 gr showing 2.735 oal. I am thinking that bullet would be better in 30/06 case..

 

Tony I agree that those bullets look like they should be seated a little deeper. I would think that where the angle breaks for the boat tail should be at the lower extreme of the neck.

 

Now that being said....308 and 30-06 bullets are the same.

[tony357 386]

their definatley the same but seems to be high on the bullet.. could just be the pic..

 

HERE IS A 150 GR REM SP NEXT TO 30/06 I RELOADED FOR M-1 GARANDE.

 

HERE IS A 30/06 NEXT TO 308 NOTICE THE TALLER NECK, I THINK THAT BULLET WAS DESIGNED AROUND THE 30/06 CASE.

 

[zeenon 0]

http://www.midwayusa.com/viewproduct/?productnumber=1165163765

[GRIZ 3,369]

Now that being said....308 and 30-06 bullets are the same.

 

Yes and no. You can shoot them in one another but bullets designed for 308 have the cannelure closer to the nose of the bullet as they are seated deeper. If you buy bulk bullets designed to be loaded in 7.62 NATO and load them to OAL of M2 Ball for a Garand the cannelure will be above the case mouth.

 

Seating them deeper may degrade accuracy and increase throat erosion. Pressure will go down as the bullet will start to move earlier unencumbered by the resistance of the rifling.

 

The 10FP is in 308 so what I said really shouldn't apply but if you want the best answer call Sierra:

 

http://www.sierrabullets.com/index.cfm?section=techservice&page=ballistictech

[Old School 611]

Now that being said....308 and 30-06 bullets are the same.

 

Yes and no. You can shoot them in one another but bullets designed for 308 have the cannelure closer to the nose of the bullet as they are seated deeper. If you buy bulk bullets designed to be loaded in 7.62 NATO and load them to OAL of M2 Ball for a Garand the cannelure will be above the case mouth.

 

Seating them deeper may degrade accuracy and increase throat erosion. Pressure will go down as the bullet will start to move earlier unencumbered by the resistance of the rifling.

 

The 10FP is in 308 so what I said really shouldn't apply but if you want the best answer call Sierra:

 

http://www.sierrabullets.com/index.cfm?section=techservice&page=ballistictech

 

Totally agree. If the bullets are designed for a specific cartridge.

[Kal 0]

There is a special place in Hell for anyone who crimps a precision bolt gun bullet :naughty: . Neck tension only and I load bullets long above the cannelure all the time, Some times the factory throats are so ridiculously long and you will want the bullet up into the lands and grooves for accuracy.

[Old School 611]

There is a special place in Hell for anyone who crimps a precision bolt gun bullet :naughty: . Neck tension only and I load bullets long above the cannelure all the time, Some times the factory throats are so ridiculously long and you will want the bullet up into the lands and grooves for accuracy.

 

You're on the money Kal. Even for hunting loads I load a dummy round touch the bullet to the rifling and then adjust it back into the case for my required length, minimizing the free bore jump.(Just make sure they work though the magazine)

 

I've said this before and I'll say it again. Reloading is a science and you cannot approach it like baking a cake. If you want to bake a cake buy factory ammo or load mediocre ammo that goes bang.

[Maksim 1,504]

great point guys. this inspired me to go digging, and found this from Sierra.

 

Bullet Seating Depth

By Rich Machholz

 

What is the best bullet seating depth for my rifle or a specific bullet is an oft asked question. Precise depth measurements are very difficult to obtain because bullets can vary in length. In view of this we often obtain an over all length (O.A.L.) by making external measurements taken from the point of the bullet to the base of the case or from a diameter on the ogive of the chosen bullet to the base of the case using a comparator and a caliper. Both methods can be very precise but technique could influence the result. Both are viable because the bullet seating die contacts the bullet on the ogive, not the point. Stoney Point makes a tool for this purpose called a Chamber-All, and when paired with their or some other company's comparator makes establishing Maximum O.A.L.'s easy. If you don't have the specific tools for establishing these lengths don't break your piggy bank just yet.

 

A useful tool can be made from an unsized case that was fired in your rifle by closing the case mouth very slightly thus providing a light slip fit for the chosen bullet. Just start the bullet in the case mouth and carefully insert in the chamber of your rifle. Close the bolt carefully and allow the lands of the rifling to push the bullet back. Carefully open and withdraw the bolt and dummy round, being careful not to disturb the bullet/case relationship. Holding the dummy round by the neck and bullet, measure carefully with calipers. Repeat several times to verify your measurements and be sure to use the same bullet each time for consistency. When satisfied, resize the case and seat the original bullet, making a dummy round to the established length. This will be the absolute maximum O.A.L. for this barrel, for this bullet. Smoke the dummy bullet and chamber the cartridge to make certain you don't have a jamb fit. If you do, adjust the seating depth accordingly until just a slight tick of copper shows through the smoke. Your bullet will be touching the lands very lightly and represents the maximum working O.A.L. for your barrel.

 

Your magazine may not accept this maximum O.A.L. so you must check your dummy round for function. A simple test is to open the floor plate and check for clearance, the cartridge must pass from top to bottom of the magazine box unimpeded. If it doesn't, adjust the dummy round to compensate for the reduction if you wish to utilize the magazine.

 

To find the optimum seating depth for a particular rifle, start with a mid-range powder charge and work up to the appropriate maximum charge levels very carefully while utilizing the maximum working O.A.L. to determine the most accurate powder charge. When the most accurate charge is established utilize it and reduce the maximum working O.A.L. by .010" increments looking for accuracy by shooting groups at each increment. A total reduction of .060 of an inch will probably tell you if more reduction is appropriate or necessary. The resultant groups should be a graphic illustration of what really is the best O.A.L. for your rifle with this bullet.

 

http://www.sierrabullets.com/index.cfm? ... =2&issue=2

 

What do they mean by smoke the bullet? i dont get it.

 

Edit: I got it now.... take a match and cover the bullet in smoke.

[tbtrout 141]

Whenever I had a question on reloading for rifles, I would call and eventually E mail the Bullet Techs at Sierra. They are a wealth of information and willing to help with any question. I wish I had this forum as a resource back then. That was a good article Maks

[Blackfox 1]

great point guys. this inspired me to go digging, and found this from Sierra.

 

Bullet Seating Depth

By Rich Machholz

 

What is the best bullet seating depth for my rifle or a specific bullet is an oft asked question. Precise depth measurements are very difficult to obtain because bullets can vary in length. In view of this we often obtain an over all length (O.A.L.) by making external measurements taken from the point of the bullet to the base of the case or from a diameter on the ogive of the chosen bullet to the base of the case using a comparator and a caliper. Both methods can be very precise but technique could influence the result. Both are viable because the bullet seating die contacts the bullet on the ogive, not the point. Stoney Point makes a tool for this purpose called a Chamber-All, and when paired with their or some other company's comparator makes establishing Maximum O.A.L.'s easy. If you don't have the specific tools for establishing these lengths don't break your piggy bank just yet.

 

A useful tool can be made from an unsized case that was fired in your rifle by closing the case mouth very slightly thus providing a light slip fit for the chosen bullet. Just start the bullet in the case mouth and carefully insert in the chamber of your rifle. Close the bolt carefully and allow the lands of the rifling to push the bullet back. Carefully open and withdraw the bolt and dummy round, being careful not to disturb the bullet/case relationship. Holding the dummy round by the neck and bullet, measure carefully with calipers. Repeat several times to verify your measurements and be sure to use the same bullet each time for consistency. When satisfied, resize the case and seat the original bullet, making a dummy round to the established length. This will be the absolute maximum O.A.L. for this barrel, for this bullet. Smoke the dummy bullet and chamber the cartridge to make certain you don't have a jamb fit. If you do, adjust the seating depth accordingly until just a slight tick of copper shows through the smoke. Your bullet will be touching the lands very lightly and represents the maximum working O.A.L. for your barrel.

 

Your magazine may not accept this maximum O.A.L. so you must check your dummy round for function. A simple test is to open the floor plate and check for clearance, the cartridge must pass from top to bottom of the magazine box unimpeded. If it doesn't, adjust the dummy round to compensate for the reduction if you wish to utilize the magazine.

 

To find the optimum seating depth for a particular rifle, start with a mid-range powder charge and work up to the appropriate maximum charge levels very carefully while utilizing the maximum working O.A.L. to determine the most accurate powder charge. When the most accurate charge is established utilize it and reduce the maximum working O.A.L. by .010" increments looking for accuracy by shooting groups at each increment. A total reduction of .060 of an inch will probably tell you if more reduction is appropriate or necessary. The resultant groups should be a graphic illustration of what really is the best O.A.L. for your rifle with this bullet.

 

http://www.sierrabullets.com/index.cfm? ... =2&issue=2

 

What do they mean by smoke the bullet? i dont get it.

 

Edit: I got it now.... take a match and cover the bullet in smoke.